393 results on '"Zno Films"'
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2. Defect modification in enhancing thermopower factor of ZnO films without doping.
- Author
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Phan, Trang Thuy Thi, Le, Oanh Kieu Truong, Nguyen, Lan Tuyet Thi, Duong, Y Nhu Ngoc, Le, My Tra Thi, Lai, Hoa Thi, Hoang, Dung Van, Doan, Uyen Tu Thi, Tran, Vinh Cao, Phan, Thang Bach, Ung, Thuy Dieu Thi, Park, Sungkyun, and Pham, Anh Tuan Thanh more...
- Subjects
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THERMOELECTRIC power , *ZINC oxide films , *THERMOELECTRIC materials , *SEEBECK coefficient , *ELECTRIC conductivity - Abstract
This study was focused on unraveling the close dependence of the structural, morphological, and thermoelectric properties of sputtered ZnO films on base pressure. The ZnO film deposited at an optimized base pressure of 5 × 10−6 torr exhibited the highest thermoelectric power factor of 374.6 μW/mK2, corresponding to an electrical conductivity of 265 S/cm and a Seebeck coefficient of −124 μV/K at 583 K. The obtained results revealed that the positive effect of base pressure on enhancing thermoelectric properties of ZnO films is attributed to point-defect modification, including zinc vacancies, singly-, and doubly-charged oxygen vacancies. Based on these results, we propose that defect engineering is a facile and effective approach for improving the thermoelectric behavior of ZnO films, even without doping by controlling the sputtering conditions. [Display omitted] [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
- View/download PDF
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3. Study of the Effect of Li Doping on ZnO Films Using RFMagnetron Sputtering Method at Low Temperature.
- Author
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Abbas, Israa Akram, Kadhm, Ameera J., and Ali, Raheem Lafta
- Subjects
OPTICAL films ,THIN films ,PERMITTIVITY ,OPTICAL properties ,OPTICAL conductivity ,ZINC oxide films - Abstract
In this study, we investigate the effect of Li-doping concentrations (3, 6, and 9%) on the optical and electrical properties of Li-doped ZnOcontaining films. Li-doped ZnO films are fabricated by the RF-magnetron sputtering process. The optical and electrical properties of thin-film deposition at different sputtering RF powers in the plasma chamber are investigated. The electrical and optical properties of the thin layer are studied. The results for the optical properties of thin films (ZnO/Li) show that the absorbance, absorption coefficient, and optical conductivity increase with increasing Li concentration, while the energy band gap and transmittance decrease with increasing Li concentration. For all tested temperatures, the D.C. conductivity of the ZnO film increases after Li doping. The D.C. test shows that all films have the same activation energy, and the value of this energy increases as the Li-doping ratio increases. The electrical properties of alternating current demonstrate that, as the frequency of the electric field increases, the dielectric constant and dielectric loss of all films decrease. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
- View/download PDF
4. Optical and Methanol Sensing Properties of Al-doped ZnO Thin Film
- Author
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Sumitra Pandey, Samundra Marasini, and Rishi Ram Ghimire
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ZnO films ,Aluminum doping ,Optical transmittance ,Bandgap reduction ,Electrical conductivity ,Gas sensor sensitivity ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Technology (General) ,T1-995 - Abstract
The study investigates the optical and electrical properties of undoped and aluminum (Al)-doped zinc oxide (ZnO) films, focusing on their performance as gas sensors and their potential applications. Optical analysis, conducted using UV-visible spectrophotometry, reveals that 1% Al-doped ZnO films exhibit the highest transmittance of 91%, indicating superior optical clarity and suitability for applications like solar cell electrodes. In contrast, 3% Al-doped ZnO films show significantly lower transmittance due to increased light scattering and photon absorption. The bandgap of ZnO films decreases with higher Al doping concentrations, from 3.3 eV for undoped ZnO to 3.15 eV for 3% Al-doped ZnO, suggesting enhanced electrical conductivity due to reduced bandgap. The extinction coefficient data demonstrate that 2% Al-doped ZnO has the highest extinction coefficient, reflecting improved light absorption and scattering properties. Electrical characterization through I-V curves indicates that 1% Al-doped ZnO films have higher current (121 µA) compared to undoped (431 µA) and higher doping concentrations, attributed to enhanced carrier concentration and mobility. Sensitivity tests show that 2.5% Al-doped ZnO films exhibit the highest sensitivity to methanol vapor, with a significant reduction in resistance compared to 0.5% Al-doped ZnO films. Resistance measurements with varying methanol volumes reveal a rapid decrease upon gas introduction, stabilizing and then increasing as the gas is removed. Sensitivity analysis indicates that 100 µL methanol provides the highest sensitivity (97%) at 60°C, while 2% Al-doped ZnO films show consistent sensitivity at 60 °C and 100 °C, but not at 80 °C. more...
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- 2024
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5. ZnO/ITO, Sn and Cu Doped ZnO/ITO Films as an Photoanode for Solar Cell: Production and Characterizations.
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KARA, İlker, Hussein ALHASANI, Dheyaaldain Mohammed, KAYIŞ, Ahmet Furkan, YALÇINKAYA, Özcan, GENÇYILMAZ, Olcay, and Rashid HAFEDH, Abjar Ibrahim
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ZINC oxide ,SOLAR cells ,COPPER ,MAGNETRON sputtering ,OPTOELECTRONIC devices - Published
- 2024
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6. Influence of Post-Annealing Treatments on Third-Order Nonlinear Optical Properties in ZnO Thin Films
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Kumar, Sanjeev, Jain, Amit, Singh, N. Santakrus, and Singh, Manohar
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- 2024
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7. Deposition of ZnO thin films with different powers using RF magnetron sputtering method: Structural, electrical and optical study
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Bassam Abdallah, Walaa Zetoun, and Ahamad Tello
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ZnO films ,RF magnetron sputtering ,Electrical measurement ,Optical and structural characteristics ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Zinc Oxide thin films at room temperature with good crystallinity quality have been deposited at different Radio Frequency powers. Magnetron sputtering technique has been carried out on glass and oriented Si(100) substrates. The film structure has been characterized by X-ray Diffraction (XRD) and MicroRaman spectroscopy, which possesses a wurtzite structure with (002) preferential orientation selecting suitable conditions. Scanning electron microscope (SEM) and atomic force microscopy (AFM) have been utilized to determine the films surface morphology. The stoichiometry has been verified by Energy dispersive X-ray spectroscopy (EDX) analysis. The optical behaviors of the deposited films have been characterized by Ultraviolet Visible (UV-Vis) (optical transmittance measurements) as well as by Photoluminance characterization. Electrical properties, Current-Voltage (I-V) and Capacitance-Voltage (C-V) have been studied in details for Zinc Oxide on Silicon film that deposited at different Radio Frequency power. The high transparency, electrical behavior and smooth surface allow to use these Zinc Oxide films in photovoltaic cells and optoelectronics application. more...
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- 2024
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8. Carrier Transport Mechanism of Pt Contacts to Atomic Layer Deposited ZnO on Glass Substrates.
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Hogyoung Kim, Ye Bin Weon, and Byung Joon Choi
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ZINC oxide films ,ATOMIC layer deposition ,CARRIER density - Abstract
We grew ZnO films at different temperatures on glass substrates using thermal atomic layer deposition and investigated the current conduction mechanism of Pt/ZnO junctions. For ZnO samples grown at 46 and 96°C, the current flow through the ZnO layer was not possible at low temperatures such as 298 and 320K because the ZnO layer under Schottky contacts were wholly depleted. However, the current conduction was observed with increasing the temperature, which was found to be dominated by the Schottky emission at 360 and 380K and the PooleFrenkel emission at 380 and 400 K. For ZnO sample grown at 141°C, the strong tunneling current could occur because very thin depletion region was formed because of the high carrier concentration of ZnO layer. The observed difference in the current conduction can provide a guidance how growth temperature of ZnO should be controlled to design the low-temperature grown ZnO based devices built on glass substrates. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
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9. P‐12.8: A Vertical Alignment Technology of Proessing ZnO Sputtered with Ozone Applied on Liquid Crystal on Silicon Display Devices.
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Zhao, Xianyu, Long, Zhen, Sun, Ren, and Li, Qing
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LIQUID crystal displays ,OZONE ,OZONE layer ,CONTACT angle ,THIN films ,ZINC oxide ,TROPOSPHERIC ozone ,ZINC oxide films - Abstract
The vertical alignment technology by processing sputtered ZnO film for LCD with ozone is proposed in this paper. The prepared ZnO thin films were treated with ozone in the ultraviolet cleaning machine through polarizer. The wettability of the treated ZnO films switched to hydrophobicity, reaching a contact angle of 92°. With the prepared ZnO film as the alignment layer in the transmissive LCD cell, the vertical alignment (VA) can be realized. The results demonstrated that the test cells not only possessed the photo‐electronic characteristics of traditional VA liquid crystal cells but also had a smaller threshold voltage of 1.95V. In addition, the ZnO films are applied into character display successfully since the VA test cell has a high contrast ratio. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
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10. Influence of the Nature of Aminoalcohol on ZnO Films Formed by Sol-Gel Methods.
- Author
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Vilà, Anna, Gómez-Núñez, Alberto, Alcobé, Xavier, Palacios, Sergi, Puig Walz, Teo, and López, Concepción
- Subjects
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SOL-gel processes , *ZINC oxide films , *GLASS coatings , *ELEMENTAL analysis , *ZINC acetate , *THIN films - Abstract
Here we present comparative studies of: (i) the formation of ZnO thin films via the sol-gel method using zinc acetate dihydrate (ZAD), 2-methoxyethanol (ME) as solvent, and the aminoalcohols (AA): ethanolamine, (S)-(+)-2-amino-1-propanol, (S)-(+)-2-amino-3-methyl-1-butanol, 2-aminophenol, and aminobenzyl alcohol, and (ii) elemental analyses, infrared spectroscopy, X-ray diffraction, scanning electron microscopy, absorption and emission spectra of films obtained after deposition by drop coating on glass surface, and thermal treatments at 300, 400, 500 and 600 °C. The results obtained provide conclusive evidences of the influence of the AA used (aliphatic vs. aromatic) on the ink stability (prior to deposition), and on the composition, structures, morphologies, and properties of films after calcination, in particular, those due to the different substituents, H, Me, or iPr, and to the presence or the absence of a –CH2 unit. Aliphatic films, more stable and purer than aromatic ones, contained the ZnO wurtzite form for all annealing temperatures, while the cubic sphalerite (zinc-blende) form was also detected after using aromatic AAs. Films having frayed fibers or quartered layers or uniform yarns evolved to "neuron-like" patterns. UV and photoluminescence studies revealed that these AAs also affect the optical band gap, the structural defects, and photo-optical properties of the films. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
- Full Text
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11. Effect of Thickness on Electrical and Optical Properties of ZnO:Al Films.
- Author
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Thawatchai Chanthong, Weerawat Intaratat, and Thanate Na Wichean
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ZINC oxide films , *ELECTRICAL resistivity , *X-ray diffraction , *CRYSTAL structure , *BAND gaps - Abstract
Zinc oxide (ZnO:Al) films were prepared on a substrate of different thicknesses by sputtering at 1x10-2 mbar argon gas pressure and 200 W power. The effect of film thickness on the structural, electrical, and optical properties was investigated by X-ray diffraction (XRD), 4-point probe technique, and ultraviolet-visible spectroscopy. The XRD film crystal structure study revealed that all sample films at thicknesses of 66, 106, 150 and 193 nm, respectively, exhibited planar Hexagonal wurtzite crystal structure (002), and ZnO crystals were grown along the c-axis. The ZnO:Al film at a thickness of 66 nm had the highest strain and the smallest crystal size compared to other films. The electrical resistivity decreases with increasing film thickness. The sample at 193 nm has the lowest resistivity (1.37 Ω.m). The results showed that light transmission revealed that all sample films had high transparency in the white and near-UV region at a wavelength of 350 to 800 nm, with an average light transmittance shift of 85 - 95 %. The energy band gap increased with the film thickness of 3.49(66 nm), 3.55(106 nm), and 3.59(150 nm) eV, and decreased to 3.57 eV at 193 nm, respectively. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
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12. Microstructure of ZnO:Er Films Prepared by Magnetron Sputtering.
- Author
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Gremenok, V. F.
- Abstract
Er-doped ZnO (ZnO:Er) thin films were grown on quartz and p-Si substrates at 25°C by radio-frequency magnetron sputtering method. The effect of the heat treatment at 600 and 900°C on the properties of the films was analyzed by scanning electron microscopy, energy dispersive x-ray spectroscopy, atomic force microscopy and X-ray diffraction analysis. A homogeneous elements distribution is revealed for all investigated films on different substrates. ZnO:Er films were found to be uniform, pinhole-free, well adherent to the substrate and the crystal grain size is dependent on the type of substrate and the preparation conditions. All the films showed a (002) preferential orientation with the c-axis perpendicular to the substrate surface. The results obtained from XRD spectra reveal that Er
3+ ions successfully substitute for Zn2+ ions in the ZnO lattice. [ABSTRACT FROM AUTHOR] more...- Published
- 2022
- Full Text
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13. Synthesis of ZnO Film as Transparent Conductive Oxide for Solar Cells
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Sarkar, Paramita, Sinha, Abhijit, Tsihrintzis, George A., Series Editor, Virvou, Maria, Series Editor, Jain, Lakhmi C., Series Editor, Dawn, Subhojit, editor, Balas, Valentina Emilia, editor, Esposito, Anna, editor, and Gope, Sadhan, editor more...
- Published
- 2020
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14. Preparation, parameter optimization of anodized ZnO films and their photocatalytic performance in organic dye degradation in wastewater.
- Author
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Zhu, Enlong, Li, Fei, Zhao, Qian, Hu, Te, Guan, Sujun, Lu, Yun, and Hao, Liang
- Abstract
Photocatalytic ZnO films were prepared by facile anodization followed by annealing. The influence of some processing parameters, including applied potential, anodization time, electrolyte concentration, and annealing temperature, on the resultants’ composition and photocatalytic activity of the prepared films, was investigated. The XRD, Raman spectra, and SEM analysis show that the nano-sized grass-like microstructure was formed with nanowires or nanorods. The films were composed of ZnO and Zn5(CO3)2(OH)6. Higher applied potential, longer anodization time, and higher electrolyte concentration made for the formation of ZnO, leading to higher photocatalytic activity. Higher annealing temperature decreased the defects and thereby increased the crystallinity of ZnO. Higher crystallinity restrained the recombination of photogenerated charge carriers; thereby, enhancing the photocatalytic activity. However, a high annealing temperature, even at 523 K, led to the adhesion decrease of the prepared films on Zn foils and thereby the films’ exfoliation. That decreased the photocatalytic performance of the as-annealed films. Therefore, the annealing temperature has a moderate value to achieve the optimal photocatalytic performance. The present systematic study on the preparation and processing parameters of ZnO by anodization followed by annealing has helpful guiding significance for the fabrication of photocatalyst films with high photocatalytic performance. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
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15. The correlation between Physicochemical and nonlinear optical studies of tin-doped zinc oxide thin films deposited by spray pyrolysis.
- Author
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Rherari, Amal, Adhiri, Rahma, Lachhab, Touria, Addou, Mohammed, Sofiani, Zouhair, Bougrine, Assia, and Kannan, Kartik
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ZINC oxide thin films , *ZINC oxide films , *ZINC oxide , *THIRD harmonic generation , *OPTICAL susceptibility , *ATOMIC force microscopy , *PYROLYSIS - Abstract
Transparent conductive thin films based on Tin (Sn) doped zinc oxide (TZO) were prepared using the chemical spray pyrolysis technique. The crystalline structure, strain, stress, roughness characteristics, electrical and nonlinear optical susceptibility of TZO were studied The films have been investigated using x-ray diffraction, atomic force microscopy (AFM), electrical resistivity, and third harmonic generation (THG) techniques. The greatest value of the susceptibility χ(3) was about 10.91×10-12(esu) obtained from the 2% doped films, which have less roughness and the low electrical resistivity of 5×10-2 Ω cm. Moreover, third order non-linear optical susceptibilities were of the order of 10-12 (esu), higher than that of the undoped ZnO. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
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16. Study on the nanoscale current of ZnO film by photoassisted peak force tunnel atomic force: A novel technique for UV detection.
- Author
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Zhang, Yidong, Dong, Zhenwei, Zhao, Lei, and Guan, Huijuan
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NUCLEAR forces (Physics) , *ZINC oxide films , *THERMIONIC emission , *TIN oxides - Abstract
ZnO film‐based ultraviolet (UV) detector was fabricated by photoassisted peak force tunnel atomic force (PFTUNA) on fluorine tin oxide (FTO) substrate. The PFTUNA current in dark and in UV light was ~0.1 and 2.0 nA, respectively. The UV sensitivity (photocurrent/dark current) is more than 20. The response time and the recovery time are ~0.12 and 0.32 s, respectively. The UV sensing mechanism is that the holes will transport to the ZnO surface to capture the adsorbed oxygen ions to weaken the depletion layer under UV illumination. The PFTUNA current between the tip and the ZnO film is consistent with the Richardson–Schottky (RS) thermionic emission model. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
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17. Effect of Fatigue Fracture on Resistive Switching of ZnO and NiO Stacking Films.
- Author
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Gu, Hong-Jian, Li, Zhen-Hai, Li, Run-Xia, and Li, Jian-Chang
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STRESS fractures (Orthopedics) , *ZINC oxide , *INDIUM tin oxide , *POLYETHYLENE terephthalate , *SCANNING electron microscopy , *CRYSTAL grain boundaries , *COMPUTER storage devices , *ZINC oxide films - Abstract
The ZnO and NiO stacking films are prepared by sol–gel spin‐coating method to explore the impact of bending on device resistive switching. Compared with others, the device with NiO/ZnO/NiO/indium tin oxide/PET stacking structure exhibits a higher ON/OFF ratio. After bending 1000 times, the switching performance is reduced by two orders of magnitude due to the branch breakage of the conductive filaments. The finite element studies indicate that stress mutation between the ZnO and NiO functional layers leads to microcrack formation and interfacial delamination, increasing the interfacial barrier and depletion width. The cracks propagate along the grain boundary and thus result in more traps, which may act as electron blocking layers to restrict the carrier transport. The scanning electron microscopy observation shows that when the crack density increases to about 0.03 μm−1, the device is broken down. Under threshold bending cycles as simulated by Comsol Multiphysics, the grain boundary is completely torn leading to fatigue fracture. The proposed work provides some information for improving the flexibility of memory devices. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
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18. Structural and optical properties of copper-doped ZnO thin films at different weight percentage.
- Author
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Najim, S. A., Alyas, M. M., and Sulaiman, A. A.
- Subjects
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ZINC oxide films , *ZINC oxide , *THIN films , *OPTICAL properties , *CHEMICAL vapor deposition , *X-ray diffraction measurement , *BAND gaps - Abstract
ZnO thin films have been synthesized by chemical vapor deposition technique at substrate temperature 400°C and doped with Cu at (1,3,5 wt.%). The morphologies of pure and doped ZnO films were investigated by SEM and the grain size was become larger by increasing the amount of Cu doped. From X-ray diffraction measurements, the maximum intensity peak was (002) for ZnO:Cu films at diffraction angle 34.4° and crystallized of hexagonal phase. Based on XPS Measurements on the surface of ZnO:Cu films, it has been found that the peak was shift to higher diffraction angle and full width half maximum of the films were become wider with increasing Cu doping. The band gap of ZnO film was 3.3 eV and it was decreased as an increasing of Cu dopant. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
- View/download PDF
19. Influence of the Nature of Aminoalcohol on ZnO Films Formed by Sol-Gel Methods
- Author
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Anna Vilà, Alberto Gómez-Núñez, Xavier Alcobé, Sergi Palacios, Teo Puig Walz, and Concepción López
- Subjects
ZnO films ,sol-gel ,aminoalcohol ,structural characterization ,elemental analysis ,IR spectroscopy ,Chemistry ,QD1-999 - Abstract
Here we present comparative studies of: (i) the formation of ZnO thin films via the sol-gel method using zinc acetate dihydrate (ZAD), 2-methoxyethanol (ME) as solvent, and the aminoalcohols (AA): ethanolamine, (S)-(+)-2-amino-1-propanol, (S)-(+)-2-amino-3-methyl-1-butanol, 2-aminophenol, and aminobenzyl alcohol, and (ii) elemental analyses, infrared spectroscopy, X-ray diffraction, scanning electron microscopy, absorption and emission spectra of films obtained after deposition by drop coating on glass surface, and thermal treatments at 300, 400, 500 and 600 °C. The results obtained provide conclusive evidences of the influence of the AA used (aliphatic vs. aromatic) on the ink stability (prior to deposition), and on the composition, structures, morphologies, and properties of films after calcination, in particular, those due to the different substituents, H, Me, or iPr, and to the presence or the absence of a –CH2 unit. Aliphatic films, more stable and purer than aromatic ones, contained the ZnO wurtzite form for all annealing temperatures, while the cubic sphalerite (zinc-blende) form was also detected after using aromatic AAs. Films having frayed fibers or quartered layers or uniform yarns evolved to “neuron-like” patterns. UV and photoluminescence studies revealed that these AAs also affect the optical band gap, the structural defects, and photo-optical properties of the films. more...
- Published
- 2023
- Full Text
- View/download PDF
20. Heteroepitaxy on Porous Silicon
- Author
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Sabet Dariani, Reza and Canham, Leigh, editor
- Published
- 2018
- Full Text
- View/download PDF
21. Highly transparent conductive ZnO films prepared by reactive RF sputtering with Zn/ZnO composite target.
- Author
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Zhu, B. L., Wang, C. C., Xie, T., Wu, J., and Shi, X. W.
- Subjects
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RADIOFREQUENCY sputtering , *REACTIVE sputtering , *ZINC oxide films , *ZINC oxide , *GAS flow , *MAGNETRON sputtering , *RAMAN spectroscopy - Abstract
Using Zn/ZnO composite target, ZnO films were prepared by RF magnetron sputtering under Ar, Ar + O2 and Ar + H2 atmospheres and substrate temperatures of 150 and 300 °C. The effects of gas (O2 or H2) flow rate and substrate temperature on the thickness, preferred orientation, crystallinity, stress, transparent conductive properties, electrically conductive stability in air, Eg and Raman spectrum of the films were investigated. The results show that the film prepared in Ar atmosphere exhibits poor transparent conductive properties and conductive stability. Substrate temperature of 300 °C is advantageous to prepare ZnO films with (002) preferred orientation, high crystallinity, low compressive stress and good transparent conductive properties under Ar + O2 atmosphere. Under Ar + H2 atmosphere, ZnO films with low compressive stress and better transparent conductive properties can be obtained at substrate temperature of 150 °C. The related mechanisms for the effect of gas flow rate and substrate temperature on structure and properties of ZnO films are discussed. [ABSTRACT FROM AUTHOR] more...
- Published
- 2021
- Full Text
- View/download PDF
22. SYNTHESIS OF Ag-DOPED ZnO NANOMATERIALS FOR DYE SENSITIZED SOLAR CELLS AND INVESTIGATION OF THE OPTIMUM Ag DOPING RATE.
- Author
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Ekmekci, Mesut, Ela, Cagatay, Erten-Ela, Sule, and Yavuz, Cagdas
- Subjects
SILVER ,ZINC oxide ,SOLAR cells ,NANOSTRUCTURED materials ,SCANNING electron microscopy ,X-ray diffraction - Abstract
Silver (Ag) doped ZnO (SZO) nanomaterials were synthesized by hydrothermal method and characterized. ZnO nanostructures were doped with 0.0%, 0.5%, 1%, 1.5mol% Ag. These obtained SZO nanomaterials were analyzed using X-ray diffraction measurement (XRD), Scanning Electron Microscopy (SEM), and Energy Dissipative X-ray (EDX) spectroscopy. The structural analysis confirmed the formation of synthesized SZO samples having a hexagonal ZnO wurtzite phase. The morphology of SZO samples changed partially and the ZnO nanorod length increased somewhat as the Ag doping ratio increased. Despite this increase, it was seen that the average crystal sizes first increased and then decreased. The crystallite sizes calculated from XRD data for 0.0, 0.5, 1.0 and 1.5mol% SZO were obtained as 41, 42, 38 and 37 nm, respectively. Ag doping concentration has increased the absorbance of SZO nanomaterials increased and the transmission decreased was observed. The band gap of the 0.0%, 0.5%, 1.0% and 1.5mol% SZO nanomaterials were measured 3.19, 3.18, 3.16 and 3.19 eV, respectively. Then dye sensitized solar cells (DSSCs) were fabricated using these SZO nanomaterials, cis-Bis(isothiocyanato)(2,2'-bipyridyl-4,4'-dicarboxylato) (4,4'-di-nonyl-2'-bipyridyl) ruthenium (II) dye (Z907), (Ditetrabutylammonium cis-bis(isothiocyanato) bis (2,20-bipyridyl-4,40 dicarboxylato) ruthenium (II) dye (N719) and examined their photovoltaic performances. The calculated efficiencies of DSSCs fabricated using Z907 dye for 0.0%, 0.5%, 1.0% and 1.5mol% SZO were 0.005, 0.51, 0.46 and 0.22%, respectively. Then the calculated efficiencies of DSSCs fabricated using N719 dye for 0.0%, 0.5%, 1.0% and 1.5mol% SZO were 0.06, 0.17, 0.07 and 0.06%, respectively. In both works, DSSCs with ZnO film doped with 0.5mol% SZO showed the best photovoltaic performance. Consequently, these results indicated that the synthesized SZO nanomaterial for DSSCs of the optimum ratio of Ag doping is 0.5mol% clearly. [ABSTRACT FROM AUTHOR] more...
- Published
- 2021
- Full Text
- View/download PDF
23. ZnO thin films prepared by RF plasma chemical vapour transport for self-cleaning and transparent conducting coatings.
- Author
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El-Hossary, F M, Mohamed, S H, Noureldein, E A, and Abo EL-Kassem, M
- Subjects
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ZINC oxide films , *THIN films , *ZINC oxide synthesis , *CONTACT angle , *SURFACE coatings , *VAPORS , *ZINC oxide - Abstract
ZnO thin films were prepared by chemical vapour transport method in inductively coupled plasma (ICP). The films were synthesized at different substrate positions and various oxygen/argon ratios. X-ray diffraction (XRD) revealed that all the synthesized films at different positions are mixture of hexagonal ZnO and hexagonal Zn phases. The relative peak integrated intensity (RPII) of the ZnO phase is 83.6, 25.3 and 45.3%, for positions 1, 2 and 3, respectively. Morphology of ZnO films was found to be sensitive to substrate position. Flat flakes, bended nanowires (NWs) and nanoparticles morphologies are observed for positions 1, 2 and 3, respectively. The sample synthesized at 1 is stoichiometric, whereas the samples prepared in positions 2 and 3 are sub-stoichiometric. The films prepared at positions 1 and 3 have relatively high transmittance and low reflectance values, whereas the film prepared at position 2 has low transmittance and high reflectance. The ZnO film prepared at position 2 is hydrophobic with water contact angle of 112.2°, which can be used as self-cleaning coating. For ZnO films prepared with various O2 ratios, the RPII was 83.2, 88.0, 96.4 and 100% for films prepared with 10, 20, 30 and 40%, respectively. With increasing O2 ratio, the nanograins became bigger and the stoichiometry improved. The transmittance and optical bandgap increased, whereas the reflectance and refractive index decreased with increase in O2 ratio. The ZnO film synthesized with 30% O2 ratio has the highest figure of merit (FOM) value; thus, this film may be considered as the best ZnO film for transparent conducting coating applications. [ABSTRACT FROM AUTHOR] more...
- Published
- 2021
- Full Text
- View/download PDF
24. The effect of electrodes on microstructures and switching behaviors of ZnO-based resistive memory.
- Author
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Jiang, Zhiyi, Zhang, Wei, Bao, Jianqiu, Cheng, Hongbo, Zhang, Xuehua, and Hu, Fangren
- Subjects
- *
ELECTRODES , *ZINC oxide films , *STRUCTURE-activity relationships , *PARTIAL pressure , *INDIUM gallium zinc oxide , *THIN films - Abstract
In this study, ITO and Pt layers were deposited on (100) Si substrate respectively as bottom electrode for ZnO-based resistive memory. The ITO layer was textured and its preferred orientation is highly dependent on the oxygen partial pressure of growth atmosphere. As the oxygen content increases in the range of 0%–15%, the preferential growth orientation tends to change from (400) to (222). (002)-textured ZnO thin films with different preferred orientation degree sputtered on Pt and two kinds of oriented ITO layers were comparatively investigated. The device with (400)-ITO bottom electrode was found to have the best resistive switching performance. Meanwhile, the differences in switching behaviors were also found to be closely related to the thickness-dependent crystalline structure and top contact electrode/interface. This study provides an in-depth understanding of the structural design and structure-activity relationship of high-performance ZnO-based resistive memory. [ABSTRACT FROM AUTHOR] more...
- Published
- 2020
- Full Text
- View/download PDF
25. EFFECT OF OXIDATION TIME ON STRUCTURAL AND OPTICAL PROPERTIES OF ZNO FILMS PREPARED BY HYDROTHERMAL OXIDATION OF ELECTRODEPOSITED ZN COATING ON ITO SUBSTRATE.
- Author
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KHAN, SHAKIL, IFTIKHAR, MUHAMMAD, ALVI, HAFIZ WASEEM AHMAD, RASHEED, MUHAMMAD ASIM, KHAN, ABDUL FAHEEM, WAHEED, ABDUL, MEHMOOD, MAZHAR, SHAH, ATTAULLAH, and MAHMOOD, ARSHAD
- Subjects
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ZINC oxide films , *OPTICAL properties , *BAND gaps , *SPECTRAL reflectance , *DEIONIZATION of water , *ZINC oxide , *ZINC alloys , *ZINC coating - Abstract
In this work, hydrothermal oxidation of electrodeposited zinc coatings is used to produce zinc oxide (ZnO) films. In the first step, zinc (Zn) coating is electrodeposited on indium tin oxide (ITO) coated glass substrate. The Zn films are then immersed in deionized water at 9 5 ∘ C. The exposure time of Zn coating in deionized water is varied from 1 h to 24 h in sequence. At the 24 h exposure time, X-ray diffraction (XRD) patterns reveal that zinc film has been completely converted to ZnO. Scanning electron microscope (SEM) results show morphological changes from flakes (for pure Zn) or 2D plates to rod (ZnO) like morphology which further changes to cotton-flower like shapes with an increase in oxidation time. Diffuse reflectance spectral measurements show the band gap tuning with oxidation time (it decreases from 3.28 eV to 3.19 eV). Photoluminescence (PL) spectra have depicted phonon replicas with energy separation of ∼ 1 2 4 meV for the ZnO films obtained after 6 and 12 h exposure time in deionized water at 9 5 ∘ C temperature. [ABSTRACT FROM AUTHOR] more...
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- 2020
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26. Passive wireless UV SAW sensor.
- Author
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Karapetyan, G. Ya., Kaydashev, V. E., Kutepov, M. E., Minasyan, T. A., Kalinin, V. A., Kislitsyn, V. O., and Kaidashev, E. M.
- Subjects
- *
SURFACE acoustic wave sensors , *ZINC oxide films , *ACOUSTIC surface waves , *DELAY lines , *FOURIER transforms - Abstract
This paper presents studies of a passive wireless ultraviolet (UV) surface acoustic wave (SAW) sensor operating in the frequency range 436–440 MHz. The sensor contains two SAW delay lines (DLs). The first DL is measuring, and the second is the reference. In the measuring DL, receiving–transmitting inter-digital transducer (IDT) is connected to the antenna and the sensing element zinc oxide film. In the reference DL, the receiving–transmitting IDT is connected to another antenna and does not contain a UV-sensitive element. Two methods of information reading from the sensor are proposed: based on the Fourier transform of the frequency dependence of the parameter S11 of the reader antenna and using reading pulses of 1.5-μs duration, which have carrier frequencies corresponding to the central frequencies of the measuring and reference channels. The sensor can measure UV intensities from 10 to 40,000 μW/cm2 with a maximum sensitivity of 6000 ppm/(μW/cm2) at low intensities, and which rapidly decreases as the UV intensity increases (less than 100 ppm at the UV intensity of 40,0000 µw/cm2). [ABSTRACT FROM AUTHOR] more...
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- 2020
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27. Raman and Photoluminescence Study of Al,N‐Codoped ZnO Films Deposited at Oxygen‐Rich Conditions by Magnetron Sputtering.
- Author
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Karpyna, Vitalii, Ievtushenko, Arsenii, Kolomys, Oleksandr, Lytvyn, Oksana, Strelchuk, Viktor, Tkach, Vasily, Starik, Sergii, Baturin, Vladimir, and Karpenko, Oleksandr
- Subjects
- *
ZINC oxide films , *MAGNETRON sputtering , *PHOTOLUMINESCENCE , *ZINC oxide , *CRYSTAL lattices , *INFRARED spectroscopy - Abstract
Optical properties of as‐grown high nitrogen‐doped ZnO:Al,N films (with a variation of nitrogen concentration from 2.3 to 4.3 atomic %) are studied by Raman, photoluminescence, and Fourier‐transform infrared spectroscopy (FTIR). The intensity of mode A1LO, peaked at 580 cm−1, increases with increasing nitrogen concentration. The silent mode B1low at 275 cm−1 is clearly observed testifying increased disorder‐activated scattering in ZnO. Photoluminescence spectra reveal near‐band edge emission as well as several defect‐related bands, the intensity of which increases with nitrogen content. The blue band (2.61 eV) can be related to the transition from shallow donor level to deep nitrogen acceptor level. Also, incorporation of nitrogen in ZnO lattice causes appearance of both Zni and Oi defects responsible for violet (3.08 eV) and yellow (2.16 eV) emission band, respectively. At the same time near‐band edge emission of ZnO:Al,N films is not suppressed by simultaneously introduced Al and N impurities. Al compensates distortions in ZnO crystal lattice caused by nitrogen doping and, thus, stabilizes near‐band edge emission. [ABSTRACT FROM AUTHOR] more...
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- 2020
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28. Effect of Fe-incorporation on Structural and Optoelectronic Properties of Spin Coated p/n Type ZnO Thin Films.
- Author
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Zegadi, C., Adnane, M., Chaumont, D., Haichour, A., kaddour, A. Hadj, Lounis, Z., and Ghaffor, D.
- Subjects
ZINC oxide films ,THIN films ,SPIN coating ,RAMAN scattering ,DIFFRACTION patterns ,ZINC oxide - Abstract
This paper reports the effect of Fe incorporation on structural and electro-optical properties of ZnO thin films prepared by spin coating techniques. The Fe/Zn nominal volume ratio was 7 % in the solution. X-ray diffraction patterns of the films showed that doped incorporation leads to substantial changes in the structural characteristics of ZnO films. All the films have polycrystalline structure, with a preferential growth along the ZnO (002) plane. The crystallite size was calculated using a well-known Scherrer’s formula and found to be in the range of 22-17 nm. The highest average optical transmittance value in the visible region was belonging to the Fe doped ZnO film. The results of the Raman scattering confirmed the observations of XRD and UV-Vis analysis techniques by the appearance of these occupancies at Zn
+2 sites. These results are explained theoretically and are compared with those reported by other workers. The results of Hall measurement of ZnO and ZnO:Fe thin films reveal a high electron concentration around 1016 cm– 3 and low mobility 2.6 cm2 /Vs. All as-grown samples show ambiguous carrier conductivity type (p-type and ntype) in the automatic Van der Pauw Hall measurement. A similar result has been observed in Li-doped ZnO and in As-doped ZnO films by other groups before. However, by characterizing our samples whit XPS, we have demonstrated that the ambiguous carrier type n in intended our ZnO films is not intrinsic behavior of the samples. It is due to the persistent photoconductivity effect in ZnO. [ABSTRACT FROM AUTHOR] more...- Published
- 2020
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29. ZnO Growth on Macroporous Si Substrates by HF Magnetron Sputtering.
- Author
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Kidalov, V. V., Dyadenchuk, A. F., Bacherikov, Yu. Yu., Rogozin, I. V., and Kidalov, Vitali V.
- Subjects
MAGNETRON sputtering ,ZINC oxide films ,THIN films ,POROUS silicon ,HYDROFLUORIC acid ,ZINC oxide synthesis ,LATTICE constants ,ZINC oxide - Abstract
It is the purpose of this work to research the formation process of zinc oxide by the method of HF magnetron sputtering on silicon substrates of orientation (100) with the previously applied system of macropores. Samples of porous silicon were obtained by electrochemical etching. n-type Si (100) wafers were used. Precipitation of thin ZnO films was carried out in an RF discharge in an argon atmosphere with oxygen by sputtering a zinc target. The target had a diameter of 80 mm and a thickness of 6 mm. The deposition time was 1200 s. The pressure in the growth chamber was maintained at a level of 10
–3 Pa. The substrate temperature was fixed at 300 °C. X-ray examination of ZnO has shown that the films have a polycrystalline nature with a wurtzite-type structure and hexagonal phase. ZnO crystallites in the coatings are highly oriented along the c-axis and perpendicular to the substrate surface. The lattice constant along the crystallographic c-axis of ZnO film was 5.2260 Å. The average crystallite size calculated by the Selyakov-Scherrer formula was 12 nm. According to SEM, grain size was ~ 50-100 nm. These discrepancies are explained by the presence of microstrains in the atomic matrix of the sample, as well as instrumental factors. The microelement analysis revealed practically perfect stoichiometry of ZnO grown on porous-Si/Si. [ABSTRACT FROM AUTHOR] more...- Published
- 2020
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30. Parameters of ZnO Semiconductor Films Doped with Mn and Fe 3d Impurities.
- Author
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Mezdrogina, M. M., Vinogradov, A. Ya., and Kozhanova, Yu. V.
- Subjects
- *
SEMICONDUCTOR films , *ZINC oxide films , *SEMICONDUCTOR doping , *MAGNETIC impurities , *SEMICONDUCTORS , *ZINC oxide - Abstract
The effect of Fe and Mn impurities on the magnetic parameters of ZnO wide-gap semiconductor films produced by high-frequency sputtering with wide variations in the defect concentration is studied. The introduction of Mn and Fe magnetic impurities brings about the existence of a magnetically ordered state in the semiconductor matrix, with different positions of the axis of easy magnetization. In the case of doping with Mn, this axis lies perpendicularly to the film plane, and in the case of doping with Fe, this axis lies in the film plane. [ABSTRACT FROM AUTHOR] more...
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- 2020
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31. Luminescence and Raman study of Zn_4In_2O_7 nanobelts and plates
- Author
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Alemán Llorente, Belén, Piqueras de Noriega, Javier, Fernández Sánchez, Paloma, García Martínez, José Ángel, Alemán Llorente, Belén, Piqueras de Noriega, Javier, Fernández Sánchez, Paloma, and García Martínez, José Ángel more...
- Abstract
© 2013 Elsevier Ltd. This work has been supported by MICINN (Project MAT2009-07882) and CSD2009-00013., Luminescence of Zn_4In_2O_7 nanobelts and microplates synthesized by a thermal evaporation-deposition method, has been investigated by photoluminescence (PL) and cathodoluminescence (CL) in the scanning electron microscope (SEM). Time resolved and temperature dependent CL measurements show that an emission at 2.37 eV appears to be characteristic of the Indium-Zinc-Oxide (IZO) compound investigated. PL and waveguiding behavior of the microplates is described Raman spectra of the structures as a function of In content has been studied., MICINN (Ministerio de Ciencia e Innovación, España), Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub more...
- Published
- 2023
32. Room temperature AC electrical, surface micro texture analysis, microwave permittivity and dielectric loss tangent in ZnO films doped by Cu, Al, and CuAl.
- Author
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Rahimi, Nasim and Dalouji, Vali
- Subjects
- *
DIELECTRIC loss , *ZINC oxide films , *SURFACE texture , *COPPER , *HOPPING conduction , *PERMITTIVITY - Abstract
The purpose of this work is the study of the correlation between the thickness of ZnO films doped by transition metals and their three-dimensional (3D) micromorphology. The as deposited ZnO films became more irregular surface hence the maximum value of Sq belong to as deposited ZnO films was in a bout of 0.1038 mm. The core roughness height Sk calculated as a difference between two extreme levels (maximal and minimal) of surface core, for ZnO films annealed at 500 °C have maximum value in a bout of 0.7325 mm. Since the surface kurtosis (Sku) of all sample's films were above 7, therefore there were high peaks or valleys on the films surface and for as deposited CAZO films with value of with 8.883. The height distribution histograms shown that as deposited films respect to annealed films have more uniform distributions. The AZO films annealed at 500 °C have maximum value of DC conductivity in about 104.167 S cm−1. The value of log (dielectric loss tan(δ)) in AZO films have maximum value in range 0.05–0.15. As the frequency of incident photons were increased the polarization orientation were increased. Log AC conductivity values of films were shown almost linear behavior with increasing incident photons frequency that indicates conduction hopping is followed by a small polaron mechanism. AC conductivity values of as deposited AZO films in all frequencies have maximum value. • The 3D surface stereometric analysis of films using the SPIP™ 6.7.4 software, according to ISO 25178–2:2012 and ASME B46.1–2009 were studied. • The as deposited ZnO films became more irregular surface hence the maximum value of Sq belong to as deposited ZnO films to be in about of 0.1038 mm. • The core roughness height Sk calculated as a difference between two extreme levels (maximal and minimal) of surface core, for ZnO films annealed at 500 ° C have maximum value of 0.7325 mm. • Since the surface kurtosis (Sku) of all samples films were above 7, therefore there are high peaks or valleys on the films surface and for as deposited CAZO films with value of with 8.883. • The AZO films annealed at 500 °C have maximum value of DC conductivity in about 104.167S.Cm−1. • The value of log (dielectric loss tan(δ)) in AZO films have maximum value in range 0.05–0.15. As the frequency of incident photons were increased the polarization orientation were increased. • Log AC conductivity values of films were shown almost linear behavior with increasing incident photons frequency that indicates conduction hopping is followed by a small polaron mechanism. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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33. Effect of Etched Silicon Substrate on Structural, Morphological, and Optical Properties of Deposited ZnO Films via DC Sputtering
- Author
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Abdallah, B., Hussin, R., and Zetoune, W.
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- 2022
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34. Deposition of ZnO thin films with different powers using RF magnetron sputtering method: Structural, electrical and optical study.
- Author
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Abdallah B, Zetoun W, and Tello A
- Abstract
Zinc Oxide thin films at room temperature with good crystallinity quality have been deposited at different Radio Frequency powers. Magnetron sputtering technique has been carried out on glass and oriented Si(100) substrates. The film structure has been characterized by X-ray Diffraction (XRD) and MicroRaman spectroscopy, which possesses a wurtzite structure with (002) preferential orientation selecting suitable conditions. Scanning electron microscope (SEM) and atomic force microscopy (AFM) have been utilized to determine the films surface morphology. The stoichiometry has been verified by Energy dispersive X-ray spectroscopy (EDX) analysis. The optical behaviors of the deposited films have been characterized by Ultraviolet Visible (UV-Vis) (optical transmittance measurements) as well as by Photoluminance characterization. Electrical properties, Current-Voltage (I-V) and Capacitance-Voltage (C-V) have been studied in details for Zinc Oxide on Silicon film that deposited at different Radio Frequency power. The high transparency, electrical behavior and smooth surface allow to use these Zinc Oxide films in photovoltaic cells and optoelectronics application., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.) more...
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- 2024
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35. Synthesis and characterization of Ca doped ZnO thin films by sol–gel method.
- Author
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Istrate, Anca-Ionela, Nastase, Florin, Mihalache, Iuliana, Comanescu, Florin, Gavrila, Raluca, Tutunaru, Oana, Romanitan, Cosmin, Tucureanu, Vasilica, Nedelcu, Monica, and Müller, Raluca
- Abstract
ZnO thin films were synthesized using sol–gel method at 0.25 and 0.5 M molarity concentration. Moreover, the obtained thin films were Calcium-doped with 1 and 5 at% concentration. In order to investigate the structural changes in the molecular binding between ZnO and Ca, Fourier Transform Infrared spectroscopy (FTIR), Micro-Raman Spectroscopy and X-ray diffraction (XRD) were performed. The surface morphology and the chemical constituents distribution of the films were studied through Scanning Electron Microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and Atomic Force Microscopy (AFM), respectively. The optical and electrical properties were studied by UV–Vis spectroscopy, Spectral ellipsometry and electrical I–V measurements. The results show that the properties of prepared ZnO thin films were strongly influenced by the molarity concentration and Ca-dopant. The band shape obtained at FTIR is a band attributable to metal oxide bonds and can be attributed to the vibrational assignment of Zn–O bond. SEM-EDX and AFM investigations reveal an enlarged surface area due to the porous nature of the thin films and confirm the presence of Ca in the ZnO matrix. The XRD and Raman analyses indicate the achievement of the high crystalline quality and confirm the wurtzite phase of the synthesized thin films. The films transmittance spectra indicate values between 81 and 93% in the 350–800 nm wavelength region. We further performed I–V characteristics, resulting that Ca has a different impact of the electrical performances. Highlights: Effect of Ca doping on morphological, structural, and opto-electrical properties of ZnO thin films synthesized by sol–gel at 0.25 and 0.5 M is studied. The films has a porous nature and a strong preferred orientation of (002) reflex when the concentration of Ca is greater. EDX study reveals the substitution of Ca atoms into ZnO lattice. Ca-doped ZnO thin films at 0.5 M exhibit superior properties when compared with 0.25 M. The 5 at%-Ca:ZnO, 0.5 M present the lowest resistivity value of 4.70 Ω cm. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
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36. Zno/GGG准2-2型单端口SAW谐振器初探.
- Author
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王城 and 钟智勇
- Subjects
ACOUSTIC surface wave devices ,YTTRIUM iron garnet ,ACOUSTIC surface waves ,ZINC oxide films ,THIN films ,MAGNETRON sputtering ,ANNEALING of metals - Abstract
Copyright of Piezoelectrics & Acoustooptics is the property of Piezoelectric & Acoustooptic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...
- Published
- 2019
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37. A surface acoustic wave impedance-loaded high sensitivity sensor with wide dynamic range for ultraviolet light detection.
- Author
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Karapetyan, G. Ya., Kaydashev, V.E., Zhilin, D.A., Kutepov, M.E., Minasyan, T.A., and Kaidashev, E.M.
- Subjects
- *
ACOUSTIC surface waves , *LIDAR , *ULTRAVIOLET radiation , *REFLECTANCE , *DETECTORS , *ACOUSTIC transducers - Abstract
• A new design of the SAW UV is proposed, in which the sensitive element is located outside the acoustic channel and does not affect the propagation of SAW, which makes it possible to use such a sensor wireless in the frequency range 2400–2483 MHz, where wireless sensors have compact antennas. • It It is proposed to connect the impedance sensitive to UV radiation not to reflective, but to the transceiver IDT, which made it possible to increase the sensitivity of the sensor to 8000 ppm/(μW/cm2). • New sensor design allowed us to obtain 8000 ppm/μW cm2 sensitivity, measure UV radiation intensity from some units μW/cm2 to 4 mW/cm2 and to reduce the response time. • The theoretical and experimental studies of reflection coefficient UV dependence can also be used for the development of passive wireless UV radiation sensors. An investigation of impedance-loaded surface acoustic waves (SAW) UV sensor is presented in this paper. New sensor design allowed us to obtain 8000 ppm/μW·cm2 sensitivity, measure UV radiation intensity from some units μW/cm2 to 4 mW/cm2 and to reduce the response time. The photosensitive film is located outside the acoustic channel in our design of the sensor, which makes it possible to avoids SAW damping by the surface of the film. The theoretical and experimental studies of reflection coefficient UV dependence can also be used for the development of passive wireless UV radiation sensors. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
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38. Investigation of the Antibacterial Activity of Silver and Zinc-Containing Solutions and Ag:ZnO Films Against some Pathogenic Bacteria.
- Author
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Hashim, Mustafa S., Al Marjani, Mohammed F., Saloom, Hussein T., Khaleel, Reem S., Khadam, Zahraa A., and Jasim, Aseel S.
- Subjects
- *
PATHOGENIC bacteria , *ZINC oxide , *MULTIDRUG resistance in bacteria , *PSEUDOMONAS aeruginosa , *ACINETOBACTER baumannii , *SPIN coating , *SILVER , *ZINC acetate - Abstract
Multidrug resistant bacteria are well-recognized as one of the greatest threats to human health worldwide. Antibacterial activity of nanoparticles has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. The antimicrobial effects of Ag, ZnO mixed solutions were examined in this work. Silver nitrate and zinc acetate were precursors for preparing two solutions (referred to as Sol1 and Sol2). These solutions contained well-known active antibacterial ions: Zn+2 and Ag+. The mixed solutions were made using Sol1 and Sol2 at three volume ratios (0.2, 0.4 and 0.8 %). The antibacterial activities of the mixed solutions were studied against Klebsiella pneumoniae; Acinetobacter baumannii; Escherichia coli; Pseudomonas aeruginosa and Staphylococcus aureus using the agar well diffusion method. All mixtures had an inhibitory effect against all pathogenic bacteria but with different inhibition zones. These zones were compared with those formed by Sol2 only to investigate the effect of Ag particles. The coexistence of nano and micro Ag particles was one of the important factors used to explain the results of inhibition zones. Utilizing the spin coating method, mixed solutions were deposited on glass substrates to produce three silver doped zinc oxide (Ag: ZnO) films. An experimental study of antiadhesive effects of Ag:ZnO films against pathogenic bacteria Pseudomonas aeruginosa has been performed. These effects increased by increasing the silver amount as a dopant material inside ZnO matrix. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
39. Effects of Cu–Zn phases on electronic properties in ZnO:Cu films.
- Author
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Gao, Yang, Li, Guojian, Liu, Shiying, Chang, Ling, Wang, Zhao, and Wang, Qiang
- Subjects
- *
VAPOR-plating , *ZINC oxide , *CHARGE carrier mobility , *ZINC oxide films - Abstract
Theory predicts Cu‐doped ZnO (ZnO:Cu) has p‐conductivity; however, this has only been demonstrated in a small number of experimental and mechanistic studies. In this paper, ZnO:Cu films were grown in situ with varying Cu content, prepared using radiofrequency atomic source–assisted molecular‐beam vapor deposition. The results indicate that ZnO:Cu films with dopant of Cu2+ only had n‐type behavior. As the Cu content increased, Cu+ was the major dopant and the ZnO:Cu films had p‐type behavior. However, excess Cu dopant resulted in the formation of second phases of Cu2O and Cu–Zn. The formation of a Cu–Zn phase increased the content of Zn vacancy, thus increasing hole concentration. Stronger alloy scattering decreased carrier mobility. Therefore, Cu+ dopant and Zn vacancy give ZnO:Cu films p‐conductivity properties. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
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40. Effect of Eu doping on the near band edge emission of Eu doped ZnO thin films after high temperature annealing.
- Author
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Heng, C.L., Xiang, W., Su, W.Y., Gao, Y.K., Yin, P.G., and Finstad, T.G.
- Subjects
- *
ZINC oxide films , *ZINC oxide synthesis , *THIN films , *ZINC oxide , *HIGH temperatures , *SCANNING electron microscopy , *DOPING agents (Chemistry) , *EUROPIUM - Abstract
Abstract We studied the effect of europium (Eu) doping on the near band edge emission of ZnO thin films, fabricated by sputtering and high temperatures annealing. The doping concentration of Eu in the ZnO films was varied from 0.01 to 0.62 at.%. Photoluminescence (PL) spectra showed that the films ultra-violet (UV) emission was enhanced very much by high temperature treatment and was stronger for the Eu doped ZnO than that for the un-doped ZnO films after 1100 °C annealing. X-ray diffraction showed the films had hexagonal wurtzite structure, the width of the ZnO (002) plane diffraction peak was sensitive to the anneal temperature and also to the Eu doping concentration, and Zn silicates had formed after the 1100 °C annealing. Scanning electron microscopy showed that the surface morphology of the films became more uneven with increasing Eu concentration. The PL decay spectra inferred that the lifetime of the UV PL was correlated with the size of ZnO nanocrystals in the films. The results support that the intensity of the UV PL is primarily influenced by the crystalline perfection of the films which is also influenced by the Eu doping concentration. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
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41. Carrier Transport Mechanism and Barrier Height of B-, Al- and B-Al-Ion-Doped ZnO Film/Graphene Schottky Contacts Prepared Using the Sol–Gel Method.
- Author
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Li, Yapeng, Ma, Kai, Li, Yingfeng, Xia, Pengju, Wang, Hua, Zou, Xiangyu, Liu, Yan, and Zhang, Qiang
- Subjects
SCHOTTKY barrier ,ZINC oxide thin films ,STRAY currents ,OXYGEN ,IONS - Abstract
In this article, graphene/ZnO Schottky contacts with different ion doping were fabricated by the sol–gel method. The results showed that the nanoparticles growth on the surface of ZnO film was limited by ion doping, and the number and size of nanoparticles decreased for B ion doping. Further, the ZnO film band gap presented a decreasing trend with B, Al and B-Al ion doping. The electrical properties of the graphene/ZnO Schottky contact incorporating an ion-doped ZnO film were investigated, where the results suggested that ion doping could effectively improve the barrier height and reduce the leakage current. This phenomenon can be explained by the reduction of the oxygen vacancies on the surface of the ZnO film by ion doping, which leads to a reduction of the defect level at the interface and weakened Fermi level pinning. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
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42. Tunable photoluminescence effect from ZnO films of Ag-decorated localized surface plasmon resonance by varying positions of Ag nanoparticles.
- Author
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Huo, Chunqing, Jiang, Hua, Lu, Youming, Han, Shun, Jia, Fang, Zeng, Yuxiang, Cao, Peijiang, Liu, Wenjun, Wangying, Xu, Liu, Xinke, and Zhu, Deliang
- Subjects
- *
ZINC oxide , *ELECTRON transitions , *FERMI level , *ENERGY bands , *SURFACE plasmon resonance , *PHOTOLUMINESCENCE - Abstract
Graphical abstract Highlights • For the ZnO films/Ag NPs (II) structure, oscillating electrons can be excited to higher energy level by LSP and transfer to the CB of ZnO, causing an enhanced PL intensity of NBE emission. • For the Ag NPs (I)/ZnO films structure, electron transition to Fermi level of metal occurs at the MS interface due to the bending energy band that excites electrons to be close to the Fermi level of the metal, leading to a reduced PL intensity of NBE emission. • The enhancement or reduction of luminescence intensity depends on the transport probability of electrons to the LSP level or to the Fermi level of the metal. • The defect emission subsequently remained almost the same with weak LSP resonance coupling and energy mismatch in the structure. Abstract By employing localized surface plasmon resonance (LSPR), the near band edge (NBE) emission intensity of ZnO films were greatly varied, while defect emission remained almost the same. This photoluminescence (PL) intensity enhancement or reduction is tunable by changing the position of Ag nanoparticles (NPs) relative to the ZnO films. The remarkable variation of the NBE emission was investigated deeply. These experimental results reveal that the Ag NPs play a key role in tuning the PL performance of the semiconductor material, where LSPR occurs. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
- Full Text
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43. Effects of Cu contents on defects formation in molecular dynamics simulations of ZnO:Cu films deposition.
- Author
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Gao, Yang, Li, Guojian, Chang, Ling, Liu, Shan, Liu, Shiying, and Wang, Qiang
- Subjects
- *
MOLECULAR dynamics , *ZINC oxide films , *ATOMIC number , *DOPING agents (Chemistry) , *COPPER-zinc alloys , *OXYGEN - Abstract
Highlights • Lots of zinc vacancies, oxygen vacancies and dislocations exist in deposition layers. • Content of zinc vacancy increases as increasing amount of deposited Cu atomic number. • Cu-Zn alloy clusters are combined easily by Cu and Zn atoms and deposit to grow. Abstract The development of p-type ZnO film is related to the acceptor doping and defects, which are difficult to assess. Copper doped ZnO (ZnO:Cu) film with varying Cu content on a ZnO(0 0 1) substrate were simulated using molecular dynamics simulations. The COMB3 potential was used to describe the interaction between the depositing and substrate atoms. The growth of the ZnO:Cu films on the ZnO(0 0 1) substrate was a 3D island mode. Numerous oxygen vacancies (V O), zinc vacancies (V Zn) and dislocations existed in the deposition layers. Cu-Zn alloy clusters combined easily with Cu and Zn atoms, increasing the mass of the deposit. This resulted in the content of acceptor defect V Zn in ZnO layers increasing with the increase of Cu atoms. This could explain the p-type characteristics of ZnO:Cu film. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
- Full Text
- View/download PDF
44. Oxygen-defective ZnO films with various nanostructures prepared via a rapid one-step process and corresponding photocatalytic degradation applications.
- Author
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Yu, Zexin, Moussa, Hatem, Ma, Yangzhou, Liu, Meimei, Chouchene, Bilel, Schneider, Raphaël, Moliere, Michel, and Liao, Hanlin
- Subjects
- *
OXYGEN , *PLASMA spraying , *PHOTOLUMINESCENCE , *SPECTRUM analysis , *DENSITY functional theory - Abstract
Graphical abstract Abstract The deposition of oxygen-defective ZnO films exhibiting varied nanostructures via Solution Precursor Plasma Spray (SPPS) route, a one-step, minute-scaled duration and large scale method, is reported. The in situ formation of oxygen vacancies in ZnO films was confirmed by UV–Visible, Raman and photoluminescence (PL) spectroscopy and the as-prepared samples exhibit a bandgap as low as 3.02 eV. Density functional theory (DFT) simulation demonstrates that the polarization of ZnO is enhanced by the created oxygen vacancies, leading to substantially improved photocatalytic activity. The comparative experiments also revealed that forming and preserving appropriate ZnO precursor clusters inside the plasma plume is requisite for obtaining propitious ZnO nanostructures, which was followed by the in situ transfer and growth of the clusters on the preheated substrate. The ZnO-NRs films fully degrade the aqueous Orange II dye solutions within 120 min and maintain a quasi-intact activity (95.8% retention) after five test runs, which highlight their good stability. The oxygen vacancies and the narrowing of the bandgap also enable a visible light-driven photodegradation activity with conversions as high as 54.1%. In summary, this work not only reveals that the photocatalytic activity of SPPS-deposited ZnO films benefit from oxygen vacancies and well nanostructures, but also suggests that the SPPS route is of high potential for preparing metal oxides films destined to functional applications. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
- Full Text
- View/download PDF
45. ZnO and La-doped ZnO films by USP method and their characterizations for ultraviolet photodetectors and photocatalysis applications.
- Author
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Roguai, Sabrina and Djelloul, Abdelkader
- Subjects
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ZINC oxide films , *ZINC oxide , *PHOTODETECTORS , *DOPING agents (Chemistry) , *THIN films , *SEEBECK coefficient - Abstract
[Display omitted] • Studies on ZnO, Zn 1-x La x O [x = 0.02, 0.05, 0.10, and 0.15] thin films were prepared by spray technique. • Influence of La-doping on the structural, microstructural, Seebeck coefficient, optical, UV photodetectors, and photocatalytic properties of ZnO thin films. • The development of the parameters: lattice parameters, average crystalline sizes, Seebeck coefficient, and band gap energy with doping are discussed. • The 5%La-ZnO layers remain the best for UV photodetection with a good sensitivity of 5.07. • The 5%La_ZnO films had a 95% degradation rate. In this study, ZnO, Zn1-xLaxO [2, 5, 10, 15 at.%] thin films were grown on glass substrates using the spray-pyrolysis technique, to investigate the effect of doping on the structural, morphological, thermoelectric and optical properties of the layers, Also the samples were tested as UV photodetectors and photocatalyst for MB degradation. Firstly, diffraction patterns showed a hexagonal structure, with preferential grain orientation along the (0 0 2) direction, for pure ZnO and 2%La_ZnO layers, and at 5 at.% the preferential orientation changes, and crystallite sizes range from 10 nm to 19 nm. However, SEM images reveal that the ZnO and 2%La_ZnO layers are nanorods distributed over their surfaces, and the other 5%LZO, 10%LZO and 15%LZO layers characterized by nanocrystals were hexagonal prisms. The UV–visible analysis of the prepared layers shows high transparency (80–90%) in the visible range, with a constant optical gap of 3.26 eV. Thermoelectric measurements show that the ZnO and LZO layers are non-degenerate, with a maximum charge concentration of 9.18 × 1017 cm−3 for the 15% LZO films. The thin films show an ability for UV detection, while the 5%La_ZnO layers remain the best for UV photodetection with a good sensitivity (5.07) compared with the other layers. In terms of methyl blue degradation, the 5%La_ZnO thin films had a better degradation of 95%. [ABSTRACT FROM AUTHOR] more...
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- 2023
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46. SYNTHESIS OF Ag-DOPED ZnO NANOMATERIALS FOR DYE SENSITIZED SOLAR CELLS AND INVESTIGATION OF THE OPTIMUM Ag DOPING RATE
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Mesut EKMEKÇİ, Çağatay ELA, Sule ERTEN ELA, Çağdaş YAVUZ, Uşak Üniversitesi Teknik Bilimler Meslek Yüksekokulu, Elektrik Bölümü, and Ekmekçi, Mesut
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Community and Home Care ,dye sensitized solar cell ,photoanot ,Engineering, Multidisciplinary ,ZnO films ,Mühendislik, Ortak Disiplinler ,DSSC ,Silver (Ag) doped ZnO,ZnO films,dye sensitized solar cell,DSSC,photoanot ,Silver (Ag) doped ZnO - Abstract
Silver (Ag) doped ZnO (SZO) nanomaterials were synthesized by hydrothermal method and characterized. ZnO nanostructures were doped with 0.0%, 0.5%, 1%, 1.5mol% Ag. These obtained SZO nanomaterials were analyzed using X-ray diffraction measurement (XRD), Scanning Electron Microscopy (SEM), and Energy Dissipative X-ray spectroscopy (EDX). The structural analysis confirmed the formation of synthesized SZO samples having a hexagonal ZnO wurtzite phase. The morphology of SZO samples changed partially and the ZnO nanorod length increased somewhat as the Ag doping ratio increased. Despite this increase, it was seen that the average crystal sizes first increased and then decreased. The crystallite sizes calculated from XRD data for 0.0, 0.5, 1.0 and 1.5mol% SZO were obtained as 41, 42, 38 and 37 nm, respectively. Ag doping concentration has increased the absorbance of SZO nanomaterials increased and the transmission decreased was observed. The band gap of the 0.0%, 0.5%, 1.0% and 1.5mol% SZO nanomaterials were measured 3.19, 3.18, 3.16 and 3.19 eV, respectively. Then dye sensitized solar cells (DSSCs) were fabricated using these SZO nanomaterials, Z907dye, N719 dye and examined their photovoltaic performances. The calculated efficiencies of DSSCs fabricated using Z907 dye for 0.0%, 0.5%, 1.0% and 1.5mol% SZO were 0.005, 0.51, 0.46 and 0.22%, respectively. Then the calculated efficiencies of DSSCs fabricated using N719 dye for 0.0%, 0.5%, 1.0% and 1.5mol% SZO were 0.06, 0.17, 0.07 and 0.06%, respectively. In both works, DSSCs with ZnO film doped with 0.5mol% SZO showed the best photovoltaic performance. Consequently, these results indicated that the synthesized SZO nanomaterial for DSSCs of the optimum ratio of Ag doping is 0.5mol% clearly. more...
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- 2021
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47. Microstructural evolution of the oxidized ZnO:Cu films tuned by high magnetic field.
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Li, Guojian, Gao, Yang, Liu, Shiying, Wang, Zhao, Liu, Shan, and Wang, Qiang
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MICROSTRUCTURE , *ZINC oxide , *MAGNETIC fields , *MAGNETIC properties of metals , *THERMAL oxidation (Materials science) , *PHOTOLUMINESCENCE - Abstract
Microstructures and native defects are very important for the optical, electrical and magnetic properties of ZnO-based materials. In this study, microstructures of the Cu-doped ZnO (ZnO:Cu) films were changed by applying high magnetic field (HMF) during different growth processes of the as-deposited Zn-Cu films and the subsequent thermal oxidation treatment. The effects of the microstructure evolutions on the defects formation and photoluminescence performance are examined. The results show that the interaction between magnetization and thermal motion promotes (002) preferred orientation of the as-deposited Zn-Cu films. Meanwhile, the variation of the atomic deposition sites due to the HMF leads to the significant differences of surface morphology of the as-deposited films. The application of the HMF during the oxidation affects the adsorption sites of O 2− and leads the surface spherical particles change to rod-like particles. Moreover, the HMF shows more significant effects during the deposition of the Zn-Cu films in enhancing on the amount of the oxygen vacancy, which improves green emission of the ZnO:Cu films. [ABSTRACT FROM AUTHOR] more...
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- 2018
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48. 射频反应磁控溅射制备ZnO薄膜的工艺研究.
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常鸿 and 许绍俊
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ZINC oxide ,PIEZOELECTRICITY ,MAGNETRON sputtering ,CRYSTAL structure ,X-ray diffraction - Abstract
Copyright of Electronic Components & Materials is the property of Electronic Components & Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...
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- 2018
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49. Sc2O3 doped Bi2O3-ZnO thin films varistor prepared by sol-gel method.
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Xu, Dong, Song, Kun, Li, Yanli, Jiao, Lei, Zhong, Sujuan, Ma, Jia, Bao, Li, Zhang, Lei, and Song, Juan
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BISMUTH oxides , *ZINC oxide films , *VARISTORS , *SOL-gel processes , *CURRENT-voltage characteristics , *NONLINEAR theories - Abstract
Sc 2 O 3 modified Bi 2 O 3 -ZnO films varistors with different doping ratios were prepared by Sol-gel method. The result indicated that doping of Sc 2 O 3 significantly enhance the nonlinear current-voltage ( I-V) characteristics of Bi 2 O 3 -ZnO films. The highest non-linearity was obtained for 0.4mol% Sc content with the nonlinear coefficient α = 3.7 and 301 μA in leakage current. The grain size of ZnO phase firstly increased with Sc 2 O 3 doping when the content of Sc 2 O 3 is no more than 0.2 mol%. Upon the much more doping of Sc 2 O 3 , the growth of ZnO crystal was inhibited, leading to smaller grain size. The threshold voltage V T was inversely proportional with grain size of ZnO phase. Doping oxides gathered in the grain boundary significant impact on threshold voltage and leakage current. [ABSTRACT FROM AUTHOR] more...
- Published
- 2018
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50. UV sensitive pulsed laser deposited ZnO thin films: Influence of growth temperature.
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Shewale, P.S., Lee, S.H., and Yu, Y.S.
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THIN films , *ZINC oxide , *CONDENSED matter physics , *SOLID state electronics , *X-ray diffractometers , *PHOTOLUMINESCENCE - Abstract
The thin films of zinc oxide (ZnO) were grown on sapphire (0 0 1) substrates using pulsed laser deposition (PLD) in O 2 gas ambient and at different growth (substrate) temperatures (200, 300, 400, 500 and 600 °C). The effect of growth temperature on the crystallographic and morphological and photoluminescence properties of the films were investigated using X-ray diffractometer (XRD), field emission scanning electron microscopy (FE-SEM) and photoluminescence spectrometer. All the films reveal a wurtzite ZnO structure. The XRD results are well supported by the surface morphological and photoluminescence studies. The film characteristics were interrelated to their ultraviolet (UV) photo-sensing properties. The UV photodetection properties of the films were investigated at room temperature in metal–semiconductor–metal (MSM) planar configurations and are observed to be strongly driven by the growth temperature dependent crystallographic properties. The dark-current and the photocurrent of the ZnO film-based UV photodetectors are relational to the crystallite/grain size and the quality of ZnO thin films. For the photodetector based on ZnO film with a greater crystallite size, a lower dark current, and a higher photocurrent were achieved under 5 V bias voltage. The time-dependent photoresponse investigations illustrate a highly stable and fast switching UV photoresponse for the photodetector with ZnO film grown at 400°C growth temperature, which exhibits the maximum responsivity of ∼21.65 mA/W upon 2 mW/cm 2 UV light exposure (365 nm), at a bias voltage of 5 V. [ABSTRACT FROM AUTHOR] more...
- Published
- 2018
- Full Text
- View/download PDF
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