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We report on the fabrication of p-Si/n-CdO and p-Si/n-CdIn2O4 junction diodes using chemically prepared pure CdO and In 5–20 wt.%-doped CdO nanoparticles. The cadmium oxide (CdO) and indium-doped cadmium oxide (ICO) nanoparticles were characterized using x-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy, energy dispersive analysis, high-resolution transmission electron microscopy (HRTEM), UV-Vis analysis, photoluminescence (PL) and electrical conductivity measurements. The strongest orientation along the (111) plane for CdO indicates a fcc crystal system. The average particle size of ICO nanoparticles vary from 26 nm to 41 nm. The FTIR bands for ICO samples at 508–511 cm−1 was strongly remodeled while increasing the doping concentration of In at 15 wt.%. HRTEM revealed a clear spherical morphology ~16.28 nm of average particle size for the ICO with 20 wt.% In. Moreover, a maximum electrical conductivity of 15.084 × 10−10 S cm−1 with higher transmittance range of about 76.11% was achieved. The photosensitivity of the p-Si/n-CdIn2O4 diode varied from 103 to 104 %. Also, high quantum efficiency ~225.92% and specific detectivity 5.1952×1011 Jones were found for p-Si/n-CdIn2O4 photodiode. These outcomes suggest that the developed p-Si/n-CdIn2O4 diode is suitable one in the fabrication of UV photodetector and solar cell devices for electronic communication. [ABSTRACT FROM AUTHOR]

Monoclinic WO3-nanoplate arrays have been effectively deposited via simple jet nebulizer spray pyrolysis technique at an optimized substrate temperature of 400 °C. These WO3-nanoplate arrays were used as an insulating layer in the metal–insulator–semiconductor (MIS) structure based Schottky barrier diodes. The effect of WO3 mol concentration during the deposition process was systematically interpreted with respect to the structural, morphological, optical and electrical properties of WO3-nanoplate array films. XRD pattern exposed the polycrystalline nature of the prepared films with a monoclinic phase. At higher concentration of 0.25 M WO3-nanoplates were firmly interconnected together and has been analyzed by a FE-SEM. From UV–Vis spectroscopy, the band gap values of the WO3 were found to vary from 3.2 to 3.4 eV with mole concentrations. DC electrical study recorded a steep increase in the electrical conductivity for the film prepared with 0.2 M of WO3. Notably, all the diodes exhibited positive photoresponse under illumination. Particularly, the MIS diode fabricated with 0.2 M revealed higher photoresponsivity and sensitivity of 960.85% and 33.40 mA W−1 respectively. [ABSTRACT FROM AUTHOR]

The synthesis, characterization, and photodetector application of pure and Ni doped CdS thin films prepared by the spray pyrolysis technique are presented in this paper. Various techniques were used to analyze the thin films that had been produced. The hexagonal phase of the produced thin films is confirmed by X-ray diffraction (XRD) and FT-Raman (FTR) measurements. Scanning electron microscopy (SEM) was used to investigate the morphology of the thin film surface, revealing the development of nanograins. The energy band gaps for all of the prepared thin films were calculated to be approximately 2.4 eV. When the films were stimulated at 450 nm wavelength, a strong photoluminescence emission was seen at ∼540 ± 6 nm. The dark/photo I-V electrical performance of the developed films was observed. The fabricated Au/CdS/Au and Au/Ni:CdS/Au photodetectors were studied for recombination behavior, dark and photo surface resistivity, and photosensitivity. Interestingly, the dark surface resistivity was found to be greater compared to the photo-resistivity. When the light intensity was increased to 1450 Lux, the photosensitivity improves from 10% to 35%. These findings indicate that the fabricated CdS/Ni:CdS films-based photodetectors are suitable for optoelectronic devices. [ABSTRACT FROM AUTHOR]

In the current work, CuO spherical and rod-shaped particles has been synthesized with help of co-precipitation technique. XRD studies reveal the presence of phase reversal of CuOH to CuO with single phase monoclinic structure. FT-IR analysis authenticates the occurrence of copper oxide nanostructures with the removal of nitrogen-based vibrations and organic species. FESEM micrographs reveals the formation of interlinked spherical and rod like structured CuO particles with an average size 57 nm. UV–Visible analysis unveils the optical bandgap reduction from 2.62 to 2.04 eV during annealing. XPS analysis portrays the dominant appearance of Cu2+ which confirms the formation of CuO particles inconsistence with XRD and FT-IR results. The improved performance of the prepared photodiode is obtained from I–V characteristics. The excellent optoelectronic properties of the developed photodiode make them suitable for future nano-electronics. • Spherical, rod and needles shaped structures of CuO are successfully prepared by co-precipitation method. • FESEM images confirm the formation of nanospheres, nanorods and nanoneedles structures composed of small voids and trenches. • I–V nature of Al/n-CuO/p-Si type MIS diode indicates higher rectifying activity with minimum n values 4.69. • Particularly, Al/n-CuO/p-Si prepared at light condition samples bespoked exceptional photodiode performance compared with other devices. [ABSTRACT FROM AUTHOR]

Pristine and Cu, Mn-doped In 2 S 3 nanoparticles (NPs) were synthesized via a simple, elegant co-precipitation route. The dopant (Cu, Mn metal) influence on the structural, optical, photoluminescence and electrical properties were investigated. The (Cu, Mn) dope In 2 S 3 exhibited polycrystalline XRD phases having particle sizes varying from 36.2 to 49 nm. We noted a substantial decrease in the crystallite size on dopant (Cu, Mn) incorporation in In 2 S 3. From FE-SEM images, nanosheets, nanowires, and needle-like structures were observed. EDS elemental detection confirmed that In, Cu, Mn, and S elements are present in the produced NPs. The increment in bandgap (2.8–3.28 eV) was observed after the Cu, Mn doping in In 2 S 3. Photoluminescence studies demonstrate the photoemission is mainly owing to the donor-acceptor pair transitions. The electrical conductivity decreases significantly with doping, and a maximum electrical conductivity of 1.28 × 10−6 (Ω m)−1 was obtained for pure In 2 S 3 NPs. Mn-doped In 2 S 3 exhibits the highest photocatalytic activity (84%) for Methylene blue. [Display omitted] • Novel metal ions (Cu and Mn) doped In 2 S 3 NSs were prepared and reported here. • Phase confirmation was done through XRD and EDS analyses. • The increment in band gap from 2.8 to 3. 28 eV was observed after the Cu, Mn doping in In 2 S 3. • The electrical conductivity decreases significantly with doping. • Mn-doped In 2 S 3 exhibits the highest photocatalytic activity ∼84% for Methylene blue. [ABSTRACT FROM AUTHOR]

Development of p-SnS:NiS (80:20)/n-Si photodiode for optoelectronic devices. [Display omitted] • Development of p-SnS:NiS and bare p-NiS/n-Si photodetectors are reported. • Phase optimization of NiS and fabrication of SnS/NiS nanocomposite. • Morphology evolution of NiS and SnS/NiS was studied on oleic acid addition. • The value of photosensitivity improved from 75.0% to 2168.1%. • The value detectivity varied from 1.45 × 109 to 5.99 × 1010 jones. Synthesis of metal chalcogenides nanostructures is of profound importance in obtaining desired properties for photo-sensing device fabrication. The present proposed work concentrates on the effect of oleic acid in the preparation of NiS and SnS/NiS composites, and their photodiode properties were examined. Synthesized NiS and SnS/NiS nanosystem characterized by XRD analysis, Raman analysis, Field Emission Scanning Electron Microscopy micrographs. Hexagonal structure of NiS and hexagonal and orthorhombic composite structures SnS/NiS composite was confirmed with XRD patterns. The single-phase SnS nanoparticle and SnS/NiS nanocomposite were confirmed with Raman analysis. The change in morphology while increasing oleic acid on the preparation of NiS and SnS/NiS as aggregated quasi sphere structures were verified with FE-SEM micrographs. SnS/NiS fabricated with different ratios, and oleic acid-assisted NiS composite particles show better photo-response, which is essential for photodiode application. [ABSTRACT FROM AUTHOR]

In this work, pure tungsten oxide (WO 3) nanoparticles (NPs) and WO 3 /CoWO 4 nanocomposites (NCs) with various cobalt concentrations from 5 to 20 wt% were prepared via a co-precipitation process and subsequent annealing at 600 °C. All the synthesized samples were characterized by different techniques to study their structural, morphological, elemental, and optical properties and also to verify the conversion of WO 3 NPs to WO 3 /CoWO 4 NCs. X-ray diffraction results confirmed the existence of a stable monoclinic phase for pure WO 3 NPs and that no phase change occurs even after the formation of CoWO 4. The average crystallite sizes calculated for pure WO 3 NPs and 20 wt% WO 3 /CoWO 4 NCs were approximately 34 and 17 nm, respectively. Field-emission scanning electron microscopy revealed that pure WO 3 consists of nanoparticles as well as some nanoplates of size in the 30 nm diameter range. On Co doping of WO 3 , the size seems decrease and reveals very small NPs of size below 20 nm. Energy-dispersive X-ray spectroscopy spectra showed the persistence of chemical elements and their amount before and after the inclusion of cobalt. The chemical composition and the oxidation state of the elements on the surface of the synthesized NPs and NCs were investigated by X-ray photoelectron spectroscopy. The type of functional groups and their corresponding vibrational modes were identified by Fourier transform infrared spectroscopy. UV–visible studies were used to calculate the bandgap (E g) of pure WO 3 NPs and WO 3 /CoWO 4 NCs by means of Kubelka-Munk function plots. There was a reduction in E g from 2.61 eV for pure WO 3 NPs to 2.51 eV for 20 wt% Co NCs. In photoluminescence studies, the intensity of the emission peaks of WO 3 /CoWO 4 NCs showed a decreasing trend in comparison with pure WO 3 NPs. The formation of WO 3 /CoWO 4 NCs effectively controls the charge carrier (electron-hole) recombination. Hence, an appreciable enhancement in the photocatalytic degradation of the toxic dye methylene blue (C 16 H 18 N 3 SCl) of up to 86.5% was accomplished with WO 3 /CoWO 4 NCs (20 wt% Co sample) under irradiation with a UV-A light source. Toxic dye degradation profile of the prepared nanocomposites and proposed mechanism of dye degradation. [Display omitted] • A facile and low-cost co-precipitation method was used to prepare WO 3 nanoparticles and WO 3 /CoWO 4 nanocomposites. • Structural and compositional analyses proved the synthesis of WO 3 and WO 3 /CoWO 4 nanocomposites. • Small nanoparticles was proved via high-resolution transmission electron microscopy, and selected-area electron diffraction analysis. • A reduction in the band gap from 2.61 to 2.51 eV was found on Co doping of WO 3. • Higher photocatalytic activity for degradation of harmful methylene blue was found for WO 3 /CoWO 4. [ABSTRACT FROM AUTHOR]

The current study demonstrates ultra-fast synthesis of highly crystalline Zinc Oxide nanoparticles (ZnO NPs) using direct injection flame synthesis technique and inveterate the performance of p-Si/n-ZnO photodiode for visible light photodetection application. The synthesized ZnO NPs properties were evaluated by XRD, UV–Vis, FESEM, PL and Raman. FESEM reveals the flame synthesized Zinc Oxide NPs has a mixed morphology, including nanorods, nono-coffins, nanoneedles, nanoplates and nano-tetrapods with an average grain size of 108 nm & particle size of 127 nm with the optical bandgap of 3.27 eV. The synthesized ZnO NPs were coated onto the p-Si substrate and it shows promising photodetection performance. The p-Si/n-ZnO photodiode device possesses an ideality factor of 2.73, Barrier height of 0.7 eV, photosensitivity of 535%, responsivity of 2.36 mA/W and detectivity of 4.04 × 109 jones indicates the promising applications of p-Si/n-ZnO photodiode as photodetectors along with blue LED devices. [ABSTRACT FROM AUTHOR]

In this work, fine nickel oxide nanoparticles (NiO NPs) were successfully made utilizing a straightforward co-precipitation approach at low temperature. The effects of precursor concentration on the structural, optical, and electrical characteristics of NiO nanoparticles were investigated. All indexed diffraction peaks in XRD demonstrate the production of NiO with cubic structure. An increase in NiO crystallite size above 16.8 nm was observed when the precursor concentration exceeds 2 M, suggesting the presence of nanostructure in the final product. In FT-Raman spectra, the band centered at ∼ 500 cm–1 is due to Ni-O stretching (LO) mode, and two-magnon (2 M) scattering mode causes the band at 1514 cm–1. The synthesized product is composed of almost rod-shaped particles with a size range of 10–20 nm, according to FESEM pictures. The UV absorption studies showed a high absorption at the fundamental absorption edges originating at 332 nm, which gradually shifted to a lower energy region up to 400 nm with increasing precursor concentration, which means a reduction in bandgap values. The effect of precursor concentration associated with the electrical characteristics of the produced NiO nanoparticles has been investigated for the temperature range 30 to 130 °C. The I-V characterization was used to compute the different photo-diode parameters including n, Ф B , I o , P S , R, QE, and D*. The remarkable high photosensitivity of 1100% and specific detectivity of 4.324 × 10−10 Jones for the diode evaluated at 120 mW/cm2 was observed in a 2 M fabricated diode. These findings imply that all the fabricated diodes are exceptionally light-sensitive and are well-suited for upcoming UV photodetector applications. [Display omitted] • Development of NiO nanostructures-based photodiode with remarkable photosensitivity is reported • The XRD and Raman analyses confirm the synthesis of cubic NiO system • Crystallite size was improved from 10 to 17 nm with an increase in molar concentrations • Rising concentrations cause a steady decrease in the band gap energy from 3.45 to 3.1 eV. • A remarkably high photosensitivity of 1100% was observed for the device developed with 2 M concentration. [ABSTRACT FROM AUTHOR]

Nanoparticles (NPs) of Cu 1- x Ni x Fe 2 O 4 (0 ≤ x ≤ 0.5) have been facilely prepared via combustion through microwave technique. X-ray diffraction outcomes confirmed single-cubic phase synthesis of titled material and mean crystallites size and lattice constants were calculated in range of 19.37–22.69 nm and 8.319–8.248 Å, respectively. The XPS study confirms the chemical elements and oxidations states of Cu 0.6 Ni 0.4 Fe 2 O 4 NPs. The high-resolutionSEM study reveals spherical NPs with agglomeration and composition of elements in Cu 1- x Ni x Fe 2 O 4 (0 ≤ x ≤ 0.5) was confirmed through EDX study. The Kubelka-Munk model was employed to determine the energy gap of Cu 1- x Ni x Fe 2 O 4 NPs and noticed to vary from 2.30 to 2.06 eV. Photoluminescence spectra study explained the rate of recombination of electron and hole pairs. The detailed magnetic study was carried out and magnetization of remanence (M r), coercivity (H c) & saturation (M s) values were estimated through recording the hysteresis plots. The magnetic M r & M s values are noticed to be enhanced from 5.21 to 11.02 emu/g &17.37–31.37 emu/g with Ni content. Furthermore, the Cu 1- x Ni x Fe 2 O 4 (0 ≤ x ≤ 0.5) NPs were studied by means of visible light induced RhB dye degradation and investigates major active species and a probable mechanism for degradation has been conferred. The photocatalytic activity of CuFe 2 O 4 NPs has been improved via Ni doping. Photoluminescence spectra showed the rate of recombination of electron-hole pairs and presence of defects. Image 1 • Novel Cu 1-x Ni x Fe 2 O 4 (0 ≤ × ≤ 0.5) NPs synthesis was achieved via microwave combustion. • Monophasic cubic structure synthesis of CuFe 2 O 4 at all Ni contents is noticed. • The energy gap was determined and noticed to reduce from 2.30 to 2.06 eV. • The M r values are noticed to be enhanced from 5.21 to 11.02 emu/g with Ni content. • The photocatalytic activity of CuFe 2 O 4 NPs has been improved via Ni doping. [ABSTRACT FROM AUTHOR]

• A polycrystalline with dual phase in nature of cubic and monoclinic structure was observed. • The largest and lowest energy gap values are found to be 4.03 eV and 2.44 eV for Gd and metal copper. • White sponge, nanorods, nanoneedles and nanorice shaped morphology has observed by FESEM. • The MIS diode was achieved a minimum ideality factor values of 5.34. • The excellent opto-electronics properties of the developed photodetectors make it suitable for future nano-electronics. Here we are reporting the development of Gadolinium based copper oxide nanocomposites via a cost-effective low-temperature co-precipitation process. X-ray diffraction study approves the dual phase polycrystalline cubic and monoclinic structure with predominant orientations along (2 2 2) and (0 0 2) directions. A strong &sharp peak is positioned at ~512 cm−1in FT-IR is assigned to metal oxide (Cu-O/Gd-O) network terminal stretching & phonon band. Absorption study reveals strong absorption peaks for the samples prepared from pure copper (Cu) and gadolinium (Gd), however poor absorption was noticed from mixed CuO-Gd2O 3 nanocomposites.The largest and lowest energy gap values are found to be 4.03 eV and 2.44 eV for Gd and metal copper, respectively. White sponge, nanorods, nanoneedles and nanorice shaped morphology has observed from FESEM analysis. X-ray photoelectron spectroscopy (XPS) survey spectrum unveils the essential elements like Cu, Gd and oxygen. The peak fitting of Gd4d exhibits two major peaks at 143.6 and 155.8 eV binding energies correspond to spin orbit doublet splitting of 12.2 eV between 4d 5/2 and 4d 3/2 , respectively. From I-V study, we observed that the presence of CuO-Gd 2 O 3 nanocomposites at p-Si/Al interface improved the performance of the MIS diode. The excellent opto-electronics properties of the developed photo-detectors make it suitable for future nano-electronics. [ABSTRACT FROM AUTHOR]

Herein, we are presenting the synthesis of pure WO 3 nanoparticles (NPs) and WO 3 /NiWO 4 nanocomposites (NCs) with improved photocatalytic activities via a simple co-precipitation process. Structural, morphological, and compositional studies approved the synthesis of the nanocomposite. Furthermore, XPS analysis confirm the chemical composition and incorporation of Ni in the final products. The Scherrer equation used to determine the crystallite size and noticed that it reduced from 34 to 21 nm on Ni added in WO 3 and also FESEM study give the average grain size of NPs around 30 nm. HRTEM and SAED studies reveals the nanocomposite phase with lattice spacing of ~0.37 nm, and ~0.29 nm, which is perfectly matched with (020) of WO 3 and (111) of NiWO 4 , respectively. FTIR analysis reveals the functional groups of the formation of WO 3 /NiWO 4 NCs. Diffused reflectance spectroscopy was employed to determine the energy gap (E g) through Kubelka-Munk relation and noticed that the E g value is reduced from 2.61 to 2.49 eV. PL emission analysis was done under 280 nm excitation and possess the intense emission peaks at 361, 383, 412, and 492 nm, among them 383 nm is high intense, which is originated from near band edge transition. The photocatalytic degradation of Methylene blue (MB) dye was investigated under UV light. The percent degradation of MB dye was observed to be ~70.83%, 71.88%, 76.39%, 86.81% and 90.63% for pure WO 3 , 5 wt% Ni, 10 wt% Ni, 15 wt% Ni and 20 wt% Ni nanocomposites, respectively. The maximum percent photodegradation of MB dye has been done ∼90.63% for 20 wt% Ni within 80 min of duration. These outcomes revealed that the prepared WO 3 /NiWO 4 NCs will be highly applicable for hazardous MB dye degradation. BET analysis, pseudo-first-order kinetic plot for photo-degradation of MB solution and elemental trapping experiment. [Display omitted] • Facile synthesis of novel WO 3 and WO 3 /NiWO 4 nanocomposites was attained via low-cost co-precipitation method. • XRD, XPS & EDX analyses confirm the synthesis of WO 3 and WO 3 /NiWO 4 nanocomposite. • TEM/HRTEM/SAED analyses confirm low dimension spherical NPs synthesis. • Energy gap systematically reduced from 2.61 to 2.49 eV on increasing the Ni concentrations in WO 3. • Highest photocatalytic degradation of MB dye was noticed for 20% Ni (WO 3 /NiWO 4) specimen. [ABSTRACT FROM AUTHOR]

Herein, the fabrication of novel pure and Zr-doped SnO 2 (Zr@SnO 2) films via sol-gel spin coating process for Schottky barrier diode (SBD) application has been reported. Phase and size analysis were carried out through X-ray diffraction and Scherrer rule was used to determine crystallite size, which is noticed between 2 and 6 nm. The SEM study reveals that the fabricated films contain very fine sphere-like grains. The optical transmittance of Zr@SnO 2 thin films reveals that the grown films possess high transmittance which is good for optoelectronics. The values of energy gap for all Zr@SnO 2 films were estimated between 3.90 and 3.96 eV. The dc conductivity analysis showed that SnO 2 films possess higher electrical conductivity at 8 wt% of Zr. The barrier heights (Φ B) and ideality factor (n) of the fabricated SBDs were calculated from both J-V and Cheung's method. Better performance was noticed for Zr (8 wt%):SnO 2 /p-Si SBD. [ABSTRACT FROM AUTHOR]