119 results on '"Yin Jiang"'
Search Results
2. Enhanced Electrical Performance and Negative Bias Illumination Stability of Solution-Processed InZnO Thin-Film Transistor by Boron Addition
- Author
-
Jiang-Hua Zhang, Jun Li, Chuan-Xin Huang, Zhi-Lin Zhang, Xifeng Li, Xue-Yin Jiang, De-Yao Zhong, and Cheng-Yu Zhao
- Subjects
010302 applied physics ,Materials science ,business.industry ,Transistor ,Doping ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,law.invention ,Threshold voltage ,Stress (mechanics) ,chemistry ,law ,Thin-film transistor ,0103 physical sciences ,Density of states ,Optoelectronics ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Boron ,Solution process - Abstract
In this paper, boron-doped indium–zinc–oxide (InZnO) thin-film transistors (BIZO TFTs) were fabricated by solution process. The electrical performance and stability under the negative bias illumination stress (NBIS) have been greatly improved by B doping. The BIZO TFT with 5 mol.% B doping ratio shows a superior electrical performance with a field-effect mobility of 10.15 cm2/ $\textsf {V}\,\cdot \, \textsf {s}$ , a threshold voltage of 3.29 V, a subthreshold swing of 0.35 V/decade, and an ON/OFF ratio of 108. Furthermore, the 5 mol.% BIZO TFT shows only a −1.59 V shift of the threshold voltage, compared with a large negative shift of −4.24 V for pure IZO TFTs. The enhancement of electrical performance and stability under NBIS is due to the reduction of oxygen vacancies, which are suppressed by B doping. The density of states is calculated to further validate the improved electrical performance and NBIS stability of BIZO TFTs.
- Published
- 2018
3. Study the best ratio of S and Se in CZTSSe solar cells with nontoxic buffer layer
- Author
-
Meng-Yin Jiang, Ji-Yu Tang, Yu-Hang Niu, Long Chen, Wen-Chao Zhang, and Rui Huang
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,Band gap ,business.industry ,020209 energy ,020208 electrical & electronic engineering ,02 engineering and technology ,Buffer (optical fiber) ,law.invention ,law ,Attenuation coefficient ,Solar cell ,0202 electrical engineering, electronic engineering, information engineering ,Transmittance ,Optoelectronics ,business ,Material properties ,Layer (electronics) ,High absorption - Abstract
Cu2ZnSn(Sx, Se1−x)4 (CZTSSe) material has attracted more and more researchers' attention due to its low cost, environmental protection, high absorption coefficient, and adjustable bandgap. The classic structure of CZTSSe solar cell is Al: ZnO (AZO)/i-ZnO/CdS/CZTSSe, so it is very important to find a suitable buffer layer material to replace the toxic cadmium (Cd). Therefore, the performance of solar cells with different buffer layers is compared. The buffer layer is replaced by the indirect bandgap n-In2S3, which has high stability and light transmittance. And in this work, spectroscopic ellipsometry is used to measure the absorption coefficient spectrum of the absorber layer CZTSSe with different sulfur-to-selenium ratio, and wxAMPS numerical simulation software is used to simulate various material properties and draw conclusions. When X = 0.4, the performance of the CZTSSe TFSC reaches the optimal value.
- Published
- 2021
4. Atomic layer deposition deposited high dielectric constant (κ) ZrAlOx gate insulator enabling high performance ZnSnO thin film transistors
- Author
-
Wenqing Zhu, Cheng-Yu Zhao, Xue-Yin Jiang, Zhi-Lin Zhang, Jun Li, Jianhua Zhang, De-Yao Zhong, and Chuan-Xin Huang
- Subjects
010302 applied physics ,Materials science ,business.industry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Capacitance ,Amorphous solid ,Threshold voltage ,Atomic layer deposition ,Thin-film transistor ,0103 physical sciences ,Optoelectronics ,General Materials Science ,Electrical and Electronic Engineering ,Thin film ,0210 nano-technology ,business ,Current density ,High-κ dielectric - Abstract
The high κ ZrAlOx gate insulators were deposited by atomic layer deposition on silicon and characterized by the different analytical techniques. The grazing incidence X-ray diffraction (GIXRD) verifies that ZrAlOx thin films show an amorphous structure. The X-ray photoelectron spectroscopy (XPS) confirms that the form of ZrAlOx phase improves the electrical properties and stability of the associated devices. Then, all ZrAlOx thin films were integrated in metal-insulator-semiconductor structures to check the electrical capabilities. They all show a low leakage current density (about 1 × 10−8 A/cm2) under a high electric field of about 2.0 MV/cm, and exhibit a stable capacitance as a function of frequency. Their associated ZTO TFTs were deposited by a radio frequency sputtering, and the influence of the ZrAlOx thickness on the stabilities under positive bias stress and electrical properties is investigated. The 130 nm ZrAlOx based TFT shows the optimized electrical properties (its mobility, threshold voltage, sub-threshold voltage swing and on-off ratio are 12.5 cm2/V, 0.3 V, 0.15 V/dec. and 8 × 107 and the good stability with 2.5 V threshold voltage shift under the positive bias voltage stress. The better properties of 130 nm ZrAlOx based TFTs are attributed to a less interface trap states and surface scattering center.
- Published
- 2017
5. A comparison of density of states between InGaZnO based TFTs and InZnO based TFTs
- Author
-
Chuan-Xin Huang, Jun Li, Zhi-Lin Zhang, Wenqing Zhu, Jianhua Zhang, and Xue-Yin Jiang
- Subjects
010302 applied physics ,Materials science ,business.industry ,Transistor ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Instability ,law.invention ,Oxide semiconductor ,law ,Thin-film transistor ,0103 physical sciences ,Density of states ,Optoelectronics ,General Materials Science ,0210 nano-technology ,business ,Layer (electronics) ,Communication channel - Abstract
We investigate thermally induced instability of thin film transistors with incorporating sputtered InZnO and InGaZnO as the channel layer at room temperature, using density of states extracted from...
- Published
- 2017
6. Stability enhancement in InGaZnO thin-film transistor with a novel Al2O3/HfO2/Al2O3 as gate insulator
- Author
-
Jiantao Song, Cunping Qin, Jianhua Zhang, Tao Xu, Xingwei Ding, Zhi-Lin Zhang, and Xue-Yin Jiang
- Subjects
010302 applied physics ,Materials science ,business.industry ,Gate insulator ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Amorphous solid ,Thin-film transistor ,0103 physical sciences ,Density of states ,Optoelectronics ,General Materials Science ,0210 nano-technology ,business - Abstract
This work reports an efficient route for enhancing the stability of amorphous InGaZnO (a-IGZO) thin film transistors (TFTs). It is clearly observed that the off-current in IGZO-TFT decreases by usi...
- Published
- 2017
7. TiSiOx gate dielectrics produced by reactive sputtering for high performance InGaZnO thin film transistors
- Author
-
Cheng-Yu Zhao, Jun Li, Jianhua Zhang, Chuan-Xin Huang, Zhi-Lin Zhang, Xifeng Li, Yi-Zhou Fu, and Xue-Yin Jiang
- Subjects
010302 applied physics ,Materials science ,business.industry ,Mechanical Engineering ,Field effect ,02 engineering and technology ,Dielectric ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Threshold voltage ,Mechanics of Materials ,Sputtering ,Thin-film transistor ,0103 physical sciences ,Optoelectronics ,General Materials Science ,Thin film ,0210 nano-technology ,business ,Current density ,High-κ dielectric - Abstract
High dielectric constant TiSiOx thin films are produced by reactive sputtering under different oxygen partial pressure ratio (P O2 ) from 15% to 30%. All the TiSiOx films show an excellent transmittance value of almost 95%. The TiSiOx film has a low leakage current density by optimizing oxygen partial pressure, and the leakage current density of TiSiOx film under P O2 of 20% is 4.88×10 −7 A/cm 2 at electrical field strength of 2 MV/cm. Meanwhile, their associated InGaZnO thin-film transistors (IGZO-TFTs) with different P O2 TiSiOx thin films as gate insulators are fabricated. IGZO-TFTs under P O2 of 20% shows an optimized electrical performance, and the threshold voltage, sub-threshold swing, field effect mobility and I on /I off ratio of this device are 2.22 V, 0.33 V/decade, 29.3 cm 2 /V s and 5.03×10 7 , respectively. Moreover, the density of states (DOS) is calculated by temperature-dependent field-effect measurement. The enhancements of electrical performance and temperature stability are attributed to better active/insulator interface and smaller DOS.
- Published
- 2017
8. Enhancement of Electrical Stability in IGZO Thin-Film Transistors Inserted with an IZO Layer Grown by Atomic Layer Deposition
- Author
-
Jiantao Song, Zhi-Lin Zhang, Xue-Yin Jiang, Jianhua Zhang, Xingwei Ding, and Sheng Li
- Subjects
Materials science ,business.industry ,020208 electrical & electronic engineering ,Electrical stability ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Electronic, Optical and Magnetic Materials ,Atomic layer deposition ,Thin-film transistor ,0202 electrical engineering, electronic engineering, information engineering ,Optoelectronics ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Layer (electronics) - Published
- 2017
9. Characterization of dual-target co-sputtered novel Hf-doped ZnSnO semiconductors and the enhanced stability of its associated thin film transistors
- Author
-
Jun Li, Chuan-Xin Huang, Yi-Zhou Fu, Jianhua Zhang, Zhi-Lin Zhang, Qiuhong Yang, and Xue-Yin Jiang
- Subjects
010302 applied physics ,Materials science ,business.industry ,Band gap ,Mechanical Engineering ,Doping ,Metals and Alloys ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Amorphous solid ,Hafnium ,Semiconductor ,X-ray photoelectron spectroscopy ,chemistry ,Mechanics of Materials ,Thin-film transistor ,0103 physical sciences ,Materials Chemistry ,Optoelectronics ,Thin film ,0210 nano-technology ,business - Abstract
The novel hafnium added ZnSnO (ZTO) thin films were deposited by a dual-target magnetron co-sputtering system. The effect of hafnium doping content on the structure, surface morphology, chemical compositions, optical and electrical properties of HZTO thin films is studied. The HZTO thin films with high hafnium content show an amorphous structure, smooth surface, less carrier concentration and wider optical bandgap. XPS results show that oxygen vacancies as electron charge carrier are effectively suppressed by increasing Hf contents. In addition, their associated application in thin film transistors (TFTs) with Al 2 O 3 gate insulator were fabricated. The interface trap states between the gate insulator and HZTO thin films become fewer with increasing the hafnium doping content. Moreover, hafnium doping content has an important influence on the electrical property and bias stability of TFTs. Although the mobility decreases with increasing the hafnium doping content, the stability is improved obviously. The improved bias stability is attributed to a fewer bulk traps in channel and interface traps between the gate insulator and channel layer, which are commonly originated from oxygen vacancies in oxide-based semiconductors. Therefore, the hafnium ion is a good electron suppressor, and the hafnium doping can effectively suppress gate bias instability of TFTs.
- Published
- 2016
10. A Compact 38-54 GHz Sub-Harmonic Mixer with Improved Linearity in 65-nm CMOS
- Author
-
Zhi-Yin Jiang, Bo-Ze Lu, Yunshan Wang, and Huei Wang
- Subjects
Materials science ,business.industry ,Transconductance ,020208 electrical & electronic engineering ,Bandwidth (signal processing) ,Harmonic mixer ,Linearity ,020206 networking & telecommunications ,02 engineering and technology ,Chip ,Superposition principle ,CMOS ,0202 electrical engineering, electronic engineering, information engineering ,Optoelectronics ,Radio frequency ,business - Abstract
This paper presents a 38-54 GHz sub-harmonic up-conversion mixer in 65 nm CMOS process using derivative superposition third-order transconductance cancellation technique. The measurement results demonstrate -2.5 dB conversion gain and -11.7 dBm OP1dB at IF input frequency of 100 MHz and RF frequency of 41 GHz with relatively low power. The 3-dB RF bandwidth covers 38 to 54 GHz. The dc power consumption of the mixer is 8.5 mW. The improvement of OIP3 is 4 dB (from 0 to 4 dBm). The chip area of the proposed mixer is 0.8 × 0.55 mm2.
- Published
- 2019
11. High Gain Fully-Integrated Broadband Differential LNAs in 0.15-μm GaAs pHEMT Process Using R-L-C Feedback Gain Compensation for Radio Astronomical Receiver
- Author
-
Huei Wang, Chau-Ching Chiong, Yunshan Wang, Zhi-Yin Jiang, and Yang Chang
- Subjects
Physics ,business.industry ,Amplifier ,020208 electrical & electronic engineering ,Bandwidth (signal processing) ,020206 networking & telecommunications ,02 engineering and technology ,High-electron-mobility transistor ,Noise figure ,Chip ,Balun ,Broadband ,0202 electrical engineering, electronic engineering, information engineering ,Optoelectronics ,business ,Monolithic microwave integrated circuit - Abstract
This paper presents two fully-integrated broadband, high-gain MMIC low noise amplifiers (LNAs) with differential input and single-ended output for Square Kilometre Array (SKA) astronomical receiver. This amplifier was implemented using 0.15-μm GaAs pseudomorphic high electron mobility transistor (pHEMT) process. The R-L-C feedback is applied for broadband design, and the fully on chip LC balun is introduced behind the first-stage in LNA1 and the third-stage in LNA2, respectively. The 3-dB bandwidth of the LNA1 covers from 2.7 to 5.7 GHz and LNA2 covers from 4.3 to 16.3 GHz. The measurement results demonstrate small signal peak gain 31.7/35.4 dB, average in-band noise figure of 0.92/1.05 dB with DC power consumption of 48/90 mW. The chip area of both the amplifiers is 2.5 × 2 mm2.
- Published
- 2019
12. Performance enhancement in InZnO thin-film transistors with compounded ZrO2–Al2O3 nanolaminate as gate insulators
- Author
-
Xingwei Ding, Xue-Yin Jiang, Jianhua Zhang, Zhi-Lin Zhang, Hao Zhang, and Jun Li
- Subjects
010302 applied physics ,Materials science ,business.industry ,Process Chemistry and Technology ,Transistor ,02 engineering and technology ,Activation energy ,Dielectric ,021001 nanoscience & nanotechnology ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,Improved performance ,Atomic layer deposition ,Thin-film transistor ,law ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,Density of states ,Optoelectronics ,0210 nano-technology ,business ,Performance enhancement - Abstract
We fabricated compounded ZrO2–Al2O3 nanolaminate dielectrics by the atomic layer deposition (ALD) and used them to successfully integrate the high-performance InZnO (IZO) thin-film transistors (TFTs). It is found that nanolaminate dielectrics combine the advantages of constituent dielectrics and produce TFTs with improved performance and stability compared to single-layer gate insulators. The mobility in IZO-TFT was enhanced about 22% by using ZrO2–Al2O3 gate insulators and the stability was also improved. The transfer characteristics of IZO-TFTs at different temperatures were also investigated and temperature stability enhancement was observed for the TFT with ZrO2–Al2O3 nanolaminates as gate insulators. A larger falling rate (∼1.45 eV/V), a lower activation energy (Ea, ∼1.38 eV) and a smaller density-of-states (DOS) were obtained based on the temperature-dependent transfer curves. The results showed that temperature stability enhancement in InZnO thin-film transistors with ZrO2–Al2O3 nanolaminate as gate insulators was attributed to the smaller DOS.
- Published
- 2016
13. Feasibility of ZnO:Al/Ag/ZnO:Al multilayer source/drain electrode to achieve fully transparent HfInZnO thin film transistor
- Author
-
Xue-Yin Jiang, Zhi-Lin Zhang, Jun Li, and Jianhua Zhang
- Subjects
010302 applied physics ,Materials science ,business.industry ,Metals and Alloys ,Field effect ,02 engineering and technology ,Surfaces and Interfaces ,021001 nanoscience & nanotechnology ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Threshold voltage ,Thin-film transistor ,Sputtering ,Electrical resistivity and conductivity ,0103 physical sciences ,Electrode ,Materials Chemistry ,Transmittance ,Optoelectronics ,0210 nano-technology ,business ,Sheet resistance - Abstract
We fabricated fully transparent hafnium indium zinc oxide (HfInZnO) thin film transistors (TFTs) with ZnO:Al(AZO)/Ag/ZnO:Al multilayer source/drain (S/D) electrodes. The effect of Ag interlayer thickness on the electrical and optical properties of AZO(60 nm)/Ag/AZO(60 nm) multilayer films was investigated. The AZO(60 nm)/Ag(10 nm)/AZO(60 nm) multilayer film shows a low sheet resistance of 10.5 Ω/square and a transmittance of 87%. Compared with HfInZnO-TFT with AZO electrode, the performance of the device with AZO/Ag/AZO multilayer electrode was significantly improved. The field effect mobility increased from 3.2 to 5.8 cm 2 /V s, and the threshold voltage reduced from 2.3 to 0.1 V. The improvement was attributed to the lower resistivity of AZO/Ag/AZO multilayer film. The result indicates that AZO/Ag/AZO multilayer electrode is a promising S/D electrode for fully transparent HfInZnO-TFTs.
- Published
- 2016
14. Amorphous LaZnSnO thin films by a combustion solution process and application in thin film transistors
- Author
-
Chuan-Xin Huang, Zhi-Lin Zhang, Jun Li, Xue-Yin Jiang, Jianhua Zhang, and Yi-Zhou Fu
- Subjects
010302 applied physics ,Materials science ,business.industry ,Doping ,Oxide ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Combustion ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Amorphous solid ,chemistry.chemical_compound ,chemistry ,Thin-film transistor ,0103 physical sciences ,Optoelectronics ,Thin film ,0210 nano-technology ,business ,Layer (electronics) ,Solution process - Abstract
Amorphous LaZnSnO thin films with different La doping concentration are prepared by a combustion solution process and the electrical performances of thin film transistors (TFTs) are investigated. The influence of La content on the structure, oxygen vacancies, optical and electrical performance of LaZnSnO thin films are investigated. At an appropriate amount of La doping (15 mol.%), LaZnSnO-TFT shows a superior electrical performance including a mobility of 4.2 cm2/V s, a subthreshold swing of 0.50 V/decade and an on/off current ratio of 1.9 × 107. The high performance LaZnSnO-TFT is attributed to the better interface between SiO2 and LaZnSnO channel layer and the suppression of oxygen vacancies by optimizing La content. It suggests that La doping can be a useful technique for fabricating high performance solution-processed oxide TFTs.
- Published
- 2016
15. Origin of the improved stability under negative gate-bias illumination stress in various sputtering power fabricated ZnSnO TFTs
- Author
-
Jun Li, Yi-Zhou Fu, Zhi-Lin Zhang, Xue-Yin Jiang, Chuan-Xin Huang, and Jianhua Zhang
- Subjects
Materials science ,business.industry ,Condensed Matter Physics ,Kinetic energy ,Power (physics) ,Ion ,Threshold voltage ,Stress (mechanics) ,Sputtering ,Thin-film transistor ,Optoelectronics ,General Materials Science ,Electrical and Electronic Engineering ,business ,Layer (electronics) - Abstract
In this work, we report the influence of ZnSnO channel layer sputtering power in the stability of ZnSnO TFTs under negative gate-bias illumination stress (NBIS). The origin of threshold voltage shift results from combined effect of two factors between the little defect-induced trap densities originated from oxygen vacancies and better channel–insulator interface. The kinetic energy of the ions at a proper rf sputtering power is responsible for less defect-induced trap density and better channel–insulator interface. Therefore, the ZnSnO TFT fabricated at 75 W sputtering power shows a better NBIS stability. In addition, the trap density is extracted by temperature-dependent field-effect measurements and it is consistent with the change of stability under NBIS and thermal stress.
- Published
- 2015
16. Characterization of novel BaZnSnO thin films by solution process and applications in thin film transistors
- Author
-
Wenqing Zhu, Jianhua Zhang, Jun Li, Chuan-Xin Huang, Zhi-Lin Zhang, and Xue-Yin Jiang
- Subjects
Materials science ,business.industry ,Mechanical Engineering ,Transistor ,Condensed Matter Physics ,law.invention ,Threshold voltage ,Semiconductor ,Mechanics of Materials ,Thin-film transistor ,law ,Optoelectronics ,General Materials Science ,Field-effect transistor ,Thin film ,business ,Solution process ,Solid solution - Abstract
Graphical abstract: This work reports the Ba content on thin film transistor based on a novel BaZnSnO semiconductor using solution process. - Highlights: • No reports about BaZnSnO thin film using solution process. • BaZnSnO thin film transistor (TFT) was firstly fabricated. • BaZnSnO-TFT shows a acceptable performace. • Influence of Ba content on BaZnSnO-TFT. - Abstract: A novel BaZnSnO semiconductor is fabricated using solution process and the influence of Ba addition on the structure, the chemical state of oxygen and electrical performance of BaZnSnO thin films are investigated. A high performance BaZnSnO-based thin film transistor with 15 mol% Ba is obtained, showing a saturation mobility of 1.94 cm{sup 2}/V s, a threshold voltage of 3.6 V, an on/off current ratio of 6.2 × 10{sup 6}, a subthreshold swing of 0.94 V/decade, and a good bias stability. Transistors with solution processed BaZnSnO films are promising candidates for the development of future large-area, low-cost and high-performance electronic devices.
- Published
- 2015
17. Temperature-dependent field-effect measurements method to illustrate the relationship between negative bias illumination stress stability and density of states of InZnO-TFTs with different channel layer thickness
- Author
-
Chuan-Xin Huang, Xingwei Ding, Jun Li, Zhi-Lin Zhang, Xue-Yin Jiang, and Jianhua Zhang
- Subjects
Materials science ,business.industry ,Field effect ,Electron ,Condensed Matter Physics ,Active layer ,Stress (mechanics) ,Photoexcitation ,Optics ,Thin-film transistor ,Density of states ,Optoelectronics ,General Materials Science ,Electrical and Electronic Engineering ,business ,Layer (electronics) - Abstract
We investigate the stability of thin film transistors incorporating sputtered InZnO as the channel layer under negative bias illumination stress. The transfer characteristic for various active layer thicknesses is shifted toward the negative direction under negative bias illumination stress and the device with thicker channel layer shows a slighter V TH negative shift than another device under negative bias illumination stress. In order to investigate channel layer thickness can have a great effect on the trap density and thus affect the V TH shift caused by charge trapping; we use temperature-dependent field-effect measurements method to accurately calculate their trap density. The results show that thicker InZnO channel layer has fewer DOSs, resulting in the decrease of charge trapping and the decrease of photoexcitation generated electron carrier. So the device with thicker channel layer shows a slighter V TH negative shift than another device under negative bias illumination stress.
- Published
- 2015
18. Effect of gate insulator thickness on device performance of InGaZnO thin-film transistors
- Author
-
Hao Zhang, Weimin Shi, Xingwei Ding, Zhi-Lin Zhang, Chaoying Fu, He Ding, Jun Li, Jianhua Zhang, and Xue-Yin Jiang
- Subjects
Materials science ,business.industry ,Mechanical Engineering ,Transistor ,Gate insulator ,Insulator (electricity) ,Condensed Matter Physics ,Capacitance ,Threshold voltage ,Ion ,law.invention ,Atomic layer deposition ,Mechanics of Materials ,law ,Thin-film transistor ,Optoelectronics ,General Materials Science ,business - Abstract
Top-contact thin-film transistors (TFTs) are fabricated in this work using atomic layer deposition (ALD) Al2O3 as the gate insulator and radio frequency sputtering InGaZnO (IGZO) as the channel layer so as to investigate the effect of Al2O3 thickness on the performance of IGZO-TFTs. The results show that TFT with 100-nm-thick Al2O3 (100 nm-Al2O3-TFT) exhibits the best electrical performance; specifically, field-effect mobility of 5 cm2/Vs, threshold voltage of 0.95 V, Ion/Ioff ratio of 1.1×107 and sub-threshold swing of 0.3 V/dec. The 100 nm-Al2O3-TFT also shows a substantially smaller threshold voltage shift of 1.1 V after a 10 V gate voltage is applied for 1 h, while the values for TFTs with an Al2O3 thickness of 220 and 280 nm are 1.84 and 2 V, respectively. The best performance of 100 nm-Al2O3-TFT can be attributed to the larger capacitance and the smaller amount of total trap centers possessed by a thinner insulator compared to the thicker ones.
- Published
- 2015
19. Temperature stress on a thin film transistor with a novel BaZnSnO semiconductor using a solution process
- Author
-
Jun Li, Wenqing Zhu, Jianhua Zhang, Chuan-Xin Huang, Zhi-Lin Zhang, and Xue-Yin Jiang
- Subjects
Materials science ,business.industry ,General Chemical Engineering ,chemistry.chemical_element ,General Chemistry ,Temperature stress ,Oxygen ,Semiconductor ,chemistry ,Thin-film transistor ,Subthreshold swing ,Density of states ,Optoelectronics ,Electrical measurements ,business ,Solution process - Abstract
We have fabricated novel BaZnSnO-TFT using a solution process and investigated the electrical performance and temperature stability. BaZnSnO-TFT shows an improved field-effect mobility of 3.2 cm2 V−1 s−1, a subthreshold swing of 0.61 V per decade and an on/off current ratio of 2 × 107 compared to those of ZnSnO-TFT. Density of state distribution of BaZnSnO and ZnSnO semiconductor has been extracted from electrical measurements. BaZnSnO-TFT shows an improved electrical performance and temperature stability due to smaller oxygen vacancies, less bulk trap density and interface state density.
- Published
- 2015
20. IGZO thin film transistors with Al2O3 gate insulators fabricated at different temperatures
- Author
-
Hao Zhang, Jun Li, Weimin Shi, Xue-Yin Jiang, Zhi-Lin Zhang, Jianhua Zhang, and Xingwei Ding
- Subjects
Materials science ,business.industry ,Mechanical Engineering ,Oxide ,Field effect ,Insulator (electricity) ,Condensed Matter Physics ,Threshold voltage ,chemistry.chemical_compound ,Bottom gate ,chemistry ,Mechanics of Materials ,Thin-film transistor ,Electrode ,Optoelectronics ,General Materials Science ,Radio frequency ,business - Abstract
Thin film transistors (TFTs) with bottom gate and staggered electrodes using atomic layer deposited Al 2 O 3 as gate insulator and radio frequency sputtered In–Ga–Zn Oxide (IGZO) as channel layer are fabricated in this work. The performances of IGZO TFTs with different deposition temperature of Al 2 O 3 are investigated and compared. The experiment results show that the Al 2 O 3 deposition temperature play an important role in the field effect mobility, I on / I off ratio, sub-threshold swing and bias stability of the devices. The TFT with a 250 °C Al 2 O 3 gate insulator shows the best performance; specifically, field effect mobility of 6.3 cm 2 /Vs, threshold voltage of 5.1 V, I on / I off ratio of 4×10 7 , and sub-threshold swing of 0.56 V/dec. The 250 °C Al 2 O 3 insulator based device also shows a substantially smaller threshold voltage shift of 1.5 V after a 10 V gate voltage is stressed for 1 h, while the value for the 200, 300 and 350 °C Al 2 O 3 insulator based devices are 2.3, 2.6, and 1.64 V, respectively.
- Published
- 2015
21. Extraction of density-of-states in amorphous InGaZnO thin-film transistors from temperature stress studies
- Author
-
Xue-Yin Jiang, Weimin Shi, Xingwei Ding, Hao Zhang, Jianhua Zhang, Chuan-Xin Huang, Zhi-Lin Zhang, and Jun Li
- Subjects
Materials science ,business.industry ,General Physics and Astronomy ,Activation energy ,Amorphous solid ,Active layer ,Threshold voltage ,Semiconductor ,Thin-film transistor ,Density of states ,Optoelectronics ,General Materials Science ,business ,Layer (electronics) - Abstract
The instability of amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) with different active layer thicknesses under temperature stress has been investigated through using the density-of-states (DOS). Interestingly, the a-IGZO TFT with 22 nm active layer thickness showed a better stability than the others, which was observed from the decrease of interfacial and semiconductor bulk trap densities. The DOS was calculated based on the experimentally-obtained activation energy ( E A ), which can explain the experimental observations. We developed the high-performance Al 2 O 3 TFT with 22 nm IGZO channel layer (a high mobility of 7.4 cm 2 /V, a small threshold voltage of 2.8 V, a high I on / I off 1.8 × 10 7 , and a small SS of 0.16 V/dec), which can be used as driving devices in the next-generation flat panel displays.
- Published
- 2014
22. Growth of IZO/IGZO dual-active-layer for low-voltage-drive and high-mobility thin film transistors based on an ALD grown Al2O3 gate insulator
- Author
-
Chuan-Xin Huang, Xue-Yin Jiang, Xingwei Ding, Zhi-Lin Zhang, He Ding, Jianhua Zhang, Hao Zhang, Jun Li, and Weimin Shi
- Subjects
Materials science ,business.industry ,Oxide ,Field effect ,Condensed Matter Physics ,Threshold voltage ,Active layer ,Atomic layer deposition ,chemistry.chemical_compound ,chemistry ,Thin-film transistor ,Density of states ,Optoelectronics ,General Materials Science ,Electrical and Electronic Engineering ,business ,Low voltage - Abstract
We successfully integrated the high-performance oxide thin film transistors with novel IZO/IGZO dual-active-layers. The results showed that dual-active-layer (IZO/IGZO) TFTs, compared with single active layer IGZO TFTs and IZO TFTs, exhibited the excellent performances; specifically, a high field effect mobility of 14.4 cm2/Vs, a suitable threshold voltage of 0.8 V, a high on/off ratio of more than 107, a steep sub-threshold swing of 0.13 V/dec, and a substantially small threshold voltage shift of 0.51 V after temperature stress from 293 K to 353 K. In order to understand the superior performance, the density-of-states (DOS) were investigated based on the temperature-dependent transfer curves. The superior electric properties were attributed to the smaller DOS and higher carrier concentration. The proposed IZO/IGZO-TFT in this paper can be used as driving devices in the next-generation flat panel displays.
- Published
- 2014
23. ZrO2 insulator modified by a thin Al2O3 film to enhance the performance of InGaZnO thin-film transistor
- Author
-
Jun Li, Weimin Shi, He Ding, Zhi-Lin Zhang, Jianhua Zhang, Xue-Yin Jiang, Chuan-Xin Huang, Xingwei Ding, and Hao Zhang
- Subjects
Materials science ,business.industry ,Bilayer ,Transistor ,Electrical engineering ,Insulator (electricity) ,Trapping ,Dielectric ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,law ,Thin-film transistor ,Optoelectronics ,Electrical and Electronic Engineering ,Safety, Risk, Reliability and Quality ,business ,Order of magnitude ,Surface states - Abstract
A high-performance InGaZnO (IGZO) thin-film transistor (TFT) with ZrO 2 –Al 2 O 3 bilayer gate insulator is fabricated. Compared to IGZO-TFT with ZrO 2 single gate insulator, its electrical characteristics are significantly improved, specifically, enhancement of I on / I off ratios by one order of magnitude, increase of the field-effect mobility (from 9.8 to 14 cm 2 /Vs), reduction of the subthreshold swing from 0.46 to 0.33 V/dec, the maximum density of surface states at the channel-insulator interface decreased from 4.3 × 10 12 to 2.5 × 10 12 cm − 2 . The performance enhancements are attributed to the suppression of leakage current, smoother surface morphology, and suppression of charge trapping by using Al 2 O 3 films to modify the high- k ZrO 2 dielectric.
- Published
- 2014
24. Effect of sputtering power densities on density-of-states in InZnO thin-film transistor
- Author
-
He Ding, Xue-Yin Jiang, Weimin Shi, Hao Zhang, Jianhua Zhang, Zhi-Lin Zhang, Jun Li, Chuan-Xin Huang, and Xingwei Ding
- Subjects
Materials science ,business.industry ,Transistor ,Condensed Matter Physics ,law.invention ,Threshold voltage ,Atomic layer deposition ,Thin-film transistor ,law ,Sputtering ,Density of states ,Optoelectronics ,General Materials Science ,Electrical and Electronic Engineering ,Thin film ,business ,Power density - Abstract
Top-contact thin-film transistors (TFTs) are fabricated in this work by using radio frequency sputtering InZnO (IZO) as the channel layer so as to investigate the effect of working power densities ( P d ) on the performance of IZO-TFTs. Good-quality Al 2 O 3 thin films that are used as gate insulators are deposited via atomic layer deposition (ALD) technique. The results show that TFT with a P d of 1 W/cm 2 exhibits the best electrical performance; specifically, field-effect mobility of 17.9 cm 2 /V s, threshold voltage of −0.46 V, on/off ratio of 10 8 and sub-threshold swing of 0.13 V/dec. In order to understand the superior performance, the density-of-states (DOS) were investigated based on the temperature-dependent transfer curves. The investigation shows that the sputtering power density has significant effect on DOS of channel layer. The superior electric properties were attributed to the smaller DOS.
- Published
- 2014
25. The Influence of Hafnium Doping on Density of States in Zinc Oxide Thin-Film Transistors Deposited via Atomic Layer Deposition
- Author
-
Xingwei Ding, Jianhua Zhang, Cunping Qin, Jiantao Song, Zhi-Lin Zhang, and Xue-Yin Jiang
- Subjects
Materials science ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,01 natural sciences ,Oxygen ,law.invention ,Atomic layer deposition ,Materials Science(all) ,law ,0103 physical sciences ,General Materials Science ,010302 applied physics ,Nano Express ,business.industry ,Transistor ,Doping ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Hafnium ,chemistry ,Thin-film transistor ,Density of states ,Optoelectronics ,Erratum ,0210 nano-technology ,business ,Layer (electronics) - Abstract
Thin-film transistors (TFTs) with atomic layer deposition (ALD) HfZnO (HZO) as channel layer and Al2O3 as gate insulator were successfully fabricated. Compared with ZnO-TFT, the stability of HZO-TFT was obviously improved as Hf doping can suppress the generation of oxygen related defects. The transfer characteristics of TFTs at different temperatures were also investigated, and temperature stability enhancement was observed for the TFT with Hf doping. The density of states (DOS) was calculated based on the experimentally obtained E a, which can explain the experimental observation. A high-field effect mobility of 9.4 cm2/Vs, a suitable turn-on voltage of 0.26 V, a high on/off ratio of over 107 and a steep sub-threshold swing of 0.3 V/decade were obtained in HZO-TFT. The results showed that temperature stability enhancement in HfZnO thin-film transistors are attributed to the smaller DOS.
- Published
- 2017
26. Improving the electrical performance of HfInZnO-TFTs by introducing a thin ITO interlayer
- Author
-
Xingwei Ding, Zhi-Lin Zhang, Jun Li, Xue-Yin Jiang, Wenqing Zhu, and Jianhua Zhang
- Subjects
Materials science ,business.industry ,Thin-film transistor ,General Physics and Astronomy ,Optoelectronics ,Electrical performance ,General Materials Science ,Nanotechnology ,business ,Performance enhancement ,Threshold voltage - Abstract
We have fabricated hafnium–indium–zinc-oxide (HfInZnO) thin film transistors (TFT) with indium–tin-oxide (ITO) interlayer. Compared with conventional HfInZnO-TFT, the electrical performance and bias stability of HfInZnO-TFTs with ITO interlayer are improved. HfInZnO-TFT with 4-nm-thick ITO interlayer shows a high mobility of 7.2 cm 2 /V s, a low threshold voltage of 0.13 V and a better bias stability. The performance enhancement is attributed to a decrease in interface trap state and an increase in carrier concentration. It suggests that introducing ITO interlayer at the ALD Al 2 O 3 /HfInZnO interface is an effective way to improve the electrical performance and bias stability.
- Published
- 2014
27. A strategy for performance enhancement of HfInZnO thin film transistors using a double-active-layer structure
- Author
-
Xing-Wei Dinga, Jianhua Zhang, Jun Li, Wenqing Zhu, Zhi-Lin Zhang, and Xue-Yin Jiang
- Subjects
Materials science ,business.industry ,Metals and Alloys ,chemistry.chemical_element ,Surfaces and Interfaces ,Conductivity ,Oxygen ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Active layer ,Threshold voltage ,Stress (mechanics) ,chemistry ,Thin-film transistor ,Materials Chemistry ,Optoelectronics ,business ,Layer (electronics) ,Communication channel - Abstract
We investigate the electrical performance and negative bias stability of thin film transistors (TFTs) using double active layer. Double active layer is consisting of low oxygen content HfInZnO film as bottom channel and high oxygen content HfInZnO film as back channel. The HfInZnO-TFT with double channel layer shows a high mobility of 6.8 cm2/V s, a low threshold voltage of − 0.3 V, and a threshold voltage shifts of 0.65 V under − 20 V gate bias for 7200 s. The results suggest that HfInZnO with low oxygen content as the bottom channel could provide high carrier concentration and good HfInZnO/Al2O3 interface to improve field-effect mobility and negative bias stress stability. HfInZnO with high oxygen content as back channel can control the conductivity to reduce the off current of TFT. Thus, a double-active-layer structure is an effective way to improve the electrical performance of HfInZnO-TFT.
- Published
- 2014
28. The Al2O3 gate insulator modified by SiO2 film to improve the performance of IGZO TFTs
- Author
-
Jun Li, Hao Zhang, Xingwei Ding, Zhi-Lin Zhang, Xue-Yin Jiang, Weimin Shi, and Jianhua Zhang
- Subjects
Materials science ,business.industry ,Transistor ,Oxide ,Field effect ,Condensed Matter Physics ,law.invention ,Threshold voltage ,chemistry.chemical_compound ,chemistry ,Sputtering ,law ,Optoelectronics ,General Materials Science ,Radio frequency ,Electrical and Electronic Engineering ,business ,Layer (electronics) ,Surface states - Abstract
High-performance thin-film transistors (TFTs) using atomic layer deposited (ALD) Al 2 O 3 as gate insulator and radio frequency (RF) sputtering In–Ga–Zn Oxide (IGZO) as channel layer were fabricated in this work. A SiO 2 buffer layer was applied between IGZO and Al 2 O 3 to prevent the picked-up defects when the samples were switched from ALD to RF sputtering. Contrasting to the TFTs without buffer layer, the SiO 2 buffer layer improved the TFTs performances greatly, such as: the field effect mobility increases from 5.2 cm 2 /V s to 6.1 cm 2 /V s, the threshold voltage downshifts from 4.9 V to 1.7 V, the I on / I off ratio increases from 2.8 × 10 7 to 9.6 × 10 7 , the sub-threshold swing decreased from 0.76 V/dec to 0.6 V/dec. The maximum density of surface states at the channel–insulator interface decreased from 2.1 × 10 12 cm − 2 to 1.53 × 10 12 cm −2 .
- Published
- 2014
29. Feasibility of using sputtered AlOx film as gate insulator for high performance InGaZnO-TFTs
- Author
-
Jun Li, Zhi-Lin Zhang, Xingwei Ding, Xue-Yin Jiang, Jianhua Zhang, and Wenqing Zhu
- Subjects
Materials science ,business.industry ,RF power amplifier ,Insulator (electricity) ,Surface finish ,Condensed Matter Physics ,Threshold voltage ,Root mean square ,Thin-film transistor ,Optoelectronics ,General Materials Science ,Radio frequency ,Electrical and Electronic Engineering ,business ,Current density - Abstract
We reported on the electrical and surface characteristics of radio frequency (rf) AlO x film and their applications in InGaZnO-based thin film transistors (TFTs). By optimizing the rf power, AlO x film with the low leakage current density and smooth surface was obtained. The leakage current density for the 180 W AlO x film was observed to be ∼2.0 × 10 −9 A/cm 2 at electrical field strength of 2 MV/cm. The root mean square (rms) roughness of 180 W AlO x film was about 1.36 nm. InGaZnO-TFTs with different AlO x insulators were fabricated. The InGaZnO-TFT with 180 W AlO x insulator exhibits a field-effect mobility of 6.9 cm 2 /V s, a threshold voltage of 4.2 V, an on/off ratio of 2.7 × 10 7 , and a much smaller V th shift of 6.6 V for 20 V bias stress duration of 10,800 s. The improvement of InGaZnO-TFT with 180 W AlO x film is attributed to smooth surface of AlO x film and smaller trap charges. The results indicate that AlO x is a promising candidate insulator for InGaZnO-TFTs.
- Published
- 2014
30. Influence of the InGaZnO channel layer thickness on the performance of thin film transistors
- Author
-
Jun Li, Zhi-Lin Zhang, Xue-Yin Jiang, Weimin Shi, Xingwei Ding, Jianhua Zhang, and Hao Zhang
- Subjects
Materials science ,business.industry ,Gate insulator ,Condensed Matter Physics ,Layer thickness ,Ion ,Threshold voltage ,Atomic layer deposition ,Thin-film transistor ,Subthreshold swing ,Optoelectronics ,General Materials Science ,Electrical and Electronic Engineering ,business ,Saturation (magnetic) - Abstract
We report on the electrical properties of bottom-gate InGaZnO (IGZO) thin film transistors (TFTs) with different channel layer thicknesses. The IGZO channel layer with thickness varied from 25 to 120 nm were deposited by radio frequency sputtering. Al2O3 films were deposited on highly-doped n-Si substrate by atomic layer deposition (ALD) as gate insulator in this work. The influence of the IGZO channel layer thickness on the performance of TFTs is studied. The performance of devices is found to be thickness dependent. The best performance of devices is obtained from a 58 nm thick IGZO TFT, which shows a field-effect mobility in the saturation region of 6.2 cm2/Vs, a threshold voltage of 2.1 V, an Ion/Ioff ratio of approximately 6.4 × 107, and a subthreshold swing of 0.6 V/dec.
- Published
- 2013
31. High Visible‐Light‐Stimulated Plasticity in Optoelectronic Synaptic Transistors for Irradiation History‐Dependent Learning.
- Author
-
Wu, Mingze, Shang, Shangyang, Wei, Qi, Liu, Chang, Li, Aidong, Gao, Xu, Wang, Suidong, Yin, Jiang, Xia, Yidong, and Liu, Zhiguo
- Subjects
TRANSISTORS ,NEUROPLASTICITY ,LONG-term potentiation ,OPTICAL rotation ,IRRADIATION - Abstract
Recent years have witnessed the emergence of visible‐light‐stimulated synaptic transistors, which has potential for the construction of visual cognition and light‐controlled neuromorphic hardware. Efforts are made to improve the visible light‐stimulated plasticity by boosting the synaptic weight after optical neural activities. However, such modulation at the expense of increased initial synaptic weight before the stimuli still results in the limited plasticity. Here, instead of employing those inherent interfacial trap‐induced effects that raise the activated synaptic weight, it is demonstrated that an interfacial modification to inhibit them can greatly reduce the initial synaptic weight. Hence, with the assistance of the charge‐trapping memory effect, the initial and the activated synaptic weight can be modulated, leading to a significantly enhanced plasticity. Such enhancement is accomplished in a type of pentacene‐based synaptic transistors in which a visible‐light‐triggered plasticity above 108% (at 0 V gate voltage and −1 V source–drain voltage) can be achieved under a moderate optoelectronic stimulus. As a demonstration, long‐term potentiation is implemented to showcase synaptic responses with high plasticity after repeated light‐triggered neural activities, suggesting the proposed mechanism and design paradigm would be beneficial for future optical neuromorphic architectures. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
32. Improving electron injection and microcavity effect for constructing highly efficient inverted top-emitting organic light-emitting diode
- Author
-
Jun Li, Jiwen Xu, Xiaowen Zhang, Hua-Ping Lin, Xue-Yin Jiang, Huarui Xu, and Zhi-Lin Zhang
- Subjects
Materials science ,business.industry ,Bilayer ,Atomic and Molecular Physics, and Optics ,Cathode ,Electronic, Optical and Magnetic Materials ,law.invention ,Dielectric spectroscopy ,law ,OLED ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Luminous efficacy ,Current density ,Layer (electronics) ,Diode - Abstract
We demonstrated a highly efficient inverted top-emitting organic light-emitting diode (ITOLED) by using Ag/Al bilayer reflective cathode and CsOx electron-injection layer. With tris(8-hydroquinoline) aluminum as electron-transport and emitting layer, the maximum luminous efficiency and power efficiency of ITOLED with CsOx electron-injection layer reached 8.3 cd/A and 4.3 lm/W, respectively, which have been enhanced by ∼40% and ∼80%, respectively, in comparison with the counterpart using LiF as electron-injection layer (5.9 cd/A and 2.3 lm/W). The improved performance is resulted from the enhanced electron-injection ability of CsOx. The superior electron-injection ability of CsOx was further verified by ‘Electron-only’ device using current density versus voltage characteristics and impedance spectroscopy measurements. Our results indicated that CsOx electron-injection layer combined with Ag/Al bilayer reflective cathode provides a convenient approach for constructing highly efficient ITOLED.
- Published
- 2013
33. Effect of oxygen partial pressure on the density of states of amorphous InGaZnO thin-film transistors
- Author
-
Xifeng Li, Jianhua Zhang, Xue-Yin Jiang, Zhi-Lin Zhang, Wenqing Zhu, Chuan-Xin Huang, and Jun Li
- Subjects
010302 applied physics ,business.industry ,Transistor ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Partial pressure ,021001 nanoscience & nanotechnology ,01 natural sciences ,Oxygen ,law.invention ,Amorphous solid ,Active layer ,Threshold voltage ,chemistry ,law ,Thin-film transistor ,0103 physical sciences ,Density of states ,Optoelectronics ,General Materials Science ,0210 nano-technology ,business - Abstract
The thin-film transistors (TFTs) with InGaZnO active layer with different oxygen partial pressures are fabricated by radio frequency sputtering. The influence of the oxygen partial pressure on the density of states (DOS) for InGaZnO-TFT is investigated by using temperature-dependent field-effect measurements. It indicates that the DOS become smaller with increasing oxygen partial pressure. The results are verified by the threshold voltage shift of InGaZnO-TFT with different oxygen partial pressures. The trend of the variation of DOS is consistent with that of the threshold voltage shift for InGaZnO-TFT. Thus, the gate bias instability is attributed to the charge trapping mechanism based on DOS. Therefore, this work offered a brief and accurate method to calculate DOS for demonstrating the bias stability of transistor.
- Published
- 2016
34. Elucidations of weak microcavity effect and improved pixel contrast ratio in Si-based top-emitting organic light-emitting diode
- Author
-
Bin Wei, Fan Zhou, Xiaowen Zhang, Zhi-Lin Zhang, Hua-Ping Lin, Jun Li, and Xue-Yin Jiang
- Subjects
Materials science ,Pixel ,business.industry ,General Physics and Astronomy ,Electroluminescence ,Reflectivity ,Spectral line ,Anode ,Optics ,OLED ,Optoelectronics ,General Materials Science ,Contrast ratio ,business ,Diode - Abstract
Microcavity effect and pixel contrast ratio (PCR) are key issues for top-emitting organic light-emitting diode (TOLED). Si and Ag are two widely used reflective anodes for constructing effective TOLEDs. The mechanism contributing to microcavity effect and PCR has been clarified by using conventional optoelectronic theory. Consequently, the differences of microcavity effect and PCR between Si-based and Ag-based TOLEDs are discovered. Our results indicate that the Si-based TOLED possesses weak microcavity effect and improved PCR in comparison with Ag-based device. This is resulted from the low reflectivity and less reflective phase change of Si. The weak microcavity effect in Si-based TOLED also contributes to negligible variation of electroluminescent spectra with viewing angles and low device efficiency. Furthermore, Si-based TOLED shows rather high PCR which is about quintuple that of Ag-based device.
- Published
- 2012
35. SiOx interlayer to enhance the performance of InGaZnO-TFT with AlOx gate insulator
- Author
-
Wenqing Zhu, Fan Zhou, Hua-Ping Lin, Jianhua Zhang, Jun Li, Zhi-Lin Zhang, and Xue-Yin Jiang
- Subjects
Materials science ,business.industry ,Contact resistance ,General Physics and Astronomy ,Gate insulator ,Biasing ,Insulator (electricity) ,Threshold voltage ,Thin-film transistor ,Electrode ,Trap density ,Optoelectronics ,General Materials Science ,business - Abstract
We have fabricated indium–gallium–zinc (IGZO) thin film transistor (TFT) using SiO x interlayer modified aluminum oxide (AlO x ) film as the gate insulator and investigated their electrical characteristics and bias voltage stress. Compared with IGZO-TFT with AlO x insulator, IGZO-TFT with AlO x /SiO x insulator shows superior performance and better bias stability. The saturation mobility increases from 5.6 cm 2 /V s to 7.8 cm 2 /V s, the threshold voltage downshifts from 9.5 V to 3.3 V, and the contact resistance reduces from 132 Ωcm to 91 Ωcm. The performance improvement is attributed to the following reasons: (1) the introduction of SiO x interlayer improves the insulator surface properties and leads to the high quality IGZO film and low trap density of IGZO/insulator interface. (2) The better interface between the channel and S/D electrodes is favorable to reduce the contact resistance of IGZO-TFT.
- Published
- 2012
36. Effect of reactive sputtered SiOx passivation layer on the stability of InGaZnO thin film transistors
- Author
-
Fan Zhou, Wenqing Zhu, Hua-Ping Lin, Xue-Yin Jiang, Jun Li, Jianhua Zhang, and Zhi-Lin Zhang
- Subjects
Materials science ,Passivation ,business.industry ,Oxide ,chemistry.chemical_element ,Condensed Matter Physics ,Oxygen ,Bias stress ,Surfaces, Coatings and Films ,Stress (mechanics) ,chemistry.chemical_compound ,chemistry ,Thin-film transistor ,Optoelectronics ,Positive bias ,business ,Instrumentation ,Layer (electronics) - Abstract
We fabricated the indium-gallium-zinc oxide (IGZO) thin film transistor (TFT) with reactive sputtered SiOx as passivation layer, and investigated the role of the SiOx passivation layer in the IGZO-TFT under gate bias stress. The bias stability of IGZO-TFT with passivation layer is much better than that of IGZO-TFT without passivation layer. After applying positive bias stress of 20 V for 10000s, the device without passivation layer shows a larger positive Vth shift of 7.3 V. However, the device with passivation layer exhibits a much smaller Vth shift of 1.3 V. It suggests that Vth instability is attributed to the interaction between the exposed IGZO back surface and oxygen in ambient atmosphere during the positive gate voltage stress. The results indicate that reactive sputtered SiOx passivation layer can effectively improve the bias stability of IGZO-TFT.
- Published
- 2012
37. Enhancement of performance for blue organic light emitting devices by utilizing an adjustable chromaticity layer
- Author
-
Zhaochun Zhang, Xue-Yin Jiang, Jiaqi Zhang, Jie Li, Xiaowen Zhang, Hua-Ping Lin, and Fan Zhou
- Subjects
Quantum optics ,Materials science ,Physics and Astronomy (miscellaneous) ,business.industry ,General Engineering ,General Physics and Astronomy ,Luminance ,Optics ,Optoelectronics ,Chromaticity ,business ,Layer (electronics) ,Current density ,Color coordinates ,Voltage - Abstract
An adjustable chromaticity layer was successfully applied to a TBADN-based blue organic light-emitting device (BOLED) for improving chromaticity and luminance efficiency. The device was constructed by sandwiching an ultrathin [DPVBi: BCzVB] layer between hole-transport layer and primary emission layer. The optimized device gives the Commission Internationale de I’eclairage (CIE) color coordinates of (0.166, 0.201) at the current density of 20 mA/cm2 and a maximum luminance efficiency of 8.43 cd/A at the driving voltage of 11 V.
- Published
- 2012
38. Enhanced photosensitivity of InGaZnO-TFT with a CuPc light absorption layer
- Author
-
Fan Zhou, Hua-Ping Lin, Jun Li, Xue-Yin Jiang, Jianhua Zhang, Zhi-Lin Zhang, and Wenqing Zhu
- Subjects
Materials science ,business.industry ,Transistor ,Electron ,Condensed Matter Physics ,Amorphous solid ,law.invention ,Organic semiconductor ,Responsivity ,Photosensitivity ,Thin-film transistor ,law ,Optoelectronics ,General Materials Science ,Electrical and Electronic Engineering ,business ,Layer (electronics) - Abstract
A copper phthalocyanine (CuPc) organic semiconductor is capped onto an amorphous indium–gallium–zinc-oxide (InGaZnO) thin film transistor (TFT) to enhance the photosensitivity of InGaZnO-TFT. The CuPc organic semiconductor is served as a light absorption layer and forms a p – n junction with the InGaZnO film. After 60 s white light illumination, light responsivity ( R ) of InGaZnO-TFT with a CuPc light absorption layer reaches a value of 148.5 A/W at a gate-source voltage ( V GS ) of 20 V, which is much larger than that (31.2 A/W) of the conventional InGaZnO-TFT. The results are attributed to the following mechanism. First, a CuPc layer is employed as the light absorption layer. Second, CuPc/InGaZnO p – n junction enables the injection of electron into InGaZnO film. Our results indicate that using CuPc as light absorption layer is an effective approach to improve the photosensitivity of InGaZnO-TFT.
- Published
- 2012
39. Suppression of bias stress-induced degradation of pentacene-TFT using MoOx interlayer
- Author
-
Jun Li, Hua-Ping Lin, Zhi-Lin Zhang, Xue-Yin Jiang, Fang Zhou, and Wenqing Zhu
- Subjects
Materials science ,business.industry ,Contact resistance ,Transistor ,General Physics and Astronomy ,Threshold voltage ,law.invention ,Pentacene ,chemistry.chemical_compound ,chemistry ,law ,Thin-film transistor ,Electrode ,Optoelectronics ,Degradation (geology) ,General Materials Science ,business ,Voltage - Abstract
The bias stress effect in pentacene thin-film transistors (TFTs) with and without MoO x interlayer was characterized. The device without MoO x interlayer showed a large threshold voltage shift of 5.1 V after stressing with a constant gate-source voltage of −40 V for 10000 s, while at the same condition, the device with MoO x interlayer showed a low threshold voltage shift of 1.9 V. The results can be attributed to the stable interface between MoO x /pentacene and small contact resistance change for the device with MoO x /Cu electrode. Pentacene-TFTs with MoO x interlayer showed a high field-effect mobility of 0.61 cm 2 /V s and excellent bias stability, which could be a significant step toward the commercialization of OTFT technology.
- Published
- 2012
40. A very simple method of constructing efficient inverted top-emitting organic light-emitting diode based on Ag/Al bilayer reflective cathode
- Author
-
Xiao-Wen Zhang, Hua-Ping Lin, Xue-Yin Jiang, Jun Li, Liang Zhang, Bin Wei, and Zhi-Lin Zhang
- Subjects
Materials science ,business.industry ,Bilayer ,Biophysics ,Analytical chemistry ,General Chemistry ,Condensed Matter Physics ,Biochemistry ,Atomic and Molecular Physics, and Optics ,Cathode ,Anode ,law.invention ,law ,Monolayer ,OLED ,Optoelectronics ,Luminous efficacy ,business ,Diode ,Common emitter - Abstract
A comparative study on top-emitting organic light-emitting diodes (TOLEDs) with normal and inverted structures is briefly investigated. In comparison with the normal TOLED having Ag reflective anode, the inverted device with monolayer Al reflective cathode shows low efficiency as a result of lower reflectance of Al and inferior electron injection. Using Ag/Al bilayer reflective cathode is demonstrated to be a simple and effective method of enhancing efficiency in inverted TOLED. With tris(8-hydroquinoline) aluminum (Alq3) as emitter the luminous efficiency reaches 5.97 0.6 cd/A, which is much higher than those of the corresponding normal TOLED (� 5.1 cd/A) and inverted TOLED with monolayer Al reflective cathode ( � 4 cd/A). The improved performance is attributed to the enhanced reflectance and significant microcavity effect. The electron-injection barrier height of � 0.1 eV from Al to Alq3 via an ultrathin LiF is estimated in the tunneling process for both normal and inverted devices.
- Published
- 2012
41. Top-gate amorphous IGZO thin-film transistors with a SiO buffer layer inserted between active channel layer and gate insulator
- Author
-
Fan Zhou, Lin Zhang, Jie Li, Hua-Ping Lin, Dong-Bin Yu, Xue-Yin Jiang, Xiaobei Zhang, and Zhaochun Zhang
- Subjects
Materials science ,business.industry ,Transistor ,General Physics and Astronomy ,Insulator (electricity) ,Dielectric ,Active layer ,Amorphous solid ,law.invention ,Semiconductor ,Sputtering ,Thin-film transistor ,law ,Optoelectronics ,General Materials Science ,business - Abstract
In this paper, top-gate thin-film transistors (TFTs) using amorphous In–Ga–Zn–O as the n-channel active layer and SiO2 as gate insulator were fabricated by radio frequency magnetron sputtering at room temperature. In this device, a SiO layer was used to be a buffer layer between active layer and gate insulator for preventing the damage of the InGaZnO surface by the process of sputtering SiO2 with relatively high sputtering power. The thickness of buffer layers was studied and optimized for enhancing the TFTs performances. Contrasting to the TFTs without buffer layer, the optimized thickness of 10 nm SiO buffer layer improved the top-gate TFTs performances greatly: mobility increases 30%, reached 1.29 cm2/V s, the Ion/Ioff ratio increases 3 orders, and the trap density at the interface of channel/insulator decreases about 1 order, indicated that the improvement of semiconductor/dielectric interface by buffering the sputtering power.
- Published
- 2012
42. White organic light-emitting diodes based on C545T doped emitting system
- Author
-
Zhi-Lin Zhang, Jun Li, Xue-Yin Jiang, Xiaowen Zhang, Fan Zhou, Hua-Ping Lin, Liang Zhang, and Jianhua Zhang
- Subjects
business.industry ,Chemistry ,Doping ,Surfaces and Interfaces ,Electroluminescence ,Condensed Matter Physics ,Fluorescence ,Luminance ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Optics ,Materials Chemistry ,OLED ,Optoelectronics ,Electrical and Electronic Engineering ,Luminous efficacy ,business ,Electrical efficiency ,Diode - Abstract
Fluorescent white organic light-emitting diodes (WOLEDs) with single-emitting layer (EML) and double-EML structures were demonstrated using a 2,3,6,7-tetrahydro-1,1,7,7,-tetramethyl-1H,5H,11H-10(2-benzothiazolyl)quinolizine-[9,9a,1gh]coumarin (C545T) doped emitting system. With the incorporation of double-EML structure, white emission with Commission Internationale de L'Eclairage (CIE) color coordinates of (0.331, 0.335) and luminous efficiency of 8.04 cd/A was obtained. Moreover, WOLED with a single-EML structure shows superior electroluminescence performances such as lower voltage, higher luminance, and enhanced power efficiency. These improvements are attributed to its high energy transfer ability via the intermediation of C545T. The Forster's radius was given to clarify the actual energy transfer process.
- Published
- 2011
43. Effects of Green Emission on the Performance of White Organic Light-Emitting Devices and Their Electroluminescent Characteristics
- Author
-
Xue-Yin Jiang, Liang Zhang, Jianhua Zhang, Fan Zhou, Hua-Ping Lin, Xiaowen Zhang, Zhi-Lin Zhang, and Jun Li
- Subjects
Materials science ,business.industry ,Astrophysics::High Energy Astrophysical Phenomena ,Exciton ,Doping ,Analytical chemistry ,chemistry.chemical_element ,Electroluminescence ,Green emission ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,General Energy ,chemistry ,Effective energy ,Aluminium ,Optoelectronics ,Physical and Theoretical Chemistry ,Diffusion (business) ,business ,Luminous efficacy - Abstract
A white organic light-emitting device (WOLED) using tris(8-hydroxyquinoline)aluminum (Alq3) as the green emission is demonstrated. Our experiments indicate that Alq3 doping not only improves the color coordinates and color stability, but also reduces current-induced fluorescence quenching. A maximum luminous efficiency of 8.87 cd/A and an applicable value of 7.92 cd/A at 20 mA/cm2 are obtained. The excellent performance predominantly results from the effective energy transfer in the emitting system and the efficient utilization of Alq3 green emission. For comparison, WOLEDs with different components as the green emission and without the component of green emission are also fabricated and investigated. Our results show that the introduction of green emission from an appropriate component significantly improves the device efficiency and color properties. This result is further verified on the basis of the theory of exciton generation and diffusion.
- Published
- 2011
44. Non-doped white organic light-emitting diodes based on ultra-thin emitting layer with aggregation-induced emission
- Author
-
Xue-Yin Jiang, Minmin Cai, Yan Qian, Xupeng Wang, Tongjun Zhu, Zhiqiang Gao, Baoxiu Mi, Zhi-Lin Zhang, and Wei Huang
- Subjects
Materials science ,business.industry ,Exciton ,Thin layer ,Non doped ,Analytical chemistry ,Surfaces and Interfaces ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Driving current ,Materials Chemistry ,OLED ,Optoelectronics ,Electrical and Electronic Engineering ,Aggregation-induced emission ,business ,Layer (electronics) ,Diode - Abstract
Based on two aggregation-induced light-emitting materials, N-(4-(benzo[d]thiazol-2-yl)-3-hydroxyphenyl) anthracene-9-carboxamide for yellow emission and N-(4-(benzo[d]oxazol-2-yl)-4-tert-butylbenzamide for Blue emission, non-doped white organic light-emitting diodes have been realized. The maximum efficiency of 2.2 cd/A and the Commission International de L'Eclairage coordinates of (0.32, 0.33) are achieved. Moreover, the device efficiency and color coordinates change slightly with increasing driving current density up to 500 mA/cm2, showing a good color stability and a small efficiency roll-off. This may due to both better confinement of excitons within the emitting layer and the utilization of a thin layer of emitting material with aggregation-induced emission.
- Published
- 2011
45. The Feasibility of Using Cu as Reflective Anode in Top-Emitting Organic Light-Emitting Diodes
- Author
-
Hua Wang, Liu Liming, Xiaowen Zhang, Jun Li, Zhi-Lin Zhang, Liang Zhang, Xin-Yu Liu, and Xue-Yin Jiang
- Subjects
Fabrication ,Materials science ,business.industry ,chemistry.chemical_element ,Condensed Matter Physics ,Reflectivity ,Copper ,Electronic, Optical and Magnetic Materials ,Anode ,chemistry ,OLED ,Optoelectronics ,Contrast ratio ,Work function ,Electrical and Electronic Engineering ,business ,Diode - Abstract
The feasibility of using Cu as reflective anode for constructing efficient top-emitting organic light-emitting diode (TOLED) has been demonstrated. The MoOx modification can considerably enhance the work function of Cu anode, which contributes to the improvement of hole injection and thereby promoting device efficiency. In comparison with the TOLED having conventional Ag anode, the device having Cu anode shows inferior efficiency partially resulted from low reflectance of Cu, but the TOLED with Cu anode takes many advantages such as low-cost fabrication, enhanced pixel contrast ratio, weak microcavity effect and reduced leakage current. These improved performances are of great importance for practical applications, suggesting that Cu provides an alternative approach for realizing TOLED-based applications.
- Published
- 2011
46. Tuning the contact resistance in organic thin-film transistors with an organic–inorganic hybrid interlayer
- Author
-
Xue-Yin Jiang, Wenqing Zhu, Fan Zhou, Jun Li, Hua-Ping Lin, and Zhi-Lin Zhang
- Subjects
Materials science ,business.industry ,Contact resistance ,Doping ,Condensed Matter Physics ,Threshold voltage ,Pentacene ,chemistry.chemical_compound ,chemistry ,Thin-film transistor ,Electrode ,Optoelectronics ,General Materials Science ,Electrical and Electronic Engineering ,business ,Layer (electronics) ,Saturation (magnetic) - Abstract
We demonstrated the tunable contact resistance in pentacene thin film transistor (TFT) by inserting an organic–inorganic hybrid interlayer between Au electrode and pentacene layer. The contact resistance of pentacene-TFT varies with concentration of pentacene-TFT varies with concentration of MoO x in organic–inorganic hybrid interlayer. MoO x in organic–inorganic hybrid interlayer. The contact resistance of the device with 55 wt% MoO x doped pentacene interlayer is about 7.8 times smaller than that of device without interlayer at the gate voltage of −20 V. Comparing the properties of pentacene-TFT without interlayer, the performance of the pentacene-TFT with 55 wt% MoO x doped pentacene was significantly improved: saturation mobility increased from 0.39 to 0.87 cm 2 /V s, threshold voltage reduced from −21.3 to −7.2 V, and threshold swing varied from 3.75 to 1.39 V/dec. Our results indicated that the organic–inorganic hybrid interlayer is an effective way to improve the performance of p -channel OTFTs.
- Published
- 2011
47. A high performance of BPhen-based white organic light-emitting devices with a dual-emitting layer and its electroluminescent spectral property
- Author
-
Liang Zhang, Fan Zhou, Zhi-Lin Zhang, Hua-Ping Lin, Jun Li, Xue-Yin Jiang, Dong-Bin Yu, and Xiao-Wen Zhang
- Subjects
Maximum power principle ,business.industry ,Chemistry ,General Chemical Engineering ,Exciton ,Electroluminescence ,Luminance ,Spectral line ,Optics ,Optoelectronics ,Chromaticity ,Diffusion (business) ,business ,Common emitter - Abstract
This work demonstrated the fabrication of white organic light-emitting devices (WOLEDs) using a dual emitting layer (d-EML) consisting of blue and ‘white’ emitters. In this d-EML system, the blue emitter not only emits but also assists the incomplete energy transfer. More importantly, it behaves as an effective trapping site for holes, which contributes to the efficient recombination of electron–hole pairs. The d-EML was constructed between the hole-transmitting layer (HTL) and the electron-transmitting layer (ETL) of Alq 3 and BPhen. The thickness of the blue emitter used in the d-EML devices has an important effect on chromaticity and efficiency. Through the optimization of device structure, the reasonable white emission with Commission Internationale de L’Eclairage (CIE) color coordinates of (0.33, 0.33) and little color shift was obtained. The device showed an applicable luminance with its maximum luminance of 22,874 cd/m 2 at a driving voltage of 16 V. The maximum luminance efficiency was achieved 8.10 cd/A, and the maximum power efficiency was reached 5.07 Lm/W. The result is explained with the help of the excitons generation and diffusion theory. According to the theory of excitons generation and diffusion, an equation has been set up which concerns electroluminescent spectra to the thickness of the two emitters and to the exciton diffusion length.
- Published
- 2011
48. Enhanced color stability and improved performance in white organic light-emitting devices by utilizing a double-graded structure
- Author
-
Fan Zhou, Hua-Ping Lin, Xiaowen Zhang, Jun Li, Liang Zhang, Zhi-Lin Zhang, Xue-Yin Jiang, and Dong-Bin Yu
- Subjects
Organic electronics ,Brightness ,Chemistry ,business.industry ,Mechanical Engineering ,Metals and Alloys ,Analytical chemistry ,Condensed Matter Physics ,Fluorescence ,Luminance ,Stability (probability) ,Electronic, Optical and Magnetic Materials ,Improved performance ,Mechanics of Materials ,Materials Chemistry ,OLED ,Optoelectronics ,Chromaticity ,business - Abstract
High efficiency fluorescent white organic light-emitting device (WOLEDs) was investigated by using a double-graded (DG) structure. This strategy can greatly improve the device performances such as better color stability, higher luminance and enhanced efficiency. The optimized WOLED gives the Commission Internationale de L’Eclairage (CIE) color coordinates of (0.324, 0.341) at 20 mA/cm 2 , a negligible color shift of Δ x , y = ±[0.000.001] from 4 to 200 mA/cm 2 , a maximum brightness of 39,740 cd/m 2 at 17 V and a maximum luminance efficiency of 11.5 cd/A at 16 V. In addition, current-induced fluorescence quenching is mostly controlled.
- Published
- 2011
49. Efficient hole injection in blue organic light-emitting devices by using a double hole injection layer to improve chromaticity and electrical characteristics
- Author
-
Xue-Yin Jiang, Dong-Bin Yu, Xiaowen Zhang, Fan Zhou, Jun Li, Liang Zhang, Hua-Ping Lin, and Zhi-Lin Zhang
- Subjects
Double layer (biology) ,Materials science ,business.industry ,General Physics and Astronomy ,Hole injection layer ,Single hole ,OLED ,Optoelectronics ,General Materials Science ,Chromaticity ,business ,Layer (electronics) ,Quantum tunnelling ,Voltage - Abstract
A double hole injection layer consisting of Ag 2 O//MoO x was applied to a 4,40-bis (2,2-diphenylvinyl)-1,10-biphenyl-based blue organic light-emitting device (OLED). The hole current injection of the device was improved and the performance of the blue OLED was enhanced. We have observed that the insertion of such double layer leads to a striking improvement in chromaticity and electrical characteristics. This device showed much better chromaticity and less current-induced color shift as compared to the corresponding single hole injection layer counterparts. Using this strategy, a striking improvement in the electrical properties with lower driving voltage, higher power efficiency and a weak current-induced fluorescence quenching was achieved. This could be explained by the fact that an interlayer of Ag 2 O//MoO x provided a stepped energy level which greatly facilitated hole injection and hence enhanced injection current. The result is verified by using the J–V curves of ‘only’ devices and further explained with the help of Fowler-Nordheim (F-N) tunneling theory.
- Published
- 2011
50. Thermoresponsive Inverse Opal Films Fabricated with Liquid-Crystal Elastomers and Nematic Liquid Crystals
- Author
-
Dan Xu, Guanglong Wu, Xiao Liang, Yin Jiang, Hong Tang, and Guangtao Li
- Subjects
Phase transition ,Materials science ,business.industry ,Band gap ,Temperature ,Physics::Optics ,Inverse ,Surfaces and Interfaces ,Models, Theoretical ,Condensed Matter Physics ,Elastomer ,Liquid Crystals ,Condensed Matter::Soft Condensed Matter ,Optics ,Elastomers ,Liquid crystal ,Condensed Matter::Superconductivity ,Thermal ,Electrochemistry ,Optoelectronics ,General Materials Science ,Photonics ,business ,Spectroscopy ,Photonic crystal - Abstract
Liquid-crystal elastomers together with nematic liquid crystals have been used as inverse opal materials to fabricate thermoresponsive photonic crystal directly. In the vicinity of the phase-transition point of the mixture, the photonic band gaps of such inverse opal films exhibited a strong temperature dependence. As the molar ratio of liquid-crystal elastomers and nematic liquid crystals changed, the character of their PBGs also changed with increasing temperature. Such a temperature-tuning effect in the photonic band gap should be of great interest in thermal switches and thermal sensors.
- Published
- 2010
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.