Article
Nanoscience & Nanotechnology
Jeonga Lee, Cheol Hee Choi, Taikyu Kim, Jaeseok Hur, Min Jae Kim, Eun Hyun Kim, Jun Hyung Lim, Youngho Kang, Jae Kyeong Jeong
Summary: The study found that doping with hydrogen (H) into oxygen sites (HO) can significantly improve the performance of amorphous In-Ga-Zn-Sn oxide (aIGZTO) thin-film transistors (TFTs).
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Wengao Pan, Yunping Wang, Yanxin Wang, Zhihe Xia, Fion Sze Yan Yeung, Man Wong, Hoi Sing Kwok, Xinwei Wang, Shengdong Zhang, Lei Lu
Summary: In this work, the multiple effects of hydrogen (H) doping on amorphous InGaZnO (IGZO) TFTs were investigated. The H content influenced the electrical performances of the TFTs, acting as a defect suppressor, donor defect, transition state, and finally an acceptor defect. The oxygen vacancy (Vo) in IGZO determined the diffusion channel of the H dopant and its concentration. Additionally, fluorine (F) doping improved the hydrogen resistibility of IGZO.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Multidisciplinary
Jiaona Zhang, Min Zhang, Kuan-Chang Chang, Zhao Rong, Yuqing Zhang, Shengdong Zhang, Mansun Chan
Summary: This study investigates the relationship between carrier behavior and channel thickness by treating a-IGZO thin-film transistors with SCCO2. The research finds that thinner channel thickness exhibits better drivability enhancement after treatment, which is attributed to the improved M-O-M structure, reduced traps, and smoother carrier transport path.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Physics, Applied
Huiwu Mao, Yixin Zhu, Ying Zhu, Baocheng Peng, Chunsheng Chen, Li Zhu, Shuo Ke, Xiangjing Wang, Changjin Wan, Qing Wan
Summary: In this study, a crossbar array of amorphous indium-gallium-zinc-oxide (a-IGZO)-based threshold switching memristors was designed for high-throughput true random number generators (TRNGs). The stochasticity of the Ag conductive filament in the IGZO memristor and the stochastic sneak paths in the crossbar array are the sources of randomness in the TRNGs. The integration scale of the memristors can be increased to further reduce the average energy consumption of the TRNGs. These IGZO-based TRNGs are of great significance for security applications.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Tan Zhang, Denggao Guan, Ningtao Liu, Jianguo Zhang, Jinfu Zhang, Chenyu Guo, Mengting Qiu, Qilong Yuan, Wenrui Zhang, Jichun Ye
Summary: This study fabricates metal-semiconductor-metal structure deep-ultraviolet photodetectors using radio-frequency sputtered amorphous Ga2O3 films at room temperature. The detectors show low dark current, high responsivity, and fast response time, and the annealing treatments are effective in improving the detector performance, showing a low-cost approach for fabrication and post-synthetic tuning.
APPLIED PHYSICS EXPRESS
(2022)
Article
Engineering, Electrical & Electronic
Han-Yin Liu, Che-Lun Chang, Pei-Huang Hsu, Wei-Ting Chen, Teng-Yuan Chang, Ching-Sung Lee, Shun-Cheng Shih, Wei-Chou Hsu
Summary: This study investigates the impact of ambient/carrier gases on the material characteristics of a-InGaZnO thin films and the performance of TFTs. The results show that using different gases can improve film quality and TFT performance.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Nanoscience & Nanotechnology
Zhi-Yue Li, Shu-Mei Song, Wan-Xia Wang, Jian-Hong Gong, Yang Tong, Ming-Jiang Dai, Song-Sheng Lin, Tian-Lin Yang, Hui Sun
Summary: In this study, homojunction thin-film transistors (TFTs) with amorphous indium gallium zinc oxide (a-IGZO) as active channel layers were fabricated by RF magnetron sputtering. The effect of oxygen partial pressure on the properties of IGZO thin films was investigated. It was found that the resistivity of IGZO thin films increases with higher oxygen partial pressure. Optimal electrical characteristics were observed in homojunction IGZO TFTs with an oxygen partial pressure of 1.96%.
Article
Materials Science, Multidisciplinary
Jinbaek Bae, Arqum Ali, Jin Jang
Summary: Spray-pyrolyzed amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistor (TFT) with self-aligned (SA) coplanar structure exhibits excellent performance and stability, making it a promising metal oxide semiconductor for high-performance TFT backplanes.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Materials Science, Multidisciplinary
Jiseob Lee, Suhui Lee, Md Mobaidul Islam, Jin Jang
Summary: A short channel coplanar amorphous indium gallium zinc oxide (a-IGZO) thin-film transistor (TFT) with a ZrAlOx (ZAO) interlayer has been developed, showing high field-effect mobility and on/off current ratio, and demonstrating stability under testing conditions of 85 degrees Celsius and 85% relative humidity for 2 days.
ADVANCED ENGINEERING MATERIALS
(2022)
Article
Chemistry, Analytical
Sunil Babu Eadi, Hyun-jin Shin, Kim Thanh Nguyen, Ki-Woo Song, Hyun-Woong Choi, Seong-Hyun Kim, Hi-Doek Lee
Summary: In this study, IGZO thin films were prepared in a N-2 environment by varying the annealing pressure and tested for NO2 gas detection. The results showed that increasing the annealing pressure led to superior sensor response and decreased recovery time. The IGZO thin film annealed at 400 degrees C at 3 atm exhibited excellent selectivity to various gases and long-term stability.
SENSORS AND ACTUATORS B-CHEMICAL
(2022)
Article
Nanoscience & Nanotechnology
Jiaona Zhang, Weihong Huang, Kuan-Chang Chang, Yuhao Shi, Changbin Zhao, Xinwei Wang, Hong Meng, Shengdong Zhang, Min Zhang
Summary: The study proposes a low-temperature posttreatment method using supercritical CO2 fluid with a dehydration function to improve the performance of flexible a-IGZO TFTs. After treatment, the TFT shows significant improvement in drivability, subthreshold swing, threshold voltage, and I-on/I-off ratio. The posttreated TFTs also exhibit good uniformity and reproducibility, with performance remaining stable even after repeated bending.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Nanoscience & Nanotechnology
Won-Gi Kim, Young Jun Tak, Hyukjoon Yoo, Hyung Tae Kim, Jeong Woo Park, Dong Hyun Choi, Hyun Jae Kim
Summary: By using sodium hypochlorite (NaClO) solution as an activation source, the activation temperature of a-IGZO TFTs was reduced from 300 to 150 degrees C, leading to satisfactory electrical characteristics. The mechanism of NaClO activation for a-IGZO TFTs involves photo-assisted oxygen radical (POR) and heat-driven oxygen radical (HOR) effects, which generate reactive oxygen species to activate TFTs at low temperatures.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Engineering, Electrical & Electronic
Hassan Ul Huzaibi, Nianduan Lu, Mohammad Masum Billah, Di Geng, Ling Li
Summary: This study investigates the hump behavior in the subthreshold current region of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors induced by positive bias stress (PBS). The origin of the hump creation is analyzed through experimentation and simulation, which confirms that it is caused by parasitic edge conduction. Simulation results show that a narrow, Gaussian trap state is created within the parasitic channel after PBS, resulting in a higher electron concentration and earlier turning on of the transistor, leading to hump behavior in the subthreshold region.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Nanoscience & Nanotechnology
Huan Yang, Xiaoliang Zhou, Haishi Fu, Baozhu Chang, Yuxin Min, Hao Peng, Lei Lu, Shengdong Zhang
Summary: The doping effect induced by aluminum treatment can improve the performance and stability of SATG a-IGZO TFTs by enhancing the conductivity of the source-drain regions. The generated oxygen vacancies and metal interstitials play a crucial role in the doping process. The results of the study demonstrate that this doping effect originates from the bulk rather than surface treatment.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
Xianyang Xue, Tingting Zhao, Xueming Tian, Li Yuan, Zhigan Wang, Tongkuai Li, Jianhua Zhang
Summary: This article proposes a flexible dual-parameter sensor array based on a-IGZO TFTs, which decouples pressure and temperature perception by optimizing the combination of MXene and carbon nanotubes hybrid films. It has potential applications in the field of multifunctional electronic skin.
ADVANCED MATERIALS TECHNOLOGIES
(2022)
Article
Materials Science, Multidisciplinary
Tong Chen, Chunyun Wang, Guoshen Yang, Qiang Lou, Qingping Lin, Shengdong Zhang, Hang Zhou
Summary: This paper introduces a polyimide assisted patterning approach for monolithic integration of perovskite based high-sensitive phototransistor array on IGZO backplane. By using this technique, high-performance phototransistors with high responsivity and detectivity can be fabricated. In addition, an image sensor containing photosensing perovskite/IGZO transistors and switching IGZO transistors is demonstrated.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Nanoscience & Nanotechnology
Pengfei Wang, Huan Yang, Jiye Li, Xiaohui Zhang, Lei Wang, Juncheng Xiao, Bin Zhao, Shengdong Zhang, Lei Lu
Summary: The large-area low-temperature processing capability and versatile characteristics of amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) are highly expected to promote the developments of next-generation displays and electronics. However, the abundance of defects in AOSs limits the performance and integration scale. To overcome this challenge, a bilayer AOS channel with an abrupt metal-oxide heterojunction is proposed to enhance the performance and reliability of AOS TFTs.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Jiye Li, Yuqing Zhang, Jialiang Wang, Huan Yang, Xiaoliang Zhou, Mansun Chan, Xinwei Wang, Lei Lu, Shengdong Zhang
Summary: Researchers successfully eliminated the defective interface in amorphous InGaZnO (a-IGZO) thin-film transistors by preoxidizing a-IGZO with nitrous oxide (N2O) plasma, achieving high performance and stability. This study is of great significance for addressing the interface reaction issue between high-k dielectrics and amorphous oxide semiconductors (AOSs) in next-generation thin-film transistors.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Engineering, Electrical & Electronic
Yuqing Zhang, Jiye Li, Jinxiong Li, Tengyan Huang, Yuhang Guan, Yuhan Zhang, Huan Yang, Mansun Chan, Xinwei Wang, Lei Lu, Shengdong Zhang
Summary: Here we present a self-aligned top gate (SATG) coplanar amorphous InGaZnO (a-IGZO) thin film transistor (TFT) technology with a down-scaled gate length (Lg) of 97 nm and a gate insulator (GI) AlOx of 4 nm (equivalent oxide thickness = 2.4 nm). The fabricated TFT exhibits excellent performance, including a large on-current (ION) of 17.9 mu A/mu m, a high on/off current ratio over 10^(9), a positive threshold voltage (V-TH) of 0.07 V, and a minimum drain-induced barrier lowering (DIBL) of 77 mV/V. These results are attributed to the abrupt homojunction at the source-drain sides and the high-quality ultrathin gate insulator of AlOx by atomic layer deposition (ALD). With the compatibility with modern integrated circuit (IC) process, the developed SATG a-IGZO TFT technology is suitable for back-end-of-line (BEOL) and 3D integrations of advanced ICs.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Guang Zeng, Hanming Li, Fang Tan, Yue Xin, Shengdong Zhang
Summary: The addition of fluorine atoms to nonfullerene small molecule acceptors (NFSMAs) is an effective method to improve device efficiency. However, the thermal stability of the device may be affected. In this study, the influence of terminal fluorine substitution on the thermal stability of organic solar cells (OSCs) was investigated. It was found that the introduction of fluorine atoms improved the efficiency but resulted in poor compatibility and decreased thermal stability when combined with a specific polymer donor.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Engineering, Electrical & Electronic
Hongyuan Xu, Guangmiao Wan, Jiaying Mai, Zhixiong Jiang, Bin Liu, Shengdong Zhang
Summary: Nanocrystalline silicon (nc-Si) films were successfully obtained through plasma enhanced chemical vapor deposition (PECVD) method. The effects of PECVD process parameters on the crystallization rate of nc-Si films were comprehensively studied, resulting in an optimized nc-Si film with a crystallinity of 50.87%. Furthermore, the electrical properties and stability of nc-Si TFTs were compared with a-Si TFTs, showing better photo stability of nc-Si TFTs due to fewer defect states in nc-Si films.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Lixuan Chen, Jinyang Zhao, Zhiqing Shi, Miao Zhou, Shengdong Zhang, Xiao Wei Sun, Xin Zhang
Summary: Semiconductor quantum rods (QRs) emit polarized light and have great potential for energy-efficient and color-enhancing modern display devices. We present the stretching of an aligned QR polarized film to improve brightness and optical efficiency in quantum-dot based displays. The study of QR material, stretching ratio, and alignment degree guides the fabrication of highly polarized QR film. A large-area film with an alignment degree of 0.635 achieved more than 1.6-fold enhancement in brightness and transmittance compared to traditional structures, making it a viable option for various energy-saving display devices.
Article
Engineering, Electrical & Electronic
Junjun An, Congwei Liao, Yuxuan Zhu, Xin Zheng, Chao Dai, Xin Zhang, Shengdong Zhang
Summary: This study presents a gate driver on array (GOA) circuit for low-temperature polysilicon and oxide thin-film transistor hybrid-driven active matrix organic light-emitting diode (AMOLED) displays, capable of both high and low refresh rate operation. The GOA utilizes shift registers to generate multiple types of scanning signals, allowing for parallel output of three signal pulses within a single stage to drive various TFTs in the AMOLED pixels. This approach reduces the layout area by 30%. Additionally, the scan signals for the emission TFT can be programmed by adjusting the number of input pulses, enabling different refresh rates. The fabricated GOAs demonstrate reliable performance even with a reduced pulse width of 2.9 μs.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
(2023)
Article
Chemistry, Physical
Wengao Pan, Yunping Wang, Yanxin Wang, Zhihe Xia, Fion Sze Yan Yeung, Man Wong, Hoi Sing Kwok, Xinwei Wang, Shengdong Zhang, Lei Lu
Summary: In this work, the multiple effects of hydrogen (H) doping on amorphous InGaZnO (IGZO) TFTs were investigated. The H content influenced the electrical performances of the TFTs, acting as a defect suppressor, donor defect, transition state, and finally an acceptor defect. The oxygen vacancy (Vo) in IGZO determined the diffusion channel of the H dopant and its concentration. Additionally, fluorine (F) doping improved the hydrogen resistibility of IGZO.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Engineering, Electrical & Electronic
Juncheng Xiao, Guang Zeng, Ji Li, Shengdong Zhang
Summary: This study simulated and studied the effect of crystallization on the etching properties of ITO film by annealing ITO films prepared by RF magnetron sputtering. It was found that when the annealing temperature was less than 200 degrees C, the ITO films could be easily etched, but when annealed at higher temperatures, the polycrystalline ITO films became difficult to be removed by etchant due to the formation of large amount of Sn4+ on the surface.
JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY
(2023)
Article
Nanoscience & Nanotechnology
Jiye Li, Yuhang Guan, Jinxiong Li, Yuqing Zhang, Yuhan Zhang, ManSun Chan, Xinwei Wang, Lei Lu, Shengdong Zhang
Summary: To enhance the downscaling potential of top-gate amorphous oxide semiconductor (AOS) thin-film transistors (TFTs), we implemented the ultra-thin gate insulator (GI) using atomic-layer-deposited (ALD) AlOx and HfOx. Both high-k GIs demonstrated good insulation properties even with a physical thickness of 4 nm. However, the HfOx-gated TFT showed higher gate leakage current and poorer subthreshold slope due to the small band offset and defective interface between a-IGZO and HfOx. The imperfect a-IGZO/HfOx interface also caused noticeable positive bias stress instability.
Article
Engineering, Electrical & Electronic
Hongyu He, Xinnan Lin, Shengdong Zhang
Summary: This article presents a current model for forward-biased organic diodes. The diode current consists of space-charge-limited current and Ohmic current, which are analyzed using two classical space-charge-limited current models. The similarity and difference between these models are clarified, and it is found that the exponential-trap-based model is suitable. Additionally, an Ohmic current model considering temperature and thickness dependence is presented. The diode current model is achieved by combining the exponential-trap-based space-charge-limited current model with the Ohmic current model, which is analytical and suitable for circuit simulation.
SOLID-STATE ELECTRONICS
(2023)
Article
Chemistry, Physical
Yuhang Guan, Yuqing Zhang, Jinxiong Li, Jiye Li, Yuhan Zhang, Zhenhui Wang, Yuancan Ding, Mansun Chan, Xinwei Wang, Lei Lu, Shengdong Zhang
Summary: In recent years, high-k gate dielectrics have received increasing attention in amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) due to the need for stronger gate controllability. This study developed an ultra-thin top-gate insulator of atomic-layer-deposited (ALD) HfOx for amorphous indium-gallium-zinc oxide (a-IGZO) TFTs. However, the reliability of the 4-nm HfOx-gated a-IGZO transistor is poor due to interface defects caused by the interface reaction between HfOx and a-IGZO during the ALD process. To improve stability, the a-IGZO channel is pre-treated with strong oxidizing plasma. However, further reducing HfOx thickness increases gate leakage current.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Guang Zeng, Hanming Li, Fang Tan, Yue Xin, Shengdong Zhang
Summary: Here, a new narrow band gap non-fullerene small molecular acceptor (NFSMA) named SNIC-F, based on a DTP unit, was synthesized. When paired with PBTIBDTT, the device showed a high J(sc) of 19.64 mA cm(-2) and a high V-oc of 0.83 V, resulting in a PCE of 11.25%. The study suggests that blending a narrow band gap NFSMA-based DTP unit with a polymer donor with small HOMO offset is an efficient strategy for achieving high performance OSCs.
Article
Engineering, Electrical & Electronic
Hongyu He, Junli Yin, Xinnan Lin, Shengdong Zhang
Summary: A surface-potential-based drain current model is developed for ambipolar organic thin-film transistors (OTFTs), which considers the multiple trapping and release (MTR) conduction mechanism and the exponentially distributed trap state density in the energy gap of the organic semiconductor. By analyzing electrons or holes in different regimes based on the model for unipolar OTFTs, the model for ambipolar OTFTs is proposed. The presented model provides compact expressions for the drain current and allows estimation of trap state density, and it is verified against experimental data considering temperature characteristics.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)