Article
Materials Science, Coatings & Films
Adrien Chauvin, Carla Bittencourt, Mathilde Galais, Lionel Sauvage, Maxime Bellefroid, Carine Van Lint, Anne Op de Beeck, Rony Snyders, Francois Reniers
Summary: Successful deposition of titanium dioxide (TiO2) thin films was achieved using atmospheric pressure dielectric barrier discharge plasma. The control of deposition parameters, such as substrate heating temperature and oxygen content, was found to be crucial for obtaining thin films with desired properties. Additionally, nitrogen doping of the TiO2 films was successfully achieved by adding ammonia (NH3) to the working gas. The lowest bandgap of 3.22 eV was obtained under specific deposition conditions.
SURFACE & COATINGS TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Rosemary R. Cranston, Mario C. Vebber, Jonatas Faleiro Berbigier, Nicole A. Rice, Claire Tonnele, Zachary J. Comeau, Nicholas T. Boileau, Jaclyn L. Brusso, Adam J. Shuhendler, Frederic Castet, Luca Muccioli, Timothy L. Kelly, Benoit H. Lessard
Summary: This study investigated eight axially substituted SiPcs and their application in solution-processed n-type OTFTs. It was found that the length of the alkyl chain affects device performance and thin-film morphology, and the effects of high-temperature annealing and spin coating time on film formation were explored. The study also revealed that thermal annealing and spin time significantly impact film crystallinity, morphology, and device performance, with bis(tri-n-butylsilyl oxide) SiPc showing the highest electron field-effect mobility among the studied materials.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Sung Hyeon Jung, Ji Sook Yang, Young Been Kim, Nishad G. Deshpande, Dong Su Kim, Ji Hoon Choi, Hee Won Suh, Hak Hyeon Lee, Hyung Koun Cho
Summary: A strategically designed electrodeposition method is proposed for the coating of p-type copper(i) oxide (Cu2O) channels for oxide thin film transistors. The vertically aligned grain boundaries in the electrodeposited Sb doped Cu2O (Sb:Cu2O) offer superior electrical performances for vertical transistors. The Cu2O vertical field effect transistors exhibit extraordinary transistor performances and power efficient logic inverter circuits with unprecedented performances.
MATERIALS HORIZONS
(2022)
Article
Physics, Applied
Shun Takamaru, Jun-ichi Hanna, Hiroaki Iino
Summary: A new fabrication process of donor and acceptor charge transfer complex thin films using thermal diffusion was proposed in this study. The results showed that the thermally annealed thin films formed charge transfer complexes of C-10-BTBT and F-4-TCNQ, which exhibited n-channel operation in air. Therefore, thermal diffusion is an effective technique for the fabrication of large area charge transfer complex thin films.
APPLIED PHYSICS EXPRESS
(2022)
Article
Physics, Applied
Yang Ming Fu, Tianye Wei, Joseph Brownless, Long Huang, Aimin Song
Summary: This study investigates the performance of indium-gallium-zinc-oxide thin-film transistors gated by sputtered silicon dioxide electrolytes in synaptic memory behavior. The results show that these devices are capable of providing an extremely wide range of memory retention time, while demonstrating pattern learning and memorizing functionalities.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Guidong Wang, Dong Li, Xinyu Wang, Yu Zhang, Hao Zhang, Jun Wang
Summary: The charge-transport modes of organic heterojunction transistors (OHJTs) have significant importance in their potential applications. In this study, OHJTs with tunable charge-transport modes were demonstrated based on a single vertical heterointerface. The competition between electrons and holes to as the dominant carriers was attributed to the variation in the densities of two charge carriers. Additionally, the function of the heterointerface was further explored through the insertion of a high-kappa organic dielectric layer.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Polymer Science
Zhengran He, Ziyang Zhang, Kyeiwaa Asare-Yeboah, Sheng Bi, Jihua Chen, Dawen Li
Summary: This study demonstrated the use of a metal-containing semicrystalline polymer as an additive to mediate the thin film morphology of solution-grown, small-molecule organic semiconductors, resulting in improved performance of organic thin film transistors.
Article
Engineering, Electrical & Electronic
Calla M. McCulley, Xin Xu, Kelly Liang, Xiao Wang, Liang Wang, Ananth Dodabalapur
Summary: This design approach significantly improves the electrical performance and mitigates short-channel effects in short-channel organic thin-film transistors, reducing the total source-to-drain resistance to about 50 ohm.cm.
ACS APPLIED ELECTRONIC MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Wensi Cai, Mengchao Li, Shirong Lu, Qingkai Qian, Zhigang Zang
Summary: In this study, a solution-based growth method of InZnO/AlInZnO heterojunction channel layers was reported and implemented in high-performance thin-film transistors. It was found that the heterojunction transistors exhibited band-like electron transport and significantly higher current ON/OFF ratio and mobility values compared to single-layer IZO and AIZO devices. The improvement was attributed to the presence of confined free electrons at the sharp heterointerface induced by the large conduction band offset between IZO and AIZO. Further channel engineering allowed the achievement of high-performance heterojunction oxide TFTs with excellent stability and potential in next-generation printable electronics.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Chemistry, Physical
Joost W. C. Reinders, Cristina Roldan-Carmona, Henk J. Bolink, Francisco Palazon
Summary: This study reports on the fabrication of Mg(3)Bi(2) thin films under Mg-rich and Mg-poor conditions and demonstrates that Mg-deficient films show p-type conduction behavior with high power factor and thermoelectric figure of merit, while increasing the amount of Mg enables the formation of Mg-rich Mg3Bi2 films with n-type conduction and higher power factor and thermoelectric figure of merit at lower temperatures.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Yu-Shien Shiah, Kihyung Sim, Yuhao Shi, Katsumi Abet, Shigenori Ueda, Masato Sasase, Junghwan Kim, Hideo Hosono
Summary: This study successfully fabricated ultrastable thin-film transistors with mobilities of 70 cm(2) (V s)(-1) by understanding the origins of instability in high-mobility amorphous oxide transistors. The research identified the sensitivity of amorphous oxide semiconductors to externally introduced impurities and defects, and explained the mechanism of how carbon-monoxide-related impurities affect the stability of high-mobility indium tin zinc oxide transistors.
NATURE ELECTRONICS
(2021)
Article
Nanoscience & Nanotechnology
Mari Napari, Tahmida N. Huq, David J. Meeth, Mikko J. Heikkil, Kham M. Niang, Han Wang, Tomi Iivonen, Haiyan Wang, Markku Leskela, Mikko Ritala, Andrew J. Flewitt, Robert L. Z. Hoye, Judith L. MacManus-Driscoll
Summary: High-performance p-type oxide thin film transistors (TFTs) have great potential for semiconductor applications, but often suffer from low hole mobility and high off-state currents. By applying a thin ALD Al2O3 passivation layer on the Cu2O channel and vacuum annealing, the TFT switching characteristics can be improved. Characterization by TEM-EDX and XPS shows that Al2O3 deposition on Cu2O reduces surface and forms a CuAlO2 interfacial layer. This, along with field-effect passivation, leads to improved TFT performance by reducing trap states and electron accumulation in the off-state.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Optics
Xi Zhang, Ming Liu, Yi Fu, Kai Kang, Xin Ding, Jianquan Yao, Zhiyong Wang, Liang Wu
Summary: The dielectric property and tunability of multilayer thin film composed of Ba0.6Sr0.4TiO3 (BST) and BaTiO3 (BTO) were investigated using terahertz time-domain spectroscopy (THz-TDS) at room temperature. The results showed that the permittivity could be modulated by external optical pumping, and the dielectric property of the composite structure could be changed by selecting the number of periodical layers and the corresponding layer thickness. These findings suggest the potential applications of multilayer thin film in tunable photonic devices in the terahertz range.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Yaoqiao Hu, Darrell Schlom, Suman Datta, Kyeongjae Cho
Summary: A Sn2+ based oxide, ilmenite SnTiO3, with a dispersive valence band and wide band gap of 2.4 eV has been investigated as a potential p-type oxide. It exhibits a high hole mobility of 60 cm(2) V-1 s(-1) and phase stability. Defect calculations show it has high hole dopability, and band alignment calculations indicate its suitability for metal contact. Amorphous phase SnTiO3 has been found to be a highly mobile hole-dopable oxide. These findings suggest that ilmenite and amorphous SnTiO3 are promising p-type oxides for future oxide electronics.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Physical
Takuto Mizoguchi, Toshifumi Imajo, Jun Chen, Takashi Sekiguchi, Takashi Suemasu, Kaoru Toko
Summary: Group-IV alloy semiconductors, particularly Ge thin films, with enhanced crystallinity and carrier mobility have been studied using a multistep heating process. The investigation of crystal and electrical properties in Si1-xGex and Ge1-ySny alloys showed that controlling the temperature in each stage can improve carrier mobility by increasing grain size. Moreover, Sb doping contributes to enlarging grain size and controlling the conduction, while electron concentration varies with composition.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Electrical & Electronic
Qi-Zhen Chen, Chun-Yan Shi, Ming-Jie Zhao, Peng Gao, Wan-Yu Wu, Dong-Sing Wuu, Ray-Hua Horng, Shui-Yang Lien, Wen-Zhang Zhu
Summary: This study investigates the transparent indium-gallium-zinc oxide thin film transistor (IGZO-TFT) prepared by all plasma enhanced atomic layer deposition (PEALD). The properties of the IGZO film and IGZO-TFT based on different In2O3 cycle ratios are examined due to the considerable impact of chemical composition on the performance of IGZO TFTs. The IGZO film prepared by PEALD exhibits amorphous state with excellent conformity and uniformity. By applying a-IGZO films with different In2O3 cycle ratios, a satisfactory electrical performance of the transistor is achieved, with a threshold voltage (V-th) of 1.7 V, a saturation mobility (mu(sat)) of 8.8 cm(2)/Vs, a subthreshold swing (SS) of 0.2 V/decade, and an I-ON/I-OFF of 2.2 x 10(8). This work provides a new approach for achieving transparent TFTs that are more suitable for practical commercial applications.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Duc Huy Nguyen, Paul C-P Chao, Chih-Chieh Chung, Ray-Hua Horng, Bhaskar Choubey
Summary: Real-time detection of atrial fibrillation is made possible through the use of a combination of one-dimensional and two-dimensional convolutional neural networks. These models can filter out low-quality data and accurately detect atrial fibrillation.
IEEE SENSORS JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Xiao-Ying Zhang, Jing Han, Duan-Chen Peng, Yu-Jiao Ruan, Wan-Yu Wu, Dong-Sing Wuu, Chien-Jung Huang, Shui-Yang Lien, Wen-Zhang Zhu
Summary: In this study, HfO2 thin films were prepared on silicon using plasma enhanced atomic layer deposition (PEALD) and the effects of substrate temperature on their structure, morphology, and electrical properties were investigated.
Article
Chemistry, Physical
Pojung Lin, Jiazhe Liu, Hongche Lin, Zhiyuan Chuang, Wenching Hsu, Yiche Chen, Poliang Liu, Rayhua Horng
Summary: In this study, GaN-based epitaxial structures were grown on high-resistivity silicon (HRSi) substrates by met-alorganic chemical vapor deposition. The p-type parasitic channels generated at the interfaces of the aluminum nitride (AlN) nucleation layers and HRSi substrates were characterized. A 2-nm thick silicon nitride (SiNx) layer was used to suppress the Al diffusion and prevent the generation of p-type parasitic channels. The insertion loss of the optimized structure was only 0.04 dB/mm higher than that of the annealed HRSi substrate at 10 GHz.
SURFACES AND INTERFACES
(2023)
Article
Crystallography
Chao-Chun Yen, Anoop Kumar Singh, Yi-Min Chung, Hsin-Yu Chou, Dong-Sing Wuu
Summary: This paper highlights the effects of furnace pressure, crucible rotation, and pulling rate on interstitial oxygen (O-i) concentrations and micro-defects during growth in a Czochralski single-crystal silicon (CZ-Si) growth furnace. Different set-points of furnace pressure and crucible rotation were controlled to achieve different degrees of O-i, which was found to have a positive correlation with furnace pressure and crucible rotation. The influence of different pulling rates on the formation of micro-defects was also investigated, with the transformation from liquid to solid being responsible for their generation. The study concludes that growth using a CZ-Si growth furnace should be carried out with low furnace pressure, low crucible rotation, and low pulling rate to reduce micro-defects.
Article
Computer Science, Information Systems
Ray-Hua Horng, Hsiao-Yun Yeh, Niall Tumilty
Summary: This study investigates the impact of thermal effects on the performance of Cu electroplated GaN-based HEMTs. The results show that GaN HEMTs with electroplated Cu demonstrate a significantly enhanced on/off current ratio compared to those without, and thinner HEMT devices with electroplated Cu samples exhibit lower channel temperature.
Article
Chemistry, Physical
Hsin-Yu Chou, Chih-Wei Lo, Kai-Ping Chang, Wei-Yi Shi, Chao-Chun Yen, Dong-Sing Wuu
Summary: Cadmium-free perovskite quantum dots (QDs) with a new structure of CsPbBr3/Cs4PbBr6 were synthesized using a chemical solution method. The perovskite QDs were passivated with a SiO2 layer and dispersed in a polar solvent to maintain their luminous properties. A photolithography process was used to fabricate pixelated perovskite QDs on a glass substrate, and a black matrix was employed to reduce crosstalk between pixels. Applying these pixelated perovskite QDs as a color conversion layer in blue light micro-LED display, excess blue light was reflected back to the QDs using a 23-layer distributed Bragg reflector (DBR), resulting in increased luminous intensity of green light and decreased transmittance of blue light. Ultimately, the attachment of graph pixelated perovskite QDs to the blue light display enabled monochrome/area color and full-color micro-LED display.
SURFACES AND INTERFACES
(2023)
Article
Engineering, Electrical & Electronic
Kai-Ping Chang, Yu-Wun Chien, Po-Hsiang Wang, Chao-Chun Yen, Ying-Xiang Lin, Ying-Jie Gao, Wan-Yu Wu, Dong-Sing Wuu
Summary: In this study, a blue transparent micro-LED display with a chip size of 20 μm × 20 μm, a pixel density of 152 PPI, a pixel spacing of 150 μm, and a resolution of 64 × 32 has been successfully fabricated. ITO/Ag/ITO transparent layers were deposited by high-power impulse magnetron sputtering. The electrical properties of the indium tin oxide (ITO) layers were analyzed using sheet resistance, while surface morphology was examined using scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. The results show that the ITO/Ag/ITO structure with 20 nm thick Ag has a lower sheet resistance (3.36 Cl/sq) and sufficient visible light transmittance (80.45%). The visible light transmittance of the ITO/Ag/ITO layers increased to 86% after rapid thermal annealing. Furthermore, surface roughness was minimized and sheet resistance was further reduced, resulting in ohmic contact on n-GaN for transparent micro-LED display applications.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Anoop Kumar Singh, Chao-Chun Yen, Chun-Fan Wen, Ray-Hua Horng, Dong-Sing Wuu
Summary: Researchers have developed a NO gas sensor with high sensing response for measuring NO gas levels. The sensor is made of ZnO:ZnGa2O4 dual-phase films and exhibits high selectivity and quick response time.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Ray-Hua Horng, Apoorva Sood, Siddharth Rana, Niall Tumity, Fu-Gow Tarntair, Catherine Langpoklakpam, Hao-Chung Kuo, Jitendra Pratap Singh
Summary: Conductive β-Ga2O3 epilayers grown on the sapphire substrate using MOCVD were studied by Si-ion implanted. A metal-insulator-semiconductor diode (MISD) was fabricated using undoped and Si-implanted β-Ga2O3 epitaxial layer. The electrical and carrier transport properties of different MISD with different distance between cathode and anode contact were investigated.
MATERIALS TODAY ADVANCES
(2023)
Article
Chemistry, Physical
Ting -Yu Chang, Anoop Kumar Singh, Jhih-Hong Shao, Chiung-Yi Huang, Jia-Min Shieh, Dong-Sing Wuu, Po-Liang Liu, Ray-Hua Horng
Summary: Gas sensors play a crucial role in various industrial and environmental monitoring applications. This study investigates the impact of plasma surface treatment on the performance of ZnGa2O4-based NO gas sensors, and the results show that Ar plasma treatment significantly improves the sensor's response. These findings provide valuable insights into enhancing the performance of gas sensors through surface modification techniques.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Zhi-Xuan Zhang, Shi-Cong Jiang, Wan-Yu Wu, Peng Gao, Linqin Jiang, Yu Qiu, Dong-Sing Wuu, Feng-Min Lai, Wen-Zhang Zhu, Lien SY
Summary: In this paper, Si derived from the SiNx sub-cycle in plasma-enhanced atomic layer deposition (PEALD) was used as a dopant to improve the ohmic contact resistance of GaN. The highest carrier concentration and lowest resistivity were achieved in a Si-doped GaN film deposited at a SiNx sub-cycle ratio of 20%.
SURFACES AND INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Siddharth Rana, Shang-Jui Chiu, Chih-Yang Huang, Fu-Gow Tairtan, Yan-Gu Lin, Dong-Sing Wuu, Jitendra Pratap Singh, Guang-Cheng Su, Po-Liang Liu, Ray-Hua Horng
Summary: In this study, a highly sensitive direct irradiating X-ray photodetector (DXPD) based on Zinc Gallium Oxide (ZnGa2O4) epilayers with a metal-semiconductor-metal structure was fabricated. The ZnGa2O4 epilayers were grown on a c-plane sapphire substrate using metalorganic chemical vapor deposition (MOCVD). The sensitivity and performance of the DXPD were tested using synchrotron hard X-ray source, and the results showed that ZnGa2O4-based DXPD had significantly higher sensitivity and potential for use in high-performance hard XPDs.
MATERIALS TODAY ADVANCES
(2023)
