Article
Chemistry, Physical
Shunli He, Lichun Zhang, Dan Tian, Zhiying Zhou, Anqi Guo, Bin Xia, Yadan Zhu, Fengzhou Zhao
Summary: In this study, high-quality Cs3Cu2Br5 thin films with good stability were prepared on GaN substrates by pulse laser deposition (PLD) for the first time. The morphology, crystal structure, and photoelectric properties of the Cs3Cu2Br5 thin films were systematically studied. A self-powered UV photodetector based on Cs3Cu2Br5/n-GaN heterojunction was fabricated, exhibiting two dominant responses in the UV region.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Physics, Condensed Matter
Madiha Khan, Vaibhav Kadam, Tushar Sant, Suhas M. Jejurikar, Arun Banpurkar, Animesh Mandal, Shubhada Adhi
Summary: In this study, ZnO/Ga2O3 and Ga2O3/ZnO heterostructures were successfully fabricated on c-Al2O3 substrates using pulsed laser deposition. A hypothetical model explaining the growth process was proposed based on structural and surface morphological investigations. It was found that the template (Ga2O3/Al2O3 and ZnO/Al2O3) used to grow the final film had a significant impact on the microstructural, electrical, and optical properties of the heterostructure. The emission processes involved in UV-blue emission, especially for the Ga2O3/ZnO/Al2O3 heterostructure, were explained by a proposed band diagram schematic.
SOLID STATE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Jianguo Zhang, Wei Wang, Simiao Wu, Zhiming Geng, Jinfu Zhang, Li Chen, Ningtao Liu, Xuejun Yan, Wenrui Zhang, Jichun Ye
Summary: This study reports the controlled growth of metastable gallium oxide films by pulsed laser deposition (PLD) and explores a comprehensive phase evolution picture tuned by synthesis parameters, substrate orientations, and Sn dopants. The stabilization of both undoped and Sn-doped α-Ga2O3 films on a-plane sapphire substrates is demonstrated, and Sn dopants can broaden the growth window of α-Ga2O3. Sn-doped ε-Ga2O3 is more favored than β-Ga2O3 to be stabilized on c-plane substrates, and oxygen pressure is critical for ε-Ga2O3 formation. The structural impact on thermal transport among these metastable Ga2O3 films is investigated, showing different thermal conductivities. This study provides a synthesis guideline for metastable Ga2O3 polymorphs and insights into selective phase stabilization of transition metal oxides.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Narathon Khemasiri, Annop Klamchuen, Sukittaya Jessadaluk, Prapakorn Rattanawarinchai, Punlapa Borklom, Adirek Rangkasikorn, Sakon Rahong, Chaiyuth Saekung, Mati Horprathum, Chanunthorn Chananonnawathorn, Tuksadon Wutikhun, Jiti Nukeaw, Navaphun Kayunkid
Summary: Transparent electrode (TE) plays a crucial role in optoelectronics, and the surface properties of TE layer greatly affect its electrical performance. This study investigates the morphological properties of laser-ablated aluminum-doped zinc oxide (AZO) films and finds a significant impact of laser fluence on the electrical properties. The optimized AZO film with low resistivity and high optical transmittance achieved from controlling the laser fluence is utilized for electrochromic devices.
Article
Computer Science, Information Systems
Wei-Lun Huang, Sheng-Po Chang, Cheng-Hao Li, Shoou-Jinn Chang
Summary: The research has shown that AGZO photo thin film transistors have high transparency and adjustable bandgap, excellent performance, and are suitable for solar-blind applications.
Article
Physics, Condensed Matter
Sergiy Khartsev, Nils Nordell, Mattias Hammar, Juris Purans, Anders Hallen
Summary: Pulsed laser ablation is used to form high-quality silicon-doped beta-Ga(2)O(3)films on sapphire by depositing Ga(2)O(3)and Si from two separate sources, achieving a single crystallinity with a Si concentration of about 1 x 10(20) cm(-3) for optimal electrical performance. Depositing Si and Ga(2)O(3)from two separate sources leads to high crystalline quality and a mobility of about 2.9 cm(2) (V s)(-1).
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2021)
Article
Chemistry, Physical
Sang Ha Jeong, Thi Kim Oanh Vu, Eun Kyu Kim
Summary: Si-doped Ga2O3 photodetectors were studied with different annealing temperatures, showing that devices annealed at 500 degrees C had the highest photoresponsivity and external quantum efficiency, while devices annealed at 800 degrees C had the fastest switching speeds. These results are attributed to changes in defect densities from chemical bond formation between Si and O atoms.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Cheng Wang, Fengzhou Zhao, Zhiying Zhou, Xiaoxuan Li, Shunli He, Menglong Zhang, Dengying Zhang, Lichun Zhang
Summary: All-inorganic perovskite CsCu2I3 thin films were prepared on Si(100) substrates using pulsed laser deposition technology. The morphology, structure, and optical properties of CsCu2I3 films were investigated, and a CsCu2I3/Si n-n heterojunction UV photodetection device was constructed. The device demonstrated excellent self-powered photoresponse performance and good spectral selectivity in the UV range.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Michal Novotny, Jan Remsa, Sarka Havlova, Joris More-Chevalier, Stefan Andrei Irimiciuc, Sergii Chertopalov, Petr Pisarik, Lenka Volfova, Premysl Fitl, Tomas Kmjec, Martin Vrnata, Jan Lanok
Summary: This study focuses on utilizing pulsed laser techniques to prepare Eu3+-doped oxide thin films, adjusting their properties through pulsed UV laser annealing in order to maximize Eu3+ photoluminescent response. The optical, structural, and surface properties were characterized using X-ray diffraction and atomic force microscopy to understand the changes induced by the annealing process.
Article
Materials Science, Multidisciplinary
C. W. Bond, Y. Jin, P. Gomez-Rodriguez, E. Nieto-Pinero, R. L. Leonard, J. Gonzalo, R. Serna, A. K. Petford-Long, J. A. Johnson
Summary: Optically-active thin films can act as photon energy converters in applications like LEDs and photovoltaics. By using novel synthesis techniques, control at the nanoscale level can lead to improved efficiency. Layered thin films with nanocrystalline layers and precise dopant distribution have shown steady emission with chromaticity coordinates close to pure white light, making them advantageous for UV-pumped white light LED applications.
Article
Materials Science, Multidisciplinary
Chen Wang, Shi-Wei Li, Yu-Chao Zhang, Wei-Hang Fan, Hai-Jun Lin, Dong-Sing Wuu, Shui-Yang Lien, Wen-Zhang Zhu
Summary: This study systematically investigated the effect of annealing temperature on the texture, optical characters, chemical valence state, and surface topography of amorphous gallium oxide films. The optimal annealing temperature was found to be 700 degrees C, resulting in good crystal quality and flat-continuous surface. However, temperature above 800 degrees C led to the appearance of cracks, possibly due to Al diffusion and thermal expansion coefficient mismatch.
Article
Engineering, Electrical & Electronic
Amit Kumar Singh, Saurabh Yadav, P. K. Kulriya, Y. S. Katharria
Summary: In this study, the annealing effects of sapphire substrate on beta-Ga2O3 thin films were investigated. The results showed that annealing improved the crystalline quality of the thin films and confirmed the presence of Ga-O bonds. The annealing temperature of the sapphire substrate influenced the film quality and the diffusion of aluminum atoms.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Materials Science, Multidisciplinary
Sergiy Khartsev, Mattias Hammar, Nils Nordell, Aleksejs Zolotarjovs, Juris Purans, Anders Hallen
Summary: Reverse-biased Er-doped beta-Ga2O3 Schottky barrier diodes, prepared by pulsed laser deposition, exhibit strong electroluminescence with a rectification ratio of over nine orders of magnitude and a leakage current density of 0.2-0.4 A cm(-2). The electroluminescence is homogeneously distributed across the diode area and the peak wavelengths are consistent with reported transitions for Er3+.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Raid A. Ismail, Abdulqader D. Faisal, Suaad S. Shaker
Summary: In this study, a zinc sulfide (ZnS) nanostructure film was successfully deposited on multi-walled carbon nanotubes (MWCNTs) using pulsed laser deposition technique. The ZnS/MWCNTs nanocomposite prepared at 5.3 J/cm² exhibited the best crystallinity. Scanning electron microscope (SEM) analysis revealed that the deposited ZnS films had a smooth structure with spherical particles attached to the surface. The current-voltage characteristics of the ZnS-decorated MWCNTs/Si heterojunction photodetectors showed high responsivity values, indicating the potential of these devices for optical sensing applications.
Article
Physics, Condensed Matter
A. Mandal, S. K. Adhi, B. P. Joshi, S. D. Shinde, A. G. Banpurkar, A. V. Limaye, K. P. Adhi, T. Sant, S. M. Jejurikar
Summary: Highly c-axis oriented, single-phase praseodymium doped ZnO thin films were deposited on cAl(2)O(3) substrate under different oxygen pressure conditions. Photoluminescence and X-ray photoelectron emission studies revealed the emission of Pr3+ ions and observed different transitions of Pr3+ ions.
PHYSICA B-CONDENSED MATTER
(2021)
Article
Chemistry, Multidisciplinary
Kai-Ping Chang, Yu-Cheng Yeh, Chung-Jui Wu, Chao-Chun Yen, Dong-Sing Wuu
Summary: CdSe/CdS core/shell quantum dots with different oleylamine (OLA) concentrations were synthesized using a one-pot method. The presence of ZnS diffraction peaks indicated the formation of a ZnS shell on the CdSe/CdS core. Interestingly, QDs with higher OLA concentration exhibited diffraction peaks of ZnS/ZnO, showing better thermal stability and slower decay in photoluminescence intensity. These QDs with tunable emission wavelength are suitable for micro-LED display applications.
Article
Chemistry, Multidisciplinary
Ming-Jie Zhao, Jin-Fa Zhang, Jie Huang, Zuo-Zhu Chen, An Xie, Wan-Yu Wu, Chien-Jung Huang, Dong-Sing Wuu, Shui-Yang Lien, Wen-Zhang Zhu
Summary: Indium tin oxide (ITO) thin films were prepared using high power impulse magnetron sputtering (HiPIMS) and were annealed in hydrogen-containing forming gas. The film resistivity decreases significantly after annealing, with the lowest value reached at 700 degrees C for 40 min. The role of hydrogen in changing film properties was studied, and it was found that hydrogen atoms occupied oxygen sites at low temperatures, leading to a decrease in resistivity. At intermediate temperatures, hydrogen defects decayed, resulting in a reduction in carrier concentration but a continued decrease in resistivity due to increased carrier mobility. At high temperatures, the film was severely reduced and transformed into gaseous metal hydride, leading to the disappearance of the film.
Article
Engineering, Electrical & Electronic
Kai-Ping Chang, Chung-Jui Wu, Chih-Wei Lo, Yu-Shan Lin, Chao-Chun Yen, Dong-Sing Wuu
Summary: This study synthesized silicon dioxide-coated cadmium selenide/zinc sulfide quantum dots and adjusted their emission wavelength. The SiO2 coating enhanced the photoluminescence intensity and reduced the fluorescence decay rate. Moreover, the hydrophilic nature of these coated quantum dots enabled their integration into the color-conversion layer of a microLED display.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Engineering, Electrical & Electronic
Anoop Kumar Singh, Chao-Chun Yen, Kai-Ping Chang, Dong-Sing Wuu
Summary: Al-doped ZnGa2O4 thin film phosphors were grown on sapphire substrates, and the effects of Al doping on the crystal structure and optical characteristics of the films were investigated.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Chemistry, Multidisciplinary
Pao-Hsun Huang, Zhi-Xuan Zhang, Chia-Hsun Hsu, Wan-Yu Wu, Sin-Liang Ou, Chien-Jung Huang, Dong-Sing Wuu, Shui-Yang Lien, Wen-Zhang Zhu
Summary: This study successfully prepared functional SnOx films with specific chemical compositions and found coexisting SnO2 and Sn3O4 phases in PEALD SnOx films. With increasing substrate temperature, the film transitioned from an amorphous to a crystalline SnO2 phase, exhibiting higher mobility.
Review
Chemistry, Multidisciplinary
Jung-Lung Chiang, Bharath Kumar Yadlapalli, Mu- Chen, Dong-Sing Wuu
Summary: This article discusses the synthesis and characterization of gallium oxide (Ga2O3) materials, including pure Ga2O3, co-doped Ga2O3 and Ga2O3-metal oxide composites. Various solution-based methods such as sol-gel, hydrothermal, and chemical bath methods are used to fabricate these materials. The influence of precursor solution types and synthesis conditions on the final product properties is thoroughly described. Applications of Ga2O3 in deep ultraviolet photodetectors, gas sensors, and photocatalysis are also highlighted.
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
Ming-Hsien Li, Keng-Tien Liang, Ze-Hao Wu, Sang-Hao Lin, Yi-Shiang Chiu, Chang-Hsueh Lee, Ming-Yu Kuo, Chia-Feng Lin, Hsiang Chen, Dong-Sing Wuu, Jung Han
Summary: ZnO/ZnS/BIQ-TIPs nanostructures were fabricated for light/gas dual sensing application. The synergic effects of ZnS shell and organic BIQ-TIPs materials enhanced the photosensing capability of ZnO NRs, and the ZnS shell further extended the photosensing spectrum. In addition, the light-assisted hydrogen gas sensing capability was boosted by the incorporation of ZnS shell and BIQ-TIPs materials.
IEEE SENSORS JOURNAL
(2022)
Article
Biochemistry & Molecular Biology
Shicong Jiang, Wan-Yu Wu, Fangbin Ren, Chia-Hsun Hsu, Xiaoying Zhang, Peng Gao, Dong-Sing Wuu, Chien-Jung Huang, Shui-Yang Lien, Wenzhang Zhu
Summary: The application of (In, Al, Ga)N materials in photovoltaic devices has attracted much attention. However, to deposit high-quality GaN material as a foundation is essential. Plasma-enhanced atomic layer deposition (PEALD) combines the advantages of ALD process with plasma utilization and has been used to deposit thin films with various requirements. In this study, NH3-containing plasma was used to eliminate the residual oxygen during the growth of GaN films, which significantly improved the quality of the films. The plasma power controlled NH2, NH, and H radicals showed strong influence on the oxygen content, growth rate, crystallinity, and surface roughness of the GaN films.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
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
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
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)
