Article
Chemistry, Multidisciplinary
Mohammad Mahdi Tavakoli, Ji-Hoon Park, Jeremiah Mwaura, Mayuran Saravanapavanantham, Vladimir Bulovic, Jing Kong
Summary: This study suggests monolayer h-BN grown via CVD as an effective replacement for HTLs in the fabrication of efficient inverted OPVs. The use of h-BN creates smaller barriers for holes and larger barriers for electrons, allowing for efficient charge separation and stability in the devices.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Physical
You-Chen Weng, Yueh-Chin Lin, Heng-Tung Hsu, Min-Lu Kao, Hsuan-Yao Huang, Daisuke Ueda, Minh-Thien-Huu Ha, Chih-Yi Yang, Jer-Shen Maa, Edward-Yi Chang, Chang-Fu Dee
Summary: In this study, a HEMT using GaN:C buffer and AlGaN EBL is investigated for millimeter-wave applications, showing lower vertical leakage, higher thermal stability, and better RF performance.
Article
Chemistry, Multidisciplinary
Mariya Zvaigzne, Alexei Alexandrov, Anastasia Tkach, Dmitriy Lypenko, Igor Nabiev, Pavel Samokhvalov
Summary: This study investigated the impact of deposition parameters of PMMA electron-blocking layer on the performance of QDLEDs, revealing that adding PMMA layer significantly improved the brightness, current efficiency, and turn-on voltage of QDLEDs. Additionally, specific characteristics of each QDLED reached their maximum at a particular PMMA layer thickness, indicating that EBL deposition conditions can serve as an additional parameter space for optimizing QDLEDs in future solid-state lighting and display devices.
Article
Physics, Condensed Matter
Muhammad Nawaz Sharif, Mussaab Ibrahim Niass, Juin J. Liou, Fang Wang, Yuhuai Liu
Summary: By utilizing a new AlInN-based electron blocking layer (EBL), the optoelectronic characteristics of AlGaN-based deep-ultraviolet LED can be improved, with enhanced hole injection, reduced electron overflow, and lower electric field. Additionally, employing an AlInN/AlInN superlattice EBL structure can further enhance carrier distribution and reduce electric field for higher electron-hole wavefunction overlap.
SUPERLATTICES AND MICROSTRUCTURES
(2021)
Article
Chemistry, Physical
Yijian Zhou, Jingjie Li, Wenbo Peng, Yue Liu, Jiahui Zhang, Guojiao Xiang, Xuefeng Zhu, Rong Li, Hui Wang, Gaoqiang Deng, Yang Zhao
Summary: White light-emitting diodes (WLEDs) are efficient, energy-saving, and long-lasting, making them the ideal choice for solid-state light sources in the future. In this study, a near-white light-emitting diode based on p-CuO/i-CuO/n-GaN heterojunction was fabricated, and the influence of CuO electron blocking layer on diode characteristics was discussed. The addition of CuO EBL enhanced the stability of the diode and improved its EL spectrum properties.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Nanoscience & Nanotechnology
Muhammad Nawaz Sharif, Muhammad Usman, Mussaab Ibrahim Niass, Juin J. Liou, Fang Wang, Yuhuai Liu
Summary: The electron blocking layer (EBL) is crucial for preventing electron overflow and reducing hole injection in AlGaN-based DUV-LEDs. This study proposes a DUV nanowire (NW) LED structure without EBL, using a compositionally continuous graded hole source layer (HSL) instead. The graded HSL without EBL improves electron blocking and hole injection efficiency, resulting in increased optical power and decreased series resistance.
Article
Chemistry, Physical
Jinbao Zhang, Yichuan Ding, Guochen Jiang, Austin C. Flick, Ziyi Pan, William J. Scheideler, Oliver Zhao, Justin P. Chen, Li Yang, Nicholas Rolston, Reinhold H. Dauskardt
Summary: The study demonstrates a cost-effective ultrasonic spray coating technique for fabricating large-area electron transport layers for planar PSCs, showing improved performance and stability. The technology not only enhances the power conversion efficiency but also maintains most of the initial performance after long-term storage.
JOURNAL OF MATERIALS CHEMISTRY A
(2021)
Article
Materials Science, Multidisciplinary
Wei-Hao Lee, Fong-Jyun Jhong, Yu-Tung Yin, Chun-Yi Chou, Jing-Jong Shyue, Miin-Jang Chen
Summary: This paper reports on the significant enhancement of the crystalline quality of nanoscale GaN thin films using a large-area and rapid electron beam annealing technique. The results demonstrate high-quality GaN epilayers with smooth surfaces, indicating potential for various applications.
MATERIALS RESEARCH BULLETIN
(2022)
Article
Materials Science, Multidisciplinary
Ramasis Goswami, Syed Qadri, Neeraj Nepal, Charles Eddy
Summary: In this study, ultra-thin AlN films were grown on different substrates using atomic layer epitaxy, showing that the substrate, particularly the strain, plays a crucial role in determining the crystal structure of AlN films. The strain level varied significantly depending on the substrate, impacting the orientation relation and crystal quality of AlN films.
Article
Nanoscience & Nanotechnology
Zicheng Li, Yifeng Gao, Zhihao Zhang, Qiu Xiong, Longhui Deng, Xiaochun Li, Qin Zhou, Yuanxing Fang, Peng Gao
Summary: The SnO2-cPCN electron transport layer shows superior electron mobility, enhancing efficiency and crystallinity of perovskite layers in PSCs. PSCs based on SnO2-cPCN demonstrate higher stability and efficiency compared to pristine SnO2.
NANO-MICRO LETTERS
(2021)
Article
Multidisciplinary Sciences
Fangyun Lu, Huiliu Wang, Mengqi Zeng, Lei Fu
Summary: This article provides an overview of the structures, properties, and synthesis strategies of ultrathin III-V semiconductors, with a focus on space confinement, atomic substitution, adhesion energy regulation, and epitaxial growth. The current challenges and future development directions of ultrathin III-V semiconductors are also summarized.
Article
Materials Science, Multidisciplinary
Anuj Kumar Singh, Kwangseok Ahn, Dongha Yoo, Seokje Lee, Asad Ali, Gyu-Chul Yi, Kunook Chung
Summary: In this study, we achieved van der Waals integration of micropatterned GaN LEDs onto foreign graphene films. The transferred LEDs showed reliable device performances and adhesive properties, allowing for wearability and homogeneous light emission under various bending conditions.
NPG ASIA MATERIALS
(2022)
Article
Optics
Chuanyu Jia, Chenguang He, Qi Wang, Zhizhong Chen
Summary: Experimental and theoretical analysis of u-AlGaN/InGaN superlattices (SLs) last quantum barrier (LQB) and p-AlGaN/InGaN SLs electron blocking layer (EBL) on the performance of InGaN light-emitting diodes (LEDs) reveal that using such structure can significantly enhance the output power and efficiency of LEDs, effectively suppressing efficiency droop.
Article
Nanoscience & Nanotechnology
Rami T. Elafandy, Jin-Ho Kang, Chenziyi Mi, Tae Kyoung Kim, Joon Seop Kwak, Jung Han
Summary: This paper introduces a technique using birefringent nanoporous DBRs to achieve polarization locking in GaN VCSELs, overcoming the challenge of laser polarization control, demonstrating a fully electrically injected blue VCSEL. This technique allows the definition of polarization angles in a planar array, opening up possibilities for novel applications.
Article
Materials Science, Multidisciplinary
Wei-Chung Kao, Fong-Jyun Jhong, Yu -Tung Yin, Hsin-Chih Lin, Miin-Jang Chen
Summary: Low-temperature atomic layer deposition and high-temperature electron beam annealing are utilized to achieve high-quality epitaxial AlN layers. A single exposure of only 1 minute results in efficient energy transfer and substantial improvement in film density and crystal quality. The technique proves to be low-damage and efficient for recrystallizing thin films prepared at low temperatures.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Optics
Yizhi Zhu, Heng Guo, Qiannan Cui, Jinping Chen, Zhuxin Li, Junfeng Lu, Tien-Chang Lu, Zhengchun Peng, Chunxiang Xu, Caofeng Pan
Summary: Manipulating photocarrier dynamics for luminescent materials is of fundamental importance for controlling the luminescent properties of optoelectronic devices. This study demonstrates the enhancement and prolongation of photoluminescence through interfacial engineering, which enables resonant coupling between localized surface plasmon and exciton. The photocarrier dynamics at the interface are mediated by plasmon-induced hot electron transfer (PHET) and plasmon-induced resonant energy transfer (PIRET) processes, which can be actively switched on and off by varying the excitation laser wavelength. These findings are highly significant for actively manipulating photocarrier dynamics in perovskite luminescent devices.
LASER & PHOTONICS REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Ya-Hui Chang, Yen-Shou Lin, Konthoujam James Singh, Hsiang-Ting Lin, Chiao-Yun Chang, Zheng-Zhe Chen, Yu-Wei Zhang, Shih-Yen Lin, Hao-Chung Kuo, Min-Hsiung Shih
Summary: A multicolor AC-driven light-emitting device was developed by integrating a WSe2 monolayer and AlGaInP-GaInP multiple quantum well (MQW) structures. The CVD-grown WSe2 monolayer was placed on top of an AlGaInP-based LED wafer to create a two-dimensional/three-dimensional heterostructure. These hybrid devices expand the wavelength range of 2-D TMDC-based light emitters and support their implementation in various applications.
Article
Chemistry, Multidisciplinary
Zhen-Ting Huang, Ting-Wei Chien, Chang-Wei Cheng, Cheng-Ching Li, Kuo-Ping Chen, Shangjr Gwo, Tien-Chang Lu
Summary: Stable electrical modulation of plasmonic nano-lasers is achieved on a hybrid graphene-insulator-metal (GIM) platform at room temperature. A zinc oxide (ZnO) nanowire is placed on the GIM platform to create a plasmonic cavity, and the graphene layer is used for electrical modulation. The lasing thresholds of the ZnO nanowire plasmonic nanolasers on the GIM platform can be modulated by the gate voltage, demonstrating high potential for plasmonic circuit applications.
Article
Engineering, Electrical & Electronic
Chia-Yen Huang, Wen-Hsuan Hsieh, Teng-Li Shao, Chang-Hsien Wu, Tien-Chang Lu
Summary: We reported an unexpected power degradation mechanism in high-power UVC LEDs grown on high-quality AlN templates. Nitrogen desorption, activated by UVC photon emitted from the active region, introduced observable nitrogen loss and created a continuous leakage path from the active region to the p-electrode via various trap-assisted transport mechanisms, resulting in the power degradation of the LEDs.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Chemistry, Physical
You-Chen Weng, Ming-Yao Hsiao, Chun-Hsiung Lin, Yu-Pin Lan, Edward-Yi Chang
Summary: A high-pressure GaN nucleation layer was inserted in an AlGaN/GaN HEMT to improve its electrical properties. By optimizing the V/III ratio during the growth of the high-pressure GaN layer, the edge dislocation density in the layer was significantly reduced. Experimental results showed lower off-state leakage current, higher maximum I-D and G(m), and lower on-state resistance, indicating the effectiveness of the high-pressure GaN nucleation layer in enhancing the performance of the AlGaN/GaN HEMT.
Article
Chemistry, Multidisciplinary
Dimitrina Petrova, Blagovest Napoleonov, Chau Nguyen Hong Minh, Vera Marinova, Yu-Pin Lan, Ivalina Avramova, Stefan Petrov, Blagoy Blagoev, Vladimira Videva, Velichka Strijkova, Ivan Kostadinov, Shiuan-Huei Lin, Dimitre Dimitrov
Summary: In this paper, aluminum-doped zinc oxide (ZnO:Al or AZO) thin films were grown using atomic layer deposition (ALD), and the effects of postdeposition UV-ozone and thermal annealing treatments on the films' properties were investigated. X-ray diffraction (XRD) revealed a polycrystalline wurtzite structure with a preferable (100) orientation. Thermal annealing increased the crystal size, while UV-ozone exposure had no significant impact on crystallinity. X-ray photoelectron spectroscopy (XPS) analysis revealed a higher amount of oxygen vacancies in the ZnO:Al after UV-ozone treatment, while the ZnO:Al had lower oxygen vacancies after annealing. The important and practical applications of ZnO:Al were found, particularly for transparent conductive oxide layers with high tunability in electrical and optical properties after postdeposition treatment, especially UV-ozone exposure for reducing sheet resistance values. Meanwhile, UV-ozone treatment did not affect the polycrystalline structure, surface morphology, or optical properties of the AZO films.
Article
Chemistry, Multidisciplinary
Lih-Ren Chen, Chia-Jui Chang, Yi-Jing Wu, Cheng-Lin Liu, Wei Lin, Tien-Chang Lu
Summary: This study presents research on InP-based photonic-crystal surface-emitting lasers (PCSELs) for high-power emission in the L band. The incorporation of embedded air voids within a 2D photonic crystal structure enables vertical laser emission. Investigation into the regrowth processes successfully retained the air holes and achieved an atomically flat p-type surface, resulting in higher output efficiency.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Engineering, Electrical & Electronic
Guan-Ying Lee, Shao-Yi Weng, Wan-Hua Ho, Chun-Wei Huang, Han-Yu Chao, Sheng-Kai Huang, Hao-Chung Kuo, Chung-Chih Wu, Chien-Chung Lin
Summary: We proposed a new method for fabricating arrays of colloidal quantum dots with ALD encapsulation. Semiconductor processes were used to transfer the arrays onto a glass substrate, allowing for small pixel sizes. A dual-color array suitable for microdisplay applications was demonstrated, and the color conversion efficiency reached 20.7%. Distributed Bragg reflector mirrors were used to increase photon recycling, resulting in a 35.7% increase in peak intensity. The use of ALD allowed for long-term storage of the CCL and projected lifetime of 44,041 hours.
IEEE PHOTONICS JOURNAL
(2023)
Article
Materials Science, Multidisciplinary
James Singh Konthoujam, Yen-Shou Lin, Yi-Hua Pai, Chiao-Yun Chang, Yu-Wei Zhang, Shih-Yen Lin, Hao-Chung Kuo, Min-Hsiung Shih
Summary: This study reports a significant enhancement in the modulation bandwidth of visible light communication (VLC) by integrating a two-dimensional semiconductor and quantum dots emitter. By integrating a WSe2 monolayer into an Au-nanorod-decorated CdSe/ZnS quantum dots emitter, high modulation performance is achieved. The hybrid quantum dot-gold-tungsten disulfide (QD-Au-WSe2) emitter exhibits a higher modulation bandwidth (130 MHz) compared to pristine quantum dots and a QD-WSe2 heterostructure without Au nanorods (79 and 91 MHz, respectively). The increased transition rate of quantum dot excitons is attributed to the integration of Au nanorods and WSe2 monolayer, which is supported by a reduction in average carrier lifetime observed from time-resolved photoluminescence analysis. This approach and findings provide an opportunity for the application of two-dimensional semiconductors in next-generation miniature VLC devices for high-speed optical communications.
ADVANCED PHOTONICS RESEARCH
(2023)
Article
Nanoscience & Nanotechnology
Chia-Jui Chang, Yu-Wen Chen, Lih-Ren Chen, Kuo-Bin Hong, Jhih-Sheng Wu, Yao-Wei Huang, Tien-Chang Lu
Summary: This article introduces a new method for directly generating vector vortex beams from photonic crystal surface emitting lasers while preserving C-6 rotation symmetry. The ability to dynamically switch between different orders is demonstrated.
Article
Chemistry, Multidisciplinary
Zhen-Ting Huang, Ting-Wei Chien, Chang-Wei Cheng, Cheng-Ching Li, Kuo-Ping Chen, Shangjr Gwo, Tien-Chang Lu
Summary: Stable electrical modulation of plasmonic nanolasers is achieved on a graphene-insulator-metal platform, where the gate voltage can adjust the lasing thresholds of the ZnO nanowire plasmonic nanolasers, providing high-speed modulation characteristics.
Article
Optics
Guan-Hong Li, Chieh Huang, Feng-Jung Kao, Min-Hsiung Shih, Hao-Chung Kuo, Yi-Jen Chiu, Chao-Kuei Lee
Summary: In this study, supercontinuum generation from 645.3 nm to 851 nm was demonstrated by using a high-order mode and engineering the dispersion within the high nonlinear refractive index material Ta2O5 waveguide. The results show clear potential for applications.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Nanoscience & Nanotechnology
James Singh Konthoujam, Yen-Shou Lin, Ya-Hui Chang, Hsiang-Ting Lin, Chiao-Yun Chang, Yu-Wei Zhang, Shih-Yen Lin, Hao-Chung Kuo, Min-Hsiung Shih
Summary: We developed a dual-color AC-driven light-emitting device by integrating WSe2 monolayer and AlGaInP-GaInP multiple quantum well structures with an AlOx insulating layer as a capacitor structure. We investigated the device characteristics using an equivalent RC circuit model and analyzed the time-resolved electroluminescence to understand the underlying physical mechanisms. This dual-color hybrid device expands the applications of 2-D TMDC-based light emitters.
Article
Nanoscience & Nanotechnology
Chia-Jui Chang, Lih-Ren Chen, Kuo-Bin Hong, Tien-Chang Lu
Summary: Photonic crystal surface-emitting lasers (PCSELs) have promising properties over traditional semiconductor lasers. However, the minimum achievable lasing threshold of PCSELs is still larger than that of vertical-cavity surface-emitting lasers (VCSELs), limiting its applications. In this study, a new design is proposed to reduce the threshold current of PCSELs by using selective quantum-well intermixing, while maintaining the advantage of small divergence angle.
Article
Chemistry, Physical
Min-Wen Yu, Yu-Tang Lin, Chia-Hung Wu, Tung-Jung Wang, Jhuang-Hao Cyue, Jun Kikkawa, Satoshi Ishii, Tien-Chang Lu, Kuo-Ping Chen
Summary: This work successfully controlled the number of sulfur vacancies in monolayer WS2 flakes synthesized by chemical vapor deposition (CVD), resulting in a difference in photoluminescence (PL) intensity. The sulfur vacancies introduce defect trap states that cause carrier recombination and reduce carrier drift to graphene, thus decreasing the photocurrent. Furthermore, the gate-tunable Fermi level of graphene allows tunable responsivity of the WS2-graphene photodetector.
APPLIED SURFACE SCIENCE
(2024)
