1
|
Cao N, Zhang L, Li X, Meng X, Liang D, Zhu Y, Zhao F. Deep-ultraviolet n-ZnGa 2O 4/p-GaN heterojunction photodetector fabricated by pulsed laser deposition. OPTICS LETTERS 2024; 49:2309-2312. [PMID: 38691706 DOI: 10.1364/ol.519668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 03/22/2024] [Indexed: 05/03/2024]
Abstract
Zinc gallium oxide (ZnGa2O4) has attracted considerable interest in deep-ultraviolet photodetectors, due to the ultrawide bandgap, high transmittance in the ultraviolet (UV) region, and excellent environmental stability. In this study, ZnGa2O4 thin films were deposited on p-GaN epi-layers using pulsed laser deposition, resulting in improved crystalline quality. The ZnGa2O4 film exhibited a bandgap of 4.93 eV, calculated through absorption spectra. A heterojunction photodetector (PD) was constructed, demonstrating a rectification effect, an on/off ratio of 12,697 at -5.87 V, a peak responsivity of 14.5 mA/W, and a peak detectivity of 1.14 × 1012 Jones (262 nm, -6 V). The PD exhibited a fast response time (39 ms) and recovery time (30 ms) under 262 nm illumination. The band diagram based on the Anderson model elucidates the photoresponse and carrier transport mechanism. This work paves the way for advancing next-generation optoelectronics.
Collapse
|
2
|
Ye L, Zhou S, Xiong Y, Tang J, Wang X, Li X, Pang D, Li H, Zhang H, Ye L, Cui Y, Li W. Self-powered Pt/a-Ga 2O 3/ITO vertical Schottky junction solar-blind photodetector with excellent detection performance. OPTICS EXPRESS 2023; 31:28200-28211. [PMID: 37710880 DOI: 10.1364/oe.494216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 07/27/2023] [Indexed: 09/16/2023]
Abstract
Self-powered solar-blind photodetectors (PDs) are promising for military and civilian applications owing to convenient operation, easy preparation, and weak-light sensitivity. In the present study, the solar-blind deep-ultraviolet (DUV) photodetector based on amorphous Ga2O3 (a-Ga2O3) and with a simple vertical stack structure is proposed by applying the low-cost magnetron sputtering technology. By tuning the thickness of the amorphous Ga2O3 layer, the device exhibits excellent detection performance. Under 3 V reverse bias, the photodetector achieves a high responsivity of 671A/W, a high detectivity of 2.21 × 1015 Jones, and a fast response time of 27/11 ms. More extraordinary, with the help of the built-in electric field at the interface, the device achieves an excellent performance in detection when self-powered, with an ultrahigh responsivity of 3.69 A/W and a fast response time of 2.6/6.6 ms under 254 nm light illumination. These results demonstrate its superior performance to most of the self-powered Schottky junction UV photodetectors reported to date. Finally, the Pt/a-Ga2O3/ITO Schottky junction photodiode detector is verified as a good performer in imaging, indicating its applicability in such fields as artificial intelligence, machine vision, and solar-blind imaging.
Collapse
|
3
|
Zhang W, Wang W, Zhang J, Zhang T, Chen L, Wang L, Zhang Y, Cao Y, Ji L, Ye J. Directional Carrier Transport in Micrometer-Thick Gallium Oxide Films for High-Performance Deep-Ultraviolet Photodetection. ACS APPLIED MATERIALS & INTERFACES 2023; 15:10868-10876. [PMID: 36794989 DOI: 10.1021/acsami.3c00124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Incorporating emerging ultrawide bandgap semiconductors with a metal-semiconductor-metal (MSM) architecture is highly desired for deep-ultraviolet (DUV) photodetection. However, synthesis-induced defects in semiconductors complicate the rational design of MSM DUV photodetectors due to their dual role as carrier donors and trap centers, leading to a commonly observed trade-off between responsivity and response time. Here, we demonstrate a simultaneous improvement of these two parameters in ε-Ga2O3 MSM photodetectors by establishing a low-defect diffusion barrier for directional carrier transport. Specifically, using a micrometer thickness far exceeding its effective light absorption depth, the ε-Ga2O3 MSM photodetector achieves over 18-fold enhancement of responsivity and simultaneous reduction of the response time, which exhibits a state-of-the-art photo-to-dark current ratio near 108, a superior responsivity of >1300 A/W, an ultrahigh detectivity of >1016 Jones, and a decay time of 123 ms. Combined depth-profile spectroscopic and microscopic analysis reveals the existence of a broad defective region near the lattice-mismatched interface followed by a more defect-free dark region, while the latter one serves as a diffusion barrier to assist frontward carrier transport for substantially enhancing the photodetector performance. This work reveals the critical role of the semiconductor defect profile in tuning carrier transport for fabricating high-performance MSM DUV photodetectors.
Collapse
Affiliation(s)
- Wenrui Zhang
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
- Yongjiang Laboratory, Ningbo 315201, China
| | - Wei Wang
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Jinfu Zhang
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Tan Zhang
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Li Chen
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Liu Wang
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Yu Zhang
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China
| | - Yanwei Cao
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Li Ji
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China
| | - Jichun Ye
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
- Yongjiang Laboratory, Ningbo 315201, China
| |
Collapse
|
4
|
Zhou S, Zheng Q, Yu C, Huang Z, Chen L, Zhang H, Li H, Xiong Y, Kong C, Ye L, Li W. A High-Performance ε-Ga 2O 3-Based Deep-Ultraviolet Photodetector Array for Solar-Blind Imaging. MATERIALS (BASEL, SWITZERLAND) 2022; 16:ma16010295. [PMID: 36614634 PMCID: PMC9822404 DOI: 10.3390/ma16010295] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/20/2022] [Accepted: 12/23/2022] [Indexed: 05/27/2023]
Abstract
One of the most important applications of photodetectors is as sensing units in imaging systems. In practical applications, a photodetector array with high uniformity and high performance is an indispensable part of the imaging system. Herein, a photodetector array (5 × 4) consisting of 20 photodetector units, in which the photosensitive layer involves preprocessing commercial ε-Ga2O3 films with high temperature annealing, have been constructed by low-cost magnetron sputtering and mask processes. The ε-Ga2O3 ultraviolet photodetector unit shows excellent responsivity and detectivity of 6.18 A/W and 5 × 1013 Jones, respectively, an ultra-high light-to-dark ratio of 1.45 × 105, and a fast photoresponse speed (0.14/0.09 s). At the same time, the device also shows good solar-blind characteristics and stability. Based on this, we demonstrate an ε-Ga2O3-thin-film-based solar-blind ultraviolet detector array with high uniformity and high performance for solar-blind imaging in optoelectronic integration applications.
Collapse
Affiliation(s)
| | | | | | | | | | - Hong Zhang
- Correspondence: (H.Z.); (L.Y.); (W.L.); Tel.: +86-23-6536-2779 (W.L.)
| | | | | | | | - Lijuan Ye
- Correspondence: (H.Z.); (L.Y.); (W.L.); Tel.: +86-23-6536-2779 (W.L.)
| | - Wanjun Li
- Correspondence: (H.Z.); (L.Y.); (W.L.); Tel.: +86-23-6536-2779 (W.L.)
| |
Collapse
|
5
|
Hou X, Zhao X, Zhang Y, Zhang Z, Liu Y, Qin Y, Tan P, Chen C, Yu S, Ding M, Xu G, Hu Q, Long S. High-Performance Harsh-Environment-Resistant GaO X Solar-Blind Photodetectors via Defect and Doping Engineering. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2106923. [PMID: 34626038 DOI: 10.1002/adma.202106923] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/02/2021] [Indexed: 06/13/2023]
Abstract
Gallium oxide (Ga2 O3 ), with an ultrawide bandgap, is currently regarded as one of the most promising materials for solar-blind photodetectors (SBPDs), which are greatly demanded in harsh environment, such as space exploration and flame prewarning. However, realization of high-performance SBPDs with high tolerance toward harsh environments based on low-cost Ga2 O3 material faces great challenges. Here, defect and doping (DD) engineering towards amorphous GaOX (a-GaOX ) has been proposed to obtain ultrasensitive SBPDs for harsh condition application. Serious oxygen deficiency and doping compensation of the engineered a-GaOX film ensure the high response currents and low dark currents, respectively. Annealing item in nitrogen of DD engineering also incurs the recrystallization of material, formation of nanopores by oxygen escape, and suppression of sub-bandgap defect states. As a result, the tailored GaOX SBPD based on DD engineering not only harvests a record-high responsivity rejection ratio (R254 nm /R365 nm ) of 1.8 × 107 , 102 times higher detectivity, and 2 × 102 times faster decay speed than the control device, but also keeps a high responsivity, high photo-to-dark current ratio, and sharp imaging capability even at high temperature (280 °C) or high bias (100 V). The proposed DD engineering provides an effective strategy towards highly harsh-environment-resistant GaOX SBPDs.
Collapse
Affiliation(s)
- Xiaohu Hou
- School of Microelectronics, University of Science and Technology of China, Hefei, 230026, China
| | - Xiaolong Zhao
- School of Microelectronics, University of Science and Technology of China, Hefei, 230026, China
- Frontiers Science Center for Planetary Exploration and Emerging Technologies, University of Science and Technology of China, Hefei, 230026, China
| | - Ying Zhang
- Key Laboratory of Microelectronics Devices and Integration Technology, Institute of Microelectronics of Chinese Academy of Sciences, Beijing, 100029, China
| | - Zhongfang Zhang
- School of Microelectronics, University of Science and Technology of China, Hefei, 230026, China
| | - Yan Liu
- School of Microelectronics, University of Science and Technology of China, Hefei, 230026, China
| | - Yuan Qin
- Key Laboratory of Microelectronics Devices and Integration Technology, Institute of Microelectronics of Chinese Academy of Sciences, Beijing, 100029, China
| | - Pengju Tan
- School of Microelectronics, University of Science and Technology of China, Hefei, 230026, China
| | - Chen Chen
- School of Microelectronics, University of Science and Technology of China, Hefei, 230026, China
| | - Shunjie Yu
- School of Microelectronics, University of Science and Technology of China, Hefei, 230026, China
| | - Mengfan Ding
- School of Microelectronics, University of Science and Technology of China, Hefei, 230026, China
| | - Guangwei Xu
- School of Microelectronics, University of Science and Technology of China, Hefei, 230026, China
- Frontiers Science Center for Planetary Exploration and Emerging Technologies, University of Science and Technology of China, Hefei, 230026, China
| | - Qin Hu
- School of Microelectronics, University of Science and Technology of China, Hefei, 230026, China
- Frontiers Science Center for Planetary Exploration and Emerging Technologies, University of Science and Technology of China, Hefei, 230026, China
| | - Shibing Long
- School of Microelectronics, University of Science and Technology of China, Hefei, 230026, China
- Frontiers Science Center for Planetary Exploration and Emerging Technologies, University of Science and Technology of China, Hefei, 230026, China
| |
Collapse
|
6
|
Yuan Y, Hao W, Mu W, Wang Z, Chen X, Liu Q, Xu G, Wang C, Zhou H, Zou Y, Zhao X, Jia Z, Ye J, Zhang J, Long S, Tao X, Zhang R, Hao Y. Toward emerging gallium oxide semiconductors: A roadmap. FUNDAMENTAL RESEARCH 2021. [DOI: 10.1016/j.fmre.2021.11.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
|
7
|
Wang Y, Li H, Cao J, Shen J, Zhang Q, Yang Y, Dong Z, Zhou T, Zhang Y, Tang W, Wu Z. Ultrahigh Gain Solar Blind Avalanche Photodetector Using an Amorphous Ga 2O 3-Based Heterojunction. ACS NANO 2021; 15:16654-16663. [PMID: 34605627 DOI: 10.1021/acsnano.1c06567] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Solar blind photodetectors with a cutoff wavelength within the 200-280 nm region is attracting much attention due to their potential civilian and military applications. The avalanche photodetectors (APDs) formed based on wide-bandgap semiconductor Ga2O3 are expected to meet emerging technological demands. These devices, however, suffer from limitations associated with the quality of as-grown Ga2O3 or the difficulty in alleviating the defects and dislocations. Herein, high-performance APDs incorporating amorphous Ga2O3 (a-Ga2O3)/ITO heterojunction as the central element have been reliably fabricated at room temperature. The a-Ga2O3-based APDs exhibits an ultrahigh responsivity of 5.9 × 104 A/W, specific detectivity of 1.8 × 1014 Jones, and an external quantum efficiency up to 2.9 × 107% under 254 nm light irradiation at 40 V reverse bias. Notably, the gain could reach 6.8 × 104, indicating the outstanding capability for ultraweak signals detection. The comprehensive superior capabilities of the a-Ga2O3-based APDs can be ascribed to the intrinsic carrier transport manners in a-Ga2O3 as well as the modified band alignment at the heterojunctions. The trade-off between low processing temperature and superior characteristics of a-Ga2O3 promises greater design freedom for realization of wide applications of emerging semiconductor Ga2O3 with even better performance since relieving the burden on the integration progress.
Collapse
Affiliation(s)
- Yuehui Wang
- State Key Laboratory of Information Photonics and Optical Communications, and School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P.R. China
| | - Haoran Li
- State Key Laboratory of Information Photonics and Optical Communications, and School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P.R. China
| | - Jia Cao
- Beijing Institute of Radio Measurement, Beijing 100039, P.R. China
| | - Jiaying Shen
- State Key Laboratory of Information Photonics and Optical Communications, and School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P.R. China
| | - Qingyi Zhang
- State Key Laboratory of Information Photonics and Optical Communications, and School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P.R. China
| | - Yongtao Yang
- State Key Laboratory of Information Photonics and Optical Communications, and School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P.R. China
| | - Zhengang Dong
- State Key Laboratory of Information Photonics and Optical Communications, and School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P.R. China
| | - Tianhong Zhou
- Institute of Modern Optics, and Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, Nankai University, Tianjin 300071, P.R. China
| | - Yang Zhang
- Institute of Modern Optics, and Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, Nankai University, Tianjin 300071, P.R. China
| | - Weihua Tang
- State Key Laboratory of Information Photonics and Optical Communications, and School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P.R. China
| | - Zhenping Wu
- State Key Laboratory of Information Photonics and Optical Communications, and School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P.R. China
| |
Collapse
|
8
|
Qin Y, Li L, Yu Z, Wu F, Dong D, Guo W, Zhang Z, Yuan J, Xue K, Miao X, Long S. Ultra-High Performance Amorphous Ga 2 O 3 Photodetector Arrays for Solar-Blind Imaging. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2101106. [PMID: 34390217 PMCID: PMC8529488 DOI: 10.1002/advs.202101106] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/06/2021] [Indexed: 05/05/2023]
Abstract
The growing demand for scalable solar-blind image sensors with remarkable photosensitive properties has stimulated the research on more advanced solar-blind photodetector (SBPD) arrays. In this work, the authors demonstrate ultrahigh-performance metal-semiconductor-metal (MSM) SBPDs based on amorphous (a-) Ga2 O3 via a post-annealing process. The post-annealed MSM a-Ga2 O3 SBPDs exhibit superhigh sensitivity of 733 A/W and high response speed of 18 ms, giving a high gain-bandwidth product over 104 at 5 V. The SBPDs also show ultrahigh photo-to-dark current ratio of 3.9 × 107 . Additionally, the PDs demonstrate super-high specific detectivity of 3.9 × 1016 Jones owing to the extremely low noise down to 3.5 fW Hz-1/2 , suggesting high signal-to-noise ratio. Underlying mechanism for such superior photoelectric properties is revealed by Kelvin probe force microscopy and first principles calculation. Furthermore, for the first time, a large-scale, high-uniformity 32 × 32 image sensor array based on the post-annealed a-Ga2 O3 SBPDs is fabricated. Clear image of target object with high contrast can be obtained thanks to the high sensitivity and uniformity of the array. These results demonstrate the feasibility and practicality of the Ga2 O3 PDs for applications in solar-blind imaging, environmental monitoring, artificial intelligence and machine vision.
Collapse
Affiliation(s)
- Yuan Qin
- Key Laboratory of Microelectronics Devices & Integration TechnologyInstitute of Microelectronics of Chinese Academy of SciencesBeijing100029China
- School of MicroelectronicsUniversity of Science and Technology of ChinaHefeiAnhui230026China
| | - Li‐Heng Li
- Wuhan National Laboratory for OptoelectronicsSchool of Optical and Electronic InformationHuazhong University of Science and TechnologyWuhan430074China
| | - Zhaoan Yu
- Key Laboratory of Microelectronics Devices & Integration TechnologyInstitute of Microelectronics of Chinese Academy of SciencesBeijing100029China
| | - Feihong Wu
- School of MicroelectronicsUniversity of Science and Technology of ChinaHefeiAnhui230026China
| | - Danian Dong
- Key Laboratory of Microelectronics Devices & Integration TechnologyInstitute of Microelectronics of Chinese Academy of SciencesBeijing100029China
| | - Wei Guo
- School of MicroelectronicsUniversity of Science and Technology of ChinaHefeiAnhui230026China
| | - Zhongfang Zhang
- School of MicroelectronicsUniversity of Science and Technology of ChinaHefeiAnhui230026China
| | - Jun‐Hui Yuan
- Wuhan National Laboratory for OptoelectronicsSchool of Optical and Electronic InformationHuazhong University of Science and TechnologyWuhan430074China
| | - Kan‐Hao Xue
- Wuhan National Laboratory for OptoelectronicsSchool of Optical and Electronic InformationHuazhong University of Science and TechnologyWuhan430074China
| | - Xiangshui Miao
- Wuhan National Laboratory for OptoelectronicsSchool of Optical and Electronic InformationHuazhong University of Science and TechnologyWuhan430074China
| | - Shibing Long
- School of MicroelectronicsUniversity of Science and Technology of ChinaHefeiAnhui230026China
| |
Collapse
|
9
|
Ji YH, Gao Q, Huang AP, Yang MQ, Liu YQ, Geng XL, Zhang JJ, Wang RZ, Wang M, Xiao ZS, Chu PK. GaO x@GaN Nanowire Arrays on Flexible Graphite Paper with Tunable Persistent Photoconductivity. ACS APPLIED MATERIALS & INTERFACES 2021; 13:41916-41925. [PMID: 34448583 DOI: 10.1021/acsami.1c13355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Flexible optoelectronic synaptic devices that functionally imitate the neural behavior with tunable optoelectronic characteristics are crucial to the development of advanced bioinspired neural networks. In this work, amorphous oxide-decorated GaN nanowire arrays (GaOx@GaN NWAs) are prepared on flexible graphite paper. A GaOx@GaN NWA-based flexible device has tunable persistent photoconductivity (PPC) and shows a conversible fast/slow decay process (SDP). Photoconductivity can be modulated by single or double light pulses with different illumination powers and biases. PPC gives rise to the high-performance SDP such as a long decay time of 2.3 × 105 s. The modulation mechanism is proposed and discussed. Our results reveal an innovative and efficient strategy to produce decorated NWAs on a flexible substrate with tunable optoelectronic properties and exhibit potential for flexible neuromorphic system applications.
Collapse
Affiliation(s)
- Yu-Hang Ji
- School of Physics, Beihang University, Beijing 100191, China
| | - Qin Gao
- School of Physics, Beihang University, Beijing 100191, China
| | - An-Ping Huang
- School of Physics, Beihang University, Beijing 100191, China
| | - Meng-Qi Yang
- Institute of New Energy Materials and Devices, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China
| | - Yan-Qi Liu
- Institute of Laser Engineering, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 999077, China
| | - Xue-Li Geng
- School of Physics, Beihang University, Beijing 100191, China
| | - Jing-Jing Zhang
- School of Physics, Beihang University, Beijing 100191, China
| | - Ru-Zhi Wang
- Institute of New Energy Materials and Devices, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China
| | - Mei Wang
- School of Physics, Beihang University, Beijing 100191, China
| | - Zhi-Song Xiao
- School of Physics, Beihang University, Beijing 100191, China
| | - Paul K Chu
- Department of Physics, Department of Materials Science and Engineering, and Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon 518057, Hong Kong, China
| |
Collapse
|
10
|
Liang X, Zhao J, Wang T, Zhang Z, Qu M, Wang C. Constructing a Z-Scheme Heterojunction Photocatalyst of GaPO 4/α-MoC/Ga 2O 3 without Mingling Type-II Heterojunction for CO 2 Reduction to CO. ACS APPLIED MATERIALS & INTERFACES 2021; 13:33034-33044. [PMID: 34229432 DOI: 10.1021/acsami.1c07757] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Constructing Z-scheme heterojunction photocatalysts is a prevalent strategy to prolong the lifetime of photoinduced charge carriers without reducing their redox potentials. Nevertheless, these photocatalysts were usually mingled with type-II heterojunction, leading to a decrease in the redox potentials of photoinduced charge carriers. Herein, based on the absolute electronegativity of semiconductors, a Z-scheme heterojunction photocatalyst of GaPO4/α-MoC/Ga2O3 was designed and successfully constructed, in which the formation of type-II heterojunction was prevented between GaPO4 and Ga2O3. In the GaPO4/α-MoC/Ga2O3 photocatalyst, the conduction band (CB) and valance band (VB) potentials and the Fermi level of Ga2O3 are higher than those of GaPO4, respectively. Under irradiation, photoinduced electrons on the CB of GaPO4 migrate to the electron mediator α-MoC and subsequently recombine with the photoinduced holes of Ga2O3, thereby retaining the photoinduced charge carriers with higher redox potentials. As a result, GaPO4/α-MoC/Ga2O3 exhibits a 4-fold enhancement of activity for CO2 photoreduction, compared to Ga2O3. Photocatalytic mechanism studies indicate that superoxide radicals might be an important intermediate for CO2 reduction to CO. The present work supplies a paradigm to construct a Z-scheme heterostructure without mingling type-II heterojunction via energy band engineering.
Collapse
Affiliation(s)
- Xinxin Liang
- School of Environmental Sciences and Engineering, Shaanxi University of Science & Technology, Xian, Shaanxi 710021, China
| | - Jie Zhao
- School of Environmental Sciences and Engineering, Shaanxi University of Science & Technology, Xian, Shaanxi 710021, China
| | - Ting Wang
- School of Environmental Sciences and Engineering, Shaanxi University of Science & Technology, Xian, Shaanxi 710021, China
| | - Zexing Zhang
- School of Environmental Sciences and Engineering, Shaanxi University of Science & Technology, Xian, Shaanxi 710021, China
| | - Miao Qu
- School of Environmental Sciences and Engineering, Shaanxi University of Science & Technology, Xian, Shaanxi 710021, China
| | - Chuanyi Wang
- School of Environmental Sciences and Engineering, Shaanxi University of Science & Technology, Xian, Shaanxi 710021, China
| |
Collapse
|
11
|
Wang Y, Yang Z, Li H, Li S, Zhi Y, Yan Z, Huang X, Wei X, Tang W, Wu Z. Ultrasensitive Flexible Solar-Blind Photodetectors Based on Graphene/Amorphous Ga 2O 3 van der Waals Heterojunctions. ACS APPLIED MATERIALS & INTERFACES 2020; 12:47714-47720. [PMID: 33045829 DOI: 10.1021/acsami.0c10259] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Flexible photodetectors (PDs) have become the latest research interest owing to their potential applications in future implantable sensors and foldable/wearable optoelectronics. Ga2O3, an emerging ultrawide band gap semiconductor, is considered as the native photosensitive material for solar-blind PDs. The reported fabrication temperature of Ga2O3 films is usually above 600 °C, which hinders its practical application for flexible devices. In this work, flexible PDs based on graphene/amorphous Ga2O3 van der Waals heterojunctions are fabricated, which demonstrate promising photoresponse to solar-blind ultraviolet light. The device yields a high photo-to-dark current ratio (∼105) and large responsivity (22.75 A/W) under 254 nm light illumination, which could be ascribed to the efficient photogenerated electron-hole pair separation by the strong built-in field. Moreover, flexible PDs also show long-term environmental stability and outstanding mechanical flexibility without any encapsulation. Our work provides a new potential candidate for realizing cost-effective high-performance flexible optoelectronic applications.
Collapse
Affiliation(s)
- Yuehui Wang
- State Key Laboratory of Information Photonics and Optical Communications & School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P. R. China
| | - Zhibin Yang
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, P. R. China
| | - Haoran Li
- State Key Laboratory of Information Photonics and Optical Communications & School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P. R. China
| | - Shan Li
- State Key Laboratory of Information Photonics and Optical Communications & School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P. R. China
| | - Yusong Zhi
- State Key Laboratory of Information Photonics and Optical Communications & School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P. R. China
| | - Zuyong Yan
- State Key Laboratory of Information Photonics and Optical Communications & School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P. R. China
| | - Xu Huang
- State Key Laboratory of Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, Sichuan, P. R. China
| | - Xianhua Wei
- State Key Laboratory of Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, Sichuan, P. R. China
| | - Weihua Tang
- State Key Laboratory of Information Photonics and Optical Communications & School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P. R. China
| | - Zhenping Wu
- State Key Laboratory of Information Photonics and Optical Communications & School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P. R. China
| |
Collapse
|