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High Sensitivity Ga2O3 Ultraviolet Photodetector by One-Step Thermal Oxidation of P-GaN Films

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SSRN 2022年

作者： Li, Peigang Wang, Jinjin Ji, Xueqiang Yan, Zuyong Yan, Xu Li, Zhitong Lu, Chao Qi, Song Li, Shan Qi, Xiaohui Zhang, Sai Hu, Shengrun School of Integrated Circuits State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing100876 China School of Science Lanzhou University of Technology Lanzhou730050 China College of Integrated Circuit Science and Engineering National and Local Joint Engineering Laboratory for RF Integration and Micro-Packaging Technologies Nanjing University of Posts and Telecommunications Nanjing210023 China

Gallium oxide (Ga2O3), with an ultra-wide bandgap, is a promising semiconductor material for the manufacture of solar blind ultraviolet photodetectors. Herein, Ga2O3 thin films were successfully prepared by simpler feasible one-step thermal oxidation of p-GaN thin films, which were oxidized at 900 °C with varying oxidation times in the environment with argon-oxygen ratio of 1000. The effect of different oxidation durations on the physical properties of the Ga2O3 thin films was studied, and particularly, the photoelectric performance of the Ga2O3 thin films was further analyzed. The Ga2O3 thin film thermally oxidized for 2 h has a single crystallographic orientation and excellent photoelectric performance. Compared with the GaN thin film, the dark current of the photodetector was approximately reduced by 2.31 × 104 times while the photocurrents of the device maintain the same order of magnitude, causing a large photo-to-dark current ratios (PDCRs) of 2.29 × 104. Furthermore, the device exhibits impressive characteristics such as high responsivity of 2.13 A/W, super high external quantum efficiency (EQE) of 1040.13%, large detectivity (D) of 1.65×1011 Jones, and fast response speed of 0.218/0.112 s under UV light illumination of 254 nm wavelength at -5 V bias. The results indicate that the one-step thermal oxidation can be used as a good application for preparing the device with high sensitivity, fast response and the high-resolution detection. © 2022, The Authors. All rights reserved.

关键词： Thin films

Design of Van Der Waals Heterostructures Composed of G-C3n4 and Ⅲ-Ⅴ Materials for Solar Cell

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SSRN 2023年

作者： Zhao, Jiaxiang Han, Lihong Jia, Baonan Zhao, Huiyan Gao, Jingming Hao, Jinbo Lu, Pengfei State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing100876 China School of Electronic engineering Beijing University of Posts and Telecommunications Beijing100876 China School of Automation and Electrical Engineering University of Science and Technology Beijing Beijing100083 China School of Science Xi’an University of Architecture and Technology Xi’an710055 China School of Integrated Circuits Beijing University of Posts and Telecommunications Beijing100876 China

As society develops, people pay more attention to the application of solar cell to harvest inexhaustible solar power, which has a benefit of greenness and cleanness. In this paper, we construct 14 heterostructures composed of g-C3N4 and Ⅲ-Ⅴ materials based on first-principles calculations. We systematically analyse their stability property and find a periodic rule of binding energy change about the atomic number of Ⅲ-Ⅴ material. We select 9 stable van der Waals (vdWs) heterostructures and further analyse their band alignment and power conversion efficiency (PCE). We find CN/GaAs-Gadown is a type-Ⅱ heterostructure with indirect band gap of 1.38 eV and the PCE reaches 15.2%. The construction of CN/GaAs-Gadown effectively promotes the optical absorption in visible-spectrum compared with two monolayers. This paper systematically analyses the stability of constructed vdWs heterostructures composed of g-C3N4 and Ⅲ-Ⅴ materials, electronic band structures and their potential application as solar cell. © 2023, The Authors. All rights reserved.

关键词： Solar cells

Interfacial Interactions and Optoelectronic Properties of Cs2agincl6/J-Tmds Heterostructures for Photovoltaic Applications

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SSRN 2023年

作者： Dong, Chao Lu, Pengfei Guan, Xiaoning Jia, Baonan Chen, Changcheng Gao, Shuli State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing100876 China School of Integrated Circuits Beijing University of Posts and Telecommunications Beijing100876 China School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing100876 China School of Science Xi’an University of Architecture and Technology Xi’an710055 China

The photoelectric performance of double perovskites is relatively poor compared to traditional perovskite materials, constructing heterojunctions to improve its optoelectronic properties is an effective strategy for designing high-performance double perovskite optoelectronic applications. In this study, we undertook a comprehensive investigation into the electronic and optical characteristics of Cs2AgInCl6/Janus transition-metal dichalcogenides (J-TMDs) heterostructures based on density functional theory (DFT) calculations. Our findings reveal that the construction of van der Waals heterostructures is only feasible when the Cs-Cl (001) surface of the double perovskite comes into contact with J-TMDs. The nature of the heterojunction formed between Cs2AgInCl6 Cs-Cl surface and J-TMDs (MXY) relies on the disparity in atomic numbers between X and Y, thereby influencing the charge transfer and interface interaction. Moreover, the Cs-Cl/WXY heterostructure exhibits the most promising features for optoelectronic applications due to its lower effective mass and lower exciton binding energy. The optical absorption coefficients of Cs-Cl/J-TMDs heterostructures surpass those of corresponding Cs2AgInCl6 monolayers, signifying their potential utility in solar cells. Additionally, we computed the power conversion efficiency (PCE) of Cs2AgInCl6/MXY heterostructures and found that the Cs-Cl/WSeTe-Se heterostructure demonstrates the highest PCE (11.25%) among all Cs2AgInCl6/MXY heterostructures, positioning it as a promising material for photovoltaic applications. These results provide valuable insights into the design and optimization of Cs2AgInCl6/MXY heterostructures for the development of high-performance optoelectronic devices. © 2023, The Authors. All rights reserved.

关键词： Electronic properties

Two-Dimensional Alloying Mns4 (M, N= Mn, Fe, Co, Ni, Pd) Materials with Pentagonal Pucker for Highly Efficient Electrocatalytic Hydrogen Reaction

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SSRN 2022年

作者： Zhao, Zhengqin Hao, Jinbo Jia, Baonan Zhang, Xinhui Li, Long Chen, Wen Wu, Ge Zhang, Chunling Lu, Pengfei School of Science Xi’an University of Architecture and Technology Xi’an710055 China State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing100876 China School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing100876 China School of Integrated Circuits Beijing University of Posts and Telecommunications Beijing100876 China

The rational design of the excellent catalytic activity electroatalyst to replace noble metal is the core of hydrogen production from water electrolysis. Herein, we designed and demonstrated two-dimensional(2D) alloying monolayer MNS4 (M, N= Mn, Fe, Co, Ni, Pd) materials with three types of pentagonal puckers. Our results showed that the Fe- sites are better than the Co-, Ni- and Pd- sites, so the earth-abundant penta-FeS2 material is expected to be well applied in the HER catalyst. The method of alloying can improve not only the catalytic activity at the metal sites, but also the sulfur sites with abundant adsorption sites for α-type penta-MNS4 materials. Especially for the sulfur sites for α-FeCoS4 materials, there are the most excellent ∆GH*(0.02 eV) and outstanding exchange current density (-1.62 A/cm2) among all of the materials. We further showed that the α-type penta-MNS4 has a wide range of excellent d-band center (Εd ), which corresponds to the better ∆GH*. Ulteriorly, we demonstrated that the reaction barrier of α-FeCoS4 is reduced by the method of alloying. Our results provide theoretical guidance for designing a novel and efficient HER electrocatalyst of pentagonal transition metal dichalcogenide. © 2022, The Authors. All rights reserved.

关键词： Electrocatalysis

Intermodal synchronization effects in multimode fibers with noninstantaneous nonlinearity

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Physical Review A 2022年第1期105卷 013516-013516页

作者： Chao Mei Günter Steinmeyer Jinhui Yuan Xian Zhou Keping Long Research Center for Convergence Networks and Ubiquitous Services University of Science and Technology Beijing 100083 Beijing China Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy Max-Born-Straße 2a 12489 Berlin Germany Institut für Physik Humboldt Universität zu Berlin Newtonstraße 15 12489 Berlin Germany State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing 100876 China

The synchronization of spatial modes in the formation of multimode solitons can be considered as the transverse analog of mode locking. In this process, the inherent Kerr nonlinearity in the fiber core binds different spatial fiber modes together. However, compared to their temporal counterparts, the binding mechanism in multimode solitons is rather weak and susceptible to perturbation. In order to mitigate this effect, the propagation in multimode fibers with noninstantaneous Kerr media (NKM) is theoretically investigated. Our study focuses on the dynamics of intermodal energy transfer for the two cases of weak and strong walk-off. Both the moment method and numerical simulations of a multimode expansion of the nonlinear Schrödinger equation are employed. Scenarios of pure, hybrid, and varying NKM are investigated. For pure NKM, it is found that for weak walk-off, higher order spatial modes are accelerated in the time domain when their energy is transferred to lower order modes, that is, an effect that has previously been discussed as self-cleaning. In the hybrid case, when an additional instantaneous Kerr effect is present, this results in an enhancement of intermodal nonlinear coupling, leading to prominent oscillating evolutions of the derivatives of energy and pulse center. For varying NKM, the nonlinear refractive index and the proportion of noninstantaneous Kerr nonlinearity may both vary with pulse width. In this case, energy transfer and temporal shift are essentially determined by the magnitude of nonlinear response time of NKM. Significant temporal self-splitting at the trailing edge is observed for the lowest order mode provided only that the response time is large enough and irrespective of strong or weak walk-off.

关键词： Solitons

Room-temperature sub-100 nm Néel-type skyrmions in non-stoichiometric van der Waals ferromagnet Fe3-xGaTe2 with ultrafast laser writability

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arXiv

arXiv 2024年

作者： Li, Zefang Zhang, Huai Li, Guanqi Guo, Jiangteng Wang, Qingping Deng, Ying Hu, Yue Hu, Xuange Liu, Can Qin, Minghui Shen, Xi Yu, Richeng Gao, Xingsen Liao, Zhimin Liu, Junming Hou, Zhipeng Zhu, Yimei Fu, Xuewen Ultrafast Electron Microscopy Laboratory The MOE Key Laboratory of Weak-Light Nonlinear Photonics School of Physics Nankai University Tianjin300071 China Guangdong Provincial Key Laboratory of Optical Information Materials and Technology Institute for Advanced Materials South China Academy of Advanced Optoelectronics South China Normal University Guangzhou510006 China School of Integrated Circuits Guangdong University of Technology Guangzhou510006 China School of Physics and Electronic and Electrical Engineering Aba Teachers University Wenchuan China Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing100190 China State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nanooptoelectronics School of Physics Peking University Beijing100871 China Laboratory of Solid State Microstructures Innovation Center of Advanced Microstructures Nanjing University Nanjing211102 China Condensed Matter Physics and Materials Science Department Brookhaven National Laboratory UptonNY11973 United States School of Materials Science and Engineering Smart Sensing Interdisciplinary Science Center Nankai University Tianjin300350 China

Realizing room-temperature magnetic skyrmions in two-dimensional van der Waals ferromagnets offers unparalleled prospects for future spintronic applications. However, due to the intrinsic spin fluctuations that suppress atomic long-range magnetic order and the inherent inversion crystal symmetry that excludes the presence of the Dzyaloshinskii-Moriya interaction, achieving room-temperature skyrmions in 2D magnets remains a formidable challenge. In this study, we target room-temperature 2D magnet Fe3GaTe2 and unveil that the introduction of iron-deficient into this compound enables spatial inversion symmetry breaking, thus inducing a significant Dzyaloshinskii-Moriya interaction that brings about room-temperature Néel-type skyrmions with unprecedentedly small size. To further enhance the practical applications of this finding, we employ a homemade in-situ optical Lorentz transmission electron microscopy to demonstrate ultrafast writing of skyrmions in Fe3-xGaTe2 using a single femtosecond laser pulse. Our results manifest the Fe3-xGaTe2 as a promising building block for realizing skyrmion-based magneto-optical functionalities. © 2024, CC BY-NC-SA.

关键词： Room temperature

Realization of Resonant optical Metasurfaces with Maximal and Tunable Chiral Response

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Realization of Resonant Optical Metasurfaces with Maximal an...

Conference on Lasers and Electro-Optics (CLEO)

作者： Tan Shi Zi-Lan Deng Guangzhou Geng Yixuan Zeng Guangwei Hu Adam Overvig Junjie Li Cheng-Wei Qiu Andrea Alù Yuri S. Kivshar Xiangping Li Institute of Photonics Technology Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications Jinan University Guangzhou China Institute of Physics Beijing National Laboratory for Condensed Matter Physics Chinese Academy of Sciences Beijing China Department of Electrical and Computer Engineering National University of Singapore Kent Ridge Republic of Singapore Photonics Initiative Advanced Science Research Center City University of New York New York NY USA Nonlinear Physics Center Australian National University Canberra ACT Australia

We employ the physics of chiral bound state in the continuum and suggest planar chiral metasurfaces with near-perfect circular dichroism (CD). We demonstrate experimentally metasurfaces with CD=0.9 with Q factor excee... 详细信息

ISBN: (数字)9781957171050

ISBN: (纸本)9781665466660

关键词： Q-factor Laser theory Resonant frequency Lighting Lasers and electrooptics Metasurfaces Electrooptical waveguides

Great chiral fluorescence from optical duality silver nanostructures enabled by 3D laser printing

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arXiv

arXiv 2020年

作者： Wen, Hongjing Song, Shichao Xie, Fei Wang, Bin Xu, Jian Feng, Ziwei Wu, Shiyu Han, Jing Guan, Baiou Xu, Xiaoxuan Cao, Yaoyu Li, Xiangping Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications Institute of Photonics Technology Jinan University Guangzhou511443 China Key Laboratory of Weak-Light Nonlinear Photonics Ministry of Education School of Physics Nankai University Tianjin300071 China

Featured by prominent flexibility and fidelity in producing sophisticated stereoscopic structures transdimensionally, three-dimensional (3D) laser printing technique has vastly extended the toolkit for delivering diverse functional devices. Yet chiral nanoemitters heavily resorting to artificial structures that manifest efficient emission and tightly confined light-mater interactions simultaneously remains alluring but dauntingly challenging for this technique at this moment. In this work, we assert the chiral photoluminescence is implemented from silver nanostructures of optical duality in one go via a twofold three-dimensional laser printing scheme. Such laser printing protocol allows the highly desired duality by simultaneously producing uniformly distributed fluorescent silver nanoclusters and aggregated plasmonic silver nanoparticles to tightly confine chiral interactions at the nanoscale. A helical emitter of 550 nm-helix-diameter as fabricated has seen a record-high luminescence anisotropic factor with the absolute value up to 0.58, which is two orders of magnitude greater than fluorescent chiral silver clusters. This method holds great promise for future versatile applications in chiroptical nanodevices. Copyright © 2020, The Authors. All rights reserved.

关键词： Fluorescence

Tellurium nanowire retinal nanoprosthesis improves vision in models of blindness

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Science (New York, N.Y.) 2025年第6751期388卷 eadu2987页

作者： Shuiyuan Wang Chengyong Jiang Yiye Yu Zhenhan Zhang Ruge Quhe Ruyi Yang Yufei Tian Xindong Chen Wenqiang Fan Yinge Niu Biao Yan Chunhui Jiang Yang Wang Zhen Wang Chunsen Liu Weida Hu Jiayi Zhang Peng Zhou State Key Laboratory of Integrated Chips and Systems (SKLICS) College of Integrated Circuits and Micro-Nano Electronics School of Microelectronics State Key Laboratory of Brain Function and Disorders MOE Frontiers Center for Brain Science Institutes of Brain Science Department of Ophthalmology and Vision Science Eye and ENT Hospital Fudan University Shanghai China. Shaoxin Laboratory Shaoxing Zhejiang China. State Key Laboratory of Infrared Physics Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai China. School of Electrical and Electronic Engineering Nanyang Technological University Singapore Singapore. State Key Laboratory of Information Photonics and Optical Communications and School of Science Beijing University of Posts and Telecommunications Beijing China.

Present vision restoration technologies have substantial constraints that limit their application in the clinical setting. In this work, we fabricated a subretinal nanoprosthesis using tellurium nanowire networks (TeNWNs) that converts light of both the visible and near-infrared-II spectra into electrical signals. The broad-spectrum coverage is made possible by a combination of narrow bandgaps, strong absorption, and engineered asymmetries. Implanted into blind mice, the TeNWNs restored pupillary reflexes and enabled visually cued learning under visible and near-infrared 1550-nanometer light. In nonhuman primates, TeNWNs elicited robust retina-derived neural responses, confirming biocompatibility and feasibility. By restoring lost photosensitivity and extending vision to near-infrared, this nanoprosthesis offers a promising approach for restoring vision.

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