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AlGaN solar‐blind APD with low breakdown voltage

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光电工程 2017年第4期44卷 405-409,467页

作者： Kexiu Dong dunjun chen Yangyi Zhang Yizhe Sun Jianping Shi School of Electronic and Electrical Engineering Chuzhou University Chuzhou 239000 China College of Physics and Electronic Information Anhui Normal University Wuhu 241000 China Key Laboratory of Advanced Photonic and Electronic Materials School of Electronic Science and Engineering Nanjing University Nanjing 210093 China

A p-i-i-n type AlG a N heterostructure avalanche photodiodes(APDs)is proposed to decrease the avalanche breakdown voltage and to realize higher gain by using high-Al-content AlG aN layer as multiplication layer and low-Al-content AlG aN layer as absorption *** calculated results show that the designed APD can significantly reduce the breakdown voltage by almost 30%,and about sevenfold increase of maximum gain compared to the conventional Al GaN *** noise in designed APD is also less than that in conventional APD due to its low dark current at the breakdown voltage ***,the one-dimensional(1D)dual-periodic photonic crystal(PC)with anti-reflection coating filter is designed to achieve the solar-blind characteristic and cutoff wavelength of 282 nm is obtained.

关键词：光电二极管击穿电压光子晶体抗反射涂层

Progress on AlGaN-based solar-blind ultraviolet photodetectors and focal plane arrays

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Light(Science & Applications) 2021年第6期10卷 976-1006页

作者： Qing Cai Haifan You Hui Guo Jin Wang Bin Liu Zili Xie dunjun chen Hai Lu Youdou Zheng Rong Zhang Key Laboratory of Advaneed Photonic and Electronic Materials School of Electronic Science and EngineeringNanjing UniversityNanjing 210093China Collaborative In novation Center for Optoelectronic Semiconductors and Efficient Devices Department of PhysicsXiamen UniversityXiamen 361005China lnstitute of Future Display Tech no logy Tan Kah Kee Inno vati on LaboratoryXiamen 361102China

Solar-blind ultraviolet(UV)photodetectors(PDs)have attracted tremendous attention in the environmental,industrial,military,and biological *** a representative Ill-nitride material,AlGaN alloys have broad development prospects in the field of solar-blind detection due to their superior properties,such as tunable wide bandgaps for intrinsic UV *** recent decades,a variety of AlGaN-based PDs have been developed to achieve high-precision solar-blind UV *** integrated optoelectronic technology advances,AlGaN-based focal plane arrays(FPAs)are manufactured and exhibit outsta nding solar-blind imaging *** sidering the rapid development of AlGaN detection techniques,this paper comprehensively reviews the progress on AlGaN-based solar-blind UV PDs and ***,the basic physical properties of AlGaN are *** epitaxy and p-type doping problems of AlGaN alloys are then *** PDs,including photoconductors and Schottky,metal-semiconductor-metal(MSM),p-i-n,and avalanche photodiodes(APDs),are dem on strated,and the physical mechanisms are analyzed to improve device ***,this paper summarizes imaging technologies used with AlGaN FPAs in recent ***!ng from the development of AlGaN materials and optoelectronic devices,solar-blind UV detection technology is greeted with significant revolutions.

关键词： optoelectronic arrays ultraviolet

InGaN/GaN multi-quantum-well-based light-emitting and photodetective dual-functional devices

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Frontiers of Optoelectronics 2009年第4期2卷 442-445页

作者： Cao MIAO Hai LU dunjun chen Rong ZHANG Youdou ZHENG Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials Department of Physics Nanjing University

In this study, we fabricated and characterized an InGaN/GaN multi-quantum-well(MQW)-based p-n junction photodetector(PD) for voltage-selective lightemitting and photo-detective applications. The photodetector exhibits a cutoff wavelength at around 460 nm which is close to its electroluminescence(EL) peak position. The rejection ratio was determined to be more than three orders of magnitude. Under zero bias, the responsivity of the device peaks at 371 nm, with a value of 0.068 A/W, corresponding to a 23% quantum *** overall responsivity gradually rises as a function of reverse bias, which is explained by the enhanced photocarrier collection efficiency.

关键词： GaN multi-quantum-well (MQW) photodetector (PD) light emitting diode (LED)

Reverse leakage current in AlGaN-based ultraviolet light-emitting diodes

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Chinese Science Bulletin 2014年第12期59卷 1276-1279页

作者： Rong Jiang Dawei Yan Hai Lu Rong Zhang dunjun chen Youdou Zheng Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials and School of Electronic Science and Engineering Nanjing University Department of Electronic Engineering Jiangnan University

The reverse leakage characteristics of AlGaNbased ultraviolet light-emitting diodes fabricated on sapphire substrate are studied by temperature-variable current–voltage(I–V)measurement from 300 to 450 *** low-reverse bias range(0–0.5 V),the reverse leakage current exhibits tunneling ***,under a more negative reverse bias range([0.5 V),the log(I)–log(V)plots exhibit close-to-linear dependency,which is in good agreement with the transport mechanism of space-charge limited current.A phenomenological leakage current model focusing on electron transmission primarily through continuous defect band formed by linear defects like dislocations is suggested to explain the reverse current–voltage characteristics.

关键词：反向漏电流发光二极管紫外线 AlGaN 空间电荷限制电流缺陷形成电压特性测量特性

High-efficiency green micro-LEDs with GaN tunnel junctions grown hybrid by PA-MBE and MOCVD

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Photonics Research 2021年第9期9卷 1683-1688页

作者： YAOZHENG WU BIN LIU FEIFAN XU YIMENG SANG TAO TAO ZILI XIE KE WANG XIANGQIAN XIU PENG chen dunjun chen HAI LU RONG ZHANG YOUDOU ZHENG Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials School of Electronic Science and EngineeringNanjing UniversityNanjing 210093China Xiamen University Xiamen 361005China

We fabricated p-i-n tunnel junction(TJ)contacts for hole injection on c-plane green micro-light-emitting diodes(micro-LEDs)by a hybrid growth approach using plasma-assisted molecular beam epitaxy(PA-MBE)and metal–organic chemical vapor deposition(MOCVD).The TJ was formed by an MBE-grown ultra-thin unintentionally doped In Ga N polarization layer and an n^(++)∕n^(+)-GaN layer on the activated p^(++)-Ga N layer prepared by *** hybrid growth approach allowed for the realization of a steep doping interface and ultrathin depletion width for efficient inter-band *** to standard micro-LEDs,the TJ micro-LEDs showed a reduced device resistance,enhanced electroluminescence intensity,and a reduced efficiency *** size-independent J-V characteristics indicate that TJ could serve as an excellent current spreading *** these results demonstrated that hybrid TJ contacts contributed to the realization of high-performance micro-LEDs with long emission wavelengths.

关键词： MOCVD MBE GaN

Avalanche mechanism analysis of 4H-SiC n-i-p and p-i-n avalanche photodiodes working in Geiger mode

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Chinese Optics Letters 2021年第9期19卷 104-108页

作者： Linlin Su Weizong Xu Dong Zhou Fangfang Ren dunjun chen Rong Zhang Youdou Zheng Hai Lu School of Electronic Science and Engineering Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210023China School of Electronic and Information Engineering Nanjing University of Information Science&Technology Binjiang CollegeWuxi 214105China

Understanding detailed avalanche mechanisms is critical for design optimization of avalanche photodiodes(APDs).In this work,avalanche characteristics and single photon counting performance of 4H-SiC n-i-p and p-i-n APDs are *** studying the evolution of breakdown voltage as a function of incident light wavelength,it is confirmed that at the deep ultraviolet(UV)wavelength region the avalanche events in 4H-SiC n-i-p APDs are mainly induced by hole-initiated ionization,while electron-initiated ionization is the main cause of avalanche breakdown in 4H-SiC p-i-n ***,at the same dark count rate,the single photon counting efficiency of n-i-p APDs is considerably higher than that of p-i-n *** higher performance of n-i-p APDs can be explained by the larger impact ionization coefficient of holes in *** addition,this is the first time,to the best of our knowledge,to report single photon detection performance of vertical 4H-SiC n-i-p-n APDs.

关键词： 4H-SiC avalanche photodiode electron-initiated ionization hole-initiated ionization

High-efficiency photon-electron coupling resonant emission in GaN-based microdisks on Si

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Chinese Physics B 2020年第8期29卷 276-280页

作者： Menghan Liu Peng chen Zili Xie Xiangqian Xiu dunjun chen Bin Liu Ping Han Yi Shi Rong Zhang Youdou Zheng Kai cheng Liyang Zhang Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials and School of Electronic Science and Engineering Nanjing UniversityNanjing 210093China Enkris Semiconductor Inc.NW-20 Nanopolis Suzhou99 Jinji Avenue 215123China

Resonance effects caused by the photon-electron interaction are a focus of attention in semiconductor optoelectronics,as they are able to increase the efficiency of ***-on-silicon microdisks can provide a perfect cavity structure for such resonance to *** we report GaN-based microdisks with different diameters,based on a standard blue LED wafer on a Si substrate.A confocal photoluminescence spectroscopy is performed to analyze the properties of all ***,we systematically study the effects of radial modes and axial modes of these microdisks on photon-electron coupling efficiency by using three-dimensional finite-difference time-domain *** thick microdisks,photon-electron coupling efficiency is found to greatly depend on the distributions of both the radial modes and the axial modes,and the inclined sidewalls make significant influences on the axial mode *** results are important for realization of high-efficiency resonant emission in GaN-based microcavity devices.

关键词： microdisks photon-electron coupling whispering gallery mode axial mode

Magnesium ion-implantation-based gallium nitride p-i-n photodiode for visible-blind ultraviolet detection

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Photonics Research 2019年第8期7卷 805-811页

作者： WEIZONG XU YATING SHI FANGFANG REN DONG ZHOU LINLIN SU QING LIU LIANG chenG JIANDONG YE dunjun chen RONG ZHANG YOUDOU ZHENG HAI LU School of Electronic Science and Engineering Nanjing University

In this work, a GaN p-i-n diode based on Mg ion implantation for visible-blind UV detection is *** an optimized implantation and annealing process, a p-GaN layer and corresponding GaN p-i-n photodiode are achieved via Mg implantation. As revealed in the UV detection characterizations, these diodes exhibit a sharp wavelength cutoff at 365 nm, high UV/visible rejection ratio of 1.2 × 10~4, and high photoresponsivity of 0.35 A/W, and are proved to be comparable with commercially available GaN p-n photodiodes. Additionally, a localized states-related gain mechanism is systematically investigated, and a relevant physics model of electricfield-assisted photocarrier hopping is proposed. The demonstrated Mg ion-implantation-based approach is believed to be an applicable and CMOS-process-compatible technology for GaN-based p-i-n photodiodes.

关键词： PF GaN visible-blind ultraviolet detection

基于SIMULINK的某型涡喷发动机转速控制系统研究

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微计算机信息 2005年第4期21卷 7-8页

作者：段翀谢寿生陈敦军陕西西安空军工程大学工程学院机械工程系

以某型涡喷发动机及其主燃油系统的机械液压式调节器为研究对象,在考虑其控制规律的前提下,建立了转速控制系统及其各部件的数学模型.根据所建立的数学模型,利用SIMULINK仿真工具对转速控制系统进行了仿真研究.研究结果表明该转速控制... 详细信息

以某型涡喷发动机及其主燃油系统的机械液压式调节器为研究对象,在考虑其控制规律的前提下,建立了转速控制系统及其各部件的数学模型.根据所建立的数学模型,利用SIMULINK仿真工具对转速控制系统进行了仿真研究.研究结果表明该转速控制系统满足了实际要求,同时本文为主燃油系统的进一步改进提供了基础.

关键词：涡喷发动机主燃油系统转速控制系统数学模型仿真