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Graphene-driving strain engineering to enable strain-free epitaxy of AlN film for deep ultraviolet light-emitting diode

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Light(Science & Applications) 2022年第5期11卷 808-819页

作者： Hongliang Chang Zhetong Liu Shenyuan yang Yaqi Gao Jingyuan Shan Bingyao Liu Jingyu Sun Zhaolong Chen jianchang yan Zhiqiang Liu Junxi Wang Peng Gao Jinmin Li Zhongfan Liu Tongbo Wei Research and Development Center for Semiconductor Lighting Technology Institute of SemiconductorsChinese Academy of Sciences100083 BeijingChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences100049 BeijingChina Center for Nanochemistry(CNC) Beijing Science and Engineering Center for NanocarbonsBeijing National Laboratory for Molecular SciencesCollege of Chemistry and Molecular EngineeringPeking University100871 BeijingChina Electron Microscopy Laboratory and International Center for Quantum MaterialsSchool of PhysicsPeking University100871 BeijingChina Beijing graphene institute(BGI) 100095 BeijingChina Academy for Advanced Interdisciplinary Studies Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced MaterialsPeking University100871 BeijingChina State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of Sciences100083 BeijingChina

The energy-efficient deep ultraviolet(DUV)optoelectronic devices suffer from critical issues associated with the poor quality and large strain of nitride material system caused by the inherent mismatch of *** this work,we have prepared the strain-free AlN film with low dislocation density(DD)by graphene(Gr)-driving strain-pre-store engineering and a unique mechanism of strain-relaxation in quasi-van der Waals(QvdW)epitaxy is *** DD in AlN epilayer with Gr exhibits an anomalous sawtooth-like evolution during the whole epitaxy *** can help to enable the annihilation of the dislocations originated from the interface between AlN and Gr/sapphire by impelling a lateral two-dimensional growth ***,it can induce AlN epilayer to pre-store sufficient tensile strain during the early growth stage and thus compensate the compressive strain caused by ***,the low-strain state of the DUV light-emitting diode(DUV-LED)epitaxial structure is realized on the strain-free AlN template with ***,the DUV-LED with Gr demonstrate 2.1 times enhancement of light output power and a better stability of luminous wavelength compared to that on bare *** in-depth understanding of this work reveals diverse beneficial impacts of Gr on nitride growth and provides a novel strategy of relaxing the vital requirements of hetero-mismatch in conventional heteroepitaxy.

关键词： sapphire diode strain

Mitigating fast thermal instability by engineered laser sweep in AlN soliton microcomb generation

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Photonics Research 2023年第8期11卷 I0012-I0020页

作者： KEWEI LIU ZIHAO WANG SHUNYU YAO yanAN GUO jianchang yan JUNXI WANG CHANGXI yanG CHENGYING BAO State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentsTsinghua UniversityBeijing 100084China Center for Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Research and Development Center for Solid State Lighting Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

Transient thermal instability represents a significant challenge in generating soliton *** laser sweep can be an efficient method to mitigate thermal instability,but it requires an ultrahigh laser sweep rate for crystalline microresonators with fast thermal ***,we engineer a laser sweep waveform to generate AlNon-sapphire soliton microcombs with an intermediate sweep speed(<30 GHz∕μs).Two laser sweep methods with backward plus forward tuning or two-step backward tuning added after the fast forward laser sweep were demonstrated to stabilize *** the soliton number is found to be useful to stabilize solitons in fast laser *** effectiveness of the methods was numerically *** measurements and simulations also reveal the impacts of different thermal relaxation processes occurring at quite different time scales on thermal *** requirement of the laser sweep protocols is discussed.

关键词： tuning laser sapphire

Deep ultraviolet light-emitting diodes based on a well-ordered AlGaN nanorod array

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Photonics Research 2019年第9期7卷 941-947页

作者： LIANG ZHANG yanAN GUO jianchang yan QINGQING WU YI LU ZHUOHUI WU WEN GU XUECHENG WEI JUNXI WANG JINMIN LI Research and Development Center for Solid State Lighting Institute of SemiconductorsChinese Academy of SciencesBeijing100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing100049China Beijing Engineering Research Center for the3rd Generation Semiconductor Materials and Application Beijing100083China State Key Laboratory of Solid-State Lighting Beijing100083China

The nanorod structure is an alternative scheme to develop high-efficiency deep ultraviolet light-emitting diodes(DUV LEDs). In this paper, we first report the electrically injected 274-nm AlGaN nanorod array DUV LEDs fabricated by the nanosphere lithography and dry-etching technique. Nanorod DUV LED devices with good electrical properties are successfully realized. Compared to planar DUV LEDs, nanorod DUV LEDs present>2.5 times improvement in light output power and external quantum efficiency. The internal quantum efficiency of nanorod LEDs increases by 1.2 times due to the transformation of carriers from the exciton to the free electron–hole, possibly driven by the interface state effect of the nanorod sidewall surface. In addition, the nanorod array significantly facilitates photons escaping from the interior of LEDs along the vertical direction, contributing to improved light extraction efficiency. A three-dimensional finite-different time-domain simulation is performed to analyze further in detail the TE-and TM-polarized photon extraction mechanisms of the nanostructure. Our results demonstrate the nanorod structure is a good candidate for high-efficiency DUV emitters.

关键词： Deep ultraviolet light-emitting diodes based on a well-ordered AlGaN nanorod array AlGaN

Comprehensive study of crystalline AlN/sapphire templates after high-temperature annealing with various sputtering conditions

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Journal of Semiconductors 2020年第12期41卷 94-100页

作者： Wen Gu Zhibin Liu yanan Guo Xiaodong Wang Xiaolong Jia Xingfang Liu Yiping Zeng Junxi Wang Jinmin Li jianchang yan Research and Development Center for Solid-State Lighting Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Beijing Engineering Research Center for the 3rd Generation Semiconductor Materials and Application Beijing 100083China Advanced Ultraviolet Optoelectronics Co.Ltd Changzhi 046000China Key Laboratory of Semiconductor Materials Science Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Youwill Hitech Co.Ltd Beijing 100083China

High-quality AlN/sapphire templates were fabricated by the combination of sputtering and high-temperature(HT)*** influence of sputtering parameters including nitrogen flux,radio frequency power,and substrate temperature on the crystalline quality and surface morphology of annealed AlN films were *** lower substrate temperature,lower power,and lower N2 flux,the full width at half maximum of the X-ray rocking curve for AlN(0002)and(102)were improved to 97.2 and 259.2 arcsec after high-temperature *** happens because the increased vacancy concentration of sputtered AlN films can facilitate the annihilation of dislocations by increasing the recovery rate during HT *** and step-bunching morphologies were clearly observed with optimized sputtering conditions.

关键词： sputter annealing AlN dislocation density

Study of the morphology evolution of AlN grown on nanopatterned sapphire substrate

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Journal of Semiconductors 2019年第12期40卷 130-134页

作者： Zhuohui Wu jianchang yan yanan Guo Liang Zhang Yi Lu Xuecheng Wei Junxi Wang Jinmin Li Research and Development Center for Solid State Lighting Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Beijing Engineering Research Center for the 3rd Generation Semiconductor Materials and Application Beijing 100083China State Key Laboratory of Solid-State Lighting Beijing 100083China

This study focused on the evolution of growth front about AlN growth on nano-patterned sapphire substrate by metal-organic chemical vapor *** substrate with concave cones was fabricated by nano-imprint lithography and wet *** samples with different epitaxy procedures were fabricated,manifesting as two-dimensional growth mode and three-dimensional growth mode,*** results showed that growth temperature deeply influenced the growth modes and thus played a critical role in the coalescence of *** a relatively high temperature,the AlN epilayer was progressively coalescence and the growth mode was *** this case,we found that the inclined semi-polar facets arising in the process of coalescence were{112^-1}*** when decreasing the temperature,the{112^-2}semi-polar facets arose,leading to inverse pyramid morphology and obtaining the three-dimensional growth *** 3 D inverse pyramid AlN structure could be used for realizing 3 D semi-polar UV-LED or facet-controlled epitaxial lateral overgrowth of AlN.

关键词： AlN epitaxial lateral overgrowth growth front evolution 2D and 3D growth modes MOCVD

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通信管道跨越桥梁建筑方式初探

信息网络 2006年第5期 20-22页

作者：严建长陕西省咸阳市电信分公司维护安装部设计所

随着改革的深入,市场经济的完善,城乡经济逐渐形成一体化,道路的同步连接成为完成城乡经济一体化的前提.由于人们对城乡景观认识程度的提高,要求地表障碍越来越少,即诸如通信管线、电力管线、集中供热供气等城市基础设施的管线需要敷设... 详细信息

随着改革的深入,市场经济的完善,城乡经济逐渐形成一体化,道路的同步连接成为完成城乡经济一体化的前提.由于人们对城乡景观认识程度的提高,要求地表障碍越来越少,即诸如通信管线、电力管线、集中供热供气等城市基础设施的管线需要敷设在地下,因而有可能遇到各种管线(包括通信管道)在修建中跨越桥梁的情况.就咸阳市而言,近几年随着西咸(西安-咸阳)一体化、城乡一体化、城市街道绿化、创建文明卫生城市步伐的加快,道路的新建及拓宽改造也跃上了快车道.道路修建会遇到跨越渭河大桥、沣河大桥、白马河大桥、陇海铁路、西宝(西安-宝鸡)高速公路高架桥等桥梁道路等特殊路段的情况.按照城建规划部门的要求,道路两边原有的各种管线全部入地,'谁家孩子谁家抱'即入地费用自理,城建部门提供管线位置图并免收开挖、占道等项行政事业性费用.

关键词：通信管线管道跨越建筑方式桥梁经济一体化城市基础设施城市街道绿化城乡经济城乡一体化市场经济

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市话光接入网选址规划与割接

信息网络 2002年第3期 15-16页

作者：严建长陕西省咸阳市电信实业公司通信工程设计所

城市市话光接入网以其安装简单、施工方便、区域集中、放号迅速得到越来越多电信公司的青睐和广泛应用.但是,由于市内电话用户相对集中、密度较大,形成了相对独立的直接配线区或交接配线区,如果在其中某一高密节点上插入光接入网络单元(... 详细信息

城市市话光接入网以其安装简单、施工方便、区域集中、放号迅速得到越来越多电信公司的青睐和广泛应用.但是,由于市内电话用户相对集中、密度较大,形成了相对独立的直接配线区或交接配线区,如果在其中某一高密节点上插入光接入网络单元(ONU),定会遇到原配线的割接、调整、改号、营业区域重新划分等一系列必须解决的具体问题.对此,笔者结合西部开发、电信先行的特点,浅谈咸阳市电信分公司在ONU选址等方面的做法,供大家参考.

关键词：割接用户号码 ONU 电信网络单元话费光接入

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中国半导体照明发展综述

光学学报 2021年第1期41卷 264-276页

作者：李晋闽刘志强魏同波闫建昌伊晓燕王军喜中国科学院半导体研究所照明研发中心北京100083 中国科学院大学北京100049 北京第三代半导体材料与应用工程技术研究中心北京100083

半导体照明是21世纪初兴起的产业,也是我国第三代半导体材料成功产业化的第一个突破口,技术发展日新月异,是国际高科技领域竞争的焦点之一。目前,我国半导体照明产业已经形成了完整的产业链,功率白光LED、硅基LED和全光谱LED等核心技术... 详细信息

半导体照明是21世纪初兴起的产业,也是我国第三代半导体材料成功产业化的第一个突破口,技术发展日新月异,是国际高科技领域竞争的焦点之一。目前,我国半导体照明产业已经形成了完整的产业链,功率白光LED、硅基LED和全光谱LED等核心技术同步国际,紫外LED、可见光通讯、农业光照和光医疗等创新应用走在世界前列。介绍了我国在半导体照明方面的研究进展,回顾了相关产业的发展情况,并对未来进行了展望。

关键词：材料半导体照明发光二极管氮化物深紫外LED

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“墙洞位置”引起的思考

信息网络 2006年第6期 39-40页

作者：严建长张彦鹏陕西省咸阳市电信分公司客户响应中心

一次,电信公司装机班同志给用户安装宽带,用户要求从户门前右侧打眼入室内,然后沿客厅墙面与顶面的阴角线走到同侧第二间卧室门上面,再通过第二间卧室木门楣进入卧室到指定的计算机桌.而装机班同志则坚持打眼到室内后直接到第一间卧室... 详细信息

一次,电信公司装机班同志给用户安装宽带,用户要求从户门前右侧打眼入室内,然后沿客厅墙面与顶面的阴角线走到同侧第二间卧室门上面,再通过第二间卧室木门楣进入卧室到指定的计算机桌.而装机班同志则坚持打眼到室内后直接到第一间卧室、第二间卧室的墙面与顶面的阴角线走到指定的计算机桌.为这两种方案的确定,双方争执不下,各说各的理.最后,装机班的同志大声说道:'就按照你(用户)说的(位置)打眼.但是,我们只负责把网线放通,网络正常就行,网线你自己固定.'用户默默地接受了.

关键词：用户要求电信公司计算机装机服务理念