650纳米谐振腔发光二极管外延生长及性能研究

采用金属有机化学气相淀积（MOCVD）方法生长了波长为650nm的谐振腔发光二极管（RCLED）。为提高界面生长质量,降低压降,采用AlGaInP材料系制作上DBRs。利用光致发光谱（PL）与电致发光谱（EL）研究了其发光特性。得到的器件在20mA注入电流下光功率平均为0.5mW,压降2.2V,光谱半峰宽（FWHM）约10nm。     

MOCVD生长双波长发光二极管

根据白光照明和可变换波长的光通信中对单芯片双波长发光二极管(LED)要求,在分析了反向偏置隧道结性质的基础上,设计了用反向偏置隧道结连接两个有源区的单芯片双波长LED,用金属有机化学气相沉积技术(MOCVD)在GaAs衬底上一次外延生长了同时发射两种波长的LED,其包含一个AlGaInP量子阱有源区和一个GaInP量子阱有源区,两个有源区由隧道结连接;通过后工艺制备了双波长LED器件,在20mA电流注入下,可以同时发射626nm和639nm两种波长,光强是127mcd,正向电压是4.17V。与传统的单有源区LED进行对比表明,双波长LED有较强的光强;对比单有源区LED的2.08V正向电压,考虑到双波长LED包含隧道结和两个有源区,隧道结上的压降很小。     

LP-MOCVD法制作n-ZnO/p-Si异质结及其电致发光研究

采用低压-金属有机化学气相沉积法(LP-MOCVD)在(100)p-Si衬底上制备未掺杂n型ZnO薄膜,并制作了相应的n-ZnO/p-Si异质结器件.通过X射线衍射(XRD)、光致发光(PL)光谱和霍尔测试分别研究了所制备薄膜的结构、光学和电学特性.得到具有较高质量的n型ZnO薄膜.在室温条件下,测得了该类异质结器件正向注入电流下可见光和近红外区域的电致发光(EL).     

高亮度AIGalnP红光发光二极管

对用于提高AlGaInP红光发光二极管(LED)出光效率的分布布拉格反射镜(DBR)和增透膜进行了分析,用金属有机物化学气相沉积(MOCVD)生长了包含DBR和增透膜的LED,在20mA注入电流下,LED的峰值波长为623nm,光强达到200mcd,输出光功率为2.14mW。与常规的LED相比,光强和输出光功率有很大的提高。     

高亮度AlGaInP红光发光二极管

对用于提高AlGaInP红光发光二极管(LED)出光效率的分布布拉格反射镜(DBR)和增透膜进行了分析,用金属有机物化学气相沉积(MOCVD)生长了包含DBR和增透膜的LED,在20 mA注入电流下,LED的峰值波长为623 nm,光强达到200 mcd,输出光功率为2.14 mW.与常规的LED相比,光强和输出光功率有很大的提高.     

一种利用发光光谱估计LED正向电压的方法

提出了一种通过发光光谱估计发光二极管(LED)正向电压的方法。推导了LED正向电压与结温的关系,探讨了利用发光光谱估计结温的方法,从而建立了发光光谱和正向电压的联系。本文方法不需要直接测量结温和理想因子等参数,只由发光光谱就可得到较为准确的LED正向电压值。实验结果表明,正向电压的光谱估计值和实际测量值能够较好的吻合。     

影响AlInGaP LED光致发光与电致发光谱的决定性因素

对AlInGaP红色发光二极管(LED)芯片的发光特性进行了测试分析,在注入强度相等的条件下,EL与PL形状相似,但存在差异,对其光致发光(PL)和电致发光(EL)特性进行了测试分析,研究结果表明,EL与PL有着相同的产生机理,影响其发光谱的因素完全相同;发光光谱之间的差异并不是注入方式的差异,而是源于载流子的不同注入方式给LEDpn结温度带来的不同影响。     

InP基MOCVD及MBE外延生长HBT的制备与分析

设计并研制了用于光电集成(OEIC)的InP基异质结双极晶体管(HBT),介绍了工艺流程及器件结构。分别采用金属有机化学气相沉积(MOCVD)及分子束外延(MBE)生长的外延片,并在外延结构、工艺流程相同的条件下,对两种生长机制的HBT直流及高频参数进行和分析。结果表明,采用MOCVD生长的InP基HBT,直流增益为30倍,截止频率约为38GHz;MBE生长的HBT,直流增益达到100倍,截止频率约为40GHz。这表明,MBE生长的HBT外延层质量更高,在相同光刻条件下,所对应的HBT器件的性能更好。     

生长停顿改善MOCVD生长InGaN/GaN多量子阱的特性

利用金属有机物化学气相淀积(MOCVD)生长了InGaN/GaN多量子阱(MQWs)结构,研究了生长停顿对InGaN/GaN MQWs特性的影响.结果表明,采用生长停顿,可以改善MQWs界面质量,提高MQWs的光致发光(PL)与电致发光(EL)强度;但生长停顿的时间过长,阱的厚度会变薄,界面质量变差,不仅In组分变低,富In的发光中心减少,而且会引入杂质,致使EL强度下降.     

表面粗化高空穴浓度InGaN:Mg性能及其发光二极管应用

利用金属有机物化学气相淀积(MOCVD)技术在蓝宝石衬底上生长了InGaN:Mg薄膜,对不同源流量InGaN:Mg材料特件进行了研究.光学和电学特性观测表明,当外延生长温度在760℃,三甲基铟(TMIn)摩尔流量不变时,随CP2Mg和Ⅲ族源摩尔比([CP2Mg]/[Ⅲ])增加,当In摩尔成分增加,空穴浓度也线性增加;当...     

Epitaxy and Characteristics of Resonant Cavity LEDs at 650 nm

Resonant-cavity light-emitting diodes (RCLED) at 650 nm wavelength were grown by metal organic chemical vapor deposition. In order to improve the interface quality and reduce the device voltage, an AlGaInP material system has been chosen to grow the top DBRs. The emission properties of the RCLED were characterized by measuring PL and EL spectra. The average emission power of the device is 0.5 mW at 20 mA and 2.2 V, and its spectrum full width at half maximum is about 10 nm.     

Optical properties of InN films grown by MOCVD

By means of optical absorption, photolumines-cence (PL), Raman scattering and ellipsometry, optical properties of indium nitride (InN) films grown by metal organic chemical vapor deposition (MOCVD) are investigated. Through absorption and PL measurements, it is proven that the band gap of high quality InN is 0.68 eV, which agrees with the recently reported value, 0.7 eV. By analysis of the Raman scattering spectrum, the comparatively low background concentration of electron results in a smaller band gap value. The transition energy of wurtzite InN at critical point is determined by ellipsometric spectra. In addition, the complex refractive index of InN at energy ranging from 0.65 to 4.0 eV is obtained for the first time.     

GaN基材料及其外延生长技术研究

介绍了GaN基材料的基本特性、三种主要外延生长技术(MOCVD、MBE、HVPE)、衬底材料的选择及缓冲层技术;分析得出目前存在的GaN体单晶技术不完善、外延成本高、衬底缺陷及接触电阻大等主要问题制约了研究的进一步发展;指出今后的研究重点是完善GaN体单晶材料的生长工艺,以利于深入研究GaN的物理特性及有效地解决衬底问题,研究缓冲层的材料、厚度、组分等以提高GaN薄膜质量。     

Effect of growth pressure on indium incorporation during the growth of InGaN by MOCVD

The effect of the growth pressure on the In incorporation in InGaN thin films, grown by metalorganic chemical vapor deposition (MOCVD) have been investigated. The InGaN thin films were grown by varying the growth pressures, while maintaining all other growth parameters constant. Photoluminescence and high resolution x-ray diffraction (XRD) measurements showed that the In incorporation in the InGaN thin film was drastically increased with decreasing growth pressures. XRD analysis also revealed that the In concentration in the films was increased by 7.5% as the growth pressure was decreased from 250 torr to 150 torr. This can be attributed to the enhanced mass transportation of precursor gases through the boundary-layer on the substrate in the MOCVD system.     

可见光共振腔发光二极管原理及发展概况

共振腔发光二极管(RCLED)是一种新型发光二极管(LED)结构,同时具备了传统LED和垂直腔面激光器(VCSEL)两者的优点,具有良好的应用价值和广阔的市场前景.介绍了RCLED的基本原理和结构.以及器件结构的设计要点,指出发射波长650 nm的RCLED在塑料光纤(POF)通信领域的应用优势,可以作为民用数据通讯系统用光发射器件的首选.对近年来RCLED尤其是红光波长范围的RCLED发展情况进行了概述,同时指出我国在这一领域的研究现状.     

Surface photoabsorption monitoring of the growth of GaAs and InGaAs at 650°C by MOCVD

By monitoring the cyclic behavior of surface photoabsorption (SPA) reflectance changes during the growth of GaAs at 650°C and with sufficient H₂ purging time between the supply of trimethylgallium and AsH₃, we have been able to achieve controlled growth of GaAs down to a monolayer. Our results show, as confirmed by photoluminescence (PL) measurements, the possibility of growing highly accurate quantum well heterostructures by metalorganic chemical vapor deposition at conventional growth temperatures. We also present our PL measurements on the InGaAs single quantum wells grown at this temperature by monitoring the SPA signal.     

低压MOCVD生长ZnO单晶薄膜的制备与性质

利用 LP-MOCVD生长技术 ,采用 Zn(C2 H5) 2 作 Zn源和 CO2 作氧源 ,在 (0 0 0 2 )蓝宝石衬底上获得了沿 c轴取向高度一致的 Zn O单晶薄膜。通过对其吸收谱的曲线拟合 ,得到室温下 Zn O薄膜的光学带隙为 3 .2 45e V。在样品的室温光荧光谱 (PL)中观察到对应于带边发射的较强的发光峰 ,对样品中蓝带的产生原因进行了讨论     

Determination of the direction of piezoelectric field in InGaN/GaN multiple quantum-well structures grown by metal-organic chemical vapor deposition

The direction of the piezoelectric field in InGaN/GaN multiple quantum-well (MQW) structures grown by metal-organic vapor deposition (MOCVD) was determined using excitation-power-density variable photoluminescence (PL). By comparing the excitation-power-density dependence of the shift of the PL peak and the change of the full-width at half-maximum (FWHM) of the peak from an InGaN/GaN MQW structure and an InGaN MQW-based light-emitting diode (LED), the piezoelectric field in the InGaN/GaN MQW structures was unambiguously determined to be pointing toward the substrate. This result helps to identify the surface polarity of the LED wafer as Ga-faced.