辐射与发光 发光与发光器件

TN312.8 2006042820GaN基发光二极管的可靠性研究进展=Research and pro-gress in reliability of GaN-based LED[刊,中]/艾伟伟(北京工业大学光电子技术实验室.北京(100022)) ,郭霞…∥半导体技术.—2006 ,31(3) .—161-165从封装材料退化、金属的电迁移、p型欧姆接触退化、深能级与非辐射复合中心增加等方面介绍了GaN基LED的退化机理以及提高器件可靠性的措施,并对GaN基LED的应用前景进行了展望。图5参23(于晓光)TN312.8 2006042821空间交会对接标志灯发光器件的选择与分析=Selectionand analyses for the luminous devices of …     

光学材料 发光材料、荧光材料

O472.3 2006043640内建电场对GaN/AlGaN单量子点发光性质的影响=In-fluence of built-in electric field onluminescent properties ofself-formed single GaN/AlxGa1 -xNquantumdots[刊,中]/危书义(河南师范大学物理与信息工程学院.河南,新乡(453007)) ,赵旭…∥液晶与显示.—2006 ,21(2) .—139-144在有效质量近似和变分原理的基础上,考虑量子点的三维约束效应,研究了GaN/Al GaN单量子点发光性质随量子点结构参数(量子点高度L和量子点半径R)的变化。结果表明,内建电场对GaN/Al GaN单量子点的发光波长和激子基态振子强度等发光性…     

发光与发光器件

TN312.8 2004010015 MOCVD生长InGaN/GaN MQW紫光LED=InGaN/GaNMQW violet-LED grown by LP-MOCVD[刊,中]/李忠辉(北京大学物理学院,介观物理国家重点实验室,宽禁带半导体研究中心.北京(100871)),杨志坚…∥发光学报.—2003,24(1).—107-109 利用LP-MOCVD系统生长了InGaN/GaN MQW紫     

辐射与发光 发光与发光器件

TN312．8 2006064817 GaN基功率型LED芯片散热性能测试与分析=Thermal dispersion of GaN-based power LEDs[刊,中]/钱可元(清华大学深圳研究生院半导体照明实验室。广东,深圳(518055)),郑代顺…//半导体光电．—2006,27(3)．—236—239与正装LED相比,倒装焊芯片技术在功率型LED的散热方面具有潜在的优势。对各种正装和倒装焊功率型     

辐射与发光 发光与发光器件

TN312．8 2005053215 GaN基发光二极管芯片提取效率的研究=Study on light extraction efficiency of GaN-based light-emitting diode chips[刊,中]／申屠伟进(清华大学电子工程系,集成光电 子学国家重点联合实验室．北京(100084)),胡飞…∥光电 子·激光．-2005,16(4)．-384-389 基于蒙特卡罗方法模拟分析了限制GaN基发光二极 管(LEDs)芯片光提取效率的主要因素。结果表明,GaN 与蓝宝石之间的较大折射率差别严重限制了芯片光提取 效率的提高,通过蓝宝石背面出光比通过p型GaN层的 正面出光的芯片光提取效率至少高20％;同时,低GaN光 吸收系数、高电极反射率以及环氧树脂封装可以有效地增 加芯片光提取效率,并且LEDs芯片尺寸在400μm以下 时光提取效率较高。图6表3参13(严寒)     

辐射与发光 发光与发光器件

TN312.8 2006031822白光LED的加速老化特性=Characteristics of the acceler-ated aging white LEDs[刊,中]/林亮(北京大学物理学院,人工微结构与介观物理国家重点实验室.北京(100871)) ,陈志忠…∥发光学报.—2005 ,26(5) .—617-621对两组GaN基白光发光二极管(LED)进行了对比温度加速老化实验,环境温度分别是80 ,100 ℃。随着老化温度的升高,电流-电压(I-V)曲线的隧道电流段、扩散电流以及反向漏电电流段均增加,而串联电阻段则变化较小,这是位错密度升高和金属杂质沿着螺旋位错聚集及移动的结果;电容-电压(C-V)曲线中反向偏压下电…     

发光与发光器件

TN312.8 2004031629 干涉效应对有机发光器件输出的影响=Influence of interference on organic electroluminescence outputs[刊,中]/徐洪光(东南大学电子工程系.江苏,南京(210096)),孟瑞平…∥光电子·激光.—2003,14(9).—905-908     

Influences of stress on the properties of GaN/InGaN multiple quantum well LEDs grown on Si(111) substrates

The influences of stress on the properties of In GaN/GaN multiple quantum wells(MQWs) grown on silicon substrate were investigated.The different stresses were induced by growing In GaN and Al GaN insertion layers(IL) respectively before the growth of MQWs in metal–organic chemical vapor deposition(MOCVD) system.High resolution x-ray diffraction(HRXRD) and photoluminescence(PL) measurements demonstrated that the In GaN IL introduced an additional tensile stress in n-GaN,which released the strain in MQWs.It is helpful to increase the indium incorporation in MQWs.In comparison with MQWs without the IL,the wavelength shows a red-shift.Al GaN IL introduced a compressive stress to compensate the tensile stress,which reduces the indium composition in MQWs.PL measurement shows a blue-shift of wavelength.The two kinds of ILs were adopted to In GaN/GaN MQWs LED structures.The same wavelength shifts were also observed in the electroluminescence(EL) measurements of the LEDs.Improved indium homogeneity with In GaN IL,and phase separation with Al GaN IL were observed in the light images of the LEDs.     

Fabrication and characterization of one-port surface acoustic wave resonators on semi-insulating GaN substrates

One-port surface acoustic wave resonators(SAWRs) are fabricated on semi-insulating high-quality bulk GaN and GaN film substrates, respectively. The semi-insulating GaN substrates are grown by hydride vapor phase epitaxy(HVPE)and doped with Fe. The anisotropy of Rayleigh propagation and the electromechanical coupling coefficient in Fe-doped GaN are investigated. The difference in resonance frequency between the SAWs between [1120] GaN and [1100] GaN is about 0.25% for the Rayleigh propagation mode, which is smaller than that of non-intentionally doped GaN film(~1%)reported in the literature. The electromechanical coupling coefficient of Fe-doped GaN is about 3.03%, which is higher than that of non-intentionally doped GaN film. The one-port SAWR fabricated on an 8-μm Fe-doped GaN/sapphire substrate has a quality factor of 2050, and that fabricated on Fe-doped bulk GaN has a quality factor as high as 3650. All of our results indicate that high-quality bulk GaN is a very promising material for application in SAW devices.     

Threading dislocation density comparison between GaN grown on the patterned and conventional sapphire substrate by high resolution X-ray diffraction

GaN epifilms are grown on the patterned sapphire substrates (PSS) (0001) and the conventional sapphire substrates (CSS) (0001) by metal-organic chemical vapor deposition (MOCVD) using a novel two-step growth. High resolution X-ray diffraction (HR-XRD) is used to investigate the threading dislocation (TD) density of the GaN epifilms. The TD density is calculated from the ω-scans full width at half maximum (FWHM) results of HR-XRD. The edge dislocation destiny of GaN grown on the PSS is 2.7×108 cm-2, which is less than on the CSS. This is confirmed by the results of atomic force microscopy (AFM) measurement. The lower TD destiny indicates that the crystalline quality of the GaN epifilms grown on the PSS is improved compared to GaN epifilms grown on the CSS. The residual strains of GaN grown on the PSS and CSS are compared by Raman Scattering spectra. It is clearly seen that the residual strain in the GaN grown on PSS is lower than on the CSS.     

制膜技术与装置

O484.12007010582δ掺杂对Si衬底GaN蓝光LED外延膜性能的影响研究=Effect ofδ-doping on performance of GaN blue LED epi-taxial fil ms on Si substrates[刊,中]/程海英(南昌大学教育部发光材料与器件工程研究中心.江西,南昌(330047)),方文卿…//光学学报.—2006,26(8).—1269-1273用X射线衍射方法通过不同晶面的ω扫描测试,分析了Si衬底GaN蓝光LED外延膜中n-型层δ掺杂Si处理对外延膜结晶性能的影响。报道了Si衬底GaN外延膜系列晶面的半峰全宽(FWHM)值。通过使用晶格-旋转(Lattice-rotation)模型拟合,计算出样品的螺位错密…     

Roles of V/III ratio and mixture degree in GaN growth: CFD and MD simulation study

To understand the mechanism of Gallium nitride (GaN) film growth is of great importance for their potential applica- tions. In this paper, we investigate the growth behavior of the GaN film by combining computational fluid dynamics (CFD) and molecular dynamics (MD) simulations. Both of the simulations show that V/III mixture degree can have important impacts on the deposition behavior, and it is found that the more uniform the mixture is, the better the growth is. Besides, by using MD simulations, we illustrate the whole process of the GaN growth. Furthermore, we also find that the V/III ratio can affect the final roughness of the GaN film. When the V/III ratio is high, the surface of final GaN film is smooth. The present study provides insights into GaN growth from the macroscopic and microscopic views, which may provide some suggestions on better experimental GaN preparation.     

High-Quality and Strain-Relaxation GaN Epilayer Grown on SiC Substrates Using AIN Buffer and AlGaN Interlayer

We study the effect of the AlGaN interlayer on structural quality and strain engineering of the GaN films grown on SiC substrates with an AIN buffer layer. Improved structural quality and tensile stress releasing are realized in unintentionally doped GaN thin films grown on 6 H—SiC substrates by metal organic chemical vapor deposition.Using the optimized AlGaN interlayer, we find that the full width at half maximum of x-ray diffraction peaks for GaN decreases dramatically, indicating an improved crystalline quality. Meanwhile, it is revealed that the biaxial tensile stress in the GaN film is significantly reduced from the Raman results. Photoluminescence spectra exhibit a shift of the peak position of the near-band-edge emission, as well as the integrated intensity ratio variation of the near-band-edge emission to the yellow luminescence band. Thus by optimizing the AlGaN interlayer,we could acquire the high-quality and strain-relaxation GaN epilayer with large thickness on SiC substrates.     

薄膜光学 光学薄膜参数测试

O484.5 2006043401GaN薄膜表面缺陷密度的提取=Density extraction of de-fects for GaNfil msurface[刊,中]/王俊平(西安电子科技大学微电子学院.陕西,西安(710071)) ,任春丽…∥微电子学与计算机.—2006 ,23(3) .—194-197通过对若干幅GaN薄膜缺陷图像的分析,提出一种GaN薄膜缺陷密度的提取方法。该方法首先采用阈值分割法二值化背影复杂的GaN薄膜表面图像;然后基于数学形态学方法提取出薄膜表面缺陷的密度;最后给出了薄膜表面缺陷粒径的分布模型。实验结果表明,此方法使GaN薄膜表面缺陷提取简单且易于测量,为分析缺陷原因提高薄膜…     

Highly Sensitive Detection of Deoxyribonucleic Acid Hybridization Using Au-Gated AlInN/GaN High Electron Mobility Transistor-Based Sensors

Gallium nitride-(GaN) based high electron mobility transistors(HEMTs) provide a good platform for biological detection. In this work, both Au-gated AlInN/GaN HEMT and AlGaN/GaN HEMT biosensors are fabricated for the detection of deoxyribonucleic acid(DNA) hybridization. The Au-gated AlInN/GaN HEMT biosensor exhibits higher sensitivity in comparison with the AlGaN/GaN HEMT biosensor. For the former, the drain-source current(V_(DS) = 0.5 V) shows a clear decrease of 69μA upon the introduction of 1μmolL~(-1)(μM) complimentary DNA to the probe DNA at the sensor area, while for the latter it is only 38μA. This current reduction is a notable indication of the hybridization. The high sensitivity can be attributed to the thinner barrier of the AlInN/GaN heterostructure, which makes the two-dimensional electron gas channel more susceptible to a slight change of the surface charge.     

Improved crystal quality of GaN film with the in-plane lattice-matched In_(0.17)Al_(0.83)N interlayer grown on sapphire substrate using pulsed metal organic chemical vapor deposition

We report on an improvement in the crystal quality of GaN film with an In0.17Al0.83N interlayer grown by pulsed metal–organic chemical vapor deposition, which is in-plane lattice-matched to GaN films. The indium composition of about 17% and the reductions of both screw and edge threading dislocations(TDs) in GaN film with the InAlN interlayer are estimated by high resolution X-ray diffraction. Transmission electron microscopy(TEM) measurements are employed to understand the mechanism of reduction in TD density. Raman and photoluminescence measurements indicate that the InAlN interlayer can improve the crystal quality of GaN film, and verify that there is no additional residual stress induced into the GaN film with InAlN interlayer. Atomic force microscopy measurement shows that the InAlN interlayer brings in a smooth surface morphology of GaN film. All the results show that the insertion of the InAlN interlayer is a convenient method to achieve excellent crystal quality in GaN epitaxy.     

Effect of Si doping in wells of AlGaN/GaN superlattice on the characteristics of epitaxial layer

An AlGaN/GaN superlattice grown on the top of a GaN buffer induces the broadening of the full width at half maximum of (102) and (002) X-ray diffraction rocking curves. With an increase in the Si-doped concentration in the GaN wells, the full width at half maximum of the (102) rocking curves decreases, while that of the (002) rocking curves increases. A significant increase of the full width at the half maximum of the (002) rocking curves when the doping concentration reaches 2.5 × 1019 cm-3 indicates the substantial increase of the inclined threading dislocation. High level doping in the AlGaN/GaN superlattice can greatly reduce the biaxial stress and optimize the surface roughness of the structures grown on the top of it.     

Synthesis and characterization of β-Ga_2O_3@GaN nanowires

In this work, we prepared the β-Ga_2O_3@GaN nanowires(NWs) by oxidizing GaN NWs. High-quality hexagonal wurtzite GaN NWs were achieved and the conversion from GaN to β-Ga_2O_3 was confirmed by x-ray diffraction, Raman spectroscopy and transmission electron microscopy. The effect of the oxidation temperature and time on the oxidation degree of GaN NWs was investigated systematically. The oxidation rate of GaN NWs was estimated at different temperatures.     

溅射制备纳米晶GaN∶Er薄膜的室温发光特性

利用直流磁控共溅射方法制备了GaN:Er薄膜.X射线衍射结果显示薄膜为纳米多晶结构,根据谢乐公式,计算得到了GaN薄膜晶粒的平均大小为58nm;透射电子显微镜结果显示为非晶基质中镶嵌了GaN纳米颗粒,尺寸在6—8nm之间;紫外可见谱结果表明在500—700nm的可见光范围内,薄膜的平均透过率大于80%,在紫外可见谱基础上,利用Tauc公式计算得到了纳米晶GaN薄膜的光学带隙为322eV;最后,测量了GaN:Er薄膜的室温光致发光谱,获得了Er³⁺离子在554nm处的强烈绿光发射. 关键词： 纳米晶GaN薄膜 3+掺杂')" href="#">Er³⁺掺杂 光学带隙 光致发光     

GaN hexagonal pyramids formed by a photo-assisted chemical etching method

A series of experiments were conducted to systematically study the effects of etching conditions on GaN by a con-venient photo-assisted chemical （PAC） etching method. The solution concentration has an evident influence on the surface morphology of GaN and the optimal solution concentrations for GaN hexagonal pyramids have been identified. GaN with hexagonal pyramids have higher crystal quality and tensile strain relaxation compared with as-grown GaN. A detailed anal- ysis about evolution of the size, density and optical property of GaN hexagonal pyramids is described as a function of light intensity. The intensity of photoluminescence spectra of GaN etched with hexagonal pyramids significantly increases compared to that of as-grown GaN due to multiple scattering events, high quality GaN with pyramids and the Bragg effect.