共查询到20条相似文献,搜索用时 15 毫秒
1.
Nitride-based near-ultraviolet multiple-quantum well light-emitting diodes with AlGaN barrier layers
C. H. Kuo S. J. Chang Y. K. Su L. W. Wu J. K. Sheu T. C. Wen W. C. Lai J. M. Tsai S. C. Chen 《Journal of Electronic Materials》2003,32(5):415-418
The In0.05Ga0.95N/GaN, In0.05Ga0.95N/Al0.1Ga0.9N, and In0.05Ga0.95N/Al0.18Ga0.82N multiple-quantum well (MQW) light-emitting diodes (LEDs) were prepared by metal-organic chemical-vapor deposition. (MOCVD).
It was found that the 20-mA electroluminescence (EL) intensity of the InGaN/Al0.1Ga0.9N MQW LED was two times larger than that of the InGaN/GaN MQW LED. The larger maximum-output intensity and the fact that maximum-output
intensity occurred at a larger injection current suggest that Al0.1Ga0.9N-barrier layers can provide a better carrier confinement and effectively reduce leakage current. In contrast, the EL intensity
of the InGaN/Al0.18Ga0.82N MQW LED was smaller because of the relaxation that occurred in the MQW active region of the sample. 相似文献
2.
研究了GaN/AlGaN异质结背照式p-i-n结构可见盲紫外探测器的制备与性能。GaN/AlGaN外延材料采用金属有机化学气相沉积(MOCVD)方法生长,衬底为双面抛光的蓝宝石,缓冲层为AlN,n型层采用厚度为0.8 μm的Si掺杂Al0.3Ga0.7N形成窗口层,i型层为0.18 μm的非故意掺杂的GaN,p型层为0.15 μm的Mg掺杂GaN。采用Cl2、Ar和BCl3感应耦合等离子体刻蚀定义台面,光敏面面积为1.96×10-3 cm2。可见盲紫外探测器展示了窄的紫外响应波段,响应区域为310~365 nm,在360 nm处响应率最大,为0.21 A/W,在考虑表面反射时,内量子效率达到82%;优质因子R0A为2.00×108 Ω·cm2,对应的探测率D*=2.31×1013 cm·Hz1/2·W-1;且零偏压下的暗电流为5.20×10-13 A。 相似文献
3.
在"日盲段"240~290 nm进行窄波段探测,具有背景干扰小的优势。相比于传统紫外探测器必须协同窄带滤光片工作,AlGaN具有固有窄波段控制和无需制冷两大优点。介绍了基于日盲型AlGaN焦平面器件的紫外相机的软、硬件设计。紫外相机由紫外透射式光学系统,日盲型AlGaN器件,偏置电路及驱动电路,低噪声前放、数据处理及传输单元构成,核心器件AlGaN采用背照式PIN阵列通过铟柱倒焊于硅基电容反馈跨导放大器(CTIA)读出电路的结构。紫外相机的设计指标为:光学口径80 mm,焦距130 mm,像元尺寸50μm,瞬时视场0.4 mrad,总视场3°,积分时间可控,帧率最高可达100帧/s。经初步室内测试,效果良好,对发展日盲型面阵AlGaN应用平台做出了有意义的探索和研究。 相似文献
4.
5.
6.
A simulation of doping and trap effects on the spectral response of AlGaN ultraviolet detectors 总被引:1,自引:1,他引:0
Sidi Ould Saad Hamady 《半导体学报》2012,33(3):034002-4
We study, by means of numerical simulation, the impact of doping and traps on the performance of the “solar blind” ultraviolet Schottky detector based on AlGaN. We implemented physical models and AlGaN material properties taken from the literature, or from the interpolation between the binary materials (GaN and AlN) weighted by the mole fractions. We found that doping and traps highly impact the spectral response of the device, and in particular a compromise in the doping concentration must be reached in order to optimize the spectral response of the detector. These results give us a powerful tool to quantitatively understand the impact of elaboration and processing conditions on photodetector characteristics, and thus identify the key issues for the development of the technology. 相似文献
7.
8.
9.
E. Monroy F. Calle E. Muñoz F. Omnès B. Beaumont P. Gibart 《Journal of Electronic Materials》1999,28(3):240-245
The influence of the photodetection mechanism on the performance of AlGaN ultraviolet (UV) detectors is analyzed by studying
the characteristics of photoconductors and photovoltaic Schottky diodes fabricated on the same samples. The photoconductive
response below the bandgap is not a direct function of the absorption coefficient. Instead, it is amplified by the dominant
photoconductive responsivity mechanism, which is attenuated as the chopping frequency increases. On the contrary, photovoltaic
detectors are characterized by a sharp UV/visible contrast, mainly dependent on the absorption properties of the material.
Thus, these detectors are more suitable for selective UV applications, such as ozone layer monitoring or flame detection. 相似文献
10.
The fabrication of AlGaN/GaN double-channel high electron mobility transistors on sapphire substrates is reported. Two carrier channels are formed in an AlGaN/GaN/AlGaN/GaN multilayer structure. The DC performance of the resulting double-channel HEMT shows a wider high transconductance region compared with single-channel HEMT. Simulations provide an explanation for the influence of the double-channel on the high transconductance region. The buffer trap is suggested to be related to the wide region of high transconductance. The RF characteristics are also studied. 相似文献
11.
正The fabrication of AlGaN/GaN double-channel high electron mobility transistors on sapphire substrates is reported.Two carrier channels are formed in an AlGaN/GaN/AlGaN/GaN multilayer structure.The DC performance of the resulting double-channel HEMT shows a wider high transconductance region compared with single-channel HEMT. Simulations provide an explanation for the influence of the double-channel on the high transconductance region.The buffer trap is suggested to be related to the wide region of high transconductance.The RF characteristics are also studied. 相似文献
12.
13.
基于电荷控制理论,考虑到极化效应和寄生漏源电阻的影响,建立了能精确模拟AlGaN/GaN高电子迁移率晶体管直流I-V特性和小信号参数的解析模型.计算表明,自发极化和压电极化的综合作用对器件特性影响尤为显著,2V栅压下,栅长为1μm的Al0.2Ga0.8N/GaN HEMT获得的最大漏电流为1370mA/mm;降低寄生源漏电阻可以获得更高的饱和电流、跨导和截至频率.模拟结果同已有的测试结果较为吻合,该模型具有物理概念明确且算法简单的优点,适于微波器件结构和电路设计. 相似文献
14.
15.
用Silvaco的ATLAS软件模拟了栅场板参数对AlGaN/GaN HEMT中电场分布的影响.模拟结果表明,场板的加入改变了器件中电势的分布情况,降低了栅边缘处的电场峰值,改善了器件的击穿特性;场板长度(LFP,length of field plate)、场板与势垒层间的介质层厚度t等对电场的分布影响很大.随着LFP的增大、t的减小,栅边缘处的电场峰值Epeak1明显下降,对提高器件的耐压非常有利.通过对相同器件结构处于不同漏压下的情况进行模拟,发现当器件处于高压下时,场板的分压作用更加明显,说明场板结构更适合于制备用作电力开关器件的高击穿电压AlGaN/GaN HEMT. 相似文献
16.
17.
基于静电学分析,得出表面态是电子的一个重要来源.基于这一分析,可以解释已发表的关于二维电子气(2DEC)的大量数据.例如,2DEG密度随着AlGaN层厚度、Al组分的变化的原因.当A10.3Ga0.7N/GaN结构中生长一层5 nm厚的GaN冒层时,2DEG浓度由1.47×1013cm-2减少到1.20×1013cm-2,减少是由于表面类施主态离化减少.由于充分厚的GaN冒层导致GaN/AlGaN/GaN上界面形成二维空穴气(2DHG),所以在超出特定的冒层厚度时2DEG浓度达到饱和. 相似文献
18.
本文论述了AlGaN/GaN双异质结高电子迁移率晶体管的特性,该结构使用Al组分为7%的AlGaN来代替传统的GaN作为缓冲层。Al0.07Ga0.93N缓冲层增加了二维电子气沟道下方的背势垒高度,有效提高了载流子限阈性,从而造成缓冲层漏电的显著减小以及击穿电压的明显提高。对于栅尺寸为0.5100μm,栅漏间距为1μm的器件,AlGaN/GaN 双异质结器件的击穿电压(~100V)是常规单异质结器件的两倍(~50V)。本文中的双异质结器件在漏压为35V、频率为4GHz下,最大输出功率为7.78W/mm,最大功率附加效率为62.3%,线性增益为23dB。 相似文献
19.
20.
正We studied the performance of AlGaN/GaN double heterojunction high electron mobility transistors (DH-HEMTs) with an AlGaN buffer layer,which leads to a higher potential barrier at the backside of the twodimensional electron gas channel and better carrier confinement.This,remarkably,reduces the drain leakage current and improves the device breakdown voltage.The breakdown voltage of AlGaN/GaN double heterojunction HEMTs (~ 100 V) was significantly improved compared to that of conventional AlGaN/GaN HEMTs(~50 V) for the device with gate dimensions of 0.5 x 100μm and a gate-drain distance of 1μm.The DH-HEMTs also demonstrated a maximum output power of 7.78 W/mm,a maximum power-added efficiency of 62.3%and a linear gain of 23 dB at the drain supply voltage of 35 V at 4 GHz. 相似文献