摘要：An accurate measurement of the refractive index is necessary for the optical design of both deep ultraviolet laser diodes and light-emitting diodes. Generally, the refractive indices along different crystallographic axes of anisotropic thin films are measured using variable angle spectroscopic ***, there are still some limitations concerning this method. Here we proposed a potential method to measure the band edge refractive index of wide bandgap semiconductor. An aperiodic oscillation emission phenomenon due to the Fabry-Perot effect was observed in the fluorescence spectrum of an AlN film with a thickness of 1500 nm. Based on the characteristics of the fluorescence spectrum and the definition of Fabry-Perot effect, we obtained the ordinary refractive index of the AlN thin film near the band edge directly. This refractive index measurement method is a supplement to the variable angle ellipsometry,and it is a more direct and effective method for transferred film and thinner samples to measure the fluorescence spectrum.

摘要：对n-p-n型AlGaN/GaN基HBTs的高频特性进行了模拟计算,分析了发射区、基区、集电区的一些材料参数对n-p-n型AlGaN/GaN基HBTs的高频特性的影响.发现基区的设计对频率性能影响很大,减小基区厚度、增大空穴浓度和迁移率将有效提高HBTs的频率性能.

摘要：设计了一种具有双Al N插入层的Al GaN/Al Na/GaN/Al Nb/GaN HEMT结构材料,用以提高沟道对2DEG的限制作用、改善材料的电学性能。采用MOCVD技术生长了该结构,重点研究了第一Al Nb插入层的生长时间对材料表面形貌和电学性能的影响,得到了最佳的Al Nb生长时间介于15~20s。对Al Nb生长时间为15s的样品进行了变温Hall测试,其2DEG迁移率在80K时达8849cm2/V.s,室温下为1967cm2/V.s,面密度始终保持在1.02×1013cm-2左右,几乎不随温度改变。用非接触式方块电阻测试系统测得该样品的方块电阻值为278.3Ω/□,不均匀性为1.95%,说明双Al N插入层的引入对提高HEMT结构材料的电学性能作用明显。