宽带隙半导体材料光电性能的测试  

Characteristics of Optoelectronic Measurement for Wide Band-Gap Semiconductor Materials

作　　者：郭媛[1] 陈鹏[1,2] 孟庆芳[1] 于治国[1] 杨国锋[1] 张荣[1] 郑有炓[1] 

机构地区：[1]南京大学电子科学与工程学院江苏省光电信息功能材料重点实验室,南京210093 [2]南京大学扬州光电研究院,江苏扬州225009

出　　处：《半导体技术》2011年第11期817-820,共4页Semiconductor Technology

基　　金：国家重点基础研究发展规划(2011CB301900);国家高技术研究发展规划(2009AA03A198);国家自然科学基金(60990311;60721063;60906025;60936004;60731160628;60820106003);江苏省自然科学基金(BK2008019;BK2010385;BK2009255;BK2010178);南京大学扬州光电研究院研发基金(2008001)

摘　　要：主要通过光致发光的实验手段,研究分析了在自支撑GaN衬底上生长的InGaN/GaN多量子阱(InGaN/GaN MQW)有源层中的载流子复合机制,实验中发现多量子阱的光致发光光谱中有一个与有源区中的深能级相关的额外的发光峰。在任何温度大功率激发条件下,自由激子的带边复合占主导地位,并且带边复合的强度随温度或激发功率的下降而减弱;在室温以下小功率激发条件下,局域化能级引入的束缚激子复合占主导地位,其复合强度随温度的下降而单调上升,随激发功率的下降而上升。带边复合在样品温度上升或者激发功率变大时发生蓝移,而局域的束缚激子复合辐射的峰值波长,随样品温度和激发功率的变化没有明显变化。Through the experimental approach of photoluminescence, the recombination mechanism of carriers in the active layer of InGaN/GaN multi-quantum well （ InGaN/GaN MQW） grown on the free-standing GaN substrate was investigated and analyzed. An extra photoluminescence peak related to the deep-level states in the active region was observed in the experiment. Under the condition of high power excitation at any temperatures, the recombination of free excitons dominates, and further recombination intensity weakens with the temperature or excitation power decreased. While under the condition of low power at lower temperatures than room temperature, the recombination of bound excitons introduced by the localized states dominates the photoluminescence, and the recombination intensity increases monotonously with the temperature and excitation power decreased. Blue shift appears in the band edge recombination when the sample temperature raises or excitation power enlarges, and the peak wavelength of the localized bound excitons recombination has no obvious change with the sample temperature and excitation power.

关 键 词：光致发光 深能级 自由激子 束缚激子 多量子阱 蓝移 

分 类 号：TN304.2[电子电信—物理电子学]