近紫外波段NEA GaN阴极响应特性的研究  

A study of spectral response for reflection-mode GaN photocathodes in UVA band

作　　者：郝广辉[1] 常本康[1] 陈鑫龙[1] 王晓晖[1] 赵静[1] 徐源[1] 金睦淳[1] 

机构地区：[1]南京理工大学电子工程与光电技术学院,南京210094

出　　处：《物理学报》2013年第9期446-450,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60871012)资助的课题~~

摘　　要：为了深入理解近紫外波段NEAGaN阴极的光谱响应特性,在超高真空系统中对MOCVD生长的不同发射层厚度和掺杂浓度的三个样品进行激活实验,并在线测试样品光谱响应.利用反射式GaN阴极量子效率公式和最小二乘法对入射光波长为0.25—0.35μm之间的阴极响应量子效率实验数据进行拟合,分别得到后界面复合速率和拟合直线L的斜率,并使用量子效率公式对入射光波长为0.35μm时的反射式GaN阴极光谱响应量子效率进行仿真.结果表明,后界面复合速率和直线L的斜率都能很好地反映GaN阴极的响应性能,当GaN阴极后界面复合速率小于105cm/s,发射层的厚度取0.174—0.212μm时,阴极光谱响应性能最好.In order to understand the spectral response characteristic of the NEA GaN photocathodes at UVA band, three samples grown by MOCVD with different emission layer thickness and doping concentration were activated in the ultra-high vacuum system, and their spectral response were tested online. We fit the experimental quantum efficiency with illumination wavelength between 0.25—0.35 μm by the use of reflection-mode GaN photocathode quantum efficiency formula and the least square approximation method. The back-interface compound rate and the slope of fitting line L are gained and the reflection-mode GaN photocathodes quantum efficiency is simulated with incident light wavelength at 0.35 μm. The results show that the back-interface compound rate and the slope of the fitting line L can reflect GaN photocathode response performance. When the back-interface compound rate of GaN photocathode is less than 105 cm/s and the thickness of the emission layer is set between 0.174—0.212 μm, the photocathode has optimal spectral response performance.

关 键 词：反射式GaN 势垒 最小二乘法 后界面缺陷 

分 类 号：TN304.055[电子电信—物理电子学]