P-I-N型GaN紫外探测器的正向电流输运  

Forward Current Transport in P-I-N Type GaN Ultraviolet Detector

作　　者：李金晓 刘震 叶思灿 卢澳 华文渊 党宁 闫大为 Li Jinxiao;Liu Zhen;Ye Sican;Lu Ao;Hua Wenyuan;Dang Ning;Yan Dawei(Engineering Research Center of Internet of Things Technology Applications,Department of Electronic Engineering,School of IoT Engineering,Jiangnan University,Wuxi 214122,Jiangsu China)

机构地区：[1]江南大学物联网工程学院电子工程系物联网技术应用教育部工程研究中心,江苏无锡214122

出　　处：《激光与光电子学进展》2023年第23期83-87,共5页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(61504050,11604124,51607022)。

摘　　要：本文在自支撑衬底上制备了P-I-N型GaN紫外探测器,测量并研究了其正向电流输运机制。结果表明,正向电压VF>2 V时,电子扩散电流才开始占主导。有效禁带宽度Eg~2.21 eV远低于理想值,这归因于可导位错引入的能带扰动;当1.35 V<VF<2 V时,理想因子n>2,表明电子缺陷辅助隧穿电流为主要电流分量。电流具有负温度系数,这主要是由电子被激发到能量更高的导带后其有效禁带宽度增大导致的;在VF<0.8 V和0.8 V<VF<1.35 V区间,电流-电压曲线为功率依赖关系,该行为与电子空间电荷限制机制一致。功率因子分别为8和4,由特征温度可得到两种不同的有效能带宽度,分别对应于两种指数衰减的缺陷态分布。In this study,we demonstrate the preparation of P-I-N type GaN ultraviolet(UV)detectors on self-supported substrates,and then investigate their forward current transport mechanisms.The results show that the electron diffusion current starts to dominate only when the forward voltage VF>2 V.Moreover,the effective forbidden bandwidth Eg~2.21 eV is much lower than the ideal value,which can be attributed to the energy band perturbation introduced by the conductive dislocations.An ideal factor n>2 when 1.35 V<VF<2 V indicates that the electron defect-assisted tunneling current is the dominant current component.The current has a negative temperature coefficient,which is primarily caused by the increase in the effective forbidden bandwidth of the electron once it is excited to a higher energy conduction band.In the VF<0.8 V and 0.8 V<VF<1.35 V regions,the current-voltage curves are power dependent;this behavior is consistent with the electron space charge confinement mechanism.The power factors are eight and four,respectively,and two different effective energy bandwidths,corresponding to two exponentially decaying defect state distributions,are obtained from the characteristic temperature.

关 键 词：探测器 GaN探测器 P-I-N型 缺陷辅助隧穿 空间电荷限制电流 

分 类 号：TN36[电子电信—物理电子学]