SiO2纳米颗粒对 a-AlGaN 金属-半导体-金属结构紫外探测器的影响

摘要

采用对a-AlGaN表面沉积SiO2纳米颗粒制备工艺得到了金属-半导体-金属(MSM)结构的a-AlGaN紫外探测器.与没有沉积SiO2纳米颗粒的探测器件相比,沉积SiO2纳米颗粒使器件的暗电流下降了一个数量级,峰值光谱响应度提高了近3个数量级,紫外/可见抑制比大于103.%The α-AlGaN Metal-semiconductor-Metal ( MSM) ultraviolet photodetector ( UV-PD) was fabricated, and the effect of SiO2 nanoparticles (SNPs) on its properties was investigated. It was shown that the dark current of the UV-PD with SNPs was more than one order of magnitude lower than that of without SNPs. The peak responsivity was enhanced more than two orders of magnitude after deposition of the SNPs. The SNPs on α-AlGaN MSM UV-PDs usually formed at the termination of screw and mixed dislocations, which acts a role of passivating the carrier transport paths. Surface-deposited SNPs make photogenerated electrons and holes collected easily in two separated contacts, which lead to a higher device property.