GaN基p-i-n和肖特基紫外探测器的响应光谱及暗电流特性

研究了p-i-n型和肖特基型Ga N基紫外探测器的响应光谱和暗电流特性。实验发现,随着p-Ga N层厚度的增加,p-i-n型紫外探测器的响应度下降,并且在短波处下降更加明显。肖特基探测器的响应度明显比pi-n结构高,主要是由于p-Ga N层吸收了大量的入射光所致。肖特基型紫外探测器的暗电流远远大于p-i-n型紫外探测器的暗电流,和模拟结果基本一致,主要是肖特基型探测器是多子器件,而p-i-n型探测器是少子器件。要制备响应度大、暗电流小的高性能Ga N紫外探测器,最好采用p-Ga N层较薄的p-i-n结构。

Spectral Response and Dark Current of p-i-n Type and Schottky Barrier GaN-based Ultraviolet Detectors

The spectral response and dark current of p-i-n type and Schottky barrier GaN-based ul-traviolet detectors are investigated. It is found that the responsivity of p-i-n detectors decreases with increasing thickness of p-GaN layer in p-i-n structure detectors , and the downward trend of respons-ivity is more pronounced at shorter wavelength of incident light . The responsivity of the Schottky barrier detector is obviously higher than that of the p-i-n structure, mainly because a lot of incident photons are absorpted in the p-GaN layer. The dark current of Schottky barrier ultraviolet detectors is far larger than the p-i-n ultraviolet detectors, and the results are basically consistent with the sim-ulations, mainly because the Schottky detectors are majority carrier devices, and p-i-n detectors are minority carrier devices. To fabricate high performance GaN ultraviolet detectors, it is better to em-ploy p-i-n structure with very thin p-GaN layer.