GaN基雪崩光电二极管及其研究进展

GaN-based avalanche photodiodes and its recent development

越来越多的民用与军事对高灵敏度紫外探测的需求促进了GaN基雪崩光电二极管（APD）的快速发展。雪崩光电二极管工作在高反偏电压状态，器件内部载流子在高场下发生碰撞离化，从而使探测信号产生增益。首先对GaN基雪崩光电二极管的研究进展进行了回顾，然后重点报道了器件的增益最大可达3＆#215;105，介绍了本征层厚度与器件暗电流的关系，简单介绍了正在组建的基于相敏探测的交流增益测试系统，并研究了过剩噪声与调制频率之间的关系，发现在低频波段（30~2 kHz），过剩噪声呈现1/f噪声特性。最后，对盖革模式的雪崩光电二极管的研究进展及应用前景进行了简单介绍。

The investigation of GaN-based avalanche photodiodes（APDs） was motivated by the demand of high sensitivity ultraviolet detectors in numerous civilian and military applications. APDs operate under high reverse bias voltage, and carriers in the device caused impact ionization under high electric fields, as a result, the avalanche multiplication could be obtained. In this paper, reviews were made on the development of GaN-based avalanche photodiodes, the largest value of gain in this work was nearly 3 ＆#215; 105. Relationship between width of the intrinsic layer and dark current has been studied. The measuring system based on phase sensitive detecting technique has been shown. Relationships between modulating frequencies and noise has also been investigated . It was found that in the range of low frequency （ 30-2 kHz）, the excess noise behaved as 1/f noise. In the end, the recent developments and applications of the Geiger mode operations of GaN-based APDs are introduced.