He Jiale, Li Qing, Wang Peng, Wang Fang, Gu Yue, Shen Chuan, Luo Man, Yu Chenhui, Chen Lu, Chen Xiaoshuang, Lu Wei, Hu Weida
Opt Express. 2020 Oct 26;28(22):33556-33563. doi: 10.1364/OE.408526.
The performance of high-operating-temperature (HOT) longwavelength infrared (LWIR) HgCdTe avalanche photodiodes (APDs) is significantly limited by the increasing dark current related to temperature. In this paper, a novel barrier-blocking LWIR pBp-APD structure is proposed and studied, and the results show that the dark current of pBp-APD is significantly restricted compared with conventional APD without sacrificing the gain at high temperature. Furthermore, the reduction of avalanche dark current is found to be the key points of the significant suppression of dark current. The physical essence of this reduction is revealed to be the depletion of carriers in the absorption region, and the feasibility of the improved structure is further confirmed by the analysis of its energy band and electric field distribution. In addition, the reduction of gain-normalized dark current (GNDC) does not need to sacrifice the gain. The proposed LWIR pBp-APD paves the way for development of high operation temperature infrared APDs.
高工作温度（HOT）长波红外（LWIR）碲镉汞雪崩光电二极管（APD）的性能受到与温度相关的暗电流增加的显著限制。本文提出并研究了一种新型的势垒阻挡型LWIR pBp - APD结构，结果表明，与传统APD相比，pBp - APD的暗电流在高温下得到了显著限制，且不牺牲增益。此外，发现雪崩暗电流的降低是暗电流显著抑制的关键所在。这种降低的物理本质被揭示为吸收区载流子的耗尽，通过对其能带和电场分布的分析进一步证实了改进结构的可行性。此外，增益归一化暗电流（GNDC）的降低无需牺牲增益。所提出的LWIR pBp - APD为高工作温度红外APD的发展铺平了道路。
