HgCdTe/black phosphorus van der Waals heterojunction for high-performance polarization-sensitive midwave infrared photodetector

Jiao et al., Sci. Adv. 8, eabn1811 (2022) 11 May 2022 SCIE N C E A D V A NCES | RESEA R CH A RT ICL E 1 of 8 M A T E RIALS SCIENC E HgCdTe/black phosphorus van der Waals heterojunction for high-performance polarization-sensitive midwave infrared photodetector Hanxue Jiao1†, Xudong Wang1*†, Yan Chen1, Shuaifei Guo2, Shuaiqin Wu1, Chaoyu Song2, Shenyang Huang2, Xinning Huang1, Xiaochi Tai1, Tie Lin1, Hong Shen1, Hugen Yan2, Weida Hu1, Xiangjian Meng1, Junhao Chu1, Yuanbo Zhang2, Jianlu Wang1* New-generation infrared detectors call for higher operation temperature and polarization sensitivity. For tradi- tional HgCdTe infrared detectors, the additional polarization optics and cryogenic cooling are necessary to achieve high-performance infrared polarization detection, while they can complicate this system and limit the integration. Here, a mixed-dimensional HgCdTe/black phosphorous van der Waals heterojunction photodiode is proposed for polarization-sensitive midwave infrared photodetection. Benefiting from van der Waals integration, type III broken-gap band alignment heterojunctions are achieved. Anisotropy optical properties of black phosphorous bring polarization sensitivity from visible light to midwave infrared without external optics. Our devices show an outstanding performance at room temperature without applied bias, with peak blackbody detectivity as high as 7.93 × 1010 cm Hz1/2 W−1 and average blackbody detectivity over 2.1 × 1010 cm Hz1/2 W−1 in midwave infrared region. This strategy offers a possible practical solution for next-generation infrared detector with high operation temperature, high performance, and multi-information acquisition. INTRODUCTION Infrared detectors, which use infrared radiation intensity and spec- trum to distinguish objects from complex backgrounds, have vitally important applications in many fields, such as environmental monitoring, thermal imaging, and free-space optical communica- tion (1–4). New-generation infrared detectors are supposed to have features including high resolution, multicolor functionality, high operation temperature (HOT), and polarization sensitivity (5–7). In 1985, the conception of realizing HOT infrared detector was pro- posed by Ashley and Elliott (8). Up to now, many heterogeneous structures have been proposed to implement HOT detectors (5, 9–11), such as p+/p−/n+ (9), p+/n−/n+ (9), and nBn (9–11) structur