High-Sensitive Self-Powered MWIR Photodetector Based on the n-PbSe/p-PbSe/PbO Heterojunction

PbSe has emerged as a prominent room-temperature mid-infrared (MWIR) photodetection material. However, its widespread application has been limited by inherent high noise levels that degrade the device performance in MWIR detection. Herein, a detector based on n-PbSe/p-PbSe/PbO heterojunction with an ultrahigh detectivity (D*) of 1.76 × 10¹² Jones at 0 V bias is reported. The exceptional performance of this MWIR photodetector stems from the band structure of II-type heterojunction formed by n-PbSe and p-PbSe, which enables rapid separation of photogenerated electron–hole pairs and efficient electron transport and the suppression in dark current by the PbO hole barrier layer. Under a bias of 0.1 V, the device demonstrates remarkable responsivity (R) of 148 A·W^1– and detectivity (D*) reaching 6.00 × 10¹² Jones. Our work may pave the way for fabricating and developing self-powered room-temperature MWIR photodetectors.