High-Performance Uncooled Mid-Infrared Detector Based on a Polycrystalline PbSe/CdSe Heterojunction

Developing high-performance, uncooled mid-wavelength infrared (MWIR) detectors is a challenging task due to the inherent physical properties of materials and manufacturing technologies. In this study, we designed and manufactured an uncooled polycrystalline PbSe/CdSe heterojunction photovoltaic (PV) detector through vapor physical deposition. The resulting 10 μm × 10 μm device exhibited a peak detectivity of 7.5 × 10⁹ and 3 × 10¹⁰ cm·Hz^1/2·W^-1 at 298 and 220 K, respectively, under blackbody radiation. These values are comparable to those of typical PbSe photoconductive detectors fabricated through standard chemical bath deposition. Additionally, the sensitization-free process used to create these PbSe/CdSe PV detectors allows for high replicability and yield, making them promising candidates for low-cost, high-performance, uncooled MWIR focal plane array imaging in commercial applications.