Enhanced performance in uncooled n-CdSe/p-PbSe photovoltaic detectors by high-temperature chloride passivation

High-temperature chloride passivation (HTCP) was proposed to improve the crystalline quality and electrical properties of PbSe epitaxial films. The PL intensity of HTCP (111) PbSe epitaxial films exhibits a 14 times higher intensity than that of as-grown films, and a threefold increase in Hall mobility has been obtained after HTCP at 300 °C for 2 h. The improvement of optical and electrical properties is attributed to the high-temperature defect passivation induced by the HTCP process. The HTCP process of PbSe films was implemented in a CdSe/PbSe heterojunction PV detector, which exhibits a room temperature peak detectivity D* of 8.5 × 10⁸ cm Hz^1/2 W^-1 in the mid-wavelength infrared region under blackbody radiation (227 °C), demonstrating potential applications in the fabrication of mid-infrared detectors and emitters.