Performance comparison of room temperature-operated mid-infrared IV-VI PbSe photoconductive and III-V InAsSb, InAs/GaSb, InAs/InAsSb T2SL photovoltaic-mode detectors for nondispersive infrared (NDIR) gas sensing application

CO2 gas sensing holds significant importance across various sectors including environmental monitoring, chemical industries, manufacturing processes, medical capnography and biomedical diagnostics. Two types of CO2 sensors primarily used for gas sensing are electrochemical sensors and non-dispersive infrared (NDIR) sensors. Among the semiconductor materials suitable for cost-effective detector applications, PbSe and InAsSb are particularly noteworthy due to their demonstrated high operating temperature (HOT) capability. This study provides a comparison of the electrical, optical, and electro-optical characteristics of photovoltaic InAsSb and photoconductive PbSe detectors. Both types of detectors were found to operate effectively at room temperature, and their performance characteristics were evaluated, including temperature-dependent dark current, shunt resistance, and cryogenic Fourier-transform infrared (FTIR) spectral response from 77K to 340K. Additionally, key performance parameters such as 1/f noise, noise equivalent power (NEP), quantum efficiency, and specific detectivity (D*) were estimated and analyzed. This paper presents a detailed analysis of these characteristics for