High-Performance Nonequilibrium InSb PIN Infrared Photodetectors

Abstract

The cooling requirement is still a great burden of sensitive infrared (IR) detectors. To overcome this challenge, a detailed investigation of InSb P-intrinsic-N diodes was conducted. Its dark current was comprehensively studied for the design and optimization of high-performance nonequilibrium IR detectors. The doping concentration, exclusion junction, and layer geometry were engineered to lower the Auger suppression trigger current density J _onset , leading to a low dark saturation current J _sat . The result indicated that the Auger suppression can be triggered at J _onset = 15 A/cm ² and V _onset = 0.8 V, while J _sat can be kept as low as 10 A/cm ² . The nature of Auger suppression has been studied by calculating the carrier concentration profile in the diode with different bias voltages. It is proven that the exclusion diode has the most significant effect on the Auger suppression. The specific detectivity of optimized nonequilibrium InSb detectors at different temperatures has been compared favorably with the results reported by other groups. Such a nonequilibrium InSb IR detector has a high potential in room temperature and above application.