Temperature-dependent Characteristics of Infrared Photodetectors Based on Surface-State Absorption in Silicon.

At various temperatures, ranging from 25°C to 50°C, we characterized two types of photodetectors based on surface-state absorption in silicon: (1) contactless integrated photonic probes (CLIPPs) and (2) normal-incidence photoconductors. Both types of photodetectors exhibited temperature-dependent AC admittance without illumination. With illumination at telecommunication wavelengths near 1550 nm, in the temperature range we measured, the photoresponse of CLIPPs, i.e., the variance of admittance due to illumination, was relatively insensitive to temperature changes; in comparison, the temperature dependence of the photoresponse of normal-incidence photoconductors was more pronounced-their responsivity increased as temperature raised.