Modeling the detection efficiency in photodetectors with temperature-dependent mobility and carrier lifetime

We proposed a modeling procedure to calculate the impact of temperature on the detection efficiency in photodetectors based on CdTe materials. Temperature increase impacts on the electrical properties of the materials such as carrier mobility and carrier recombination lifetime. This impact which can be effective in some cases has been normally ignored in the modeling approaches presented in the literature. Here we show that increasing the temperature from 190 K to 300 K not reduces the mobility of both electrons and holes but also significantly reduces the carrier lifetime. The result will impact on electric-field within the depletion width of the device, drift and diffusion lengths which are used to calculate the carrier collection or detection efficiency of photodetectors. We have collected the temperature-dependency of carrier mobility and lifetime from the experimental reports in literature and showed that detection efficiency of photodetectors is temperature dependent not only by kT constant in the conventional equations but also by temperature-dependency of carrier mobility and lifetime. A practical conclusion of this modeling is to measure both mobility and lifetime after every temperature processing of the semiconductor devices. The model can be further extended to be applied to other optoelectronic devices such as LEDs and Solar cells or humidity sensors.