Effects of material parameters on the temperature dependent spectral response of In0.83Ga0.17As photodetectors

The effects of material parameters on the temperature dependent features of the spectral response of wavelength extended In0.83Ga0.17As photodetector have been investigated both experimentally and theoretically. The decline of the responsivity with drop of temperature has been observed using Fourier transformed infrared spectroscopy. Adopting a simple but clear analytical model, the material and structural parameters of the photodetector were connected with the temperature dependent characteristics of responsivity effectively; the main temperature dependent parameters have been analyzed and taken into account by using simulation method. Results show that the temperature dependent diffusion length of the minority carriers in absorption layer plays the most important role on the distinct positive temperature coefficient of responsivity. Our calculation results also suggest that the enhanced minority carrier diffusion length and depletion width could readily restrain the temperature effects of the responsivity and thus improve the device performance.