Simulation and evaluation of PIN photodetectors based on material and thickness of intrinsic layer

In this paper, we present the simulation, evaluation and comparison of the dark current, spectral and frequency response, depending on type of material, absorption coefficient and the thickness of the intrinsic layer of PIN photodetectors, by finite element method. According to the results of the simulation, the GaAs and InP materials have more linear spectral response while InP has a higher gain and spectral response, while GaAs has a higher cutoff frequency related to the other material like Si, Ge, ZnSe and AlGaAs. Also, increasing of intrinsic layer thickness enhances the spectrum response and light current in the Si, Ge and ZnSe materials, but has small effect on InP and GaAs. Furthermore it decreases the frequency response in all materials above.