The influence of indium percentage on properties of short wave infrared (SWIR) InGaAs/PI photodetector
In this study, the properties of the materials from which the InGaAs photodetector is made representing both the compounds Indium arsenide InAs and Gallium Arsenide GaAs were first studied, where the energy gap values for these materials were determined at different temperatures. The main task of this paper, some important parameters of InxGa1−xAs photodetector material such as direct bandgap Eg and its corresponding cutoff wavelengths λco, lattice matching ao, and refractive index (n) at ddifferent wavelengths, is calculated using MATLAB software. The spectral dependence of these parameters is calculated for whole indium composition range (1<x>0). Also, through the results, it became clear to us that the energy gap is affected by the change in the concentration of indium and it is becomes narrower as the indium percentage increases. By changing x, InGaAs material can covers the wavelength range of (0.815 - 3.502μm). From the results it was found that the band gap of InxGa1−xAs photodetector spans from 1.520eV (0.815 µm) for GaAs to 0.354eV (3.502 µm) for InAs, and also sensitivity of InGaAs photodetector will be accomplished at (1.55-1.87μm), and (2-2.6μm) SWIR windows when (x=0.53), and (x=0.82) respectively.