Calculation of Quantum Efficiency of Photodetectors Based on A3B5 Metal-Solid Solutions Contacts

In our investigation, we have modelled the quantum efficiency of the photodetecting structures based on the p-n junction and metal-semiconductor contacts. The calculation has been performed based on the solution of the continuity equation, taking into account the impact of the surface recombination. In most cases, this process has an adverse effect on the parameters of instruments; in particular, in photodetectors, this effect should reduce sensitivity. However, in our investigation it is shown that the effect of the surface recombination may be used as a useful factor for developing selective photodetectors. The effect of the surface recombination process will significantly increase with an increase of the absorption coefficient, since in this case more photons will be absorbed at the surface. Since there is a significant dependence of the absorption coefficient on the incident photon energy in semiconductors, the effect of the surface recombination on the photodetector sensitivity in the long-wave and short-wave regions of the spectral range will be significantly different.