Optimization for mid-wavelength InSb infrared focal plane arrays under front-side illumination

The quantum efficiency for mid-wavelength InSb infrared focal plane arrays has been numerically studied by two dimensional simulators. Effects of thickness of p-type layer on the quantum efficiency under front-side illumination have been obtained. The calculated results can be used to extract the optimal thickness of the p-type layer for different absorption and diffusion lengths. It is indicated that the optimal thickness of the p-type layer strongly depends on the absorption coefficient and the minority carrier lifetimes. The empirical formulas are also obtained to describe the correlation between the optimal thickness of the p-type layer, and the absorption and diffusion lengths.