Photoelectric Characteristics of Multielement Photodiode-Based IR FPAs by the Monte Carlo Method on Epitaxial HgCdTe Films

The calculations of photocharacteristics, such as spatial resolution, threshold sensitivity with photosensitive elements sized from 5 µm × 5 µm to 20 µm × 20 µm under uniform illumination, for multielement IR FPAs and also for point objects are presented. The obtained results are based on the simulation of a three-dimensional diffusion process of photo-excited minority charge carriers in the photosensitive layer of photodiode elements by the Monte Carlo method. Numeric estimates are presented for IR FPAs based on photodiodes for epitaxial HgCdTe films, but the model is applicable for the calculations of photoelectric characteristics for photodiodes on other substrates. The requirements for the main photoelectric and design parameters of photosensitive elements and optical system (spot diameter from a point source), which provide reaching IR FPA maximal sensitivity and spatial resolution values, are formulated.