Influence of Be doping placement in InAs/GaSb superlattice-based absorber on the performance of MWIR photodiodes
Doping of the absorption region is one of the most crucial aspects of narrow-bandgap semiconductor design of a photodiode, especially, if it is adjacent to the p-n junction area. It significantly impacts various dark current mechanisms and thus the overall performance of these devices. In this work, the influence of a Be doping placement in the absorption region of type-II InAs/GaSb superlattice-based homojunction photodiodes on their performance was investigated. The analysis of diffusion, generation-recombination, shunt and tunnelling dark current components in a wide range of temperatures was performed. Moreover, performance-limiting factors were considered as well as their impact on most important figures of merit of photodetectors was considered. The photodiodes with Be-doped InAs layers in absorption region achieved the best performance.