Midwave infrared InAs/GaSb strained layer superlattice hole avalanche photodiode

Midwavelength infrared InAs–GaSb strained layer superlattice n+-n−-p avalanche photodiodes, specifically designed to have hole dominated avalanching, with a zero percent cutoff wavelength of ∼6.3 μm are fabricated and characterized. Maximum multiplication gain of 105 is measured at −3.6 V at 77 K. Measured excess noise factors are significantly improved compared to unity hole to electron ionization ratio and corresponds to a theoretical value between 40 and 50 when compared with the McIntyre model. Exponential nature of the gain as a function of reverse bias along with low excess noise factors confirms single carrier hole dominated impact ionization.