Origin of noise currents in ion-implanted MW Hg1-xCdxTe PV arrays

Origin of noise currents in ion implanted MW Hg1-xCdxTe photodiodes is investigated with an optimized variable area diode array test structure. Unambiguous experimental evidence for the surface origin of G-R currents has been obtained from these state-of-the-art photodiodes. It is also found that the lateral diffusion current reduces the RoAj product to 1/5 of that of a planar diode when the diode diameter is equal to a minority carrier diffusion length. The data show excellent agreement with 3-D numerical modeling results, suggesting the variable area diode array as a viable tool for measuring the diffusion length.