Analysis of optical and electrical crosstalk in small pitch photon trapping HgCdTe pixel arrays

Abstract

We have investigated the optical and electrical crosstalk in HgCdTe photovoltaic pixel arrays employing a photon trapping (PT) structure realized with a periodic array of pillars. We have used a finite-difference time-domain approach to compute the carrier generation rate in the device and evaluate the optical crosstalk. Subsequently, solving the drift-diffusion equations, we have computed the quantum efficiency and the electrical crosstalk. We have found that, compared to a conventional pixel array, the one employing the photon trapping structure has a slightly higher optical crosstalk. However, the presence of the photon trapping region drastically reduces the electrical (total) crosstalk.