Characterisation of crosstalk in HgCdTe n-on-p photovoltaic infrared arrays

摘要

In this paper, a theoretical and experimental study is carried out of crosstalk between neighbouring devices within a back-side illuminated two dimensional HgCdTe photovoltaic infrared sensing array. Theoretical calculations are performed utilising Dhar's model. a 2D simulated current approximation to crosstalk. Experimental results stem from spatial photo-response (SPR) measurements, which have been performed on HgCdTo MWIR photodiode arrays. The characterised devices are part of an 8x8 array fabricated using LPE grown p-type HgCdTe, with pho-todiodes fabricated in-house at The University of Western Australia. A scanning laser microscope is used to measure the spatial photo-response as a function of temperature. The theoretical model uses finite analysis techniques of probabilistic equations describing photogenerated carrier diffusion within the array. The Dhar model is a two dimensional model of simulated currents generated within the array. The basis of this model is the Kammins Fong (KF) model, a simplistic one dimensional representation of similar simulated currents. Inclusion of diffusion characteristics in the Dhar model is shown to result in greater levels of accuracy.