A simple model of dislocation band formed by the dangling bonds of atoms of a dislocation core was presented and discussed. The parameters of this model, which could be verified experimentally, were the average energy of the dislocation band states and the average length of the dislocation as well as electron and hole emission coefficients. The formulas for statistical functions of distribution of electrons in these bands were derived. Next, a model was developed for the SRH recombination channel connected with dislocation band states and it was adopted in order to determine an effective lifetime of electron-hole pairs including effect of dislocations. In addition, influence of the tunnelling current from and into dislocation band was considered, which seemed to be a serious issue in reverse biased heterostructue HgCdTe photodiodes. Exemplary results of calculations for HgCdTe structures showed that the number of the ionized atoms of the dislocation cores was of the order of a few percent. Moreover, the electric potential distributions in the area of the dislocation core was calculated. Some experimental I-V characteristics of near room temperature HgCdTe devices were presented and compared with numerical simulations.

Simplified Model of Dislocations as a SRH Recombination Channel in the HgCdTe Heterostructures. K.Jóźwikowski, A.Jóźwikowska, M.Kopytko, A.Rogalski, L.R.Jaroszewicz: Infrared Physics & Technology, 2012, 55[1], 98-107