Influence of Impurity Charge Correlation on Free-Carrier Absorption

Impurity-mediated free-carrier absorption was analyzed theoretically taking into account the possible spatial impurity correlations. The effect of correlations was included via the structure factor S(q) obtained from finite temperature Monte Carlo simulations of ordering in the impurity system. From the comparison of the experimental data with the results of calculations it is demonstrated that the ordering of charged centers exists for HgSe:Fe in a wide temperature range.