Characterization of ZnSe:N Using Screening Effects

Abstract

AbstractPhotoluminescence (PL) and Hall measurements allow one to obtain important parameters of semiconductors, such as impurity concentrations, compensation, and activation energies (EA). Usual analyses of such data assume constant EA. However, it is well known that EA depends on free carrier and impurity concentrations, and thus on temperature, due to screening effects. We here analyze literature data on ZnSe:N using screening effects. An observed decrease of EA with temperature (from PL data) had been used to suggest an interstitial site for N. With inclusion of screening, we obtained good agreement with the data, so that the idea of interstitial N is not required. In applying the screening theory to Hall measurements, we obtained lower impurity concentrations than with use of a constant EA. It is also to be noted that we fit both optical and electrical data with this approach. We further suggest that screening is the cause of an observed difference between optically observed and thermal activation energies.