An optical method for evaluation of the net acceptor concentration in p-type ZnSe

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Abstract
We report photoluminescence (PL) results obtained on p‐type ZnSe epilayers grown by molecular beam epitaxy. As an acceptor dopant, we used an active nitrogen beam produced by a free radical nitrogen source. On the basis of a detailed analysis of PL data we propose a simple semiquantitative method for a quick and contactless evaluation of the net acceptor concentration in p‐type ZnSe. In particular, we show that the intensity ratio of the donor–acceptor pair (DAP) emission to the acceptor‐bound exciton (I1) emission strongly depends on both the excitation power and the quality of the sample, and because of that it cannot by itself be regarded as a good measure of the net acceptor concentration. On the other hand, the intensity of the DAP emission under saturation excitation shows a simple direct proportionality to the net acceptor concentration, thus providing a reliable tool for determining the relative doping level in p‐type ZnSe films.