Magneto-optical characterization of the nitrogen-related impurities in p-type ZnSe epilayers

The impurity properties of nitrogen-doped ZnSe epilayer structures in the d oping concentration range from 2 x 10(17) up to 1.5 x 10(18) cm(-3) have be en investigated by means of photoluminescence (PL) experiments under high m agnetic field up to 15 T at liquid helium temperature. The main feature is the pronounced decrease in intensity of the deep-donor-acceptor pair (D(d)A P) transition as the magnetic field is applied in Faraday configuration. Th is transition involves a deep level of a nitrogen-related complex center an d a nitrogen acceptor. This inhibition of the D(d)AP line is very pronounce d (approximate to 70%) for samples with a doping density below the compensa ting limit [N] = 1 x 10(18) cm(-3), and it is very weak for samples above t his limit. This difference of regime is tentatively explained by the model of wave function shrinkage, giving the donor state radius as a determined p arameter. Calculations within a simple model strongly suggest correlations between donor levels beyond the compensating limit.