Epitaxial layers of N-doped and N-implanted material were grown by using molecular beam epitaxy, and were studied by means of photoluminescence spectroscopy. The results were compared with those obtained from samples which had been implanted with other impurities. Only N-containing samples gave rise to transitions which corresponded to a predominant shallow donor with a binding energy of 0.0291eV. This donor was not a residual impurity in ZnSe, but was associated with N. It was proposed that it involved N atoms that were located at interstitial sites. In addition, a deep compensating donor was already present in lightly-doped samples. These results demonstrated that the N doping of ZnSe was accompanied by a concomitant creation of N-related defects, both shallow and deep, from the onset of doping. An unavoidable and marked compensation of N acceptors then occurred.

E.Tournié, C.Morhain, G.Neu, J.P.Faurie: Physical Review B, 1997, 56[4], R1657-60