Compensation of nitrogen acceptor in ZnSe : N/ZnSe grown by MOCVD

It has been proved that the net acceptor concentration as high as 2x10(17) cm(-3) can be obtained when ZnSe:N homoepitaxial layers grown by metalorgan ic chemical vapor deposition (MOCVD) are annealed in molten zinc. However, it was found that the emission intensity of two sets of donor-acceptor pair (DAP), shallow DAP (D(s)AP) and deep DAP (D(d)AP), increased with the incr ease in annealing temperature. In order to clarify the compensation effect, the study on the origin and the concentration of deep donor related to the DdAP emission should be carried out. The ionization energies of acceptor a nd deep donor were estimated to be 101 +/- 1 and 44 +/- 5 meV, respectively , by examining the dependence of their emission peaks with the excitation i ntensity. Furthermore, the upper limit of the deep donor concentration was estimated to be 1 x 10(16) cm(-3). This is one magnitude smaller than the n et acceptor concentration obtained from the annealed ZnSe:N homoepitaxial l ayer in our previous paper. By studying on the behaviors of deep donor. the main reason to lead to a low net acceptor concentration in the ZnSe:N epit axial layers is not attributed to deep donor complex containing nitrogen at oms. but hydrogen passivation, although a part of doped-nitrogen atoms comb ine with other defects to form complicated defects. (C) 2000 Elsevier Scien ce B.V. All rights reserved.