Nitrogen-doped p-type ZnSe, p-type ZnSySe1 (y), and p-type Zn-1 xMgxSySe1 (y) epilayers were grown on n-type GaAs ( 1 0 0) substrates by molecular beam epitaxy. Photoluminescence (PL) spectra for the p-type ZnSe and the lattice-matched p-type ZnS0.06Se0.94, and p-type Zn0.92Mg0.08S0.12Se0.88 epilayers showed a deep acceptor bound exciton emission and a donor-acceptor pair emission. Temperature-dependent PL measurements were carried out to determine the activation energies of these states. The activation energies of the acceptor-bound excitons and the donor-acceptor pairs were determined to be 40 and 65 meV in the p-type ZnSe epilayer, 20 and 45 meV in the p-type ZnS0.06Se0.94, and 45 and 43 meV in the p-type Zn0.92Mg0.08S0.12Se0.88 epilayers. (c) 2009 Published by Elsevier B.V.