Zn-Related Donor-Acceptor Pair Emission in CuAlSe2 Epitaxial Layers

Abstract
Photoluminescence (PL) studies have been carried out on the intense blue-green emission at 2.51 eV observed at low temperature (8 K) in Zn-doped CuAlSe2 epitaxial layers grown on GaAs by means of the low-pressure metal-organic chemical vapor deposition technique. Based on the analyses of the dependences of PL spectra on excitation intensity, decay time and temperature, this emission is interpreted as donor-acceptor pair recombination involving a donor with activation energy of 0.11 eV and an acceptor with activation energy of 0.23 eV.