Chemical bath deposited MgxZn1-xS(O) thin films and their photoluminescence properties

Abstract

A zinc sulfide (ZnS) specimen was intentionally doped with transition metal (Mg-donor) elements using a chemical bath deposition (CBD) technique. Both the un-doped and the magnesium (Mg)-doped ZnS samples were confirmed to have hexagonal wurtzite ZnS crystal structure. The XRD patterns showed no characteristic peak for Mg indicating that the Mg2+ ions had been incorporated into ZnS(O ) lattice sites. In contrast to un-doped samples, Mg doping resulted in changes in the morphological features of the spherical clusters which resulted in porous, spongy vermicular structures. The energy band gap of the MgxZn1-xS(0) film was slightly larger than that for the ZnS(O) film. A photoluminescence study revealed that the emissions were near violet-blue-green in color. The emission characteristics consist of two components; emission in the near violet and in visible region. That is the first is between 4160 and 4400 angstrom and the second is at 5190 angstrom, and these are associated with the donor-acceptor transitions with sulfur vacancies as acceptors and the magnesium related defects (trap states) in the samples respectively. (C) 2015 Elsevier B.V. All rights reserved.