Study of rapid thermal annealing effect on CdZnO thin films grown on Si substrate

CdZnO thin films were grown on Si (100) substrates by plasma-assisted molecular beam epitaxy. As-grown samples show near band edge emissions at 1.87, 2.03, and 2.16 eV, respectively, while the emission peak energy dramatically increases to up to ultraviolet region with increasing rapid thermal annealing temperature. Room temperature photoluminescence (PL), and temperature dependent PL show phase separations in the samples after the annealing process. Secondary ion mass spectroscopy measurements show redistribution of Cd in the as-annealed sample, which is believed to be the reason of PL peaks shift. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3374435]