Abstract:
Photoluminescence (PL) spectra of ZnO thin films produced by isovalent substitution method by means of thermal treatment of zinc selenide single crystal substrates in air are studied in 350 – 750 nm range at room temperature. Irrespective of annealing temperature (500 – 870 °C) and annealing time (20 – 120 min), PL spectra consist of a short-wavelength violet radiation with maximum localized between 396 and 423 nm and a long-wavelength yellow-orange radiation with maximum localized between 575 and 600 nm. Both PL bands are attributed to donor-acceptor (DA) pairs. It is shown that the violet PL band intensity decreases and the yellow-orange PL band intensity increases with increasing ZnO film thickness that is caused by self-absorption of the short-wavelength radiation and energy transmission to DA-pair centres of the long-wavelength radiation.
