Fabrication and optical transition dynamics of Er-doped ZnO thin films formed on Si substrates

Er-doped ZnO (ZnO :Er) thin films fabricated on Si substrates were investigated by photoluminescence (Pt) and PL excitation (PLE) spectroscopy. The ZnO : Er thin films emit sharp and intense 1.54 mu m luminescence. It is shown that the Er-related PL gives rise to different features under direct and indirect excitations. An over band-gap excitation leads to a faster lifetime of the 1.54 mu m PL indicating a strong interaction of electron-hole pairs in the host with 4f electrons in the Er3+ ions. The ZnO:Er is a promising candidate for optoelectronic devices excited by carrier injection because of its high electrical conductivity. (C) 2000 Elsevier Science B.V. All rights reserved.