Transparent amorphous oxide semiconductor thin film phosphor, In-Mg-O:Eu

Abstract

We succeeded in fabricating light-emitting amorphous oxide (LEAO) thin films by doping Eu3+ ions to amorphous In-Mg-O deposited at room temperature using (In, Eu)(2)MgO4 polycrystalline targets by pulsed laser deposition. Clearly visible photoluminescence (PL) with a peak at 615 nm was observed at room temperature by 270 nm light excitation even without post-deposition thermal annealing. The unusual variation of PL intensity with Eu concentration is understood in terms of non-radiative Auger recombination via conduction carriers. The PL intensity also exhibited maximums with respect to oxygen pressure during deposition (PO2) and annealing temperature (T-a), which are explained by recombination centers generated by oxygen deficiency-related defects at low PO2, by excess/weakly-bonded oxygen at high PO2, and by hydrogen depletion at high T-a. Since the LEAO films can be obtained even by room-temperature deposition, it is expected to have flexible optoelectronic applications using plastic substrates. (C) 2016 The Ceramic Society of Japan. All rights reserved.