Structural, electrical and luminescent properties of ZnO:Li films fabricated by screen-printing method on sapphire substrate
Abstract
Undoped and Li-doped ZnO thick films were fabricated by a screen-printing technique on sapphire substrate. The effect of sintering temperature (TS = 800, 900 and 1000 °C) and Li content ([Li] = 0.003, 0.03 and 0.3 wt%) on the photoluminescence (PL), electrical and structural properties of the films was investigated. The X-ray diffraction shows that all the films are polycrystalline with a wurtzite structure. It is found that both high sintering temperature and low Li content favour formation of the low-resistive films with an enhanced UV emission. The high Li content stimulates an appearance of semi-insulating behaviour of the films and deteriorated PL properties. It is shown that the effect of Li-doping on light-emitting properties of the films consists mainly in the modification of the film crystallinity and the engineering of the concentration of intrinsic defects. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
