Crystallization effect of Al-Ag alloying layer in PL enhancement of ZnO thin film

ZnO/Ag/Al multilayer structures were deposited on glass with different annealing conditions and were compared with as-deposited ZnO thin film. The results show that the alloying effects of the Al-Ag film not only induced different interface mechanisms through annealing, but also improved the optoelectronic properties. The alloying ratio of the Al-Ag film increased with the increasing temperatures. Due to the higher ratio of Al-Ag alloying layer, some atoms diffused into the ZnO matrix at higher annealing temperatures, and the PL of the ZnO thin film was destroyed. Oppositely, at lower annealing temperatures, the Al-Ag alloying layer had a better ratio (Al:Ag = 4:1) which could enhance the PL spectra of the ZnO thin film.