Enhanced photoluminescence in epitaxial ZnGa2O4:Mn thin-film phosphors using pulsed-laser deposition

Abstract
The growth and properties of ZnGa2O4:Mn thin-film phosphors on single crystal substrates using pulsed-laser deposition were investigated. Epitaxial film properties were compared to polycrystalline films deposited on glass substrates. Green photoluminescence was observed for as-deposited films with no postannealing required. Enhanced luminescent intensity in the epitaxial films was observed as compared to randomly oriented polycrystalline films, suggesting that grain boundaries and grain alignment strongly influence the luminescent properties. The ratio of Zn/Ga in the films also affected photoluminescence properties, with strong green emission observed in Zn-deficient films.