Structural, optical, photoluminescence, and photoconductive properties of rare-earth-doped β-Ga<inf>2</inf>O<inf>3</inf> thin films

Rare-earth doped semiconductors have attracted continuous attentions for their potential applications in both scientific research and practical fields. It is well-known that the luminescence efficiency of dopant emissions could be highly improved with a wide bandgap host material. As a highly thermally and chemically stable wide bandgap semiconductor, β-Ga ₂ O ₃ is one of the ideal host materials for lanthanide ions, which could introduce additional energy transitions leading to new luminescence. We have successful grown (2 01) oriented rare-earth (RE) doped β-Ga ₂ O ₃ (RE: Er, Nd, Pr and Ce) thin films on (000l) Al ₂ O ₃ substrates using radio frequency magnetron sputtering method. The influences of the dopant contents on the structural, optical, photoluminescence, and photoconductive properties of the thin films have been systematically studied. We found that both the crystal lattice and the photoluminescence of the obtained films depends crucially on the doping level. Moreover, by embedding lanthanide ions, RE:β-Ga ₂ O ₃ could be a sensitive photoluminescence detecting sensor. This work may provide a prominent candidate for further developing advanced composite materials incorporated with luminescent ions.