Elaboration and tunable photoluminescence of Β -Ga₂O ₃: Eu³⁺ films by urea-assisted aqueous chemical bath deposition

Β -Ga2 O3: Eu3+ films were prepared by a chemical bath deposition of GaOOH: Eu3+ in an aqueous solution of Ga3+, Eu3+, and urea on SnO2 -coated glass substrates and subsequent heat-treatments. The resultant films showed red photoluminescence which was characteristic of Eu3+ ions upon irradiation with ultraviolet light of 271 nm. An additional blue-green band emission, which was attributed to emissive defect centers in the Β -Ga2 O3 host, was observed with excitation at a shorter wavelength of 254 nm. Our results then demonstrate that Β -Ga2 O3: Eu3+ can be excited by two different mechanisms of the charge transfer and the energy transfer, resulting in tunable photoluminescence.