Pechini sol–gel deposition and luminescence properties of Y3Al5−xGaxO12:Ln3+ (Ln3+=Eu3+, Ce3+, Tb3+; 0≤x≤5) thin films

Abstract Rare earth ions (Eu 3+ , Ce 3+ and Tb 3+ )-doped Y 3 Al 5− x Ga x O 12 (0≤ x ≤5) films were deposited on quartz glass substrates by a simple Pechini sol–gel method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric and differential thermal analysis (TG–DTA), atomic force microscopy, field-emission scanning electron microscope, photoluminescence spectra, and lifetimes were used to characterize the resulting films. The results of XRD indicated that the films began to crystallize at 900 °C and fully crystallized at 1000 °C. Both the results of FT-IR spectra and TG–DTA were in agreement with those of XRD. Uniform and crack-free films annealed at 1000 °C were obtained with an average grain size of 480 nm, a root mean square roughness of 13 nm and a thickness of 287 nm. The doped Ln 3+ ions showed their characteristic emission in crystalline Y 3 Al 5− x Ga x O 12 films, i.e., Eu 3+ 5 D 0 - 7 F J ( J =1, 2, 3, 4), Ce 3+ 5d-4f and Tb 3+ 5 D 3, 4 - 7 F J ( J =6, 5, 4, 3) emissions, respectively. The optimum doping concentrations of the Eu 3+ , Ce 3+ and Tb 3+ were determined to be 1.5, 1.0, and 4.0 mol% of Y 3+ in Y 3 Al 5 O 12 films, respectively. At the same time, the effects of the contents of Ga 3+ ( x ) in Y 3 Al 5− x Ga x O 12 films on the luminescence properties of Ln 3+ were also investigated.