Substrate temperature dependence of structure and optical properties of ZnTiO(3):Er(3+)/Yb(3+) thin films synthesized by pulsed laser deposition

ZnTiO(3):Er(3+),Yb(3+) thin film phosphors were successfully deposited by pulsed laser deposition (PLD) at different substrate temperatures. The distribution of the ions in the films was investigated and the chemical analysis showed that the doping ions were homogeneously distributed in the thin films. The optical response of the phosphors revealed that the reflectance percentages of the ZnTiO(3):Er(3+),Yb(3+) vary with the silicon substrate temperature due to the differences in the thickness and morphological roughness of the thin films. Under 980 nm diode laser excitation, the ZnTiO(3):Er(3+),Yb(3+) film phosphors displayed up-conversion emission from the Er(3+) electronic transitions, with violet, blue, green, and red emission lines at 410, 480, 525, 545 and 660 nm from (2)H(9/2) → (4)I(15/2), (4)F(7/2) → (4)I(15/2), (2)H(11/2) → (4)I(15/2), (4)S(3/2) → (4)I(15/2) and (4)F(9/2) → (4)I(15/2) transitions, respectively. The up-conversion emission was enhanced by increasing the silico (Si) substrate temperature during the deposition. Based on the photoluminescence properties and decay lifetime analysis, the energy level diagram was established and the up-conversion energy-transfer mechanism was discussed in detail.