Optical properties of Tb3+-doped GeO2–ZrO2 thin films prepared by sol-gel method

Abstract Thin films of the system yTb2O3–xGeO2–(100−x)ZrO2 were prepared by sol–gel and dip-coating techniques, and their optical properties were investigated by measuring luminescence and excitation spectra, luminescence quantum yield (QY) values, and luminescence decay curves. The influences of crystallization and composition of the films on optical properties were also examined from X-ray diffraction patterns. In yTb2O3–xGeO2–(100−x)ZrO2 films with x = 0–10, the crystallization temperature showed a tendency to increase with increasing y and x values. Strong luminescence was observed both in amorphous or cubic ZrO2 films with y ⩾ 5 and x = 0 and in amorphous films with y ⩾ 5 and x = 5 or 10, and the strongest QY values were observed in yTb2O3–5GeO2–95ZrO2 and yTb2O3–10GeO2–90ZrO2 amorphous films heat treated at 400 or 500 °C.