Color tunable up-conversion emission of ZrO2:Yb3+, Er3+ thin films prepared by chemical solution deposition

The color-tunable up-conversion (UC) emission was observed in ZrO2:Yb3+, Er3+ thin films synthesized on fused silica substrates using a chemical solution deposition method. The crystal structure, surface morphology image and optical transmittance of ZrO2:Yb3+, Er3+ thin films were detected in the matter of Yb3+/Er3+ doping content. Under excitation by 980 nm infrared light, intense UC emission can be obtained from ZrO2:Yb3+, Er3+ thin films. Photoluminescence study shows that there are two emission bands centered at 548 nm and 660 nm in the UC luminescence spectra, which can be owing to (2H11/2,4S3/2)→4I15/2 and 4F9/2→4I15/2 transitions of Er3+ ions, respectively. In addition, the color coordinate of UC emission between green-red can be tuned by properly adjusting the dopant concentration, because the composition of Yb3+/Er3+ affect the red/green ratio via the process of cross relaxation and energy back transfer. Our study suggests that ZrO2:Yb3+, Er3+ thin films can be considered as promising materials for new photoluminescence devices.