Er3+ and Yb3+ up conversion on oxide matrix obtained by non-hydrolytic sol-gel

In this work the yttrium-aluminum [1] and gadolinium-aluminum [2] oxide were prepared by non-hydrolytic sol-gel methodology. The matrices were synthesized with Er3+ and Er3+/Yb3+, the molar ratio was 1%. The samples were treated at 800oC during 4 h. The samples were characterized by X-rays (XRD) diffraction and up conversion photoluminescence (PL). The XRD present peaks ascribed to the different oxides, yttrium, yttrium aluminum garnet, gadolinium and gadolinium aluminate peroviskite. The emission spectrum were use to laser system with excitation wavelength fixed at 980 nm and 2.0 W power. The samples containing only Er3+ ion present bands in the green (542 nm) and red (660 nm) regions, correspondent to 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions, respectively, the similar intensity was observed. The samples containing Er3+ and Yb3+ the emission spectrum present the bands in the same regions, however as band in the red region is more intense than green. The increase in the intensity of transition 4F9/2 → 4I15/2, is an indicative that the excited state 2F9/2 of the Yb3+ ion transfer energy to the 4F9/2 level. The incorporation of the Yb3+ ion as sensitizer showed an increase on emission of the activator Er3+ ion. The matrices present different behavior in the emission of the Er3+ ion. The figure 1 presents the emission spectrum to the samples.