Yb掺杂对Er/Yb共掺Al_2O_3薄膜光致荧光性能的影响

Photoluminescence Performance as a Function of Ytterbium Doping Concentration from Er/Yb Co-Doped Al _2O _3 Films

采用反应射频磁控溅射技术,通过调整溅射靶面上金属Er和Yb的面积比例制备出了不同Yb含量的Er/Yb共掺Al2O3 薄膜,重点探讨了薄膜制备过程中Er、Yb成分比例控制的可靠性及Yb的掺杂浓度对 Er/Yb共掺 Al2O3薄膜室温光致荧光谱强度及峰型的影响。利用卢瑟福背散射谱(RBS)和电子能谱(EDX)对薄膜成分进行的分析表明:薄膜中Er、Yb成分的比例与实际的Er、Yb靶面积比基本一致。薄膜经过1000 ℃退火2 h的室温光致发光谱表明:Yb掺杂显著提高了薄膜的光致荧光强度,当Yb/Er靶面积比为4∶1时,光致荧光强度和半峰全宽最大。研究结果表明:对于Al2O3 薄膜,合适的Yb/Er浓度,不仅可以显著改善薄膜的发光效率,而且可以增加频带带宽。

Er/Yb co-doped Al2O3 films with variant Yb concentrations, which are controlled through adjusting the area ratio of Yb to Er in the surface of the target, are fabricated by radio-frequency (RF) reaction magnetron sputtering technique. The reliability of composition control of Er/Yb ratio in film preparation and the influence of Yb doping concentration on room temperature photoluminescence (PL) spectral intensity and distribution of Er/Yb co-doped Al2O3 films are mainly investigated. Rutherford backscattering spectroscopy (RBS) and energy dispersive X-ray analysis (EDX) are used to determine the composition of the films. It is shown that the concentration ratio of Yb to Er in the films accorded with the area ratio of Yb to Er in the surface of the target. The room temperature PL spectrum of the films after annealing at 1000°C for 2 h shows that the PL intensity of Er3+ can be enhanced by Yb doping. The PL intensity and full width at half maximum (FWHM) reaches its maximum when the area ratio of Yb to Er reaches to 4:1. The results of the research show that, as far as Al2O3 films are concerned, appropriate concentration of Yb/Er not only improves the luminescence efficiency of the films, but also enhances the channel bandwidth.