磁控溅射制备Er^(3+)/Yb^(3+)共掺杂TiO_2薄膜的上转换发光特性

Upconversion luminescence properties in Er^(3+)/Yb^(3+) codoped TiO_2 films prepared by magnetron sputtering

采用射频磁控溅射法制备得到Er^(3+)/Yb^(3+)TiO_2薄膜,980 nm的抽运源作用下上转换可以得到490 nm的绿光和670 nm的红光,上转换红、绿光发光强度受到烧绿石Er_xYb_(2-x)Ti_2O_7晶体的生成以及Er^(3+)/Yb^(3+)掺杂浓度的影响,实验表明,适量共掺杂Er^(3+)/Yb^(3+)可明显增强上转换发光,Er^(3+)在上转换发光中起主要作用,而引入敏化离子Yb^(3+)可以大大提高上转换发光效率,磁控溅射法制备的TiO_2薄膜声子态密度较小,从而抑制了无辐射跃迁过程,导致490nm绿光形成以及红光强度大于绿光强度。

The Er3＋/Yb3＋ codoped TiO2 films prepared by magnetron sputtering can emit the green light at 490 nm and the red light at 670 nm by using a 980 nm diode laser irradiation. The emission intensity of upconversion is influenced by ErxYb2-xTi2O7 crystal and concentration of Er3＋/Yb3＋. The experiment shows that an appropriate codoping proportion of Er3＋/Yb3＋ brings a notable enhancement of upconversion luminescence intensity. Er3＋ plays a main role in the upconversion luminescence, and the sensitized ion Yb3＋can greatly improve the efficiency of upconversion. The TiO2 film prepared by magnetron sputtering has a small density of phonon states, thus it inhibits the process of non-radiative transitions, which leads to the formation of green light at 490 nm and the intensity of red light being greater than green light.