利用简单的水热合成法成功制备出α-TeO2∶Ho3+, Yb3+、α-TeO2∶Tm3+, Yb3+和 α-TeO2∶Tm3+, Ho3+, Yb3+纳米材料, 用 980 nm 的近红外光作为激发光源测定了样品的室温上转换发射光谱。结果表明: 样品α-TeO2∶Ho3+, Yb3+分别发射绿光(545 nm)和红光(651 nm), 分别对应于Ho3+离子的5S2 →5I8 和5F5→5I8能级跃迁。随着Yb3+的摩尔分数从5% 增加到15%, 样品在545 nm处的绿光强度明显变大, 发光颜色由黄光向绿光转变。样品α-TeO2∶ Tm3+, Yb3+ 在476 nm处发射出蓝光, 对应于Tm3+离子的1G4→ 3H6能级跃迁, 两个弱红光峰( 651,675 nm)分别对应于Tm3+离子的1G4→3F4和3F2→3H6能级跃迁。随着Yb3+离子浓度的提高, 蓝光与红光的相对强度也在显著提高。基于可调控性蓝光、绿光和红光的产生, α-TeO2∶Tm3+, Ho3+, Yb3+纳米材料能产生不同颜色的光, 包括白光。

α-TeO2∶Ho3+, Yb3+, α-TeO2∶Tm3+, Yb3+ and α-TeO2∶Tm3+, Ho3+, Yb3+ nanoparticles were prepared via a hydrothermal process. Under 980 nm excitation, α-TeO2∶Ho3+, Yb3+ nanoparticles showed green (545 nm) and red (651 nm) emission, which were attributed to the 5S2 → 5I8 and 5F5→ 5I8 transitions, respectively. The upconversion emission color changed markedly from yellow to green when the mole fraction of Yb3+ ions changed from 5% to 15% due to the green emission at 545 nm increased. The α-TeO2∶Tm3+, Yb3+sample showed blue emission at 476 nm, which was attributed to the 1G4→3H6 transition, and two weak red (651, 675 nm) emissions, which were attributed to the 1G4→3F4 and 3F2→3H6 transitions, respectively. The relative intensity ratio of the blue emission to the red emissions increased gradually with increasing Yb3+ concentration. Based on the generation of blue, green and red emissions, the α-TeO2∶Tm3+, Ho3+, Yb3+ nanoparticles could compose different color, including white, by controlling the doping concentration of rare earths in the α-TeO2 nanoparticles.