Dy^(3+)掺杂TeO_2单晶的生长及其发光性能研究

Growth and Luminescence Properties of Dy^(3+) Doped TeO_2 Single Crystal

通过坩埚下降法成功生长出直径为1inch、等径部分长度达到7cm的掺0.2mol%Dy^(3+)的TeO_2晶体,该晶体主体部分无色透明、无裂纹、无明显包裹物,但后半部有裂痕,且有灰白色析出物,在可见光波段透过率约为70%。测试了TeO_2:Dy晶体的荧光光谱,观察到了Dy^(3+)离子外层4f电子能级跃迁产生的特征激发峰和吸收峰,并给出了简单的能级跃迁发光机理图。结果表明,它在363nm近紫外光激发下,能够发射中性白光,在348nm和387nm近紫外光、453nm蓝光激发下,能够发射稳定的暖白光,从而实现通过改变激发光波长调节该晶体发射不同的白光。因此,TeO_2:Dy是一种能够实现可调谐白光发射的荧光单晶候选材料。

0.2mol% Dy3＋ doped TeO2 crystal with 1 inch in diameter and 7 cm in length was grown by Bridgeman method. The main part of it was transparent and free of cracks and inclusions, but it was cracked at the latter part while gray, white precipitate occurred at the top part, and the transmittance reached about 70%. The fluorescence spectrum of TeO2： Dy crystal was examined and observed the characteristic excitation and emission peaks for 4f electron energy level transition of Dy3＋ , while a simple light emission mechanism was given. The results show that the crystal emitted neutral white light when excited by NUV light of 363 nm, and emitted stable warm white light when excited by NUV light of 348 nm, 387 nm and blue light of 453 nm. It realized adjusting the crystal to emit different white light by changing the wavelength of excitation light. TeO2： D y crystal is a candidate of fluorescent single crystal which could realize tunable white light emission.