Tm3+和 Yb3+共掺杂PGETYA玻璃的直接敏化上转换发光

制备了一种稀土离子掺杂的PGETYA氟氧玻璃材料,它不仅具有较高的上转换发光效率,而且还避免了氟化物基质的缺点。其组分为58.52PbF₂-34.43GeO₂-3Al₂O₃ -0.05Tm₂O₃-4Yb₂O₃,以共掺杂Tm³⁺和Yb³⁺离子为上转换研究的对象。测量了该玻璃系统在980 nm LD激发下的上转换发光光谱,观察到很强的476 nm的蓝色荧光,它来源于Tm³⁺离子的¹G₄→³H₆跃迁。同时,还有两个较弱的红色荧光来源于Tm³⁺离子的¹G₄→³H₄和³F₃→³H₆跃迁。对上转换发光强度与泵浦电流关系曲线的拟合结果表明:此材料的蓝色上转换为三光子过程,红色上转换为双光子过程。

Direct-sensitized Upconversion in Yb3+ and Tm3+ Codoped PGETYA Glass

Over the several passed decades, the upconversion luminescence of rare earths doped glasses has been attracted much interest due to its applications in short wavelength laser devices, three dimensional displays and optical storage sources. Therefore, exploring novel materials with high luminescent efficiency and good chemical and mechanical stability has become a challenge to the researchers. It has been of technical and applied importance to understand the mechanisms of the upconversion luminescence in the inorganic materials doped by rare earths. In this paper, a novel oxyfluoride glass sample PGETYA was prepared by a melt-quenching technique. This glass system not only has the higher up-conversion luminescence efficiency, but also avoids the drawback of both the oxide and fluoride host materials. The PGETYA sample consists of 58.52PbF_2-34.43GeO_2-3Al_2O_3-0.05Tm_2O_3-4Yb_2O_3 (in molar), among which GeO_2 is the main component, namely glass former, others are introduced as adjustors to improve the glass performance. Tm~(3+) and Yb~(3+) ions are doped as co-operative luminescent activators. The upconversion emission spectrum was measured under 980 nm excitation by using a semiconductor laser diode. Very strong blue upconversion emission at 476 nm originating from ~1G_4→~3H_6 transition of Tm~(3+) can be seen by naked eyes. Meanwhile two weaker red emissions originating from ~1G_4→~3H_4 and ~3F_3→~3H_6 transitions of Tm~(3+) were also observed. Upconversion luminescence intensity variations with the increase of excitation density viz the increase of LD working currents were investigated. The nonlinear curve fittings of the relationship between the up-conversion emission intensity and LD working current to the theoretical result were carried out, and it was concluded that the blue up-conversion for this material is nicely fitting in with the three-photon process and red one fulfills the two-photon process. These results suggested that the studied oxyfluoride glass with the designed composition may be a good candidate material for the practical applications in short wavelength laser and three dimensional displays.