本文采用普适的固相法合成一种新型硅酸盐K3(Y0.88Yb0.10Ho0.02)Si2O7荧光粉,并系统研究样品的上转换光致发光和光学测温性能.研究表明,在980 nm激发下,K3(Y0.88Yb0.10Ho0.02)Si2O7荧光粉表现出红光发射,主发射峰位于665 nm,归属于Ho3+的5F5→5I8跃迁.通过对发光强度和激发功率的对数变换,研究荧光粉的上转换机制和可能导致的上转换的光子反应,证明(5S4,5F2)→5I8跃迁上转换发光机制为三光子机制,5F5→5I8跃迁则为双光子机制.K3(Y0.88Yb0.10Ho0.02)Si2O7荧光粉的5F5/(5F4,5S2)的非热耦合能级的荧光强度比结果表现出其良好的光学测温潜力,经计算其最大灵敏度约为0.17 K-1(423 K).
In this work,a new type of silicate K3(Y0.88Yb0.10Ho0.02)Si2O7 phosphor was synthesized by solid state method.The up-conversion photoluminescence and optical thermometry properties of samples were systematically studied.The results show that K3(Y0.88Yb0.10Ho0.02)Si2O7 phosphor exhibits red emission under 980 nm excitation.The main emission peak is located at 665 nm,which is attributed to the 5F5 →5I8 transition of Ho3+.The up-conversion mechanism of the phosphor and the photon reaction which may lead to up-conversion were studied by logarithmic transformation of the luminescence intensity and excitation power.It is proved that the up-conversion luminescence process for the(5S4,5F2)→5I8 transition is a three-photon mechanism,and the 5F5 →5I8 transition is a two-photon mechanism.The fluorescence intensity ratio of the 5F5/(5F4,5S2)non-thermal coupling energy level of K3(Y0.88Yb0.10Ho0.02)Si2O7 phosphor shows its good optical thermometry potential,and the maximum sensitivity is calculated to be about 0.17 K-1(423 K).