偏硅酸钙中Ce^(3+)的发光性质

LUMINESCENCE PREPERTIES OF Ce^(3+) IN CALCIUM METASILICATE

制备了Ce^(3+)激活的CaSiO_3磷光体。在77K和室温下研究讨论了它们的激发和发射光谱以及荧光寿命等光学性质,分析了结构和电荷补偿剂的影响。在UV或CR激发下,Ce^(3+)发射较强的蓝紫光,峰值为396nm。室温下,Ce^(3+)离子的荧光寿命大约为30ns。

Calcium metasilicate is a kind of practicable luminescence host.A new phosphor which is Ce3+ activated CaSiO3 was prepared by a solid state reaction at high temperature. The emission and excitation spectra of CaSiO3:Ce3 + were investigated at liquid nitrogen temperature and at room temperature. Under ultraviolet or cathode-ray excitation CaSiO3:Ce3+ phosphors show a considerably strong bluish-purple emission consisting of two overlapping bands with peaks at about 396nm and 430nm,respectively.With a energy separation of about 2000cm-1, these two bands correspond with the transition of the lowest-5d state to the 2F5/2 and 2F7/2 terminal levels.The excitation spectrum of Ce3+ in CaSiO3 distributes in the region from 230nm to 380nm, which is a broad band at least consisting of three overlapping subbands. These bands rise from the ground state to different 5d levels splited by the crystal field and from different Ce3+ ions positioned at distinct Ca2 + sites.This Ce3 + -activated phosphor shows a very fast fluorescence decay. The fluorescence lifetime of Ce3+ in CaSiO3 rs approximately 30ns with' excitationof a 337.1nm laser pulse with a width of 6ns at room temperature.In the paper, the influence of preparing condition, Ce3+ concent ration, crystal structure as well as charge compensator on the luminescence properties of Ce3+ are discussed.