新型单一基质型白色荧光粉是当前白光LED荧光粉研究的热点.宽带隙半导体BiOCl物化性质稳定,声子能量低,晶体结构对称性低、极化性强,具有作为稀土掺杂荧光粉基质材料的潜质.采用固相法制备了BiOCl:Dy3+及BiOCl:Li+,Dy3+荧光粉,并采用XRD、激发和发射光谱研究了其结构和发光特性.XRD结果显示在500 ℃低温下即可成功合成出纯四方相的稀土掺杂BiOCl晶体,而Li+掺入可进一步提高样品结晶度.在389 nm近紫外光激发下,荧光粉具有位于478 nm(蓝)和574 nm(黄)波段的Dy3+特征发射峰,并呈现较低的蓝黄光发射比例和优异的白光发射特性.相比单掺体系,Li+掺杂不仅使荧光粉发射增强,还实现了发光颜色的调节.研究结果表明,BiOCl:Dy3+荧光粉制备温度低,具有良好的近紫外光激发和白光发射特性,其较低黄蓝光发射比例性质可能与BiOCl独特的晶体结构有关;上述特性使其可能成为一种新型的潜在近紫外激发白光LED荧光粉。

In the present paper,we reported the luminescence properties of BiOCl:Dy3+ and BiOCl:Dy3+,Li+ phosphor synthesized by conventional solid state method.X-ray diffraction (XRD) and excitation and emission spectroscopy were used to characterize the samples.Results show that pure tetragonal BiOCl:Dy3+ crystals can be synthesized successfully at 500 ℃,and Li+ ion dopant improves the crystallinity of samples furtherly.Under near UV light excitation,the samples give the characteristic luminescence of Dy3+ ions located at 478 (blue) and 574 nm (yellow),which show a low yellow-to-blue intensity ratio (Y/B) of Dy3+ emission and white light emission.Moreover,codoping of Li+ ion can realize the enhancement of emission intensity and the adjustment of emission color.The characteristics of BiOCl:Dy3+ phosphor,low temperature preparation,good near ultraviolet excitation and white light emission make it to a promising near-ultraviolet WLED phosphor.