尿素辅助的共沉淀模板法制备LSO:Ce^(3+)发光粉体

Synthesis of LSO:Ce^(3+) Luminescent Powders via Urea-assisted Coprecipitation Template Method

采用尿素辅助的共沉淀模板法,通过在单分散的SiO2微球模板上包覆Lu(OH)3制备出了具有核-壳结构的SiO2@Lu(OH)3粉体颗粒,经煅烧后得到了LSO:Ce3+荧光粉体.结果发现煅烧温度对荧光粉的相组成和形貌都产生了很大影响.当在1200℃下煅烧2 h时,得到了单相LSO:Ce3+粉体.在900℃煅烧后的粉体颗粒呈球形,粒径大约为400～500 nm,随着煅烧温度的升高,粉体形状变得不规则,而且有团聚现象.采用PL光谱仪对1200℃煅烧的粉体进行了光学性能表征,结果表明其激发谱中的最强激发峰位于360 nm处,发射谱表现为位于384～440 nm范围内宽发射峰中心420 nm,归因为Ce3+的5d→4f间的电子跃迁.

Core-shell structured SiO2·Lu（OH）3 particles have been successfully fabricated via a urea-assisted homogeneous precipitation method using St6ber method derived silica as templates. LSO：Ce3＋ phosphors were obtained by a subsequent calcination procedure. It was found that the calcinations tempera- ture had a great influence on the phase and morphology of the final phosphors. A single-phase LSO：Ce3＋ was prepared at 1200℃ for 2 h. The sample treated at 900℃ shows spherical morphology with the particle size of about 400～500 nm, while the sample calcined at higher temperature displays irregular shape with some aggregation. The photoluminescence （PL） spectra of the sample treated at 1200℃ were investigated. The excitation spectrum is dominated by a broad band centered at 360 nm. Monitored with 360 nm UV emission, the emission spectrum consists of a broad band ranging from 384 nm to 440 nm with a maximum peak at 420 nm, which can be attributed to the 5d→4f transition of Ce3＋.