Eu^(3+)掺杂YPO_4荧光材料的柠檬酸辅助溶胶-凝胶法合成及其荧光性能研究

Citric Acid-assisted Sol-Gel Synthesis and Fluorescence Research of Eu^(3+)-doped YPO_4 Phosphors

采用柠檬酸辅助溶胶-凝胶法合成了Eu3+掺杂YPO4荧光材料,并研究了合成产物的晶体结构和荧光性能。结果表明,热处理温度及时间直接影响着产物的物相结构。在热处理过程中,干凝胶首先形成YPO4·0.8H2O六方晶系晶体,随后发生脱水反应转变为四方晶系YPO4晶体。样品的发射光谱表明,所制备Eu3+掺杂YPO4可被222nm波长光有效激发,在595nm和621nm等处发射出强烈的橙红色光;当Eu3+掺杂浓度(摩尔分数)高于8%时样品出现浓度猝灭现象;提高热处理温度和延长热处理时间可有效提高Eu3+掺杂YPO4材料的荧光性能。

Eu3＋-doped YPO4 phosphors were synthesized via citric acid-assisted sol-gel process, and their crystal structure and fluorescence properties were investigated. The results show that both heat treatment temperature and heat treatment time have direct influence on phase structure of the products. During the heat treatment,the hexagonal YPO4 · 0.8H20 crystal is generated from xerogel before tetragonal YPO4 crystal is developed from the dehydration of YPO4 · 0.8H2O crystal. Emission spectra of the samples show that the synthesized Eu3＋-doped YPO4 can be effectively excited with 222 nm wavelength light, emittng intense orange-red light at 595 nm and 621 nm. Concentration quenching phenomenon occurs when Eu3＋ dosage is over 8% （molar fraction）. Furthermore,fluorescence properties can be effectively improved by in- creasing heat treatment temperature or prolonging heat treatment time.