水热法稀土掺杂LaF3发光材料的制备及其荧光性能研究

稀土掺杂LaF₃发光材料因具有优越的物理与化学性能,已广泛应用于LED显示、照明节能、光学通讯和荧光探针等领域。笔者以氧化镧、氧化铕、硝酸、氟化钠、十六烷基三甲基溴化铵(CTAB)为原料,采用简单水热法合成了LaF₃∶Eu³⁺红色荧光粉,并探讨pH值、反应温度以及表面活性剂用量对产物的物相结构、形貌尺寸和荧光性能的影响。研究结果表明:水热产品均是六方晶系的LaF₃∶Eu³⁺纳米晶,晶粒尺寸介于20~100 nm内。荧光结果表明:LaF₃∶Eu³⁺纳米晶在397 nm(7F0→5L6)光源激发下表现出良好的橙红色发射(592 nm,5D0→7F1)。当Eu^3+离子掺杂摩尔浓度为9%时,样品的荧光强度达到最大值,更高的Eu掺杂浓度会引起荧光猝灭。

Study on Preparation and Fluorescence Properties of Rare Earth Doped LaF3 Luminescent Materials with Hydrothermal

LaF₃ phosphors doped by rare earth ions have been applied in LED,illuminating and energy source-saving,optics communication and fluorescence probe due to its outstanding physical and chemical properties.With La 2O 3,Eu 2O 3,HNO 3,NaF,cetyl-trimethyl ammonium bromide(CTAB)as materials,a facile hydrothermal method was adopted to synthesize LaF₃∶Eu³⁺red phosphors,and the effects of the pH value,reaction temperature,and surfactant dosage upon the crystal structure,morphology and fluorescence of the product were investigated in detail.The testing results show that the re-prepared samples are hexagonal LaF₃∶Eu^ 3+nanocrystals with the average grain size of 20~100 nm.It is found from the FL testing that all LaF₃∶Eu³⁺nanocrystals have a good orange-red emission(592 nm,5D 0→7F 1)excited by 397 nm(7F 0→5L 6).When the concentration of Eu^ 3+doped is 9%(mol),LaF₃∶Eu³⁺nanocrystal exhibits the strongest orange-red emission,but more Eu³⁺ions doped easily result in fluorescence quenching.