Ba_3Si_6O_9N_4∶Eu^(2+)荧光粉制备及其表征

Study on the Preparation of Ba_3Si_6O_9N_4∶Eu^(2+) Phosphor and the Characterization of Their Luminescence Properties

采用基于高温固相的两步合成法,以BaSiO3为前驱体制备了Ba3Si6O9N4∶Eu2+荧光粉,主要研究了不同Eu2+掺杂浓度对Ba3Si6O9N4∶Eu2+荧光粉发光性能的影响机理,并与传统高温固相法制备的Ba3Si6O9N4∶Eu2+荧光粉的发光机理进行了对比分析。结果表明:与传统高温固相法相比,两步法制备的Ba3Si6O9N4∶Eu2+荧光粉具有更高的纯度和结晶度。Eu2+掺杂浓度大于9%时,两步法和传统高温固相法制备的样品都发生浓度猝灭现象。传统高温固相法与两步法制备Ba3Si6O9N4:Eu2+荧光粉的浓度猝灭机理一致,均是由于电偶极-电偶极相互作用造成的。在330nm的激发光下,两步法制备的Ba3Si6O9N4∶Eu2+荧光粉的发射光谱(峰值489nm)与传统的高温固相法(峰值512nm)相比,出现了蓝移的现象,更加接近于理论发射光谱中心(480nm)。能谱分析结果显示,两步法制备的荧光粉的元素组分更接近理论值,能有效降低晶格缺陷。两步法制备的Ba3Si6O9N4∶Eu2+荧光粉样品具有更好的热稳定性,更利于白光LED的应用。

Ba3Si6O9N4∶Eu2＋phosphors were synthesized by two-step synthesis processes based on high temperature solid phase using BaSiO3 as a precursor.The influence mechanism of the Eu2＋doping concentration to the luminescence properties of Ba3Si6O9N4∶Eu2＋phosphors were mainly investigated.This paper made a comparison between the luminescence properties of Ba3Si6O9N4∶Eu2＋phosphors prepared by two-step processes and solid-state reaction method.The results showed that the Ba3Si6O9N4∶Eu2＋phosphors synthesized by two-step processes had higher purity and higher crystallinity.There exists concentration quenching in Ba3Si6O9N4∶Eu2＋phosphors for both two-step processes and solid-state reaction when the doping concentration xis more than 9%.Both the concentration quenching mechanism of Ba3Si6O9N4∶Eu2＋phosphor prepared by solid-state reaction and two-step processes is electric dipole-dipole interaction.The emission peak of Ba3Si6O9N4∶Eu2＋phosphors（peak489nm）prepared by two-step processes had a blue shift compared to the emission peak of Ba3Si6O9N4∶Eu2＋phosphors（peak512nm）prepared by solid-state reaction.The emission peak of Ba3Si6O9N4∶Eu2＋phosphors prepared by two-step processes relatively close to the theoretical value（480 nm）.The spectrum analysis result showed that the element component of Ba3Si6O9N4∶Eu2＋phosphors prepared by two-step processes was closer to the theoretical value,it means that the two-step processes can effectively reduce the lattice defects.The Ba3Si6O9N4 ∶Eu2＋phosphors synthesized by two-step processes had better thermal stability,which demonstrates to be a highly promising phosphor for white-LED applications.