利用碳热还原法制备了LaSi3N5∶Ce3+蓝色荧光粉, 重点研究了原料中掺C量和退火对样品纯度及发光性能的影响。 通过X射线衍射仪和荧光光谱仪分别表征样品的晶体结构和发光性能。 研究结果表明: 1 600 ℃时能够合成主相为LaSi3N5∶Ce3+的荧光粉。 在360 nm紫外光激发下样品可获得波段范围在380~600 nm的单峰宽带发射谱, 归结于Ce3+的5d-4f的能级跃迁。 当nC/nLa=4/1时样品发光强度达到最大, 并且光谱出现先红移后蓝移的现象。 经过退火的样品的发光强度与退火前相比提高了60%~345%。 将热处理后的nC/nLa=4/1的样品与商用YAG混合涂覆在UV芯片上(λem=365nm)封装成WLED, 证实了LaSi3N5∶Ce3+在白光LED领域潜在的应用价值。

LaSi3N5∶Ce3+blue phosphors were prepared by carbothermal reduction method. The influence of C content and heat-dealing on purity and luminescence of samples were investigated. The phosphors were characterized by X-ray diffraction (XRD) and fluorescence spectrophotometer (PL). XRD patterns revealed that LaSi3N5∶Ce3+could be combusted at 1 600 ℃. There was a single-peak broadwide emission spectrum between 380~600 nm due to the electron transfer of Ce3+ from 5d-4f excited by 360 nm. The luminescence intensity reached the maximum value atnC/nLa=4/1 followed by a continuous decline with a red shift and then a blue shift appeared in the spectrum. The luminescence intensity of samples improved 60%~345% after heat-dealing. WLED were fabricated by applying a blend mixture of the sample and commercial YAG on a UV chip (λ blend m), which indicated that LaSi3N5∶Ce3+blue phosphor had a potential application value in WLED.