Syntheses and Photoluminescence Properities of LaSi3N5 : Ce3+ Blue Phosphors by Carbothermal Reduction Method
- 材料学院－已发表论文 
利用碳热还原法制备了LaSi3 N5: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:1600℃时能够合成主相为LaSi3 N5: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n C/n La=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n C/n La=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LaSi3 N5: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 degrees C. There was a single-peak broadwide emission spectrum between 380 similar to 600 nm due to the electron transfer of Ce3+ from 5d-4f excited by 360 nm. The luminescence intensity reached the maximum value atn(C)/n(La) =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%similar to 345% after heat-dealing. WLED were fabricated by applying a blend mixture of the sample and commercial YAG on a UV chip (lambda blend m), which indicated that LaSi3N5 : Ce3+ blue phosphor had a potential application value in WLED.