Yb 3+、Ho 3+共掺杂NaYF 4上转换发光材料制备及其发光性能
Synthesis of Yb 3+, Ho 3+ Co-doped NaYF 4 Phosphors and Their Up-conversion Photoluminescence Properties
-
摘要: 为了提高单结非晶硅太阳能电池的光电转换效率,缓解日益严重的能源和环境问题,采用高温固相法制备了稀土离子Yb 3+和Ho 3+共掺的NaYF 4上转换粉体,并对其进行了X射线衍射测试、扫描电镜以及光致发光测试. 对Yb 3+和Ho 3+共掺的NaYF 4上转换发光材料在热处理工艺下的变化进行了研究,分析了表面形貌和相结构对上转换发光性能的影响. 发现在980nm近红外光的激发下,共产生3个发射峰,中心波长分别位于541、649、750nm,为非晶硅太阳能电池的最佳响应波段,表明该材料可应用于非晶硅太阳能电池提升其电池效率. 进一步研究表明:可通过改变退火温度来改变样品的表面形貌和相结构,进而大幅度提高样品的上转换发光性能. 在退火温度为700℃时,样品呈标准六方相结构、表面致密、粒径均匀、上转换性能提高近40倍.Abstract: To improve the photoelectric conversion efficiency of the single junction amorphous silicon (a-Si) solar cells and alleviate the increasingly serious energy and environmental problems, Yb 3+, Ho 3+doped NaYF 4 phosphors were prepared by high temperature solid state method. The transformation of Yb 3+ and Ho 3+ co-doped NaYF 4 phosphors on photoluminescence were studied under the heat treatment process, and the effect of the transformation on surface morphology and phase structure were analyzed. The samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) testing. Results show that under the 980nm excitation, three up conversion emission bands 541,649 and 750nm are clearly resolved. The material can be used for promoting the conversion efficiency of a-Si solar cells. Further study shows that by changing the annealing temperature to modulate the surface morphology and phase structure of the samples, their PL density can be enhanced up to a great extent nearly 40 times, which is the strongest PL density of these samples at an annealing temperature of 700℃.
下载: