【摘要】 采用简单的水热方法制备了一系列Ce3+-Yb3+共掺的CaF2纳米粒子。XRD测试结果表明,Ce3+和Yb3+不同掺杂浓度下的CaF2纳米粒子结晶良好。SEM和TEM分析表明,纳米粒子的平均粒径为30 nm左右。系统地研究了各样品的发光性质包括激发谱、紫外-可见发射谱、近红外发射谱和荧光寿命。激发Ce3+的5d能级,在900～1050 nm波长范围得到很强的近红外发射。随着Yb3+离子浓度的增加,Ce3+的发射强度降低,Yb3+的发射强度先升高后降低,Ce3+的寿命减少,能量传递效率增加。作为一个下转换光转换器,这种材料应用于硅基太阳能电池前端,能够减少电池热损失,增加电池转换效率。更多还原

【Abstract】 A series of Ce3+-Yb3+ co-doped CaF2 nanoparticles with Yb3+ concentrations from 0 to 10% and Ce3+ concentration keeping at 1% were prepared by hydrothermal method and characterized by X-ray diffraction(XRD),scanning electron microscope(SEM) and transmission electron microscopy(TEM).Their photoluminescence properties including excitation spectra,ultraviolet-visibe(UV-Vis) and near infrared(NIR) emission spectra and fluorescence dynamics of Ce3+ were systemically studied.In Ce3+-Yb3+ co-doped CaF2 nanoparticles,a strong infrared emission originated from Yb3+ 2F5/2-2F7/2 transition at 900～1050 nm matching to energy of Si band gap of Si-based solar cells was observed under the excitation of 5d level of Ce3+.The lifetime of Ce3+ decreased and the energy transfer efficiency increased with increasing Yb3+ concentration.As a downconversion luminescent convertor,these kinds of materials were used in front of Si-based solar cells to reduce thermalization losses and enhance conversion efficiency of the cells.更多还原