基于能量传递的宽带太阳光谱调制近红外下转换CaNb2O6发光薄膜研究

Solar cell that can convert sunlight to electricity based on the photovoltaic effect is a very important device, which can utilize solar energy reasonably. How to enhance the photoelectric conversion efficiency of the silicon solar cell is one of the focus issues presently. Therefore, a down-conversion layer containing luminescent materials doped with rare earth ions or transition metal ions is proposed to be placed at the front of solar cell to increase the photoelectric conversion efficiency of the silicon solar cells.Near-infrared down-conversion CaNb2O6 films are prepared by pulsed laser deposition (PLD) technique. The broadband strong absorption characteristics 4f-5d transition of rare earth Ce3 +, Eu2 +, and d-d transition transition metal ions Cr3+ ware selected to enhance the absorption of UV and blue light, and finally a near-ultraviolet - blue-green light is converted into efficient near infrared lightsilicon can be obtained through the Yb3 +, Nd3 + ions based on energy transfer . The optical properties of ion-doped electron energy level structure, fluorescence dynamics in CaNb2O6 film are studied by low temperature and high-resolution time-resolved fluorescence spectroscopy and other means.Study the relation between the film forming process, morphology, thickness and down-conversion luminescence effects and mechanism of the down-conversion, stable for improving the efficiency of the silicon solar cell, a transparent, efficient broadband near-infrared spectral. Stable,transparent, efficient broadband NIR CaNb2O6 films are get to improve the efficiency of silicon photovoltaic cells.Explore the application possibility of NIR quantum cutting in solar cells.

采用脉冲激光沉积(PLD)技术制备近红外下转换铌酸钙(CaNb2O6)发光薄膜。以能量传递为基础，选择具有宽带强吸收特性的4f-5d跃迁的稀土Ce3+、Eu2+ 和d-d跃迁的过渡金属离子Cr3+，增强对紫外光和蓝光的吸收，最终通过Yb3+、Nd3+离子获得将太阳光谱中的近紫外-蓝绿光高效转换成硅太阳能电池可利用的近红外光。应用低温高分辨荧光和时间分辨光谱等手段，系统地研究掺杂离子在CaNb2O6薄膜中的电子能级结构、荧光动力学等光学性能，揭示其薄膜成膜过程、形貌、厚度对下转换发光效率的影响及下转换机理，获得用于提高硅基太阳能电池效率的稳定、透明、高效的宽带光谱调制近红外下转换CaNb2O6薄膜，研究并优化CaNb2O6薄膜的近红外下转换方式、效率与机制，探索研究其在硅太阳电池的光电性能，为未来提高硅电池光电效率提高实验依据。

太阳能是一种清洁的、可再生的以及分布广泛的能源。太阳能电池当前新能源技术研究中最重要的研究领域之一，但其光电转换效率较低是硅太阳能电池的一个技术瓶颈。硅基太阳能电池由于只能吸收太阳光很窄波段的能量，大约损失 50%太阳光。通过在太阳能电池前表面增加一层下转换材料, 把短波长太阳光通过下转换光功能材料转换为近红外光；上转换发光材料能把长波长红外光转化成易吸收的可见，光都可以有效地提高硅基太阳能电池光电转换效率。本项目基于能量传递的思想制备具有宽谱带吸收特性的上转换/下转换发光材料，通过共掺过渡金属、稀土离子来实现。项目首先探索掺杂离子的合成方法和光谱性质，再深入研究某些有潜力的材料体系，为制备可提高太阳能电池光电转换效率的光转换材料提供经验和理论指导。 在下转换发光材料方面，研究了Cr3+、Ce3+和Yb3+在Y3Al5O12薄膜中的发光，为器件的应用做评估。在上转换发光材料方面，详细研究了Ho3+、Er3+、Pr3+和Yb3+共掺的CaNb2O6上转换发光，把透过电池的那部分长波长太阳光利用起来增强电池效率，这在太阳能电池应用领域具有重要意义。