太阳能电池用表面等离子体增强量子剪裁级联发光体系的构建及机理研究

Aiming at the problem of low photoelectric conversion efficiency for crystalline silicon solar cells, the coupling of surface plasmon effect of nano-metal, photoluminescence (PL) and quantum cutting (QC) is proposed to construct nano-metal coupled two-style cascade fluorescent system, which is used to obtain a high efficiency luminescence material with a wide absorption about 300-500nm based on a two-step frequency conversion and synchronous fluorescence enhancement, the obtained luminescence material will be introduce to the SiO2-based antireflection film to greatly enhance the the photoelectric conversion efficiency of solar cells. The core of this study is to improve the cooperative energy transfer efficiency between Ln3+ (Ln=Tb, Tm, Pr, etc.) and Yb3+. The effort will be devote to exploration the controllable preparation methods for the materials with core-shell structure, such as PL@QC@M and QC@PL-M, and illustrate the cascade energy transfer mechanism of the luminescent system, achieve the effective cascade luminescence between PL and QC based on the luminescent properties and structure characterization. Meanwhile, the influencing factors on the surface plasmon enhanced fluorescence will be investigated under the assistance of time-resolved spectrum and theoretical calculation, and the coupling mechanism model will be established, to obtain a new method for solar light frequency conversion and regulation, and finally achieve the efficient use of solar energy based on the down-conversion and antireflection difunctional film. This project will provide a new academic ideas for designing new materials for solar cells based on the above research results.

针对晶硅太阳能电池光电转换效率低的问题，提出将纳米金属的表面等离子体效应、光致发光（PL）和量子剪裁（QC）耦合，构建纳米金属耦合双模式级联发光体系，通过两级光谱转换与同步荧光增强，获得300-500nm宽吸收高量子效率发光材料，将其与SiO2基质减反射薄膜复合，实现太阳能电池光电转换效率大幅度提高。本项目以提高Ln3+-Yb3+（Ln=Tb、Tm、Pr等）之间的合作能量传递效率为核心,重点研究PL@QC@M、QC@PL-M等核-壳结构材料的可控合成工艺，通过发光性能及结构表征，阐明体系中的多级能量传递机理，实现PL→QC的有效级联发光。同时利用时间分辨光谱和理论计算等手段，弄清表面等离子体增强荧光的影响因素，建立耦合机制模型，获得太阳能光谱调控新策略。最终借助下转换-减反射双功能薄膜实现太阳能的高效利用。本课题为太阳能电池新材料的设计提供了新的学术思路。

针对晶硅太阳能电池光电转换效率低的问题，本项目将纳米金属的表面等离子体效应、光致发光（PL）和量子剪裁（QC）耦合，构建纳米金属耦合双模式级联发光体系，实现荧光同步增强，进一步将其与SiO2基质减反射薄膜复合，实现太阳能电池光电转换效率大幅度提高的研究目标。重点围绕YBO3、CaF2、CeF3、Y2O3以及SiO2@Y2O3等核壳结构Ln3+光致发光和Ln3+-Yb3+量子剪裁特性展开研究。在上述基质中Ce3+-Yb3+、Tb3+-Yb3+共掺杂体系均可实现紫外光子向近红外光子的转化，Ce3+-Yb3+、Tb3+-Yb3+之间表现出较高的能量传递效率和较好的稳定性；分别在YBO3: Ce3+, Tb3+, Yb3+和CeF3: Tb3+, Yb3+共掺杂纳米荧光粉中，实现了Ce3+-Yb3+离子之间的直接能量传递和Ce3+-Tb3+-Yb3+三种离子之间的逐级能量传递，进而实现了UV-Vis，Vis-NIR的级联宽光谱发光，同时使样品的近红外发光强度得到进一步提高。其中YBO3: Ce3+、Yb3+共掺杂荧光粉用于单晶硅太阳能电池光伏玻璃，其光电转换效率相对纯SiO2减反射薄膜提高了0.25%，较纯玻璃提高了0.52%；CaF2: Ce3+、Yb3+共掺杂荧光粉用于单晶硅太阳能电池光伏玻璃，其光电转换效率相对纯SiO2减反射薄膜提高了0.50%，较纯玻璃提高了1.20%；在Ag@Y2O3: Tb3+-Yb3+体系中，由于Ag纳米颗粒的局域表面等离子体共振效应(LSPR)，使得Ag纳米颗粒附近的电磁场增强，从而使原本不能被Tb3+吸收利用的光能量被吸收利用，导致Tb3+可见区域发光增强，进而提高Yb3+近红外区域发光强度，提高了Tb3+→Yb3+之间的能量传递效率。此外在本项目的支持下，课题组在上转换及量子点荧光纳米材料的制备及性能、新颖二维纳米片及其异质结的合成探索及性能研究等方面也取得了系列丰硕成果。本项目的开展为太阳能电池新材料的设计提供了新思路、新途径，对推动局域表面等离子体共振技术、光波转换-减反射双功能复合薄膜用于太阳能电池领域的基础研究和技术应用具有重要意义。