有机-无机杂化有源层中局域电、磁场优化及柔性太阳电池研究

To achieve high quality photoelectric conversion flexible materials and devices, organic-inorgainc hybrid semiconductor film with structure, function hybrid feature will be introduced in this project. A high flexible conductive substrate fabricated by roll to roll process will be introduced in the project. Also, surface plasmon will be introduced in the semiconductor film to investigate the interaction mechanism among electric field, magnetic field and incident light. The light absorption, build in field and charge transfer properties of the hybrid film will be optimized through controlling the morphology of micro/nano-structures in the film, enhancing interface performance and introducing new effects. An important scientific issue, localization and direction of built-in field in bulk heterojunction (BHJ), is aroused. The formation mechanism and distribution property of built-in filed will be investigated. Based on localization property of the surface plasmon, we will combine it with bulk heterojunction by interface modification method, realizing enhanced light absorption of the whole active layer. At the same time, the enhanced filed introduced by surface plasmon will promote the exciton generation and dissociation in situ. In order to increase the efficiency of hybrid solar cells, we will design several localized surface plasmon. The effect of localized charge transfer, localized field enhanced light absorption and scattering, density of localized states on exciton generation and dissociation, carrier transportation, carrier recombination will also be investigate. We will try to reveal the mechanism of enhanced photoelectric conversion in organic-inorganic hybrid system and develop high specific power(kW/kg), light, flexible, high efficiency solar cells.

以柔性光电转换薄膜材料和器件为目标，使用适宜卷对卷压印技术制备的高柔性导电衬底，构筑具有结构、功能杂化特性的有机-无机杂化半导体薄膜，在薄膜内引入表面等离激元，研究电、磁场与入射光子的相互作用规律。结合薄膜内微结构设计调控光吸收、内建电场及载流子输运性能，基于新原理实现高效光电转换。提出体异质结结构中内建电场的局域化与方向性问题，研究依赖于体异质结的内建电场形成原理与分布特征。针对表面等离激元作用的近场特征，提出以界面修饰方法将表面等离激元与体异质结相结合，实现有源层整体增强光吸收，电场增强效应促进光生激子产生和原位分离。以提高大面积柔性太阳电池效率为核心目标，设计表面等离激元结构，研究局域的电荷转移、光吸收和光散射等因素对光生激子产生、分离及载流子输运、复合过程的影响规律。揭示有机-无机杂化体系的光电转换增强机制，研制高比功率（kW/kg）的轻质、柔性、高效太阳电池。

可溶液加工的有机无机杂化太阳电池在轻质、柔性、低成本和半透明等方面具有广阔的应用前景。本项目主要开展太阳电池中有源层中的电、磁场优化研究，同时研制出高性能的柔性太阳电池。项目完成了研究计划的各项内容，根据领域发展情况和工作进展情况，增加了一些研究内容。.项目揭示了太阳电池中激子分离和载流子输运与异质结内建电场方向和收集电极方向之间的内在关系，通过引入互穿网络结构、等离激元调控局域电场强度、构建合适的界面能带弯曲、优化异质结内建电场方向，提升了载流子输运和收集的驱动力。创新性引入了泵浦-探测光电导技术，实现了对三元体异质结体系中激子分离和载流子传输路径问题的直接实验研究。揭示了ITIC在三元体系中光电流产生和电荷传输中的主导作用，而PCBM在三元体系中的主要作用是接受PBDB-T的电子并以比ITIC更快的速度传递到阴极。此方法为解析多元体异质结中的激子分离和载流子传输路径提供了有效手段，为优化选择多元体异质结材料，实现有源层宽光谱吸收和高效电荷传输提供了重要参考。.原创性地基于曲面阵列陷光结构研制了有机太阳电池，解决了传统平面异质结和体异质结的局限性，实现了有源层中电场和光场的协同优化，为研制基于较小有源层厚度的高效太阳电池提供了基础。利用水浸法冲洗PEDOT：PSS空穴传输层，使有机太阳电池的光电转换效率提升到16.75%。开展了有机无机杂化钙钛矿太阳电池中电、磁场优化及载流子输运动力学研究，通过多层协同优化，反型结构电池效率达到了20.5%，突破了当时同类型器件效率纪录。基于银网格柔性衬底研制了柔性有机太阳电池，效率达到7.27%，器件弯折1000次之后，效率保持初始值的88.3%。制备出杂化钙钛矿柔性太阳能电池，效率达到15.36%，能够满足一些便携可穿戴设备的应用需求。.本项目实施过程中共发表SCI论文19篇，申请发明专利9项，获得授权专利1项，培养博士研究生8名，硕士研究生2名。先后与美国、德国及波兰相关课题组开展了合作交流，参加学术会议并作报告9次。