基于可印刷银纳米线复合透明导电薄膜的柔性聚合物太阳电池

The advantages of polymer solar cells (PSCs) lie in their light weight, mechanical flexibility and low-cost roll-to-roll solution-processible manufacturing in comparison to other types of solar cells. In addition to boost the power conversion efficiency (PCE) of PSCs through developing novel donor/acceptor materials and optimizing the electrode interfaces, it is imperative to develop solution-processible Indium Tin Oxide (ITO)-free transparent electrode to accommodate the roll-to-roll manufacturing of PSCs for their future commercialization. Herein, it is proposed to carry out the study on flexible PSCs employing ITO-free substrate. We will develop flexible substrate employing Ag nanowire (AgNWs)-based composite as the transparent electrode to replace the ITO/PET substrate due to its mechanical brittleness, high cost and the requirement for vacuum deposition. The patterned transparent conductive film comprising of AgNWs and metal oxide nanoparticles will be prepared on the glass or flexible PET substrate via layer-by-layer blade-coating at relatively low temperature. Therein, various kinds of solution-processible metal oxide nanoparticles such as NiOx, CuOx, MoOx and ZnO, etc, will be used to optimize the optoelectronic properties of the resultant AgNWs-based film including conductivity, surface work function and transmittance, and other properties including adhension and mechanical flexibility. The graphene quantum dots will be also attempted to futher enhance the conductivity of the AgNWs-based composite film. We will optimize the photovoltaic performance of the flexible PSCs based on the printable AgNWs-based composite substrate by improving charge extraction at the electrode interfaces and optimizing the donor/acceptor BHJ morphology. High-performance flexible PSCs will be fabricated on the solution-processible AgNWs-based composite/PET substrate. We will not only develop high-quality printable AgNWs-based transparent electrode compatible with roll-to-roll manufacturing of flexible PSCs, but also provide effective approaches for fabricating efficient flexible PSCs based on this kind of ITO-free substrate.

同其他类型太阳电池相比，聚合物太阳电池的优势在于它的质轻、柔性和低成本连续印刷制备。因此，在努力提高聚合物太阳电池能量转换效率的同时，基于柔性透明导电基板的聚合物太阳电池的光伏行为及相应印刷制备技术是其能否顺利实现产业化的关键。本项目提出开展柔性聚合物太阳电池研究，针对目前柔性ITO/PET基板光电性能差、无法印刷加工等实际问题，重点研制基于银纳米线(AgNWs)复合透明导电薄膜的可印刷柔性透明基板及相应高性能柔性聚合物太阳电池，拟利用多层图案化刮涂工艺路线结合可溶液加工无机半导体氧化物纳米粒子或石墨烯量子点辅助的方式协同改善AgNWs基复合透明导电薄膜的电导率、功函数、透光率以及对基板黏附性和弯折性等性能，改善基于新型透明电极的界面光生载流子提取能力和优化印刷活性层的凝聚态结构，制备出高性能可印刷的柔性聚合物太阳电池，为未来规模印刷制备柔性聚合物太阳电池提供有实际应用价值的方法和途径。

有机太阳电池的优势在于它的质轻、柔性和低成本连续印刷制备。随着新型高性能有机给/受体光伏材料的不断涌现，有机太阳电池的能量转换效率提升较快。但是，目前的报道的高效率有机太阳电池均采用刚性铟锡氧化物(ITO)透明导电玻璃作为衬底，成本较高，不具有柔性且不适合大面积连续加工。因此，努力提高聚合物太阳电池能量转换效率的同时，基于柔性透明导电基板的有机太阳电池及其相应印刷制备是其能否顺利实现产业化的关键。本项目提出开展柔性有机太阳电池研究，重点研究了基于银纳米线(AgNWs)复合透明导电薄膜的可印刷柔性透明导电基板及相应高性能柔性聚合物太阳电池的制备，研究内容涉及了高性能柔性银纳米线(AgNWs)复合透明导电薄膜的设计与制备，采用无卤溶剂和可大面积加工的刮涂工艺制备活性层薄膜及其形貌调控，给受体共混薄膜的固溶体效应以及二元/多元共混体系中的超快光物理过程研究。主要研究成果包括开发出多种可溶液加工的基于银纳米线复合透明电极/柔性基板制备方法，相应柔性太阳电池的能量转换效率达到13%以上，且表现出良好的耐弯折特性；开发了基于非卤代溶剂刮涂调控共混薄膜相分离结构的方法，电池的效率可达15%以上，为大面积加工有机太阳电池提供了有效途径；系统了研究了有机半导体共混薄膜的固溶体特性，利用固溶体特性提升了低空穴迁移率给体材料的有机太阳电池的光伏特性。研究了二元/三元共混体系的超快光物理特性和光伏行为，通过采用三元结构降低了电压损失和提高了光伏器件的能量转换效率，为制备高效率有机太阳电池提供了有效的实施途径。在项目执行期间，共发表SCI学术论文18篇，申请中国发明专利1件，撰写英文编著1章节，培养博士研究生4名。