非富勒烯有机太阳能电池研究进展:从器件物理到磁场效应

Advances in Non-fullerene Organic Solar Cells:from Device Physics to Magnetic Field Effects

非富勒烯受体(NFA)材料是现阶段非常受欢迎的有机光电材料之一。基于非富勒烯受体的有机体异质结(BHJ)太阳能电池发展迅速,其单结能量转换效率(PCE)现已达到18%。有机半导体中单线态与三线态在磁场作用下的相互转换会影响其电子-空穴的解离与复合,从而对光伏性能有一定的影响。此外,三线态激子寿命和扩散距离较长,三线态-电荷反应的几率较大,增加光电流,使得三线态材料对于光伏性能的提高具有一定的作用。因此,本文主要从以下几个方面对非富勒烯有机太阳能电池进行叙述,首先讨论了有机太阳能电池中电荷分离、重组及能量损失对开路电压的影响;其次总结了有机太阳能电池磁场下自旋依赖的光物理过程及三线态材料在有机太阳能电池中的应用,了解二者对提高光伏性能的影响;最后对有机光伏性能的进一步提高以及有机半导体磁场下的自旋问题进行了展望。

Non-fullerene acceptor materials are one of the most popular organic optoelectronic materials at present stage.Organic bulk heterojunction(BHJ)solar cells based on non-fullerene acceptors(NFAs)have been developing rapidly,and their single-junction power conversion efficiencies(PCE)have reached 18%.The mutual conversion between singlets and triplets in organic semiconductors under the magnetic field will affect the dissociation and recombination for electrons and holes,thereby will have a certain impact on the photovoltaic performance.Moreover,the triplet excitons have a longer lifetime and diffusion distance,as well as higher probabilities for the triplet-charge reaction,which gives rise to the photocurrent,so that the triplet material has a certain effect on the improvement of photovoltaic performance.Thus,this article mainly discusses non-fullerene organic solar cells from the following aspects.Firstly,to discuss the effect of charge separation,recombination and energy loss on the open-circuit voltage;secondly,to talk about the spin-dependent photophysical process for the organic solar cells under the magnetic field and the application of the triplet materials in organic solar cells,both of which influence the improvement of photovoltaic performance;finally,a prospective for further improvements of the organic photovoltaic performance and the spin problem under the organic semiconductor magnetic field will be given.