无规共聚策略设计聚合物太阳能电池的展望与思考

Overview and Outlook of Random Copolymerization Strategy for Designing Polymer Solar Cells

近年来,有机聚合物太阳能电池获得了快速的发展,引起全球科研工作者的广泛关注.目前,相比富勒烯聚合物太阳能电池,非富勒烯聚合物太阳能电池的能量转换效率(PCE)已经超过14%.广泛研究的有机光伏(OPV)材料包括小分子和聚合物给体以及小分子和聚合物受体,但是,无规共轭聚合物给体和受体的研究相对较少.基于此种情况,本文综述了以p-型无规共轭聚合物为电子给体、n-型三元共轭聚合物为电子受体的富勒烯/非富勒烯聚合物有机太阳能电池材料的最新研究进展,包括可溶液加工p-型和n-型无规共聚物有机光伏材料.目前基于聚合物给体(PBDB-T)和无规共轭聚合物受体(PNDI-2T-TR)的全聚合物光伏效率最高达到8.13%,是到目前为止以无规共聚物为电子受体的全聚合物有机太阳能电池的最高能量转换效率之一,展现了很好的发展前景.最后对无规共轭聚合物太阳能电池的未来发展做了展望和总结.

Organic polymer solar cells which have achieved rapid development in recent years,therefore,attract wide attention around the world.At present,compared with fullerene polymer solar cells,the energy conversion efficiency(PCE)of non-fullerene polymer solar cells has already exceeded 14%.Organic photovoltaic(OPV)materials were widely studied including small-molecule/polymer donors and small-molecule/polymer acceptors.However,the studies on random conjugated polymer donors and acceptors are relatively rare.By introducing the third component into D-A conjugated polymer system to construct random conjugated polymer donor or acceptor,the absorption and the electron orbital energy levels could be well adjusted,and the open-circuit voltage(Voc),short-circuit current density(Jsc),and fill factor(FF)could be improved.Moreover,this strategy could also decrease the crystallinity of D-A polymer donor or acceptor availably,promoting the formation of better blend film morphology,appropriate phase separation size,and increase the electron or hole mobility.In order to adjust blend topography,the design and synthesis of molecular structures played an important role to improve the PCE of organic solar cells.Adding different ratios of electron-rich unit or electron-deficient unit to lower the strong crystallinity of polymers,which resulted in large phase separation,is not conducive to effective charge transport,thus reducing the efficiency of organic photovoltaics.Based on this situation,fullerene/non-fullerene polymer organic solar cells with p-type random conjugated polymer as electron donor and n-type ternary conjugated polymer as electron acceptor are summarized.At present,the total polymer photovoltaic efficiency based on the polymer donor(PBDB-T)and the random conjugated polymer acceptor(PNDI-2T-TR)reach up to 8.13%,which is one of the highest energy conversion efficiencies of polymer organic solar cells using the random copolymer as the electron acceptor so far,showing a good development prospect.Finally,the future development of the random conjugated polymer solar cells is summarized and prospected in this review.