基于非富勒烯电子受体的半透明有机太阳能电池

半透明有机太阳能电池以其独特的光电特性在建筑集成光伏上具有广阔的应用前景。非富勒烯小分子受体近几年发展十分迅速。其中,基于非富勒烯小分子受体的半透明有机太阳能电池具有较高的光电转换效率和平均可见光透过率,因而得到了广泛关注。本文总结了近几年来非富勒烯受体型半透明有机太阳能电池的最新研究进展,探究活性层材料设计及器件构型优化对半透明有机太阳能电池的影响,希望为半透明有机太阳能电池在今后研究中新材料体系的优选提供一定的参考。

Semitransparent Organic Solar Cells based on Non-Fullerene Electron Acceptors

Semitransparent organic solar cells(ST-OSCs)have attracted attention for use in building integrated photovoltaics because of their large range tunability in colors,transparency,and high efficiency.However,the development of semitransparent devices based on fullerene acceptors remained almost stagnant in the early period.This was due to the weak absorption of fullerene small molecules in the visible and near-infrared regions as well as the large non-radiative energy loss,resulting in drastic open-circuit voltage loss.In addition,the energy level and chemical structure of fullerene molecules cannot be easily regulated,and the strong aggregation characteristics of fullerenes greatly limit the development of OSCs.In contrast,the designability of the chemical structures and controllability of the energy levels of non-fullerene electron acceptors has encouraged researchers to explore highperformance organic solar cells while and simultaneously stimulating the development of ST-OSCs.In this review,the recent progress in non-fullerene small molecule acceptors for ST-OSCs is summarized.The article focuses on ST-OSCs from the aspects of device structures and active layers.In view of the semitransparent device structure,except for replacing the traditional electrodes with semitransparent electrodes,researchers have introduced suitable interface layers to regulate the absorption and reflection of sunlight.The interface layers mainly contain a reflective layer(evaporated on the top electrode to reflect near-infrared light);an anti-reflection layer(located below ITO(indium tin oxide)to mitigate light reflection at the air-glass interface and thus enhance the absorption of sunlight);and an optical outcoupling layer(simultaneously increasing reflection and transmission).From the active layer,it is mainly divided into two categories.First,researchers have optimized the photovoltaic performance of semitransparent devices from the perspective of molecular structures,mainly by broadening the absorption window of non-fullerene small molecule acceptors,thus improving the crystallinity and charge mobility of small molecules,and regulating the stacking behavior and orientation of molecules in the films.Second,regarding the active layer processing,much effort has been undertaken to optimize the light absorption,morphology,and charge carrier transport channels of blended films.