Yang Dan, Löhrer Franziska C, Körstgens Volker, Schreiber Armin, Cao Bing, Bernstorff Sigrid, Müller-Buschbaum Peter
Lehrstuhl für Funktionelle Materialien Physik-Department Technische Universität München James-Franck-Str. 1 Garching 85748 Germany.
Department of Chemistry University of Alberta Edmonton AB T6G 2G2 Canada.
Adv Sci (Weinh). 2020 Jul 1;7(16):2001117. doi: 10.1002/advs.202001117. eCollection 2020 Aug.
Solvent additives are known to modify the morphology of bulk heterojunction active layers to achieve high efficiency organic solar cells. However, the knowledge about the influence of solvent additives on the morphology degradation is limited. Hence, in operando grazing-incidence small and wide angle X-ray scattering (GISAXS and GIWAXS) measurements are applied on a series of PffBT4T-2OD:PCBM-based solar cells prepared without and with solvent additives. The solar cells fabricated without a solvent additive, with 1,8-diiodoctane (DIO), and with -chlorobenzaldehyde (CBA) additive show differences in the device degradation and changes in the morphology and crystallinity of the active layers. The mesoscale morphology changes are correlated with the decay of the short-circuit current and the evolution of crystalline grain sizes is codependent with the decay of open-circuit voltage . Without additive, the loss in dominates the degradation, whereas with solvent additive (DIO and CBA) the loss in rules the degradation. CBA addition increases the overall device stability as compared to DIO or absence of additive.
已知溶剂添加剂可改变本体异质结活性层的形态，以实现高效有机太阳能电池。然而，关于溶剂添加剂对形态降解影响的了解有限。因此，对一系列在制备过程中有无添加溶剂的基于PffBT4T-2OD:PCBM的太阳能电池进行了原位掠入射小角和广角X射线散射（GISAXS和GIWAXS）测量。未添加溶剂添加剂、添加1,8-二碘辛烷（DIO）和添加对氯苯甲醛（CBA）添加剂制备的太阳能电池在器件降解以及活性层的形态和结晶度变化方面表现出差异。中尺度形态变化与短路电流的衰减相关，晶粒尺寸的演变与开路电压的衰减相互依存。不添加添加剂时，Isc的损失主导降解，而添加溶剂添加剂（DIO和CBA）时，Voc的损失主导降解。与DIO或不添加添加剂相比，添加CBA可提高器件的整体稳定性。
