Operando study of the influence of small molecule acceptors on the morphology induced device degradation of organic solar cells with different degrees of π–π stacking

Abstract

Due to the development of efficient non-fullerene acceptors with excellent crystallinity and effective inter-mixing with donor polymers, the power conversion efficiencies (PCEs) of organic solar cells (OSCs) have reached levels...

Defining Solid Additive's Pivotal Role on Morphology Regulation in Organic Solar Cells Produced by Layer‐by‐layer Deposition

“…Aside from general phase separation, the molecular packing, crystallization behavior, and donor‐acceptor vertical segregation are subsequently studied through grazing incidence wide angle X‐Ray scattering (GIWAXS) experiment. [ 60–62 ] Herein, 0.2° X‐ray incidence is used for neat PM6 and L8‐BO films, as well as BHJ and LBL films, while 0.05° X‐ray incidence is applied for LBL films to investigate the vertical phase segregation. [ 63 ] The 2D GIWAXS patterns and corresponding line cuts alongside in‐plane (IP) and out‐of‐plane (OOP) orientations are displayed from Figures S9–S15 (Supporting Information).…”

Understanding photochemical degradation mechanisms in photoactive layer materials for organic solar cells

“…30,37,80,81,107,109,111,112,143,144,146,148,214,215 Under illumination, morphological changes at nm-scale also occur, either due to molecular alterations or light-induced molecular movements at the nm-scale. 29,216–220 As depicted in Fig. 26, conducting thermal stability measurements at temperatures close to those during photostability measurements can aid in understanding thermally induced morphological effects.…”

“…80 It is also reasonable that light-induced molecular changes (chemical degradation) at the sub-nm scale could trigger the morphological changes at the nm-scale. 29,216,220,221…”

“…While AFM and GIWAXS exhibited only minor changes during photoaging, notably, a clear trend of light-induced nm scale morphological changes emerged from operando-GISAXS measurements. 216 This highlights the necessity of addressing the photochemically induced molecular changes at the sub-nanometer scale in conjunction with the light-induced nano-scale morphological changes.…”