Morphology evolution with polymer chain propagation and its impacts on device performance and stability of non-fullerene solar cells

Abstract

Blending morphology evolves with polymer chain propagation with reduced phase separation scale and increased phase purity while blending morphological stability is dominated by the miscibility between the donor and acceptor.

Efficient organic solar cells with superior stability based on PM6:BTP-eC9 blend and AZO/Al cathode

“…But relatively less has been dedicated to efficient NFA-based systems about this topic ( Du et al., 2020 ). To promote the stability of NFA-based OSCs, different strategies including tailoring of NFA ( Du et al., 2020 ; Hu et al., 2020 ; Labanti et al., 2021 ) and donor ( Zhang et al., 2021 ), designing new active materials ( Bin et al., 2020 ), ternary-blend method ( Yang et al., 2020 ), utilization of stabilizer/dopant ( Linglong Ye et al., 2020 ; Zhang et al., 2019 ), and interface engineering ( Lin et al., 2020 ; Yao et al., 2020 ), have been adopted. Focusing on photo-stability, Brabec ( Du et al., 2020 ) and coworkers systematically studied the PM6/derivatives: IT-4F blend systems.…”

“…To improve device thermal-stability, polymer donors with different molecular weights were utilized for blend (PBDB-T4Cl5S:Y6) morphology optimization by Huang et al. ( Zhang et al., 2021 ). Much improved shelf- and thermal-stability were accomplished with a medium molecular weight owing to optimal miscibility between donor and Y6.…”

“…Thermal stress is considered another sensitive and key factor causing performance decay as its strong impact on blend nanoscale morphology by phase separation (Speller et al, 2019;Zhang et al, 2017). To improve device thermal-stability, polymer donors with different molecular weights were utilized for blend (PBDB-T4Cl5S:Y6) morphology optimization by Huang et al (Zhang et al, 2021). Much improved shelf-and thermal-stability were accomplished with a medium molecular weight owing to optimal miscibility between donor and Y6.…”

Modulating Chlorination Position on Polymer Donors for Highly Efficient Nonfullerene Organic Solar Cells

“…The phase separation of the blends will be disturbed and thus makes a great difference to the short-circuit current ( J SC ) and fill factor (FF) of the devices. [16][17][18] However, introducing a substituent group to the polymer donors is an effective methodology to further improve the device performance. However, the correlation between the position of substituent groups and the photovoltaic properties of polymer donors has rarely been carefully studied and compared.…”

Understanding the molecular mechanisms of the differences in the efficiency and stability of all-polymer solar cells

“…Importantly, the spontaneous phase separation of the PM6:PYT-H blend probably forms over-purified domains, which result in the composition of the amorphous mixed-phase away from the percolation threshold and the relatively low PCE (9.91%). 55,56 Overall, having fully understood the P D -P A pair miscibility and molecular crystallinity of the PBDB-T congeners:PYT blend films by the GIWAXS, GISAXS, AFM and contact angle characterization, it is possible now to illustrate the corresponding schematic morphologies, as depicted in Fig. 5D.…”