A Terpolymer Acceptor Enabling All‐Polymer Solar Cells with a Broad Donor:Acceptor Composition Tolerance and Enhanced Stability

Abstract

Achieving a broad donor:acceptor (D:A) composition tolerance in efficient organic solar cells (OSCs) is important for printing large‐area solar cell modules. Herein, all‐polymer solar cells (all‐PSCs) based on new terpolymer acceptors and a well‐known polymer donor PTB7‐Th are fabricated to explore the effect of D:A ratio on morphology and photovoltaic performances. The all‐PSCs show a promising power conversion efficiency (PCE) of 7.23% with an optimum D:A ratio of 1:2 and retain over 40% of its optimal PCE with ultrabroad D:A composition tolerance from 1:30 to 10:1. In addition, the all‐PSCs can maintain 90% of its original PCE after 400 h of storage despite such broad range of D:A ratio, which is much better than those of other types of OSCs and even better than the benchmark all‐polymer system with N2200 as the acceptor under the same condition. The results show the superiority of the all‐PSCs in terms of D:A ratio tolerance and performance stability, which should be conducive to practical applications of all‐PSCs.

Developing Y‐Branched Polymer Acceptor with 3D Architecture to Reconcile Between Crystallinity and Miscibility Yielding >15% Efficient All‐Polymer Solar Cells

“…In comparison to PYT, PYTT‐based device displays lower leakage currents at reverse bias and higher currents as the forward bias is larger than 1.0 V, suggestive of more efficient charge transfer and suppressed carrier recombination in device. [ 34 , 35 ] Subsequently, the dependence of J SC on light intensity was evaluated to probe the non‐geminate recombination dynamics. The relation between J SC and P light is expressed by an equation of J SC ∝ P light S where S indicates the degree of bimolecular recombination.…”

Recent Research Progress in Random Copolymerization of Polymer Photovoltaic Materials for High‐Performance Polymer Solar Cells

“…Liu et al reported a series of random copolymer acceptors that consisted of different side chain‐substituted BTI2‐based units and ‐fluorinated thiophene units, namely, PBTI2(0HD)‐FT, PBTI2(30HD)‐FT, PBTI2(50HD)‐FT, and PBTI2(70HD)‐FT. [ 112 ] Thereinto, the PBTI2(30HD)‐FT: PTB7‐Th‐based devices achieved a higher PCE of 7.23%. Interestingly, benefiting from the sufficient D: A interface and well‐maintained interpenetrating network, the all‐polymer devices presented an ultrawide D:A ratio tolerance from 1:30 to 10:1 and could maintain exceeding 40% of its original PCE value despite at extremely high or low loading of PBTI2(30HD)‐FT.…”

Domain size control in all-polymer solar cells

“…Moreover, the long-chain polymers prefer to run through different crystalline regions, which invested the active layer with continuous paths and mechanical flexibility (Zhou et al, 2022). Because of these characteristics, all-PSCs exhibit better stability compared with polymer/fullerene or polymer/nonfullerene-based solar cells, which indicate that all-PSCs hold a great potential applications in large-area flexible devices (Zhang and Li, 2021;Xu et al, 2019;Liu et al, 2020a).…”