π-Extended Conjugated Polymer Acceptor Containing Thienylene-Vinylene-Thienylene Unit for High-Performance Thick-Film All-Polymer Solar Cells with Superior Long-Term Stability

作者：Zhang, Jiabin; Tan, Ching-Hong; Zhang, Kai^*; Jia, Tao^*; Cui, Yongjie; Deng, Wanyuan; Liao, Xunfan; Wu, Hongbin; Xu, Qinghua; Huang, Fei^*; Cao, Yong

来源：Advanced Energy Materials, 2021, 11(48): 2102559.

DOI：10.1002/aenm.202102559

• all-polymer solar cells
• face-on orientation
• long-term stability
• thickness-insensitivity
• thienylene-vinylene-thienylene

Despite the rapid developments in all-polymer solar cells (all-PSCs) due to the progress of polymerized small molecular acceptors (PSMA), the effect of linkage unit conjugation on the polymer acceptor (P-A) is not well understood and P(A)s with high efficiency, good stability, and thickness-insensitivity are rarely seen. Herein, two novel PSMAs, named PJTVT and PJTET are designed, by incorporating conjugated thienylene-vinylene-thienylene (TVT) and unconjugated thienylene-ethyl-thienylene (TET) units, respectively. Results show that the energy levels, energy losses, and energy offset of the two PSMAs have little difference (0.03 eV). However, due to the pi-extended coplanar backbone of PJTVT, when blended with polymer donor JD40, a more ordered pi-pi stacking and enhanced face-on orientation morphology is observed, which contributes to enhanced exciton dissociation, superior charge transport, and faster charge extraction, leading to a record power conversion efficiency of 16.13% (10.93% for JD40:PJTET). Impressively, the JD40:PJTVT device shows superior thickness-insensitivity and long-term stability, both of which make it an ideal choice for industrialization. These results demonstrate that molecular modulation in the linking unit is a promising strategy to construct PSMAs for high-performance thick-film all-PSCs with superior long-term stability, and shows the superiority of conjugated backbones for PSMAs.

• 单位
  南昌大学