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

Abstract

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 (PA) is not well understood and PAs 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 π‐extended coplanar backbone of PJTVT, when blended with polymer donor JD40, a more ordered π–π 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.

Quasiplanar Heterojunction All‐Polymer Solar Cells: A Dual Approach to Stability

“…As the development of molecular structure design and device processing continues, all-polymer solar cells (all-PSCs) have attracted more and more attention, especially in the study of device stability. [1,2] Bulk heterojunction (BHJ) all-PSCs use processing [30,31] with two different solvents can be achieved in all-PSCs. The donor and acceptor are deposited sequentially from two orthogonal solvents, and the lower layer will not be damaged by the solvent used for the upper layer during its spin coating.…”

A Vinylene‐Linker‐Based Polymer Acceptor Featuring a Coplanar and Rigid Molecular Conformation Enables High‐Performance All‐Polymer Solar Cells with Over 17% Efficiency

“…Moreover, PM6:PY-V-γ demonstrates a more balanced μ h /μ e ratio, which facilitates the charge extraction and collection, thus the best FF among the devices. [61] To correlate the charge transport properties with the morphology of the blends, grazing incidence wide-angle X-ray scattering (GIWAXS) experiments were conducted to investigate the morphology features of the pristine and blend films. [62] As shown in Figure S8 (Supporting Information), the (010) peaks of the pristine PY-V-γ, PY-T-γ, and PY-2T-γ films appeared at q z ≈ 1.62 Å -1 , demonstrating preferential face-on orientation.…”

Recent progress in organic solar cells based on non-fullerene acceptors: materials to devices

“…99 Very recently, Huang et al reported a polymer acceptor named PJTVT, which contains the hienylene–vinylene–thienylene (TVT) unit. 100 The devices of JD40: PJTVT showed a PCE of 16.13% as well as superior thickness-insensitivity and long-term stability. Huang et al synthesized a narrow-band-gap polymer acceptor PJ1 via linking the SMA building block TTPBT-IC.…”