Abstract
Ternary strategies have attracted extensive attention due to their potential in improving power conversion efficiencies (PCEs) of single-junction polymer solar cells (PSCs). In this work, a novel wide bandgap polymer donor (Eg opt ≈ 2.0 eV) named PBT(E)BTz with a deep highest occupied molecular orbital (HOMO) level (≈−5.73 eV) is designed and synthesized. PBT(E)BTz is first incorporated as the third component into the classic PBDB-T-SF:IT-4F binary PSC system to fabricate efficient ternary PSCs. A higher PCE of 13.19% is achieved in the ternary PSCs with a 5% addition of PBT(E)BTz over binary PSCs (12.14%). Similarly, addition of PBT(E)BTz improves the PCE for PBDB-T:IT-M binary PSCs from 10.50% to 11.06%. The study shows that the improved PCE in ternary PSCs is mainly attributed to the suppressed charge carrier recombination and more balanced charge transport. The generality of PBT(E)BTz as a third component is further evidenced in another efficient binary PSC system—PBDB-TF:BTP-4Cl: an optimized PCE of 16.26% is realized in the ternary devices. This work shows that PBT(E)BTz possessing a deep HOMO level as an additional component is an effective ternary PSC construction strategy toward enhancing device performance. Furthermore, the ternary device with 5% PBT(E)BTz displays better thermal and light stability over binary devices.
Original language | English |
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Article number | 1910466 |
Journal | Advanced Functional Materials |
Volume | 30 |
Issue number | 27 |
DOIs | |
Publication status | Published - 1 Jul 2020 |
Keywords
- deep HOMO level
- efficient ternary PSCs
- generality
- improved light stability
- WBG polymer donor
ASJC Scopus subject areas
- General Chemistry
- General Materials Science
- Condensed Matter Physics