A Novel Wide-Bandgap Polymer with Deep Ionization Potential Enables Exceeding 16% Efficiency in Ternary Nonfullerene Polymer Solar Cells

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Ying Zhang
  • Delong Liu
  • Tsz-Ki Lau
  • Lingling Zhan
  • Patrick W. K. Fong
  • Cenqi Yan
  • Shaoqing Zhang
  • Xinhui Lu
  • Jianhui Hou
  • Hongzheng Chen
  • Gang Li

Detail(s)

Original languageEnglish
Article number1910466
Journal / PublicationAdvanced Functional Materials
Volume30
Issue number27
Online published17 May 2020
Publication statusPublished - 2 Jul 2020

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 (Egopt ≈ 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.

Research Area(s)

  • deep HOMO level, efficient ternary PSCs, generality, improved light stability, WBG polymer donor

Citation Format(s)

A Novel Wide-Bandgap Polymer with Deep Ionization Potential Enables Exceeding 16% Efficiency in Ternary Nonfullerene Polymer Solar Cells. / Zhang, Ying; Liu, Delong; Lau, Tsz-Ki; Zhan, Lingling; Shen, Dong; Fong, Patrick W. K.; Yan, Cenqi; Zhang, Shaoqing; Lu, Xinhui; Lee, Chun-Sing; Hou, Jianhui; Chen, Hongzheng; Li, Gang.

In: Advanced Functional Materials, Vol. 30, No. 27, 1910466, 02.07.2020.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review