Heating induced aggregation in non-fullerene organic solar cells towards high performance

Baocai Du, Renyong Geng, Wenliang Tan, Yuchao Mao, Donghui Li, Xue Zhang, Dan Liu, Weihua Tang, Wenchao Huang, Tao Wang

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Molecular ordering within the photoactive layer plays a crucial role in determining the device performance of organic solar cells (OSCs). However, the simultaneous molecular ordering processes of polymer donors and non-fullerene acceptors (NFAs) during solution casting usually bring confinement effect, leading to insufficient structural order of photovoltaic components. Herein, the molecular packing of m-INPOIC NFA is effectively formed through a heating induced aggregation strategy, with the aggregation of PBDB-T, which has a strong temperature dependence, is retarded by casting on a preheated substrate to reduce its interference toward m-INPOIC. A sequent thermal annealing treatment is then applied to promote the ordering of PBDB-T and achieve balanced aggregation of both donors and acceptors, resulting in the achievement of a maximum efficiency of 13.9% of PBDB-T:m-INPOIC binary OSCs. This work disentangles the interactions of donor polymer and NFA during the solution casting process and develops a rational strategy to enhance the molecular packing of NFAs to boost device performance.

Original languageEnglish
Pages (from-to)131-137
Number of pages7
JournalJournal of Energy Chemistry
Volume54
DOIs
Publication statusPublished - Mar 2021

Keywords

  • Heating induced aggregation
  • Non-fullerene acceptor
  • Organic solar cells

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