Rational Strategy to Stabilize an Unstable High‐Efficiency Binary Nonfullerene Organic Solar Cells with a Third Component
Abstract
Long device lifetime is still a missing key requirement in the commercialization of nonfullerene acceptor (NFA) organic solar cell technology. Understanding thermodynamic factors driving morphology degradation or stabilization is correspondingly lacking. In this report, thermodynamics is combined with morphology to elucidate the instability of highly efficient PTB7‐Th:IEICO‐4F binary solar cells and to rationally use PC71BM in ternary solar cells to reduce the loss in the power conversion efficiency from ≈35% to 71BM in PTB7‐Th of 48 vol% is well above the percolation threshold. At the same time, PC71BM is partly miscible in IEICO‐4F suppressing crystallization of IEICO‐4F. This work systematically illustrates the origin of the intrinsic degradation of PTB7‐Th:IEICO‐4F binary solar cells, demonstrates the structure–function relations among thermodynamics, morphology, and photovoltaic performance, and finally carries out a rational strategy to suppress the degradation: the third component needs to have a miscibility in the donor polymer at or above the percolation threshold, yet also needs to be partly miscible with the crystallizable acceptor.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 03, 2019
- Source ID
- 10.1002/aenm.201900376
Entities
People
- Abay Gadisa
- Harald Ade
- Long Ye
- Masoud Ghasemi
- Suling Zhao
- Xu Zheng
- Youqin Zhu
- Zhengxing Peng
Organizations
- Beijing Jiaotong University
- China Scholarship Council
- National Science Foundation
- North Carolina State University
- Office of Naval Research
- United States Department of Energy