Modulation of Morphological, Mechanical, and Photovoltaic Properties of Ternary Organic Photovoltaic Blends for Optimum Operation
Abstract
Ternary solar cells comprising both fullerene and nonfullerene acceptors have shown a rapid increase in power conversion efficiency, which holds promise in commercial applications. Despite the rapid progress, there is still a lack of fundamental understanding of the relations between microstructure and (photovoltaic/mechanical) properties in these ternary blend systems. In this work, the dependence of molecular packing, phase separation, mechanical properties, and photovoltaic performance on acceptor composition of a recently certificated ternary system is thoroughly investigated by combined scattering and microscopy characterizations. It is demonstrated that incorporating a small amount (20% by weight) PC71BM to the PM6:N3 binary blend can afford the best device efficiency and the highest ductility simultaneously. This maximum performance is due to the optimized molecular order, orientational texture, and phase separation. Additionally, increasing the amount of PC71BM results in higher elastic modulus, as probed by two distinct methods. A more crucial observation is that the elastic modulus of ternary blends can be well captured by an extended Halpin–Tsai model. This finding is expected to enable the prediction of the elastic modulus of various kinds of ternary blends that are widely used in solar cells and other electronics.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 14, 2021
- Source ID
- 10.1002/aenm.202003506
Entities
People
- Brendan T O'Connor
- Harald Ade
- Kui Jiang
- Long Ye
- Miaomiao Li
- Nrup Balar
- Yanhou Geng
- Yunpeng Qin
- Zhongxiang Peng
Organizations
- City University of Hong Kong
- National Natural Science Foundation of China
- National Science Foundation
- National University of Singapore
- North Carolina State University
- Office of Naval Research
- Tianjin University