Effect of Ring‐Fusion on Miscibility and Domain Purity: Key Factors Determining the Performance of PDI‐Based Nonfullerene Organic Solar Cells
Abstract
Compared to the rapid development of nonfullerene organic solar cells (OSCs) based on the state‐of‐the‐art indacenodithiophene (IDT)‐based small molecule acceptors (SMAs), the progress for perylene diimide (PDI)‐based electron acceptors has lagged behind owing to the lack of understanding on the structure–morphology–performance relationship of PDI SMAs. Given the ease of synthesis for PDIs and their high intrinsic electron mobility, it is crucial to identify key material parameters that influence the polymer:PDI blend morphology and to develop rational approaches for molecular design toward high‐performance PDI‐based SMAs. In this study, three pairs of PDI‐based SMAs with and without ring‐fusion are investigated and it is found that ring‐fusion and domain purity are the key structural and morphological factors determining the fill factors (FFs) and efficiencies of PDI‐based nonfullerene OSCs. This data shows that nonfullerene OSCs based on the ring‐fused PDI‐based SMAs exhibit much higher average domain purity and thus increased charge mobilities, which lead to enhanced FFs compared to those solar cells based on nonfused PDIs. This is explained by higher Florry Huggins interaction parameters as observed by melting point depression measurements. This study suggests that increasing repulsive molecular interactions to lower the miscibility between the polymer donor and PDI acceptor is the key to improve the FF and performance of PDI‐based devices.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 31, 2018
- Source ID
- 10.1002/aenm.201800234
Entities
People
- Guangye Zhang
- Harald Ade
- He Yan
- Huawei Hu
- Jiachen Huang
- Jianquan Zhang
- Jingming Xin
- Kui Jiang
- Lik‐kuen Ma
- Tingxuan Ma
- Wei Ma
- Yunke Li
- Zhengxing Peng
Organizations
- Hong Kong University of Science and Technology
- Innovation and Technology Commission
- National Natural Science Foundation of China
- North Carolina State University
- Office of Naval Research
- Research Grants Council, University Grants Committee
- United States Department of Energy
- University of North Carolina
- Xi'an Jiaotong University