The Molecular Ordering and Double‐Channel Carrier Generation of Nonfullerene Photovoltaics within Multi‐Length‐Scale Morphology
Abstract
The success of nonfullerene acceptor (NFA) solar cells lies in their unique physical properties beyond the extended absorption and suitable energy levels. The current study investigates the morphology and photophysical behavior of PBDB‐T donor blending with ITIC, 4TIC, and 6TIC acceptors. Single‐crystal study shows that the π–π stacking and side‐chain interaction dictate molecular assembly, which can be carried to blended films, forming a multi‐length‐scale morphology. Spontaneous carrier generation is seen in ITIC, 4TIC, and 6TIC neat films and their blended thin films using the PBDB‐T donor, providing a new avenue of zero‐energy‐loss carrier formation. The molecular packing associated with specific contacts and geometry is key in influencing the photophysics, as demonstrated by the charge transfer and carrier lifetime results. The 2D layer of 6TIC facilitates the exciton‐to‐polaron conversion, and the largest photogenerated polaron yield is obtained. The new mechanism, together with the highly efficient blending region carrier generation, has the prospect of the fundamental advantage for NFA solar cells, from molecular assembly to thin‐film morphology.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 15, 2022
- Source ID
- 10.1002/adma.202108317
Entities
People
- Alex K.‐y. Jen
- Feng Liu
- Francis Lin
- Guanqing Zhou
- Jinqiu Xu
- Ke Gao
- Lei Zhu
- Ming Zhang
- Sae Byeok Jo
- Tianyu Hao
- Wei Feng
- Xiankai Chen
- Xuan Su
- Xueliang Shi
- Yecheng Zou
- Yongming Zhang
Organizations
- City University of Hong Kong
- Kyushu University
- National Natural Science Foundation of China
- Natural Science Foundation of Shandong Province
- Natural Science Foundation of Shanghai
- Office of Naval Research
- Shandong University
- Shanghai Jiao Tong University
- Sungkyunkwan University
- University of Washington