题目： | Improved Charge Generation via Ultrafast Effective Hole-Transfer in All-Polymer Photovoltaic Blends with Large Highest Occupied Molecular Orbital (HOMO) Energy Offset and Proper Crystal Orientation |
作者： | Feng Jin, Jianyu Yuan, Wenping Guo, Yalong Xu, Yannan Zhang, Chuanxiang Sheng*, Wanli Ma* and Haibin Zhao* |
单位： | 1Shanghai Ultra-precision Optical Manufacturing EngineeringResearch Center and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education) Department of Optical Science and Engineering Fudan University Shanghai 200433, China. 2Institute of Functional Nano & Soft Materials (FUNSOM) & Collaborative Innovation Center of Suzhou Nano Science and Technology Soochow University Suzhou, Jiangsu 215123, China. 3School of Electronic and Optical Engineering Nanjing University of Science and Technology Nanjing Jiangsu 210094, China |
摘要： | Improved charge generation via fast and effective hole transfer in all-polymer solar cells (all-PSCs) with large highest occupied molecular orbital (HOMO) energy offset (ΔEH) is revealed utilizing ultrafast transient absorption (TA) spectroscopy. Blending the same nonfullerene acceptor poly{[N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene) (N2200) with three different donor polymers produces all-polymer blends with different ΔEH. The selective excitation of N2200 component in blends enables to uncover the hole transfer process from hole polaron-induced bleaching and absorption signals probed at different wavelength. As the ΔEH is enhanced from 0.14 to 0.37 eV, the hole transfer rate rises more than one order and the hole transfer efficiency increases from 12.9% to 86.8%, in agreement with the trend of internal quantum efficiency in the infrared region where only N2200 has absorption. Additionally, Grazing-incidence wide-angle X-ray scattering measurements indicate that face-on crystal orientation in both polymer donor and acceptor also plays an important role in facilitating the charge generation via hole transfer in all-PSCs. Hence, large ΔEH and proper crystal orientation should be considered in material design for efficient hole transfer in N2200-based heterostructures. These results can provide valuable guidance for fabrication of all-PSCs to further improve power conversion efficiency. |
影响因子： | 13.325 |
分区情况： | 一区 |
链接： | https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.201801611 |
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