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 Engineering Research 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 (ΔE_H) 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 ΔE_H. 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 ΔE_H   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 ΔE_H 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