题目：

Ultrafast Electron Transfer in Low-Band Gap Polymer/PbS Nanocrystalline Blend Films

作者：

Wenping Guo¹, Jianyu Yuan², Haochen Yuan¹, Feng Jin¹, Lu Han², Chuanxiang Sheng³, Wanli Ma², and Haibin Zhao¹

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

²Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University

³School of Electronic and Optical Engineering, Nanjing University of Science and Technology

摘要：

Ultrafast charge transfer dynamics in hybrid blend films of a low band-gap polymer poly(2,6-(N-(1-octylnonyl)dithieno[3,2-b:20,30-d] pyrrole)-alt-4,7-(2,1,3-benzothiadiazole)) (PDBT) and PbS quantum dots (QDs) are studied by using ultrafast transient transmission spectroscopy. It is observed that the transient bleaching signal arising from excitons of the PDBT displays a much faster recovery, within the time delay of ≈5 ps, in hybrid films than in the neat PDBT film. In contrast, the bleaching signal resulting from the electron filling of the QDs in hybrid films shows an extra rising component during ≈1�5 ps, which is absent in the pristine QDs. These results indicate the ultrafast electron transfer from the lowest unoccupied molecular orbital energy level of the PDBT to the conduction band of the QDs in the time scale of several ps after laser excitation. A transient absorption signal within 1 ps in the hybrid films is also found, indicating the emergence of charge transfer states (CTs). The CTs formed at the interface of the hybrid blend may facilitate the charge separation and transfer. It is estimated that over 80% of the photoexcited electrons in the PDBT may betransferred into the QDs. The transfer efficiencies show a positive correlation with the power conversion efficiencies of the corresponding hybrid solar cells.

影响因子：

11.805

分区情况：

1区

链接：

http://onlinelibrary.wiley.com/doi/10.1002/adfm.201503556/abstract

(责任编辑：杨阳，联系方式：yangyangcnst@suda.edu.cn)