Highly Efficient Charge Collection in Bulk-Heterojunction Organic Solar Cells by Anomalous Hole Transfer and Improved Interfacial Contact

Wen Feng; Chaoyu Song; Xiaofeng Hu; Shaobo Liu; Ruichen Yi; Xinju Yang; Hugen Yan; Xiaoyuan Hou

doi:10.1021/acsami.8b08390

Highly Efficient Charge Collection in Bulk-Heterojunction Organic Solar Cells by Anomalous Hole Transfer and Improved Interfacial Contact

ACS Appl Mater Interfaces. 2018 Aug 29;10(34):28256-28261. doi: 10.1021/acsami.8b08390. Epub 2018 Aug 20.

Authors

Wen Feng^{1

2

3}, Chaoyu Song^{1

2

3}, Xiaofeng Hu^{1

3}, Shaobo Liu^{1

2

3}, Ruichen Yi^{1

2

3}, Xinju Yang^{1

3}, Hugen Yan^{1

2

3}, Xiaoyuan Hou^{1

2

3}

Affiliations

¹ State Key Laboratory of Surface Physics and Department of Physics , Fudan University , Shanghai 200433 , China.
² Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education) , Fudan University , Shanghai 200433 , China.
³ Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China.

PMID: 30117726
DOI: 10.1021/acsami.8b08390

Abstract

The dilute donor-fullerene bulk heterojunction (BHJ) has been proven to be an efficient architecture of organic solar cells. However, the hole-extraction pathway and the origin of the high open-circuit voltage ( V_OC) in this peculiar architecture remains elusive. Direct evidence is provided here that the photogenerated holes can be extracted via the acceptor phase even under the operating conditions. Meanwhile V_OC is found to be closely correlated with the surface composition at the MoO₃/BHJ interface. Extending these findings into device optimization, more than 37% enhancement is achieved in a prototype BHJ device. These results evoke renewed insight into the underlying physics in organic solar cells.

Keywords: MoO3; charge extraction; heterojunction; open-circuit voltage; organic solar cells.