Toward Efficient Polymer Solar Cells Processed by a Solution-Processed Layer-By-Layer Approach

Yong Cui; Shaoqing Zhang; Ningning Liang; Jingyi Kong; Chenyi Yang; Huifeng Yao; Lijiao Ma; Jianhui Hou

doi:10.1002/adma.201802499

Toward Efficient Polymer Solar Cells Processed by a Solution-Processed Layer-By-Layer Approach

Adv Mater. 2018 Jul 8:e1802499. doi: 10.1002/adma.201802499. Online ahead of print.

Authors

Yong Cui^{1

2}, Shaoqing Zhang³, Ningning Liang^{1

2}, Jingyi Kong³, Chenyi Yang³, Huifeng Yao¹, Lijiao Ma¹, Jianhui Hou^{1

2}

Affiliations

¹ State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
² School of Chemistry and Biology Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
³ School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China.

PMID: 29984486
DOI: 10.1002/adma.201802499

Abstract

The solution-processed layer-by-layer (LBL) method has potential to achieve high-performance polymer solar cells (PSCs) due to its advantage of enriching donors near the anode and acceptors near the cathode. However, power conversion efficiencies (PCEs) of the LBL-PSCs are still significantly lower than those of conventional one-step-processed PSCs (OS-PSCs). A method to solve the critical problems in LBL-PSCs is reported here. By employing a specific mixed solvent (o-dichlorobenzene [o-DCB]/tetrahydrofuran) to spin-coat the small-molecular acceptor IT-4F onto a layer of the newly designed polymer donor (PBDB-TFS1), appropriate interdiffusion between the PBDB-TFS1 and the IT-4F can critically be controlled, and then an ideal phase separation of the active layer and large donor/acceptor interface area can be realized with a certain amount of o-DCB. The PSCs based on the LBL method exhibit PCEs as high as 13.0%, higher than that of the counterpart (11.8%) made by the conventional OS solution method. This preliminary work reveals that the LBL method is a promising approach to the promotion of the photovoltaic performance of polymer solar cells.

Keywords: high performance; layer-by-layer; polymer solar cells; tunable interdiffusion.