Achieving Balanced Crystallization Kinetics of Donor and Acceptor by Sequential‐Blade Coated Double Bulk Heterojunction Organic Solar Cells. Issue 28 (11th June 2020)

• Record Type: Journal Article
• Authors: Wang, Yilin; Wang, Xiaohui; Lin, Baojun; Bi, Zhaozhao; Zhou, Xiaobo; Naveed, Hafiz Bilal; Zhou, Ke; Yan, Hongping; Tang, Zheng; Ma, Wei
• Is Part Of: Advanced energy materials. Volume 10:Issue 28(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-06-11
• Subjects: balanced crystallization kinetics -- crystal nuclei -- organic solar cells -- sequential‐blade cast -- vertical phase separation; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.202000826
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Sequential deposition has great potential to achieve high performance in organic solar cells due to the resulting well‐controlled vertical phase separation. In this work, double bulk heterojunction organic solar cells are fabricated by sequential‐blade cast in ambient conditions. Probed by the in situ grazing incidence X‐ray diffraction and in situ UV–vis absorption measurements, the seq‐blade system exhibits a different tendency from each of the binary films during the film formation process. Due to the extensive aggregation of FOIC, the binary PBDB‐T:FOIC film displays a strong and large phase separation, resulting in low current density ( J sc ) and unsatisfactory power conversion efficiency. In the seq‐blade cast system, the bottom layer PBDB‐T:IT‐M produces many crystal nuclei for the top layer PBDB‐T:FOIC, so the PBDB‐T molecules are able to crystallize easily and quickly. Balanced crystallization kinetics between polymer and small molecule and an ideal percolation network in the film are observed. In addition, the balanced crystallization kinetics are favorable toward realizing lower recombination loss through charge transport processes. Abstract : A successful double bulk heterojunction is fabricated with a blade coating method, which sheds light on innovative approaches to rationally realize balanced crystallization kinetics for donors and acceptors and further improve the photovoltaic efficiency of organic solar cells.