Control of the Crystallization and Phase Separation Kinetics in Sequential Blade‐Coated Organic Solar Cells by Optimizing the Upper Layer Processing Solvent. Issue 7 (1st January 2023)

• Record Type: Journal Article
• Authors: Wang, Yilin; Xue, Jingwei; Zhong, Huaying; Everett, Christopher R.; Jiang, Xinyu; Reus, Manuel A.; Chumakov, Andrei; Roth, Stephan V.; Adedeji, Michael A.; Jili, Ncedo; Zhou, Ke; Lu, Guanghao; Tang, Zheng; Mola, Genene Tessema; Müller‐Buschbaum, Peter; Ma, Wei
• Is Part Of: Advanced energy materials. Volume 13:Issue 7(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-01
• Subjects: morphology -- organic solar cells -- sequential blade coating -- solvents; 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.202203496
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Sequential deposition of the active layer in organic solar cells (OSCs) is favorable to circumvent the existing drawbacks associated with controlling the microstructure in bulk‐heterojunction (BHJ) device fabrication. However, how the processing solvents impact on the morphology during sequential deposition processes is still poorly understood. Herein, high‐efficiency OSCs are fabricated by a sequential blade coating (SBC) through optimization of the morphology evolution process induced by processing solvents. It is demonstrated that the device performance is highly dependent on the processing solvent of the upper layer. In situ morphology characterizations reveal that an obvious liquid–solid phase separation can be identified during the chlorobenzene processing of the D18 layer, corresponding to larger phase separation. During chloroform (CF) processing of the D18 layer, a proper aggregation rate of Y6 and favorable intermixing of lower and upper layers results in the enhanced crystallinity of the acceptor. This facilitates efficient exciton dissociation and charge transport with an inhibited charge recombination in the D18/CF‐based devices, contributing to a superior performance of 17.23%. These results highlight the importance of the processing solvent for the upper layer in the SBC strategy and suggest the great potential of achieving optimized morphology and high‐efficiency OSCs using the SBC strategy. Abstract : An enhanced crystallinity and a more suitable phase separation of donor and acceptor is finely controlled by optimizing the processing solvents in sequential blade coated organic solar cells, resulting in a superior performance of 17.23%.