TY - DATA T1 - Origin of Efficient Inverted Nonfullerene Organic Solar Cells: Enhancement of Charge Extraction and Suppression of Bimolecular Recombination Enabled by Augmented Internal Electric Field PY - 2017/10/13 AU - Yiwen Wang AU - Bo Wu AU - Zhenghui Wu AU - Zhaojue Lan AU - Yongfang Li AU - Maojie Zhang AU - Furong Zhu UR - https://acs.figshare.com/articles/journal_contribution/Origin_of_Efficient_Inverted_Nonfullerene_Organic_Solar_Cells_Enhancement_of_Charge_Extraction_and_Suppression_of_Bimolecular_Recombination_Enabled_by_Augmented_Internal_Electric_Field/5496997 DO - 10.1021/acs.jpclett.7b02308.s001 L4 - https://ndownloader.figshare.com/files/9636955 KW - PTB 7-Th OSCs benefit KW - stability KW - power conversion efficiency KW - Augmented Internal Electric Field KW - configuration KW - Efficient Inverted Nonfullerene Organic Solar Cells KW - PTB 7-Th OSCs KW - charge extraction KW - ITIC KW - Bimolecular Recombination Enabled KW - recombination N2 - We report our effort to unravel the origin of efficient operation of nonfullerene organic solar cells (OSCs), based on a poly­[4,8-bis­(5-(2-ethylhexyl) thiophen-2-yl)­benzo­[1,2-b;4,5-b′]­dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno­[3,4-b]­thiophene-)-2-carboxylate-2-6-diyl)]­(PTB7-Th):3,9-bis­(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis­(4-hexylphenyl)-dithieno­[2,3-d:2′,3′-d′]-s-indaceno [1,2-b:5,6-b′]­dithiophene (ITIC) blend system. The effects of buildup of space charges, charge extraction, and bimolecular recombination processes on the performance and the stability of PTB7-Th:ITIC-based regular and reverse configuration OSCs are analyzed. It is found that the high-performing inverted PTB7-Th:ITIC OSCs benefit from the combined effects of (1) suppression of bimolecular recombination enabled by an augmented effective internal electric field and (2) improvement of charge extraction by avoiding the holes passing through ITIC-rich region, which would otherwise occur in a regular configuration cell. The inverted PTB7-Th:ITIC OSCs possess a significant improvement in the cell stability and a high power conversion efficiency of ∼8.0%, which is >29% higher than that of an optimized regular configuration control cell (6.1%). ER -