Ternary organic solar cells with enhanced open circuit voltage. (July 2017)

• Record Type: Journal Article
• Authors: Wang, Chuanfei; Xu, Xiaofeng; Zhang, Wei; Dkhil, Sadok Ben; Meng, Xiangyi; Liu, Xianjie; Margeat, Olivier; Yartsev, Arkady; Ma, Wei; Ackermann, Jörg; Wang, Ergang; Fahlman, Mats
• Is Part Of: Nano energy. Volume 37(2017:Jul.)
• Page Start: 24
• Page End: 31
• Publication Date: 2017-07
• Subjects: Ternary organic solar cell -- Self-organization -- Higher open circuit voltage -- Generality -- More thermal stable; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2017.04.060
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: By introducing a non-fullerene small molecule acceptor as a third component to typical polymer donor: fullerene acceptor binary solar cells, we demonstrate that the short circuit current density ( J sc ), open circuit voltage ( V oc ), power conversion efficiency (PCE) and thermal stability can be enhanced simultaneously. The different surface energy of each component causes most of the non-fullerene acceptor molecules to self-organize at the polymer/fullerene interface, while the appropriately selected oxidation/reduction potential of the non-fullerene acceptor enables the resulting ternary junction to work through a cascade mechanism. The cascade ternary junction enhances charge generation through complementary absorption between the non-fullerene and fullerene acceptors and aids the efficient charge extraction from fullerene domains. The bimolecular recombination in the ternary blend layer is reduced as the ternary cascade junction increases the separation of holes and electrons during charge transportation and the trap assistant recombination induced by integer charge transfer (ICT) state potentially reduced due to the smaller pinning energy of inserted non-fullerene acceptor, leading to an unprecedented increase in the open circuit voltage beyond the binary reference values. Graphical abstract: Highlights: Ternary organic solar cells with higher Voc compared to reference binary solar cells are prepared for the first time. The third component m-ITIC could self-organize at the interface of the host donor and acceptor because of the different surface energy. The strategy could be general applied to other systems. Ternary solar cells show higher thermal stability in addition of enhanced V oc, J sc and PCE.