2D Conjugated Polyelectrolytes Possessing Identical Backbone with Active‐Layer Polymer as Cathode Interlayer for Organic Solar Cells. Issue 5 (24th January 2020)

• Record Type: Journal Article
• Authors: Liu, Xuan; Nie, Wei; Tu, Dandan; Guo, Xin; Li, Can
• Is Part Of: Macromolecular rapid communications. Volume 41:Issue 5(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-01-24
• Subjects: 2D conjugated polyelectrolytes -- cathode interface layers -- polymer solar cells -- structural similarity; Macromolecules -- Periodicals; Polymers -- Periodicals; Chemistry -- Periodicals; 547.705
• DOI: 10.1002/marc.201900624
• Languages: English
• ISSNs: 1022-1336

Abstract

Abstract: A 2D conjugated polyelectrolyte (CPE), PBDTTh‐TT‐NBr, having the same backbone as the highly efficient donor polymer PTB7‐Th and the quaternary ammonium pendant, is synthesized as a cathode interlayer (CIL) material for PTB7‐Th‐based fullerene and non‐fullerene solar cells. The quaternary ammonium group is connected to the 2D conjugated backbone by a long, flexible alkyl chain, facilitating the modification of cathode via forming interface dipoles. Moreover, compared with another CPE analogue to PTB7, PBDT‐TT‐NBr, without the 2D conjugated backbone, the PBDTTh‐TT‐NBr presents a higher similarity in polymer structure to the donor polymer PTB7‐Th. This feature makes it more compatible with the PTB7‐Th‐based active‐layer film, improving the electron transport. With the PBDTTh‐TT‐NBr as the CIL, devices afford higher performances than those using the PBDT‐TT‐NBr in both fullerene and non‐fullerene systems. This work offers guidance on choosing the CIL material that ought to possess a highly similar structure to the active‐layer component. Abstract : A 2D conjugated polyelectrolyte (CPE) having the same backbone as the polymer PTB7‐Th is synthesized as a cathode interlayer material for PTB7‐Th‐based fullerene and non‐fullerene solar cells. The highly structural similarity of the two polymers favors their compatibility, improving the interface contact and the electron transport, and thus providing a higher device efficiency than that based on a traditional CPE.