A Bromo‐Functionalized Conjugated Polymer as a Cross‐Linkable Anode Interlayer of Polymer Solar Cells. Issue 8 (23rd December 2015)

• Record Type: Journal Article
• Authors: Meng, Bin; Xie, Zhiyuan; Liu, Jun; Wang, Lixiang
• Is Part Of: Chemistry, an Asian journal. Volume 11:Issue 8(2016)
• Page Start: 1218
• Page End: 1222
• Publication Date: 2015-12-23
• Subjects: active layer morphology -- anode interlayer -- cross link -- polymer solar cells; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.201501199
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: A cross‐linkable conjugated polymer with bromo groups on the side chain has been developed and used as an anode interlayer to improve the active layer morphology and consequently enhance the device performance of polymer solar cells (PSCs). The polymer, PCDTBT‐Br, has cross‐linkable bromo groups attached to the side chain of a widely‐used donor polymer, poly[N‐9‐heptadecanyl‐2, 7‐carbazole‐ alt ‐5, 5‐(4, 7‐di‐2‐thienyl‐2, 1, 3‐benzothiadiazole)] (PCDTBT). The pendant bromo groups do not significantly change the LUMO/HOMO energy levels and absorption spectrum of the PCDTBT polymer backbone.PDCTBT‐Br can crosslink under UV irradiation to give a robust film, which enables multilayer PSC device fabrication. Moreover, the much lower surface energy ofPCDTBT‐Br (20.4 mJ m −2 ) compared to PEDOT:PSS (91.6 mJ m −2 ) is beneficial for achieving optimal active layer morphology. As a result, with PCDTBT:[6, 6]‐phenyl‐C71 butyric acid methyl ester (PC71 BM) as the active layer, the PSC device withPCDTBT‐Br as the underlying layer shows a power conversion efficiency (PCE) of 6.59 %, in comparison to a PCE of 5.86 % of the control device. The device performance enhancement is ascribed to the much improved phase separation with a fibrillar nanostructure in the active layer. Abstract : The right anode interlayer : A cross‐linkable donor polymerPCDTBT‐Br has been developed and used as an anode interlayer to improve the active layer morphology of PCDTBT:PC71 BM‐based polymer solar cells (PSCs). The power conversion efficiency (PCE) of PSC devices withPCDTBT‐Br is 6.59 %, compared to 5.86 % of the control device.