title: Counterbalancing of morphology and conductivity of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate based flexible devices.
abstract: The importance of conductive polymer electrodes with a balance between the morphology and electrical conductivity for flexible organic photovoltaic properties has been demonstrated. Highly transparent PEDOT:PSS anodes with controlled conductivity and surface properties were realized by insertion of dimethyl sulfoxide (DMSO) and a fluorosurfactant (Zonyl) as efficient additives and used for flexible organic photovoltaic cells (OPVs) which are based on a bulk-heterojunction of polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7):[6,6]phenyl-C71-butyric acid methyl ester (PC71BM). We investigated the correlation between the electrical properties of PEDOT:PSS electrodes and their influences on the surface morphology of the active materials (PTB7:PC71BM). When the device was prepared from the PEDOT:PSS layer functioning as an anode of OPV through an optimized ratio of 5 vol% of DMSO and 0.1 wt% of fluorosurfactant, the devices exhibited improved fill factor (FF) due to the enhanced coverage of PEDOT:PSS films. These results correlate with reduced photoluminescence and increased charge extraction as seen through Raman spectroscopy and electrical analysis, respectively. The conductive polymer electrode with the balance between the morphology and electrical conductivity can be a useful replacement for brittle electrodes such as those made of indium tin oxide (ITO) as they are more resistant to cracking and bending conditions, which will contribute to the long-term operation of flexible devices.
authors: School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756, Republic of Korea. king0401@cau.ac.kr.
authors: Woongsik
authors: W
authors: Jang
authors: School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756, Republic of Korea. king0401@cau.ac.kr.
authors: Sunyong
authors: S
authors: Ahn
authors: School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756, Republic of Korea. king0401@cau.ac.kr.
authors: Soyun
authors: S
authors: Park
authors: Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea. lutts@yonsei.ac.kr.
authors: Jong Hyeok
authors: JH
authors: Park
authors: School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756, Republic of Korea. king0401@cau.ac.kr.
authors: Dong Hwan
authors: DH
authors: Wang