Pt- and TCO-Free Flexible Cathode for DSSC from Highly Conducting and Flexible PEDOT Paper Prepared via in Situ Interfacial Polymerization

• Published in: ACS applied materials & interfaces Vol. 8; no. 1; pp. 553 - 562
• Main Authors: Anothumakkool, Bihag, Agrawal, Ishita, Bhange, Siddheshwar N, Soni, Roby, Game, Onkar, Ogale, Satishchandra B, Kurungot, Sreekumar
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 13.01.2016
• Subjects: counter electrode; polyethylenedioxythiophene; impedance analysis; flexible and thin devices; dye-sensitized solar cell; interfacial polymerization
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.5b09579

Here, we report the preparation of a flexible, free-standing, Pt- and TCO-free counter electrode in dye-sensitized solar cell (DSSC)-derived from polyethylenedioxythiophene (PEDOT)-impregnated cellulose paper. The synthetic strategy of making the thin flexible PEDOT paper is simple and scalable, which can be achieved via in situ polymerization all through a roll coating technique. The very low sheet resistance (4 Ω/□) obtained from a film of 40 μm thick PEDOT paper (PEDOT-p-5) is found to be superior to the conventional fluorine-doped tin oxide (FTO) substrate. The high conductivity (357 S/cm) displayed by PEDOT-p-5 is observed to be stable under ambient conditions as well as flexible and bending conditions. With all of these features in place, we could develop an efficient Pt- and TCO-free flexible counter electrode from PEDOT-p-5 for DSSC applications. The catalytic activity toward the tri-iodide reduction of the flexible electrode is analyzed by adopting various electrochemical methodologies. PEDOT-p-5 is found to display higher exchange current density (7.12 mA/cm2) and low charge transfer resistance (4.6 Ω) compared to the benchmark Pt-coated FTO glass (2.40 mA/cm2 and 9.4 Ω, respectively). Further, a DSSC fabricated using PEDOT-p-5 as the counter electrode displays a comparable efficiency of 6.1% relative to 6.9% delivered by a system based on Pt/FTO as the counter electrode.