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

Abstract

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/cm(2)) and low charge transfer resistance (4.6 Ω) compared to the benchmark Pt-coated FTO glass (2.40 mA/cm(2) 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.

Free‐Standing Graphene/Conducting Polymer Hybrid Cathodes as FTO and Pt‐Free Electrode for Quasi‐State Dye Sensitized Solar Cells

“…The FSG based q‐DSSC shows low FF due to poor charge transfer of tri‐iodide species at electrode/electrolyte interface.This was clearly observed in LSV of FSG dummy cells (Figure S8, Supporting Information) that implies the absence of faradaic or non‐faradaic reaction even at higher potential. After the growth of CPs on FSG surface, an efficient reduction of tri‐iodide species was observed and hence the enhancement in PCE.However, the open circuit voltage (V oc ) of FSG/CPs is less compared to Pt/FTO asit is similar to reported literature based on CPs CEs. To understand the CE/electrolyte interface, EIS characterization was examined under illumination conditions and its interface studies was observed at high frequency region and photoanode‐electrolyte interface at low frequency region.…”

Flexible Electronics Based on Micro/Nanostructured Paper

“…Although the overall thickness of the device was only 0.17 mm, a power density of 1 mW h cm −3 was delivered (Figure c). Moreover, such flexible PEDOT paper can be extended to other electronic devices, such as solar cells, LEDs, and other devices,[22a,145] owing to its simple and scalable synthetic approach.…”

Printed Solar Cells and Energy Storage Devices on Paper Substrates

“…GD:PEDOT:PSS paper electrodes also presented lower resistance and higher flexibility compared to Pt coated cellulose. [100] Anothumakkool et al [117] reported a PEDOT:PSS electrode deposited using immersion technique. The high conductivity of the electrode (Rs = 4 Ω/□) was attributed to the multi-layer structure of PEDOT.…”