Environmentally Friendly Plasma-Treated PEDOT:PSS as Electrodes for ITO-Free Perovskite Solar Cells

Abstract

Solution processed poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) transparent electrodes (TEs) offer great potential as a low cost alternative to expensive indium tin oxide (ITO). However, strong acids are typically used for enhancing the conductivity of PEDOT:PSS TEs, which produce processing complexity and environmental issues. This work presents an environmentally friendly acid free approach to enhance the conductivity of PEDOT:PSS using a light oxygen plasma treatment, in addition to solvent blend additives and post treatments. The plasma treatment was found to significantly reduce the sheet resistance of PEDOT:PSS TEs from 85 to as low as 15 Ω sq, which translates to the highest reported conductivity of 5012 S/cm for PEDOT:PSS TEs. The plasma treated PEDOT:PSS TE resulted in an ITO-free perovskite solar cell efficiency of 10.5%, which is the highest reported efficiency for ITO-free perovskite solar cells with a PEDOT:PSS electrode that excludes the use of acid treatments. This research presents the first demonstration of this technology. Moreover, the PEDOT:PSS TEs enabled better charge extraction from the perovskite solar cells and reduced hysteresis in the current density-voltage (J-V) curves.

Tailored PEDOT:PSS hole transport layer for higher performance in perovskite solar cells: Enhancement of electrical and optical properties with improved morphology

“…6 (c)). The longer decay time indicates higher quality perovskite layer formation on the treated PEDOT:PSS [63] , which is consistent with the XRD results ( Fig. 4 (g)) and grain size observations from the AFM topography ( Fig.…”

Generating semi-metallic conductivity in polymers by laser-driven nanostructural reorganization

“…2c). The peak shift for the chemically treated PEDOT:PSS films has been widely reported, [21][22][23] which is attributed to the conformational change of PEDOT chains as well as the enlarged PEDOT-rich cores by phase separation between PEDOT and PSS. Note that the laser-treated films do not show any peak shift in comparison with the pristine film.…”

Research Progress on Polymer Solar Cells Based on PEDOT:PSS Electrodes

“…Other environmentally friendly acid-free approaches through solvent additives, post treatments, and a mild oxygen plasma treatment were also presented to enhance the conductivity of PEDOT:PSS for TCO-free PeSCs. The achieved 10.5% was one of the highest reported efficiencies for TCO-free PeSCs with a PEDOT:PSS electrode that excludes the use of acid treatments [67]. Considering the high enough work function of PEDOT:PSS, it can serve as hole transport layer at the same time.…”