Single Step Blending of PEDOT:PSS/SPGO Nanocomposite via Low Temperature Solid Phase Addition of Graphene Oxide for Effective Hole Transport Layer in Organic Solar Cells

Abstract

Herein, we report the modification of PEDOT:PSS by in-situ direct addition of graphene oxide powder processed by spray dryer (SPGO) for the enhancement in the performance of organic solar cell. The preparation of PEDOT:PSS/SPGO composite was done by direct incorporation of graphene oxide powder at lower temperature i.e., below 5 °C. Raman spectroscopy of the prepared PEDOT:PSS/SPGO nanocomposites at low temperature suggested that low temperature plays a vital role to improve the ability of these composite as hole transport layer by improving adhesive properties of the composite. Atomic force microscopy (AFM) analysis suggested that the adhesive ability of these composite decreased surface roughness and thus providing smoother path for the hole transportation. After the successful synthesis of PEDOT:PSS/SPGO nanocomposites, ITO/PEDOT:PSS/SPGO/PTB7:PC71BM/Al based organic solar cell was fabricated. The J–V curves under AM 1.5G illumination (100 mW/cm ²) of the PTB7:PC ₇₁BM based OSCs using PEDOT:PSS/SPGO as a HTL exhibit V _oc = 0.67 V, J _sc = 17.3 mA, FF = 41.5%, PCE = 4.82%, and device with PEDOT:PSS as HTL exhibit V _oc = 0.68 V, J _sc = 16.0 mA/cm ², FF = 38.7% and PCE = 4.04%. The enhance PCE in case of PEDOT:PSS/SPGO based devices depicted that the direct inclusion of graphene oxide in PEDOT:PSS increased the PCE almost 16%, which arises due the high conductivity and stable pi–pi stacking of the spray dryer processed graphene sheets with PEDOT:PSS which ease the charge carrier mobility, thus providing feasible path for charge transportation.