Highly conductive spray deposited poly(3, 4-ethylenedioxythiophene):poly (styrenesulfonate) electrodes for indium tin oxide-free small molecule organic photovoltaic devices

Abstract

Spray deposition is currently attracting significant attention as a low cost method for organic photovoltaic (OPV) device fabrication. We report indium tin oxide (ITO)-free small moleule OPV devices comparing spin coated and spray deposited highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the transparent conducting electrode (TCE). Conductive atomic force microscopy studies indicate that despite an increase in surface roughness, spray deposited PEDOT:PSS TCEs display a similar distribution in the surface composition of PEDOT and PSS and provide comparable device performance to spin coated PEDOT:PSS TCEs. Therefore, the TCEs fabricated by spray deposition show potential as an inexpensive solution processable alternative to the conventionally used ITO TCE for OPV devices.