Effect of 1 wt% Dimethyl Sulfoxide on the Electrical and Photovoltaic Parameters of Schottky Diodes and Organic Solar Cells Based on PEDOT:PSS

Abstract

Herein, the electrical conductivity of poly(3,4‐ethylenedioxythiophene)–poly(styrenesulfonate) (PEDOT:PSS) polymer is improved by adding dimethyl sulfoxide (DMSO) and electrical characterization of the obtained Schottky diode and organic solar cell (OSC) devices are performed from I–V measurements under the light and dark conditions. The scanning electron microscope images of the poly(3‐hexylthiophene):[6,6]‐phenylC61‐butyric acid methylester active layer and PEDOT:PSS layer are obtained. The series resistance (Rs), barrier height (Фb), and ideality factor (n) parameters are obtained from different techniques as a function of light and dark conditions. Furthermore, photovoltaic parameters are calculated for n‐Si/PEDOT:PSS/Au device without DMSO doping and with DMSO doping as a parameter of the light condition and the interface state densities of these devices are obtained for light and dark conditions. DMSO organic solvent improves the short‐circuit current density (Isc), power convert efficiency (or η), open circuit‐voltage (Voc), shunt resistance (Rsh), and series resistance (Rs) values of OSCs. In summary, DMSO solvent rearranges the conductive of PEDOT:PSS, decreases the work function of this conductive polymer (≈5 eV), decreases energy loss in the charge transportation, and increases photovoltaic parameters of Schottky barrier diode and OSC devices.