Highly Conductive PEDOT:PSS Electrode Treated with Polyethylene Glycol for ITO-free Polymer Solar Cells

Abstract

We used polyethylene glycol (PEG) and enhanced the conductivity of PEDOT:PSS from 0.3 S cm(-1) to 805 S cm(-1) with only 2% PEG additive. The conductivity was further enhanced to 1100 S cm-1 by combining PEG and methanol treatment. PEG treated PEDOT: PSS films showed better phase separation between PEDOT and PSS with fiber like 3D PEDOT networks. The carrier concentration increased by three orders of magnitude after PEG treatment. ITO-free polymer solar cells with PEG treated PEDOT: PSS anodes were fabricated and optimized. Double layer PEDOT: PSS treated with 2% PEG200 anodes showed power conversion efficiency of 3.71% while and the ITO counterpart showed 3.73%.