Structure Influence of Amine-Containing Additives on the Solution State and Out-of-plane Conductivity of PEDOT:PSS for Efficient Organic Solar Cells.

Additives are extensively explored for improving PEDOT:PSS performances mainly through the removal of excess PSS and as a secondary dopant. In this work, amine-containing additives were introduced to PEDOT:PSS solutions as processing additives where the interactions to the PSS was anticipated through electrostatic interactions. Such interactions affected solution property where the increased viscosity was found to significantly increase the out-of-plane conductivity of the PEDOT:PSS thin films. Organic solar cells adopting these additive-assisted processed PEDOT:PSS layers as hole transporting layers (HTL) showed the improved device performances which resulted from the reduced series resistance provided by the PEDOT:PSS HTL. A top power conversion efficiency of 18.28% was achieved with para-phenylenediamine (PPD) additive in the PEDOT:PSS HTL, which is 3.5% higher compared to devices with neat PEDOT:PSS thin film as the HTL. This article is protected by copyright. All rights reserved.