Conductive Glassy Non-conjugated Open-shell Radical Polymer with Organosulfur Backbone for Macroscopic Conductivity

Abstract

Abstract Non-conjugated organic radical with open-shell radical active group exhibits unique functionality due to their radical pendant site. Compared to the previously studied doped conjugated polymer, radical polymers reveal superior processability, stability, and optical properties. Despite the success of organic radical polymer conductors based on the TEMPO radicals, it still requires the potential designing substitutions to meet the fundamental limits of charge transport in the radical polymer. To do so, we demonstrate that the amorphous, non-conjugated radical polymer with backbone-pendant group interaction and low-glass transition temperature enables the macromolecules to have rapid charge transport in the solid state, resulting in conductivity higher than 32 S m-1. This charge transport is due to the formation of the local ordered regime with energetically favored orientation caused by the strong coupling between the backbone and pedant group, which can significantly modulate the polymer packing with active electronic communications. The non-conjugate nature of radical polymer maintains the optical transparency up to 98% at 1.5 μm thick film. Thus, this effort will be a dramatically advanced model in the organic radical community for the creation of next-generation polymer conductors.