Band-filling effects in single-crystalline oligomer models for doped PEDOT: 3,4-ethylenedioxythiophene (EDOT) dimer salt with hydrogen-bonded infinite sulfate anion chains

A single-crystalline 3,4-ethylenedioxythiophene dimer salt involving hydrogen-bonded infinite sulfate chains exhibited considerably improved conductivity compared to the analogs with a donor's valency (delta) of 1. The hydrogen-bonded chain modulated delta from 1 (delta not equal 1) and deviated the band-filling from the half-filled state, reducing the effective Coulomb repulsion between the conducting carriers.