Water content control during solution-based polymerization: a key to reach extremely high conductivity in PEDOT thin films

Conductive polymers are a very promising alternative for the fabrication of transparent conductive materials. They have many advantages compared to existing materials, like a low-cost and a high flexibility. However, electrical conductivity still needs to be improved. We report a straightforward solution-based approach for the fabrication of poly(3,4-ethylenedioxythiophene) (PEDOT) thin films with conductivity as high as 6046 ± 510 S cm−1, based on accurate water content control during the polymerization step. The crystallinity improvement is evidenced by GIWAXS characterization, and low temperature electrical conductivity measurements give new insights on the transport mechanisms at stake. This very high conductivity is, to our knowledge, the highest reported value for solution-based synthesis of PEDOT based materials.