Thermally Activated in Situ Doping Enables Solid-State Processing of Conducting Polymers

Area of Science:

• Materials Science
• Polymer Chemistry
• Electronics

Background:

• Highly doped conjugated polymers are crucial for wearable electronics.
• Current doping methods face challenges with processability and diffusion in thick structures.

Purpose of the Study:

• To introduce a novel in situ bulk doping method for conjugated polymers using thermally activated latent dopants.
• To overcome limitations of traditional doping techniques in achieving uniform doping in thick polymer films.

Main Methods:

• Synthesis of two latent acid dopants based on aryl sulfonic acids and an o-nitrobenzyl capping moiety.
• Coprocessing of dopant precursors with three different polythiophenes.
• In situ doping of polymer films via thermal activation of the latent dopants.

Main Results:

• Latent dopant precursors were successfully coprocessed noninteractively with polythiophenes.
• Thermal activation enabled in situ doping of conjugated polymer films.
• Doping of polymer films exceeding 100 μm thickness was demonstrated, overcoming diffusion limitations.

Conclusions:

• Thermally activated latent dopants offer a viable solution for in situ bulk doping of conjugated polymers.
• This method facilitates noninteractive coprocessing and eliminates thickness-dependent doping limitations.
• The approach is suitable for fabricating thick, highly doped polymer structures for advanced electronic applications.