Photopatternable and Stretchable Random Polymer Semiconductor via Oxetane Side-Chain Engineering

Area of Science:

• Materials Science
• Polymer Chemistry
• Organic Electronics

Background:

• Flexible electronic devices require advanced semiconducting materials.
• Conventional photolithography is not suitable for polymer semiconductors.
• Existing photo-crosslinking methods can reduce charge transport performance.

Purpose of the Study:

• To engineer a polymer semiconductor with high charge mobility and mechanical resilience.
• To enable photopatterning of polymer semiconductors using mild UV irradiation.
• To develop intrinsically photopatternable and stretchable polymer semiconductors.

Main Methods:

• Synthesized a diketopyrrolopyrrole (DPP)-based random terpolymer (PDPPSe-oxe17) with oxetane side chains.
• Utilized UV irradiation and iodonium salt photoinitiators for crosslinking via ring-opening polymerization.
• Fabricated organic field-effect transistors (OFETs) to evaluate charge transport properties and mechanical robustness.

Main Results:

• The polymer exhibited high initial hole mobility (2.19 cm² V⁻¹ s⁻¹), which slightly increased post-crosslinking (2.27 cm² V⁻¹ s⁻¹).
• Crosslinked films demonstrated excellent mechanical robustness, retaining high mobility up to 100% strain.
• Achieved high-resolution photopatterning compatible with flexible electronics fabrication.

Conclusions:

• Oxetane side-chain engineering provides a viable strategy for creating photopatternable and mechanically robust polymer semiconductors.
• The developed material overcomes key limitations in flexible electronics manufacturing.
• This approach offers a generalizable molecular design principle for advanced semiconductor materials.