Mixing Insulating Commodity Polymers with Semiconducting n-type Polymers Enables High-Performance Electrochemical...

Area of Science:

• Materials Science
• Organic Electronics
• Bioelectronics

Background:

• Diluting organic semiconductors with insulating polymers increases electronic mobility and reduces costs in organic electronic devices.
• Organic electrochemical transistors (OECTs) require both electronic and ionic mobility, posing challenges for integrating hydrophobic polymers.

Purpose of the Study:

• To investigate the effect of diluting an n-type conjugated polymer (p(N-T)) with polystyrene on OECT performance.
• To develop cost-effective and stable organic mixed ionic-electronic conductors.

Main Methods:

• Blending the n-type conjugated polymer p(N-T) with high molecular weight polystyrene (10 KDa) at a 1:6 ratio.
• Fabricating and characterizing organic electrochemical transistors (OECTs) using the polymer blend.

Main Results:

• The p(N-T):Polystyrene 10 KDa blend resulted in OECTs with over three times higher mobility-volumetric capacitance product (µC*) compared to pristine p(N-T).
• Electronic mobility increased by two orders of magnitude (from 0.059 to 1.3 cm² V⁻¹ s⁻¹).
• Devices exhibited improved stability, retaining 77% of initial drain current after 60 minutes, versus 12% for pristine p(N-T).

Conclusions:

• Diluting conjugated polymers with commodity polymers like polystyrene is a viable strategy for enhancing OECT performance and stability.
• This approach enables the development of low-cost organic mixed ionic-electronic conductors for next-generation bioelectronic devices.