Vertical organic electrochemical transistors for complementary circuits.

Area of Science:

• Organic electronics
• Bioelectronics
• Semiconductor physics

Background:

• Organic electrochemical transistors (OECTs) show promise for bioelectronics and neuromorphic applications due to low voltage, low power, and biocompatibility.
• Current limitations include instability, slow switching, integration challenges, and poor n-type performance.

Purpose of the Study:

• To develop high-performance, stable p- and n-type OECTs.
• To create complementary logic OECT circuits using a novel vertical architecture.

Main Methods:

• Fabrication of vertical OECTs by blending redox-active and inactive polymers for the semiconducting channel.
• Implementation of a scalable vertical architecture with a dense, impermeable top contact.

Main Results:

• Achieved balanced, ultra-high performance with current densities >1 kA cm⁻², transconductances of 0.2-0.4 S, and transient times <1 ms.
• Demonstrated ultra-stable switching (>50,000 cycles) in complementary vertical OECT logic circuits.
• Successfully created the first complementary vertical OECT logic circuits.

Conclusions:

• The novel vertical architecture overcomes OECT limitations, enabling balanced high performance and stability.
• This advancement facilitates fundamental studies of organic semiconductor redox chemistry and opens doors for wearable and implantable devices.