Trap Healing for High-Performance Low-Voltage Polymer Transistors and Solution-Based Analog Amplifiers on Foil

Area of Science:

• Materials Science
• Organic Electronics
• Semiconductor Physics

Background:

• Solution-processed conjugated polymers offer potential for large-area electronics due to low-cost, high-throughput fabrication.
• Achieving high-performance, low-voltage operation in polymer transistors remains a significant challenge for practical circuit integration.
• Existing paradigms for low-voltage operation often compromise device performance due to bulk trapping and contact issues.

Purpose of the Study:

• To investigate the limitations of enhanced gate-to-channel capacitive coupling for low-voltage operation in poly(indacenodithiophene-benzothiadiazole) transistors.
• To identify and overcome the detrimental effects of reduced longitudinal fields on device performance, such as bulk trapping and contact degradation.
• To demonstrate a viable strategy for achieving high-performance, low-voltage operation in polymer transistors suitable for analog electronics.

Main Methods:

• Fabrication and characterization of state-of-the-art polymer thin-film transistors (TFTs) based on poly(indacenodithiophene-benzothiadiazole).
• Analysis of device behavior under low-voltage operating conditions, focusing on the impact of longitudinal electric fields.
• Implementation of a trap-reduction technique utilizing small molecule additives to mitigate bulk trapping and improve contact properties.

Main Results:

• The general approach for low-voltage operation via enhanced capacitive coupling was found to be insufficient for high-performance devices.
• Reduced longitudinal fields in low-voltage operation significantly contribute to bulk trapping and compromise contact characteristics.
• The small molecule additive technique successfully enabled low-voltage, high-mobility operation, overcoming the limitations of bulk trapping.

Conclusions:

• A novel trap-reduction strategy using small molecule additives is crucial for achieving high-performance, low-voltage polymer transistors.
• This approach facilitates the integration of polymer transistors into low-voltage circuits, demonstrated by high-performance analog differential amplifiers.
• The findings represent a significant advancement for solution-based analog electronics, meeting power and performance requirements for battery-powered smart-sensing applications.