Polymeric Semiconductor in Field-Effect Transistors Utilizing Flexible and High-Surface Area Expanded...

Area of Science:

• Materials Science
• Organic Electronics
• Semiconductor Physics

Background:

• Organic field-effect transistors (OFETs) are crucial for flexible electronics.
• Gate dielectric properties significantly influence OFET performance.
• Expanded-poly(tetrafluoroethylene) (ePTFE) offers unique microstructures and flexibility.

Purpose of the Study:

• To investigate the impact of annealing on OFETs utilizing ePTFE gate dielectrics.
• To enhance the charge carrier mobility of semiconducting polymer-based OFETs.
• To explore the potential of ePTFE membranes for flexible electronic devices.

Main Methods:

• Fabrication of OFETs with ePTFE membranes and poly[2,5-bis(2-octyldodecyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-3,6-diyl)-alt-(2,2':5',2″:5″,2‴-quaterthiophen-5,5‴-diyl)] (PDPP4T) semiconductor.
• Annealing OFETs at temperatures ranging from 50 °C to 200 °C.
• Characterization using scanning electron microscopy (SEM) and transistor performance measurements.
• Development of a mobility model accounting for ePTFE's microporous structure.

Main Results:

• Annealing above 50 °C significantly improved OFET behavior and output current.
• A maximum hole mobility of 1.8 ± 1.0 cm²/V s was achieved with ePTFE at 200 °C annealing.
• This represents a substantial increase compared to OFETs with conventional silicon wafer oxide (0.09 ± 0.03 cm²/V s).

Conclusions:

• Thermally durable ePTFE membranes with unique microstructures enhance charge carrier mobility in OFETs.
• Responsive semiconducting polymer films can be effectively deposited on flexible, non-wetting ePTFE membranes.
• This approach offers a pathway to significantly improve OFET performance for flexible electronic applications.