Flexible Temperature Sensor with 2D In₂Se₃ Ferroelectric-Semiconductor Field Effect Transistor Exhibiting Record High...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Electrical Engineering

Background:

• Ferroelectric-semiconductor materials offer unique properties for electronic devices.
• Indium Selenide (In2Se3) is a promising material combining ferroelectric and semiconducting characteristics.
• Developing highly sensitive and stable temperature sensors is crucial for various applications.

Purpose of the Study:

• To develop a highly sensitive temperature sensor using an In2Se3 ferroelectric-semiconductor field-effect transistor.
• To investigate the mechanism behind the high thermal sensitivity in In2Se3.
• To demonstrate the feasibility of flexible and large-area temperature sensing arrays.

Main Methods:

• Fabrication of In2Se3 thin films using low-temperature spray pyrolysis (240 °C).
• Integration of In2Se3 into a field-effect transistor (FET) structure.
• Characterization of the FET's electrical properties and temperature sensing performance.

Main Results:

• Achieved a high thermal sensitivity of 696%/°C.
• Demonstrated temperature sensing from room temperature to 200 °C with high stability.
• Observed off-currents sensitive to temperature variation via variable range hopping conduction.
• Fabricated a flexible In2Se3 temperature sensor array for spatial sensing.

Conclusions:

• The In2Se3 ferroelectric-semiconductor FET exhibits excellent potential for highly sensitive temperature sensing.
• The device's performance is attributed to the interplay of ferroelectricity and semiconducting properties, particularly under variable range hopping conduction.
• The developed flexible sensor technology is suitable for broad temperature detection and large-area spatial sensing applications.