Highly sensitive thermoelectric touch sensor based on p-type SnO _x thin film

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Tin oxide (SnOₓ) thin films are explored for thermoelectric applications.
• Optimizing film thickness is crucial for tuning thermoelectric properties.

Purpose of the Study:

• Investigate p-type SnOₓ thin films for thermal sensing capabilities.
• Optimize thermoelectric performance by controlling film thickness.
• Evaluate the potential of SnOₓ films in display technologies.

Main Methods:

• Fabrication and characterization of SnOₓ thin films with varying thicknesses (60-160 nm).
• Measurement of thermoelectric properties (Seebeck coefficient, electrical conductivity).
• X-ray photoelectron spectroscopy (XPS) for phase analysis and optical measurements for band gap determination.

Main Results:

• A 60 nm SnOₓ film achieved a high Seebeck coefficient (+263 μV K⁻¹) and conductivity (4.1 × 10² S m⁻¹).
• The optimal film contained SnO (79.7%) and SnO₂ (20.3%) phases with specific optical band gaps.
• The 60 nm film demonstrated a Vsignal/Vnoise ≈ 20 and a rise time <1 s as a thermoelectric touch sensor.

Conclusions:

• Optimized SnOₓ thin films show promise as efficient thermoelectric thermal sensors.
• The study highlights the potential of these films for integration into display technologies.
• Film thickness control is key to achieving desired thermoelectric and sensing performance.