Nanotransistor-based gas sensing with record-high sensitivity enabled by electron trapping effect in nanoparticles

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Hydrogen gas sensors are crucial for safety and industry.
• Existing palladium nanoparticle (PdNP)-functionalized FET sensors have limited sensitivity due to weak capacitive coupling.
• There is a need for highly sensitive, low-power, chip-scale hydrogen sensors.

Purpose of the Study:

• To develop a novel nanoscale FET gas sensor with enhanced sensitivity and efficiency for hydrogen detection.
• To investigate the electron tunneling and trapping mechanism for improved signal transduction.
• To demonstrate ultra-low power consumption and high sensitivity at room temperature.

Main Methods:

• Fabrication of a nanoscale FET gas sensor functionalized with Pd nanoparticles.
• Utilizing electron tunneling between the FET channel and PdNPs for rapid equilibration.
• Investigating gas reactions with PdNPs that perturb electron equilibrium via trapping/de-trapping.

Main Results:

• Achieved record-high responses to hydrogen (H2) gas across a concentration range of 1-1000 ppm at room temperature.
• Demonstrated a detection limit in the low parts-per-billion (ppb) regime.
• Exhibited ultra-low power consumption of less than 300 nW.

Conclusions:

• The developed nanoscale FET gas sensor based on the electron trapping effect offers supersensitive hydrogen detection.
• The direct communication between gas reaction and channel via electron transfer enables highly efficient signal transduction.
• The demonstrated mechanism holds potential for ultrasensitive detection of other gases.