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

Highly sensitive, low-power, and chip-scale H₂ gas sensors are crucial. Pd nanoparticle (PdNP)-functionalized field-effect transistors (FETs) show promise but suffer from weak capacitive coupling. This work introduces a nanoscale FET sensor where electrons tunnel between the channel and PdNPs, equilibrating them. Gas reactions with PdNPs perturb this equilibrium, triggering electron transfer via trapping/de-trapping. This direct communication enables efficient signal transduction, resulting in record-high responses to 1–1000 ppm H₂ at room temperature, a detection limit in the low ppb regime, and ultra-low power consumption (~300 nW). The mechanism is potentially applicable to other gases.

Qitao Hu, Paul Solomon, Lars Österlund, Zhen Zhang