Ultrasensitive single crystalline TeO₂ nanowire based hydrogen gas sensors

We report a high performance tellurium dioxide (TeO₂) nanowire (NW)-based hydrogen gas sensor fabricated by standard photolithography. High-quality single crystalline TeO₂ NWs were synthesized using gold as a catalyst with high reproducibility. The resulting NW diameters were as small as 30 nm. The gas sensing properties were investigated at various temperatures at two different H₂ concentrations (0.5% and 1%). We observed ΔR/R responses of 28% and 57% at 25 °C and 140 °C, respectively. Furthermore, detailed sensitivity-versus-temperature analysis shows that sensitivity of up to 138% can be obtained at 140 °C for 1% H ₂ concentration.