Preparation and NO2-gas sensing property of individual β-Ga2O3 nanobelt

Monoclinic gallium oxide (β-Ga2O3) nanobelts are synthesized from gallium and oxygen by thermal evaporation in an argon atmosphere and their NO2 sensing properties are studied at room temperature. Electron microscopy studies show that the nanobelts have breadths ranging from 30 to 50 nm and lengths up to tens of micrometers. Both the x-ray diffraction (XRD) and the selected are electron diffraction (SAED) examinations indicate that β-Ga2O3 nanobelts have grown into single crystals. Room temperature NO2 sensing tests show that the current of individual β-Ga2O3 nanobelt decreases quickly, and then gently when the NO2 concentration increases from low to high. It is caused by the NO2 molecule chemisorption and desorption processes in the surface of β-Ga2O3 nanobelt.