Sn–Ga co-doped ZnO nanobelts fabricated by thermal evaporation and application to ethanol gas sensors

• Sn–Ga co-doped ZnO nanobelts were synthesized using the thermal evaporation method.
• HRTEM image showed that numerous dots of diameter 5 nm were distributed on the backbone.
• The bright and dark contrast marked the appearance of stacking fault and twin defects.
• Sn–Ga co-dopants modified the morphology of ZnO nanostructures and introduced planar defects which further improved the ethanol sensitivity.

ZnO nanobelts doped with SnO2 and Ga2O3 were synthesized in large scale using a thermal evoparation method without any catalyst. It was demonstrated that obvious contrasts were presented between the backbone and double rough edges. On the basis of HRTEM, numerous nanodots of diameter 5 nm deposited randomly on the backbone surfaces. They were grown with the same orientation along [0001] direction. Gas sensitivity experiments on Sn–Ga codoped ZnO nanobelts were carried out at different temperatures. The results indicated a good response toward 400 ppm ethanol which was as high as 31.033 at the operating temperature of 225 °C.