Synthesis, structure and ethanol sensing properties of Ga2O3-core/WO3-shell nanostructures

Abstract Ga 2 O 3 -core/WO 3 -shell nanostructures were synthesized by thermal evaporation of Ga 2 S 3 powders followed by thermal evaporation of WO 3 powders and their C 2 H 5 OH gas sensing properties were examined. Ga 2 O 3 –WO 3 heterostructure formation turned out to enhance the C 2 H 5 OH gas sensing properties remarkably. Ga 2 O 3 -core/WO 3 -shell nanostructure sensors showed far stronger and faster response to C 2 H 5 OH gas than pristine Ga 2 O 3 nanostructures sensors. The significant improvement in the response of the Ga 2 O 3 nanostructures to C 2 H 5 OH gas by Ga 2 O 3 –WO 3 heterostructure formation can be explained by a combination of the potential barrier-controlled carrier transport mechanism and the surface-depletion mechanism.