Photoelectric properties of ZnO/Ag2S heterostructure and its photoelectric ethanol sensing characteristics

The photoelectric properties of ZnO microspheres, ZnO/Ag2S heterogeneous microspheres and Ag2S hollow microspheres were investigated systematically by surface photovoltage, transient photovoltage and surface photocurrent techniques. The ZnO/Ag2S heterostructure shows superior photoelectric properties in visible-light region compared with pure Ag2S. Transient photovoltage results reveal the separation processes of photo-generated charge carriers in the samples. The photoelectric ethanol sensing property induced by visible light for the ZnO/Ag2S heterostructure has been found, which should be valuable for the practical application of semiconductor gas sensors at room temperature.

► The ZnO/Ag2S heterostructure shows good photoelectric properties under visible-light irradiation.
► Transient photovoltage results reveal the separation process of photo-generated charges and give further evidence of interfacial effects.
► Photoelectric ethanol sensing characteristics have been found for the ZnO/Ag2S heterostructure at room temperature.