H2S-sensing properties of Cu2O submicron-sized rods and trees synthesized by radio-frequency magnetron sputtering

• Submicron-sized rods and trees of Cu2O were synthesized by RF magnetron sputtering.
• The H2S sensing properties of Cu2O multi-structures were studied.
• Cu2O tree-like sensor performed the best sensitivity comparing with the rest samples.
• Influences of the morphologies onto the sensing properties are analyzed and compared.

Cuprous oxide is a famous p-type material which possesses a great potential in the gas sensing applications. In this paper, thin films and submicron-sized rods and trees of Cu2O were deposited on glass substrates from metallic Cu targets by tailoring the Ar/O2 ratio during the sputtering process. The obtained samples are used to fabricate gas sensors. The H2S-sensing properties of the sensors at working temperatures from 100 °C to 300 °C are studied, in which the Cu2O tree-like sensor performed the best sensitivity comparing with the rest samples. A transformation from Cu2O to CuS is considered as the sensing mechanism of the sensors. Finally, influences of the morphologies onto the sensing properties are analyzed and compared.