title: Remarkable improvement of gas-sensing abilities in p-type oxide nanowires by local modification of the hole-accumulation layer.
abstract: This paper proposes a method for improving the reducing or oxidizing gas-sensing abilities of p-type oxide nanowires (NWs) by locally modifying the hole-accumulation channel through the attachment of p-type nanoparticles (NPs) with different upper valence band levels. In this study, the sensing behaviors of p-CuO NWs functionalized with either p-NiO or p-Co3O4 NPs were investigated as a model materials system. The attachment of p-NiO NPs greatly improved the reducing gas-sensing performance of p-CuO NWs. In contrast, the p-Co3O4 NPs improved the oxidizing gas-sensing properties of p-CuO NWs. These results are associated with the local suppression/expansion of the hole-accumulation channel of p-CuO NWs along the radial direction due to hole flow between the NWs and NPs. The approach proposed in this study provides a guideline for fabricating sensitive chemical sensors based on p-CuO NWs.
authors.affiliation: Department of Materials Science and Engineering, Inha University , Incheon 402-751, Republic of Korea.
authors.forename: Sun-Woo
authors.initials: SW
authors.lastname: Choi
authors.forename: Akash
authors.initials: A
authors.lastname: Katoch
authors.forename: Jae-Hun
authors.initials: JH
authors.lastname: Kim
authors.forename: Sang Sub
authors.initials: SS
authors.lastname: Kim
keywords: electronic sensitization; gas sensor; oxide nanowires; p-type; sensing mechanism