title: Self-assembled and highly selective sensors based on air-bridge-structured nanowire junction arrays.
abstract: We describe a strategy for creating an air-bridge-structured nanowire junction array platform that capable of reliably discriminating between three gases (hydrogen, carbon monoxide, and nitrogen dioxide) in air. Alternatively driven dual nanowire species of ZnO and CuO with the average diameter of ∼30 nm on a single substrate are used and decorated with metallic nanoparticles to form two-dimensional microarray, which do not need to consider the post fabrications. Each individual nanowires in the array form n-n, p-p, and p-n junctions at the micro/nanoscale on single substrate and the junctions act as electrical conducting path for carriers. The adsorption of gas molecules to the surface changes the potential barrier height formed at the junctions and the carrier transport inside the straight semiconductors, which provide the ability of a given sensor array to differentiate among the junctions. The sensors were tested for their ability to distinguish three gases (H2, CO, and NO2), which they were able to do unequivocally when the data was classified using linear discriminant analysis.
authors.affiliation: School of Mechanical and Advanced Materials Engineering, KIST-UNIST-Ulsan Center for Convergent Materials, Ulsan National Institute of Science and Technology, Ulsan, Korea.
authors.forename: Won Jeong
authors.initials: WJ
authors.lastname: Park
authors.forename: Kyung Jin
authors.initials: KJ
authors.lastname: Choi
authors.forename: Myung Hwa
authors.initials: MH
authors.lastname: Kim
authors.forename: Bon Hyeong
authors.initials: BH
authors.lastname: Koo
authors.forename: Jong-Lam
authors.initials: JL
authors.lastname: Lee
authors.forename: Jeong Min
authors.initials: JM
authors.lastname: Baik