title: Fabrication of dual-type nanowire arrays on a single substrate.
abstract: A novel method for fabricating dual-type nanowire (NW) arrays is presented. Two growth steps, selective-area epitaxy (SAE) in the first step and vapor-liquid-solid (VLS) in the second step, are used to grow two types of NWs on the same GaAs substrate. Different precursors can be used for the growth steps, resulting in sophisticated compositional control, as demonstrated for side-by-side grown GaAs and InP NWs. It was found that parasitic growth occurs on the NWs already present on the substrate during the second growth step and that the SAE NWs shadow the growth of the VLS NWs. Optical reflectance measurements revealed the dual-type array having improved light trapping properties compared to single-type arrays. Dual-type NW arrays could be practical for thermoelectric generation, photovoltaics and sensing where composition control of side-by-side NWs and complex configurations are beneficial.
authors: Department of Micro- and Nanosciences, Micronova, Aalto University , P.O. Box 13500, FI-00076 Aalto, Finland.
authors: Joona-Pekko P
authors: JP
authors: Kakko
authors: Tuomas
authors: T
authors: Haggrén
authors: Veer
authors: V
authors: Dhaka
authors: Teppo
authors: T
authors: Huhtio
authors: Antti
authors: A
authors: Peltonen
authors: Hua
authors: H
authors: Jiang
authors: Esko
authors: E
authors: Kauppinen
authors: Harri
authors: H
authors: Lipsanen
keywords: III−V; dual-type; metallo-organic vapor phase epitaxy; nanowire; selective-area epitaxy; vapor−liquid−solid