title: Photoinduced conductivity of a porphyrin-gold composite nanowire.
abstract: Negatively charged phosphine groups on the backbone of DNA are known to attract gold nanoclusters from a colloid, assembling the clusters at fixed intervals. Bridging these intervals with porphyrin-dye linkers forms an infinite conducting chain, a quantum wire whose carrier mobility can be enhanced by photoexcitation. The resulting nanoassembly can be used as a gate: a wire with a controllable conductivity. The electronic structure of the porphyrin-gold wire is studied here by density functional theory, and the conductivity of the system is determined as a function of the photoexcitation energy. Photoexcitations of the dye are found to enhance the wire conductivity by orders of magnitude.
authors.affiliation: Quantum Theory Project, Departments of Chemistry and Physics, University of Florida, Gainesville Florida 32611-8435, USA.
authors.forename: Dmitri S
authors.initials: DS
authors.lastname: Kilin
authors.forename: Kiril L
authors.initials: KL
authors.lastname: Tsemekhman
authors.forename: Svetlana V
authors.initials: SV
authors.lastname: Kilina
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Balatsky
authors.forename: Oleg V
authors.initials: OV
authors.lastname: Prezhdo