title: Ultra-small photoluminescent silicon-carbide nanocrystals by atmospheric-pressure plasmas.
abstract: Highly size-controllable synthesis of free-standing perfectly crystalline silicon carbide nanocrystals has been achieved for the first time through a plasma-based bottom-up process. This low-cost, scalable, ligand-free atmospheric pressure technique allows fabrication of ultra-small (down to 1.5 nm) nanocrystals with very low level of surface contamination, leading to fundamental insights into optical properties of the nanocrystals. This is also confirmed by their exceptional photoluminescence emission yield enhanced by more than 5 times by reducing the nanocrystals sizes in the range of 1-5 nm, which is attributed to quantum confinement in ultra-small nanocrystals. This method is potentially scalable and readily extendable to a wide range of other classes of materials. Moreover, this ligand-free process can produce colloidal nanocrystals by direct deposition into liquid, onto biological materials or onto the substrate of choice to form nanocrystal films. Our simple but efficient approach based on non-equilibrium plasma environment is a response to the need of most efficient bottom-up processes in nanosynthesis and nanotechnology.
authors.affiliation: Nanotechnology & Integrated Bio-Engineering Centre, Ulster University, BT37 0QB, UK. d.mariotti@ulster.ac.uk and Department of Physics, Chemistry and biology (IFM), Linköping University, SE-581 83 Linköping, Sweden.
authors.forename: Sadegh
authors.initials: S
authors.lastname: Askari
authors.affiliation: Nanotechnology & Integrated Bio-Engineering Centre, Ulster University, BT37 0QB, UK. d.mariotti@ulster.ac.uk.
authors.forename: Atta
authors.initials: A
authors.lastname: Ul Haq
authors.affiliation: Nanotechnology & Integrated Bio-Engineering Centre, Ulster University, BT37 0QB, UK. d.mariotti@ulster.ac.uk.
authors.forename: Manuel
authors.initials: M
authors.lastname: Macias-Montero
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4000, Australia.
authors.forename: Igor
authors.initials: I
authors.lastname: Levchenko
authors.affiliation: EaStChem, School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK.
authors.forename: Fengjiao
authors.initials: F
authors.lastname: Yu
authors.affiliation: EaStChem, School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK.
authors.forename: Wuzong
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Institute for Future Environments and School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4000, Australia and CSIRO-QUT Joint Sustainable Processes and Devices Laboratory, Commonwealth Scientific and Industrial Research Organization, P.O. Box 218, Lindfield, NSW 2070, Australia.
authors.forename: Kostya Ken
authors.initials: KK
authors.lastname: Ostrikov
authors.affiliation: Nanotechnology & Integrated Bio-Engineering Centre, Ulster University, BT37 0QB, UK. d.mariotti@ulster.ac.uk.
authors.forename: Paul
authors.identifier: http://orcid.org/0000-0002-2725-4647
authors.initials: P
authors.lastname: Maguire
authors.affiliation: Research Center of Photovoltaics, National Institute of Advanced Industrial Science and Technology-AIST, Central 2, Tsukuba, Japan.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Svrcek
authors.affiliation: Nanotechnology & Integrated Bio-Engineering Centre, Ulster University, BT37 0QB, UK. d.mariotti@ulster.ac.uk.
authors.forename: Davide
authors.initials: D
authors.lastname: Mariotti