title: Size Control of Porous Silicon-Based Nanoparticles via Pore-Wall Thinning.
abstract: Photoluminescent silicon nanocrystals are very attractive for biomedical and electronic applications. Here a new process is presented to synthesize photoluminescent silicon nanocrystals with diameters smaller than 6 nm from a porous silicon template. These nanoparticles are formed using a pore-wall thinning approach, where the as-etched porous silicon layer is partially oxidized to silica, which is dissolved by a hydrofluoric acid solution, decreasing the pore-wall thickness. This decrease in pore-wall thickness leads to a corresponding decrease in the size of the nanocrystals that make up the pore walls, resulting in the formation of smaller nanoparticles during sonication of the porous silicon. Particle diameters were measured using dynamic light scattering, and these values were compared with the nanocrystallite size within the pore wall as determined from X-ray diffraction. Additionally, an increase in the quantum confinement effect is observed for these particles through an increase in the photoluminescence intensity of the nanoparticles compared with the as-etched nanoparticles, without the need for a further activation step by oxidation after synthesis.
authors.affiliation: Department of Materials Science and Engineering, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Emilie
authors.initials: E
authors.lastname: Secret
authors.affiliation: Department of Materials Science and Engineering, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Camille
authors.initials: C
authors.lastname: Leonard
authors.affiliation: Department of Materials Science and Engineering, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Stefan J
authors.initials: SJ
authors.lastname: Kelly
authors.affiliation: Department of Materials Science and Engineering, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Amanda
authors.initials: A
authors.lastname: Uhl
authors.affiliation: Department of Materials Science and Engineering, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Clayton
authors.initials: C
authors.lastname: Cozzan
authors.affiliation: Department of Materials Science and Engineering, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Andrew
mesh_terms: D049449:Luminescence; D053758:Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D010316:Particle Size; D016062:Porosity; D012825:Silicon / Q000737:chemistry*; D013010:Sonication; D014961:X-Ray Diffraction
chemical_list: D012825:Silicon