title: Monodispersed spherical colloids of Se@CdSe: synthesis and use as building blocks in fabricating photonic crystals.
abstract: Monodispersed spherical core-shell colloids of Se@Ag(2)Se have been exploited as a chemical template to synthesize Se@CdSe core-shell particles using a cation-exchange reaction. A small amount of tributylphosphine could facilitate the replacement of Ag(+) by Cd(2+) in methanol at 50 degrees C to complete the conversion within 150 min. The orthorhombic structure of beta-Ag(2)Se changed to a well-defined wurtzite lattice for CdSe. The CdSe shells could be converted back to beta-Ag(2)Se by reacting with AgNO(3) in methanol at room temperature. Because of the uniformity in size and high refractive index associated with the Se@CdSe core-shell colloids, they could serve as a new class of building blocks to fabricate photonic crystals with wide and strong stop bands.
authors.affiliation: Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA.
authors.forename: Unyong
authors.initials: U
authors.lastname: Jeong
authors.forename: Jong-Uk
authors.initials: JU
authors.lastname: Kim
authors.forename: Younan
authors.initials: Y
authors.lastname: Xia
authors.forename: Zhi-Yuan
authors.initials: ZY
authors.lastname: Li
mesh_terms: D019187:Cadmium Compounds / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects; D003102:Colloids / Q000032:analysis / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D008027:Light; D008422:Materials Testing; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D043942:Nanotubes / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure*; D010316:Particle Size; D010777:Photochemistry / Q000295:instrumentation / Q000379:methods*; D012643:Selenium / Q000032:analysis / Q000737:chemistry / Q000528:radiation effects; D018036:Selenium Compounds / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects; D012666:Semiconductors
chemical_list: D019187:Cadmium Compounds; D003102:Colloids; D018036:Selenium Compounds; C058667:cadmium selenide; D012643:Selenium