Accession Number : ADA311224

Title :   Chemistry Involving the Preparation, Isolation, and Immobilization of III-V Compound Semiconductor Nanocrystals and Quantum Dots.

Descriptive Note : Final technical rept. 1 Oct 92-30 Sep 95,

Corporate Author : DUKE UNIV DURHAM NC DEPT OF CHEMISTRY

Personal Author(s) : Wells, Richard L. ; Coury, Louis A.

PDF Url : ADA311224

Report Date : 17 JUN 1996

Pagination or Media Count : 10

Abstract : Dehalosilylation reactions have afforded the unique III-V (13-15) dimers X2GaP(SiMe3)22 (X = Cl, Br, I) and a stable substance having the empirical formula Cl3Ga2P is isolable, all of which have been thermally decomposed to yield nanocrystalline GaP; thus, they are new single-source precursors to GaP. Also, Cl3Ga2(As,P)n has been synthesized and shown to be a single-source precursor to the ternary semiconductor GaAsP. In addition, a new, low temperature solution phase metathetical synthesis of the nanocrystalline III-V semiconductors GaP, GaAs, GaSb, InP, InAs and InSb has been developed. Optical characterization techniques revealed strong evidence for quantum confinement effects, and XRD, HRTEM, BET, STM and AFM data have shown the materials to be nanometer size particles. A comparison of the electrical properties of nanocrystalline InAs and a p-type InAs wafer using STS showed clear evidence of a larger bandgap for the nanoparticles. Also, poly(pyrrole) films were grown which contained either GaAs or InAs particles and were imaged by HRTEM and STM. Methanol extraction of the as-synthesized nanocrystals from the metathetical reaction of GaCl3 with (Na/K)3As resulted in surface derivatization of the nanoparticles in which methanol capped GaAs quantum dots were obtained. Also, the heterogeneous reaction between GaBr3 and Li3N afforded a precursor which, on pyrolysis under vacuum or NH3, yielded nanosized GaN and elemental Ga. The gallium nitride was characterized by XRD, XPS, and UV/vis spectroscopies, TEM microscopy and elemental analysis. p1

Descriptors :   *ISOLATION, *SEMICONDUCTORS, *CHEMISTRY, *GROUP III COMPOUNDS, *GROUP IV COMPOUNDS, *GROUP V COMPOUNDS, THERMAL PROPERTIES, OPTICAL PROPERTIES, LOW TEMPERATURE, STABILITY, SOLUTIONS(MIXTURES), METHYL RADICALS, POLYMERS, QUANTUM THEORY, GALLIUM ARSENIDES, VACUUM, FILMS, SODIUM, ELECTRICAL PROPERTIES, NITRIDES, PHASE, MICROSCOPY, LITHIUM, PARTICLES, SILICON, METHANOLS, IODINE, PYRROLES, HETEROGENEITY, PHOSPHIDES, EXTRACTION, CONFINEMENT(GENERAL), TERNARY COMPOUNDS, DECOMPOSITION, INDIUM, ANTIMONIDES, POTASSIUM, PYROLYSIS, GALLIUM COMPOUNDS, CHLORINE, BROMINE.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Electrical and Electronic Equipment
      Crystallography
      Atomic and Molecular Physics and Spectroscopy
      Optics
      Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE