ZnO nanocrystals Chemical Vapor Synthesis of Size-Selected Zinc Oxide

ZnO can be regarded as one of the most important metal oxide semicon-ductors for future applications. Similar to silicon in microelectronics, it is not only important to obtain nanoscale building blocks of ZnO, but also extraordinary purity has to be ensured. A new gas-phase approach to obtain size-selected, nanocrystalline ZnO particles is presented. The tetra-meric alkyl-alkoxy zinc compound [CH3ZnOCH(CH3)2]4 is chemically transformed into ZnO, and the mechanism of gas-phase transformation is studied in detail. Furthermore, the morphological genesis of particles via gas-phase sintering is investigated, and for the first time a detailed model of the gas-phase sintering processes of ZnO is presented. Various analyti-cal techniques (powder XRD, TEM/energy-dispersive X-ray spectrosco-py, magic-angle spinning NMR spectroscopy, FTIR spectroscopy, etc.) are used to investigate the structure and purity of the samples. In particu-lar, the defect structure of the ZnO was studied by photoluminescence spectroscopy. Keywords: · gas-phase reactions · nanocrystalline materials · semiconductors · single-source precursors · zinc oxide 1