Accession Number : ADA317313

Title :   Electrochemical Formation of CdSe Monolayers on the Low Index Planes of Au.

Descriptive Note : Technical rept. 1 Jun 95-15 Oct 96

Corporate Author : GEORGIA UNIV ATHENS DEPT OF CHEMISTRY

Personal Author(s) : Lister, T. E. ; Colletti, L. P. ; Stickney, J. L.

PDF Url : ADA317313

Report Date : 15 OCT 1996

Pagination or Media Count : 36

Abstract : The electrochemical analog of atomic layer epitaxy (ALE) is being studied. ALE is a method for growing thin films of materials using a cycle of surface limited reactions. The surface limited reactions control the deposition by limited the growth to an atomic layer at a time. In electrochemistry, a surface limited deposition is generally referred to as under-potential deposition (UPD), and UPD is used to form the atomic layers in electrochemical ALE (ECALE). The work presented here is an atomic level study of the deposition of the first few monolayers of CdSe via ECALE: by the alternated UPD of atomic layers of Se and Cd on the low index planes of Au. UPD of Se resulted in the formation of ordered structures on each of the low index planes of Au, as observed by low energy electron diffraction (LEED) and scanning microscopy (STM). The subsequent UPD of Cd resulted in CdSe deposits which exhibited 1:1 stiochiometry, as determined by coulometry and Auger electron spectroscopy (AES). The following LEED patterns were observed for the CdSe monolayers: Au(111) (square root of 7 times square root of 7)Rl9.1deg2, Au(111)(3X3), Au(11O)(2X3), and the Au(100)(square root of 2 times square of 2)R45 deg. Similar LEED patterns were observed on each surface for deposits formed using up to three ECALE cycles.

Descriptors :   *ELECTROCHEMISTRY, *CADMIUM, *GOLD, *SELENIDES, SCANNING, MATERIALS, THIN FILMS, MICROSCOPY, DEPOSITION, LOW ENERGY, SURFACE REACTIONS, ELECTRON DIFFRACTION, AUGER ELECTRON SPECTROSCOPY, ANALOG SYSTEMS, ATOMIC ENERGY LEVELS, COULOMETERS, ATOMIC LAYER EPITAXY.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Crystallography
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE