Accession Number:

ADA282294

Title:

Preparation of Au Single Crystals for Study of the ECALE Deposition of CdTe

Descriptive Note:

Technical rept.. no. 15

Corporate Author:

GEORGIA UNIV ATHENS DEPT OF CHEMISTRY

Report Date:

1994-06-25

Pagination or Media Count:

49.0

Abstract:

A sequence of questions concerning the preparation of atomically flat Au surfaces is addressed. In addition, the formation of a 12 monolayer Te adlayer of a Au100 is discussed. The 12 coverage of Au100-Te surface is desired as a first step in the electrodeposition of CdTe by the ECALE methodology. The use of oxidationreduction cycles ORCs to clean the Au100 surface is shown to be counter productive, if atomically flat planes are also desired. Roughening results from the ORCs as the surface reconstructs at low potentials, then unreconstructs at high potentials. The reconstructed surface contains excess surface atoms, such that upon lifting of the reconstruction, monoatomically high Au islands are formed on the surface. It is also shown that treatment in a mM I- solution results in the formation of ordered iodine adlattices on each of the low index planes. In addition, electrochemical annealing is facilitated, resulting in removal of previously formed Au islands, and formation of large, atomically flat terraces. Te can be deposited directly on these I coated surfaces, displacing the I and forming thin films of bulk Te. The excess, bulk, Te can then be removed either reductively or oxidatively, to form ordered atomic layers of Te with coverages near 12.

Subject Categories:

  • Inorganic Chemistry
  • Physical Chemistry
  • Crystallography
  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE