Accession Number : ADA291917

Title :   Structural and Electronic Properties of adsorbates on Semiconductors, Metal-Semiconductor Interfaces and Semiconductor Heterojunctions.

Descriptive Note : Rept. for 1 Nov 91-31 Oct 94,

Corporate Author : NORTHWESTERN UNIV EVANSTON IL DEPT OF PHYSICS AND ASTRONOMY

Personal Author(s) : Freeman, A. J.

PDF Url : ADA291917

Report Date : 07 MAR 1995

Pagination or Media Count : 10

Abstract : Studies of the electronic structure of adsorbates on metal-semiconductor and semiconductor-semiconductor interfaces and semiconductor surfaces were carried out using the molecular cluster LCAO-DVM method (as developed into the DMo1 program) also in a full potential local (spin) density approach. The new capability of DMo1 to calculate atomic forces allows automatic geometry optimization; and allowed us to study atomic relaxation and reconstruction at the surfaces and interfaces with and without adsorbates. The method calculated variationally self-consistent highly precise solutions of the local density equations with which to determine the structural and electronic properties of the system. Specific problems addressed included studies of: (1) semiconductor heterojunctions (and their bulk constituents) such as Sn/Ge, and (2) adsorbates on silicon and germanium. The research led to the development of general concepts and simpler theoretical models with which to understand the electronic structure and the relevant parameters governing the interaction between the adsorbate and the substrate. Predictions of theory were compared with experiment. Accurate total energy investigations were undertaken to determine from first principles, equilibrium, internuclear distances, vibrational frequencies, separations and positional (geometric) bonding configurations. jg

Descriptors :   *ELECTRONICS, *METALS, *QUANTUM CHEMISTRY, *INTERFACES, *STRUCTURAL PROPERTIES, *HETEROJUNCTIONS, *SEMICONDUCTORS, *ADSORBATES, FREQUENCY, LINEAR SYSTEMS, DENSITY, VIBRATION, OPTIMIZATION, PREDICTIONS, MODELS, MOLECULES, ELECTROMAGNETIC PROPERTIES, ENERGY, SUBSTRATES, ATOMIC ORBITALS, SURFACES, SOLUTIONS(GENERAL), SILICON, CONFIGURATIONS, PRECISION, GEOMETRY, BONDING, GERMANIUM, AUTOMATIC, SPIN STATES.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Electrical and Electronic Equipment
      Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE