Modeling of interfaces: Adsorption of 2-methyl-4-nitroaniline on hydrogen-terminated Si(100) 2x1 surface

COMP 188

Suely M. Black, smblack@nsu.edu, Department of Chemistry and Center for Materials Research, Norfolk State University, 700 Park Avenue, Norfolk, VA 23504 and Sheena Inge, adimom@yahoo.com, Center for Materials Research, Norfolk State University, 700 Park Avenue, Norfolk, VA 23504.
Materials obtained by deposition of organic layers on inorganic substrates may lead to the development of novel devices. Combination of non-linear optical properties of MNA with processability of silicon may lead to applications to electronic devices preparation and design. This study aims to determine the orientation of MNA on the H/Si(100) surface. The long-term goal is to determine the least expensive, yet reliable, theoretical method and model system to describe the adsorption of organic molecular compounds on inorganic surfaces. The inorganic surface was modeled by a limited number of silicon atoms from the infinite crystal with the dangling bonds terminated with hydrogen atoms. Two cluster, Si31H46 and Si58H72, were used in the investigation. The organic and inorganic systems were optimized with different theoretical approaches, and then brought together for constrained geometry optimizations using ONIOM, a multi-theory level method. The results are strongly dependent on the cluster size and theoretical approach.