Accession Number:

ADA470275

Title:

Structural Design and Photochemical Preparation of Ultrathin Molecular Film Materials

Descriptive Note:

Final technical rept. 1 Jan 2005-31 Dec 2006

Corporate Author:

PENNSYLVANIA UNIV PHILADELPHIA DEPT OF CHEMISTRY

Personal Author(s):

Report Date:

2006-12-01

Pagination or Media Count:

6.0

Abstract:

Toward the goal of developing fundamental understanding of structural properties of molecular thin films to form a scientific basis for designing and preparation of molecular thin film materials, we have made important advances during the past three years. These advances were enabled through applying a combination of ultrahigh vacuum surface science and nonlinear optical techniques to the characterization of thin molecular films. Specifically we have demonstrated for the first time that the nonlinear optical technique Second Harmonic Generation can be used to determine the geometric structure of the interfacial layer of molecules buried in between the molecular film and the solid substrate, and that surface-state enhanced SHG can be used to probe the wetting-dewetting transition of monolayer molecular adsorbates on a metal. The nature of bonding between the layer of linear acenes, molecules such as tetracene and pentacene that have great potential as organic semiconducting materials, have been determined. Overall, we have gained to great extend a fundamental understanding of molecular film deposition, growth, and crystallization mechanisms. This research effort has resulted in a total of 13 referred publications since 2004 to date listed at the end of the report. A more detailed description of research results are presented below.

Subject Categories:

  • Physical Chemistry
  • Electrical and Electronic Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE