Format

Send to

Choose Destination
J Phys Chem B. 2005 May 19;109(19):9622-30.

Effect of molecular binding to a semiconductor on metal/molecule/semiconductor junction behavior.

Author information

1
Department of Materials and Interfaces and Chemical Support Services, Weizmann Institute of Science, Rehovot 76100, Israel.

Abstract

Diodes made by (indirectly) evaporating Au on a monolayer of molecules that are adsorbed chemically onto GaAs, via either disulfide or dicarboxylate groups, show roughly linear but opposite dependence of their effective barrier height on the dipole moment of the molecules. We explain this by Au-molecule (electrical) interactions not only with the exposed end groups of the molecule but also with its binding groups. We arrive at this conclusion by characterizing the interface by in situ UPS-XPS, ex situ XPS, TOF-SIMS, and Kelvin probe measurements, by scanning microscopy of the surfaces, and by current-voltage measurements of the devices. While there is a very limited interaction of Au with the dicarboxylic binding groups, there is a much stronger interaction with the disulfide groups. We suggest that these very different interactions lead to different (growth) morphologies of the evaporated gold layer, resulting in opposite effects of the molecular dipole on the junction barrier height.

PMID:
16852158
DOI:
10.1021/jp0504470

Supplemental Content

Full text links

Icon for American Chemical Society
Loading ...
Support Center