Graduation Year

2005

Document Type

Thesis

Degree

M.S.E.E.

Degree Granting Department

Electrical Engineering

Major Professor

Rudy Schlaf.

Keywords

XPS, UPS, Interface, Amino acid, Electronic structure

Abstract

Using photoemission spectroscopy (PES) the interface between the amino acid L-cysteine and a Au substrate was characterized to determine its electronic and chemical structure. L-cysteine was deposited on a Au substrate in several experiments via dipping into solution or via evaporation. The depositions were performed in several steps. Between deposition steps x-ray photoemission spectroscopy (XPS) and ultraviolet photoemission spectroscopy (UPS) measurements were taken. XPS was used to characterize the chemical interaction at the interface while UPS was used to determine the orbital line-up at the interface and the highest molecular orbital (HOMO) structure of L-cysteine. The results indicate the formation of an interface state at approximately 1.5 eV above the L-cysteine HOMO.

Share

COinS