Research Overview

Our research focuses on determining the electronic properties of surfaces, ultrathin films and nanoscale structures using a number of experimental techniques. Our work spans a wide range of materials from simple metals to complex oxides. Current projects include studying fundamental aspects of dye molecule adsorption on oxide surfaces related to solar energy capture; probing the electronic structure of transition metal oxyfluorides for energy storage applications; investigating structure-reactivity relationships of gas-phase reactions catalized at nanofaceted surfaces; exploring the role of radiation-induced reactions in the contamination of multilayer mirrors used in extreme ultraviolet lithography and in the production of planetary exospheres; and exploring energy and momentum correlations between coincident pairs of photoemitted electrons. 

We use a variety of techniques to perform these studies including high-resolution photoemission, inverse photoemission using a newly developed grating spectrograph, the novel technique of Auger-photoelectron coincidence spectroscopy (APECS) with synchrotron radiation (which was developed in our labs), and a variety of scanning probe techniques including variable temperature STM and AFM.

Please click on the links at the left for more information.

       Recent Highlight

Surface topography of MOCVD-deposited epitaxial ZnO films
When doped with certain transition metal ions, ZnO is an attractive candidate material for a dilute magnetic semiconductor with a transition temperature above room temperature. To use these materials in technological applications, it is essential to characterize and understand the film surface morphology on the atomic scale. Furthermore, the way in which metal doping affects the surface properties can affect device performance. The figure at the left shows a (100 x 100 nm) STM image of the surface of a typical MOCVD grown ZnO epitaxial film. The film is grown on r-sapphire with the (11-20) surface exposed. The surface shows a pronounced rectangular structure with height difference that show the presence of monatomic steps, as well as a number of bilayer and trilayer steps. The surface exhibits terraces with widths ranging from 50 to several hundred Angstroms.

       Recent Publications