Stephen Kelty, Ph.D.

Professor
Department of Chemistry and Biochemistry

Research Interests:

The Kelty group, which is part of the Center for Computational Research, focuses on the use of advanced computational methods to investigate the structure and properties of condensed matter materials. Listed below are several projects currently underway.

• Investigation of electronic structure of mixed InxGa1-xN semiconductors. These materials have shown great promise as variable band gap solar energy conversion devices. By varying the value of x (0 - 1), the band gap also changes. This can permit a much broader range of the solar spectrum to be captured thus significantly enhancing the viability of increasing solar energy's contribution to the national energy budget. At present, a controversy exists about the properties of these materials and the actual band gap obtained for a given value of x. Proposed studies will help solve this problem by calculating the variation in band gap as a function of x, and the location of the In or Ga defect in the lattice. These studies will make use of quantum mechanical simulations to determine the band structure of the target materials.
   
• Interfacial phenomenon of mixed metal oxide thin films. This project is designed to advance the fundamental understanding of metal oxide - metal oxide interfaces which are of critical importance to a variety of application areas including solar energy conversion, solid oxide fuel cells, advanced catalysts, and sensor technology. The chemical and physical properties of interest generally involve the chemical composition and morphology of the interface that affect the function of the material in a given application.
   
• Molecular Dynamics simulation of metal oxide surfaces and thin films. Investigation of the equilibrium structure of metal oxides either as pure material surfaces or as thin films of one oxide on top of another. The current materials under investigation are La2O3 and SiO2. This project is to be expanded to include other lanthanide and transition metal oxide materials such as ZrO2 and HfO2. The prime method used is simulated amorphization and recrystallization (classical MD) and DFT methods.