Research Description

Optical Properties of Semi-Conductor Surfaces

The past has shown that even though it is the curiosity of inquisitive minds that push the limits of our knowledge in the physical sciences, the direction in which this discipline moves in is within the jurisdiction of the demands and values of modern society. All of the recent publicity on the current “energy crisis” has catalyzed an increase in pressure for research promoting the development and utilization of eco-friendly materials and industrial processes notably, the rising prices of oil have sparked inquiry into the realm of potential alternative-energy sources, such as solar cells.

My research investigates the electronic structure and optical properties of semi-conducting materials—with a focus on silicon surfaces and the effect of added dopants—and is applicable within the domain of photovoltaic materials. The systems of this study are constructed according to theoretical predictions derived from the subject areas of chemistry, physics, mathematics, and quantum mechanics. With the aid of computational software, calculations will be run on the generated models providing numerical approximations of many distinctive atomic and molecular properties. This task will be approached using primarily the methods of Density Functional Theory (DFT) to elucidate characteristic ground-state information such as energy levels, dipole moments, and orbital occupancy. To mimic the absorption of a photon on such surfaces, a time-dependent DFT treatment will be applied, inducing the promotion of an electron to a higher-energy level and effectively exciting the system. This is beneficial in that it yields valuable information such as the wavelength/energy of the absorbed light, and the oscillator strengths corresponding to specific electron excitations. The quantitative data that is computed can be used qualitatively in the formulation conceptual explanations and in predictions of optical spectra, surface photovoltage, and other properties of interest.