Modeling and Optimization of Chemical Vapor Deposition

Min Yao

The pressing needs of an ever-expanding population have driven the chemical industry forward in developing new materials and methods for constructing cost-competitive photovoltaic systems. Conventional silicon-based solar cells are currently the most sophisticated, but are not ideal due to the poor optical absorption of silicon over much of the spectrum of visible light. Gallium arsenide (GaAs), which has a much higher absorption coefficient, is an attractive alternative for creating more efficient solar cells.

The present GaAs solar cells are usually produced via epitaxial processes, among which hydride vapor phase epitaxy (HVPE) is well known for its significantly higher growth rate than metal organic vapor phase epitaxy (MOVPE) and molecular beam epitaxy (MBE). Though the HVPE process is relatively mature, certain aspects of the process remain unclear. My aims are to clarify the limitations to GaAs growth within the HVPE system based on our existing understanding of the growth models, explore the optimization of high-throughput rapid-growth semiconductor growth systems, and demonstrate through device-like structures the performance of this new approach.