Overview

Currently Accepting Graduate Students

Research interests and current projects:
Photovoltaics (Solar cells)
-III-V on Silicon multi-junction devices
-Advanced characterization of PV materials and devices
Satellite-based optical communications
Materials development for quantum computing

Photovoltaics (Solar cells)

The development of viable sustainable energy resources is arguably the most pressing technological demand of our time due to the high monetary and environmental costs of fossil fuel usage. The depletion of supplies has significantly increased their cost and the concomitant burning has led to rapid and dramatic signs of climate change. The associated pollutants have had increasingly severe effects on public health. None of these problems will be solved without the development of a clean sustainable energy supply. The stability of our economies, climate and health are depending on a technical solution to this unfolding crisis.

My research program is a multi-faceted effort to develop high efficiency and low cost photovoltaic devices. Theoretical efficiencies for single junction devices are limited to ~30% at 1 sun, based upon standard assumptions for the conversion of light to electron-hole pairs in a semiconductor. A proven route to higher efficiencies is via multijunction solar cell technology in which monolithic series-connected solar cells are fabricated, with each cell optimized for a different part of the solar spectrum. Current multijunction devices are expensive relative to single junction devices due to the high cost of their exotic substrates. We are developing a new generation of multijunction solar cells, based upon the growth of III-V semiconductors on high quality ubiquitous Silicon substrates to achieve high efficiencies, providing a significantly lower cost per installed Watt. We are also developing other third generation devices, based upon novel materials, concepts and architectures.