Alumni Profile - Duke Alum Designs Better PV Cells at NASA's GRC

Wednesday, October 14, 2009

Duke alum Sheila Brown Bailey has spent the last 24 years working on solar cells at the NASA’s Glenn Research Center in Cleveland. “My job basically is to make a better solar cell, meaning one that is more efficient or that lasts longer or is cheaper to make,” she says. “Right now I’m doing some fundamental research in quantum dot solar cells.”

She and her colleagues are using nanostructures called quantum dots to manipulate the width of the band gap in photovoltaic cells. “The name of the game in PV is to absorb as much of the solar spectrum as you can,” she says. “If you can expand that capability by engineering the band gap to cover a larger portion of the solar spectrum, then you have a more efficient solar cell.”

Bailey works on PV cells used in space, but her work has applications on Earth as well, especially now that the race is on to improve solar technology as part of a strategy to reduce carbon dioxide emissions. While quantum dot technology shows a lot of promise, challenges remain. “Most of the obstacles relate to the material properties and interactions in the interfaces,” she says. Using quantum dots to improve the absorption of sunlight has the potential to degrade the materials in the cell.

Bailey graduated from Duke in 1967, one of two women to earn a degree in physics that year. Horst Meyer was her faculty advisor and she worked in his lab one summer. “I very much enjoyed the experience that he provided and I discovered I am a true experimentalist,” she says.

She got married the day after she graduated, then earned a master’s degree from UNC, a PhD from the University of Manchester in England, and completed a post-doc at the University of New South Wales in Australia. She and her husband settled in Cleveland where he had been offered a job.

When the youngest of her three children entered kindergarten in 1985, Bailey landed a position at NASA’s Glenn Research Center. “I’ve really enjoyed being in PV research,” she says. “I’m not in a hurry to retire since I’m having fun.”