Modern society is very much defined by its access to electricity. What if researchers could advance sustainable energy technologies to the point where everyone around the world had access to clean, cheap energy sources? Richard Smalley, 1996 Nobel Prize winning chemist, called it the greatest challenge facing the world in the 21st century and coined the phrase "terawatt challenge." Researchers at the Quantum Energy and Sustainable Solar Technologies (QESST) Center are hoping to meet much of the terawatt challenge with solar technology alone by vastly improving the performance of photovoltaic cells. Part of the National Science Foundation Series “Science Nation.”