Solar cells are becoming more viable sources of energy -- and as they become more efficient, they're only getting smaller and cheaper to produce. Liquid nanocrystal cells are traditionally inefficient at converting sunlight into electricity, but by adding a synthetic ligand to help transmit currents, researchers at USC have improved their effectiveness. The advantage of these liquid solar cells? They're cheaper than single-crystal silicon wafer solutions, and they're also a shockingly minuscule four nanometers in size, meaning