Engineers at Stanford have developed a process which can harness the light and heat of the sun simultaneously, which could lead to solar cells that are twice as efficient as those currently available. Called photon enhanced thermionic emission -- or PETE for short -- the process differs from traditional cells which lose efficiency as temperatures rise, and the materials needed to build the cells are cheap and widely available. The engineers got around the lower efficiencies by coating a piece of semiconducting material with a thin layer of the metal cesium, which enables the material to use both heat and light simultaneously. Whil
