A new process from Stanford makes electricity from both heat and light from the sun. The technology spear current solar cells with horse lengths, according to the researchers.

A team of scientists at the U.S. Stanford University has developed a process that uses both light and heat from the sun to generate electricity. The technology is more than twice as efficient as today's solar cells and also cheap, the researchers argue.

In the August issue of Nature Materials presented innovation known as PETE - photon enhanced thermion emission. As the name suggests, this is known as thermal emission which is exacerbated by light. Sunlight photons excite electrons from a cathode as in a conventional solar cell. Since the sun's heat the electron gives an extra boost before the landing at the anode.

According to the researchers is the secret in order to benefit from both light and heat to cover a semiconductor material with a thin layer of cesium.

- This is really a breakthrough, a new process for energy conversion and not just a new material or a minor change, "said research team leader Nick Melosh statement.

While conventional solar cells of silicon does not work in temperatures above 100 ° C, so PETE process requires temperatures well above 200 ° C to be most effective. Scientists believe that technology can be interesting in the solar power plant where the sun's rays are focused by large mirrors.

Until now, scientists have verified that the concept works with a prototype made of cesium covered with gallium nitride, a material chosen to withstand high temperatures. Demonstrator did not as high efficiency as PETE concept is said to have potential. The researchers had not expected. But with different material, presumably a gallium arsenide semiconductor, which they argue that the efficiency could be higher than 50 percent, another advantage is that you do not need as much material.