A Step Closer to the Optimum Solar Cell
We are conversant with the fact that solar cells absorb the visible light of the sun, though half of the sun’s output is made up of infrared light that too strikes the earth and it remains completely un-utilized. That is why only about 30% of the total sunlight can be converted to electricity thus lowering photovoltaic cells’ efficiency. But Spanish scientists have developed a new material that can absorb this invisible infrared light too. It will possibly give a boost to the solar cells producing energy and help in combating the current energy crisis. These special solar cells are developed by the scientists from Institute for Solar Energy at the Polytechnic University and the Institute of Catalysis of the Spanish Higher Scientific Research Council in Madrid, Spain.
This technology is not new. Even back in 1997 a group of Spanish scientists from the Lawrence Berkeley National Laboratory in California made the very first cells based on the technology with a theoretical absorption limit of 57 percent. Now researchers led by Perla Wahnón and José Conesa both in Madrid, have used that idea to design their new solar-cell material. They added titanium and vanadium atoms into a conventional semiconductor, altering its electronic properties to create the intermediate energy level. The Spanish team calculates that its material can theoretically capture 63% of the Sun’s rays.
Though practically the real-world effectiveness of cells based on the new design wouldn’t be attainable by 63%, explains Conesa. “But if the [theoretical] limit is higher, you can presume that the real figure that you will be able to reach will also be higher.” Early versions of the material match the properties predicted and, although a solar cell hasn’t yet been made, the team aims to in the near future.