Today one of the main problems in the development of solar panels is the creation of photovoltaic cells that can absorb as much solar energy as possible without overheating to such an extent that they begin to simply radiate the absorbed energy back into the atmosphere. Previously, this meant that commercially available solar cells are capable of converting into energy only about 30 percent of the sunlight they absorb.
Researchers at Purdue University have found an innovative way to overcome this problem by modifying commonly used silicon wafers, which thanks to the new technology are able to more efficiently absorb energy at higher temperatures than ever before.
A new study published in the journal Applied Physics Letters describes a method in which silicon wafers are coated with a thin film of tantalum and silicon nitride, while their ability to absorb sunlight increases many-fold.
The modified surface is capable to absorb selectively the photons in a certain range of the light spectrum, reflecting those that can not be used.
The innovative solar cells can withstand temperatures of up to 535 degrees Celsius without any performance or stability problems, turning a staggering 50 (!) percent of sunlight into useful energy.
This research has several interesting applications - for example, the same film can be placed on the surface of mirror parabolic cylinders used on concentrating solar plants to make them even more effective.
Although the innovative film is not yet ready for any commercial application, the authors of the study are confident that this technology will inspire scientists and manufacturers to try a similar experimental approach to increasing the absorption of solar energy.