Solar cells are getting all the attention! Researchers all over the world are working towards making them efficient, possibly because they all realise that solar cells are the future with traditional power sources depleting soon. In the latest, researchers in Sweden and Germany have created highly efficient solar cells that are based on nanowires.
The researchers have displayed how the solar cells, made from tiny wires of the semiconductor indium phosphide (InP) can have efficiencies as high as 13.8 per cent while covering only about 12 per cent of the surface of a device. While an efficiency of 13.8 per cent is not as good as the best commercial silicon devices, the team believes that it could be improved significantly by further research, reports Physics World.
For the uninitiated, nanowires are basically small semiconductor wires with a thickness of just a few hundred nanometres or less. They can help create solar cells that are not only flexible and lightweight but are also cheaper than conventional planar devices. These nanostructures can absorb light efficiently and can act as “antennas”, harvesting much more light than a device with a planar surface. Throwing light on the process, Magnus Borgstrom, team member at the Lund University said, “One consequence of this strong absorption on nanowires is that we observe high light-absorption efficiencies even though only a small part of the device’s surface is covered by the nanomaterials.”
According to the report, the devices made by the team measured about a square millimetre and each contains about four million InP nanowires. Borgstrom further added, “Our nanowires needed to be uniform, having a certain diameter and length in a certain pitch. From our first working p–n InP junctions, it has taken us four years to reach this result.”
