Nano Flakes promise greater solar energy efficiency

The inefficiency of solar cells in converting the sun’s rays into electricity is a key contributor to the high costs of solar energy, but new research into a novel shape of semiconductor nanostructures known as "nano flakes" may revolutionize the process and help improve the viability of clean energy derived from the sun.

Details of the research by Martin Aagesen, a PhD from the Nano-Science Center and the Niels Bohr Institute at University of Copenhagen were recently published in nature nanotechnology. If his "future solar cells" meet expectations, they may be a huge step towards boosting the world’s exploitation of solar energy. Aagesen believes that the nano flakes have the potential to convert up to 30 per cent of the solar energy into electricity and that is roughly twice the amount that the average solar cell converts today.

The discovery was made during Aagesen’s work on his PhD thesis when he found a new and untried material. “I discovered a perfect crystalline structure. That is a very rare sight. While being a perfect crystalline structure we could see that it also absorbed all light. It could become the perfect solar cell,” he said. The technology has the potential to reduce the solar cell production costs which rely on expensive semiconducting silicium. At the same time, the "future solar cells" will exploit solar energy more effectively and lessen the loss of energy.

Aagesen is also director of the company SunFlake Inc. which is pursuing development of the new solar cell.

Other recent efforts to address the issue of solar cell efficiency include a breakthrough from SANYO in June this year which saw the company broke its own record for the world's highest energy conversion efficiency in practical size crystalline silicon-type solar cells by demonstrating an efficiency of 22%. In December last year Spectrolab achieved a world record in terrestrial concentrator solar cell efficiency, using a photovoltaic cell to convert 40.7 percent of the sun's energy into electricity. More recently, Global Warming Solutions announced the development of new solar energy conversion technology based on a special coating that can be applied to existing solar cells.