US researchers develop method to triple solar cell efficiency

13 December 2012 (Last Updated December 13th, 2012 03:30)

A new technique to nearly triple the efficiency of organic solar cells has been developed by researchers at Princeton University in the US state of New Jersey.

sun

A new technique to nearly triple the efficiency of organic solar cells has been developed by researchers at Princeton University in the US state of New Jersey.

The scientists, led by electrical engineer Stephen Chou, have found a way to increase the efficiency of the solar cells by 175% by using a nanostructured 'sandwich' of plastic and metal that traps and collects light.

The sandwich, called a subwavelength plasmonic cavity, was able to dampen reflection from the cell and fully capture light entering into the cell - the two primary challenges that cause solar cells to lose energy.

The nanoscale lattice on top of the sandwich is able to trap light with openings called a 'plasmonic cavity with subwavelength hole array' or PlaCSH.

Using the new technique, the team has developed a solar cell that reflects just 4% of light and absorbs almost 96%, demonstrating a 52% higher efficiency in converting light to electrical energy when compared to a conventional solar cell.

Researchers used a fine metal mesh, each hole of which is 175 nanometers in diameter and 25 nanometers apart, on the top layer of the new solar cell.

The top layer, called window layer, is made of gold and is only 30 nanometers thick, while the mesh layer replaces the brittle layer made of indium-tin-oxide (ITO) with extremely bendable PlaCSH, noted the researchers.

Plans are underway to expand this research by further increasing the efficiency of the PlaCSH system.

Chou noted that the technology is also expected to increase the efficiency of conventional inorganic solar collectors, such as silicon solar panels.


Image: Princeton University developed a solar cell that reflects just 4% and absorbs almost 96% of light. Photo: courtesy of FreeDigitalPhotos.net.