New solar cell sets world record for efficiency

Thursday, September 13, 2012 9:59:00 AM



An international group of researchers led by U of T Engineering Professor Ted Sargent (Dept. of Electrical and Computer Engineering) has created the most efficient CQD solar cell the world has ever seen -- a record-breaking 7.0% efficiency, representing a 37% increase in efficiency over the previous certified record.   

CQD stands for colloidal quantum dot - a type of semiconductor only a few nanometres in size which is used to harvest electricity from the entire solar spectrum, including both visible and invisible wavelengths.

"Our world urgently needs innovative, cost-effective ways to convert the sun's abundant energy into usable electricity," said Sargent. "This work shows that the abundant materials interfaces inside colloidal quantum dots can be mastered in a robust manner, proving that low cost and steadily-improving efficiencies can be combined."

The findings were published in Nature Nanotechnology and are the result of work by the University of Toronto and King Abdullah University of Science & Technology (KAUST).

"Previously, quantum dot solar cells have been limited by the large internal surface areas of the nanoparticles in the film, which made extracting electricity difficult," said post-doctoral fellow Susanna Thon, a lead co-author of the paper. "Our breakthrough was to use a combination of organic and inorganic chemistry to completely cover all of the exposed surfaces."

This advance opens up many avenues for further research and improvement of device efficiencies, which could contribute to a bright future with reliable, low cost solar energy.

This is an edited excerpt of an article from

Read the article published in Nature Nanotechnology (available online to U of T faculty, staff and students):
Ip, A. and S. Thon et al. 2012. Hybrid passivated colloidal quantum dot solids. Nature
. doi:10.1038/nnano.2012.127 (published online July 29, 2012)

More information on Dr. Sargent's research group: