The next generation of devices will be able to produce more electricity

Jul 30, 2012 07:18 GMT  ·  By

Working alongside colleagues at the King Abdullah University of Science & Technology, scientists from the University of Toronto, in Canada, announce the development of a new type of film, which could significantly improve the efficiency of future generations of solar cells.

The colloidal quantum dot (CQD) films the group has created will make it easier for investigators to produce the most efficient CQD cells ever. Details of the new investigation were published in the latest issue of the top scientific journal Nature Nanotechnology.

According to engineering professor Ted Sargent, from the University of Toronto, the research team was recently able to create a CQD solar cell that functioned at a record-breaking 7.0% efficiency. This is the highest conversion value ever reached by such a cell.

Quantum dots can best be described as nanoscale semiconductors. They are capable of collecting and converting significantly higher amounts of light than conventional solar cells, because they operate at both optical and infrared wavelengths.

One of the most interesting aspects of CQD films is that they can be produced inexpensively, at about the same rate as paint or ink. This opens the way for many wide-scale applications, the scientists say.

“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,” expert Dr. Susanna Thon says.

“Our breakthrough was to use a combination of organic and inorganic chemistry to completely cover all of the exposed surfaces,” adds the investigator, who was also the lead co-author on the new paper.

According to the research team, the 7 percent efficiency represents a 37 percent increase in efficiency over the previous conversion record. The research effort was led by KAUST professor Aram Amassian.

“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,” Sargent explains.

In the near future, producing electrical energy by converting sunlight could become significantly cheaper and more efficient than before. At this time, high costs are what primarily blocks the wide-scale adoption of this technology.

“Our world urgently needs innovative, cost-effective ways to convert the sun's abundant energy into usable electricity,” Sargent concludes, quoted by EurekAlert.