I’ve written about colloidal quantum dot solar cells and University of Toronto professor Ted Sargent’s work before (June 28, 2011). He and his team have been busy again. From the Sept. 18, 2011 news item on Nanowerk,
Researchers from the University of Toronto (U of T), King Abdullah University of Science & Technology (KAUST) and Pennsylvania State University (Penn State) have created the most efficient colloidal quantum dot (CQD) solar cell ever.
The discovery is reported in the latest issue of Nature Materials.
The first time (June 28) I wrote about the colloidal quantum dot (CQD) solar cells, the team had made a breakthrough with the architecture of the solar cell by creating what they called a ‘graded recombination layer’ allowing infrared and visible light harvesters to be linked without compromising either layer. The next time I wrote about Sargent’s work (July 11, 2011), it concerned self-assembling quantum dots and DNA.
The very latest work is focussed on making the CQD solar cells more efficient by packing them closer together,
Until now, quantum dots have been capped with organic molecules that separate the nanoparticles by a nanometer. On the nanoscale, that is a long distance for electrons to travel.
To solve this problem, the researchers utilized inorganic ligands, sub-nanometer-sized atoms that bind to the surfaces of the quantum dots and take up less space. The combination of close packing and charge trap elimination enabled electrons to move rapidly and smoothly through the solar cells, thus providing record efficiency.
I gather this last breakthrough has made commercialization possible,
As a result of the potential of this research discovery, a technology licensing agreement has been signed by U of T and KAUST, brokered by MaRS Innovations (MI), which will enable the global commercialization of this new technology.
Here’s the competitive advantage that a CQD solar cell offers,
Quantum dots are nanoscale semiconductors that capture light and convert it into electrical energy. Because of their small scale, the dots can be sprayed onto flexible surfaces, including plastics. This enables the production of solar cells that are less expensive than the existing silicon-based version.
There are more details about this latest breakthrough both in the Nanowerk news item and in this University of Toronto Sept.19, 2011 news release credited to Liam Mitchell. For anyone who’s curious about MaRS, it’s located in Toronto, Ontario and seems to be some sort of technology company incubator or here’s how they describe themselves (from their How did MaRS get started page?),
A charitable organization could be created to better connect the worlds of science, business and government. A public-private partnership with a mission to remove the barriers between silos. Nurture a culture of innovation. And help create global enterprises that would contribute to Canada’s economic and social development.