Published on September 28th, 2011 | by Glenn Meyers3
Quantum Dot Solar Cell Improvements Show Remarkable Potential to Balance Solar Performance & Cost
Next time someone needs an extra PV panel, they might think about bringing along a spray can so they can create their own spray-on quantum dot solar cells.
For those wondering about this odd-sounding configuration, qizmag has written about the very heady topic of colloidal quantum dot solar cells. This report is based on an innovative study recently published in Nature Materials. “Quantum dot solar cells use nanoscale semiconductors to produce electricity and promise low-cost production. Better, because they can be sprayed or painted on, they provide many low-cost benefits in terms of installation,” concludes Noel McKeegan at gizmag.
As far as innovation on the technology front, this one is a winner. In tabulating efficiency ratings, however, quantum cells don’t seem to perform as well as either silicon-based or CIGS solar cells. This may soon change. Nature Materials writes that a new efficiency record for wrapping colloidal quantum dot solar cells may represent a step towards narrowing the gap.
To make quantum dot solar cells that can be sprayed or painted on, the tiny nanoscale semiconductors need to be dispersed evenly within another substance – this is known as a colloid. Organic molecules have successfully been used to create colloidal quantum dot (CQD) solar cells but the minute space they take up between the nanoparticles has a negative impact on the flow of electrons and in turn the efficiency of the cell.
On improving the efficiency of a colloidal quantum dot solar cell, researchers from the University of Toronto, King Abdullah University of Science & Technology and Pennsylvania State University report having developed a way to coat or passivate the quantum dots in inorganic ligands. This approach improves efficiency by reducing electron “traps” in the material and packing more quantum dots into the same amount of nanospace, while at the same time retaining the colloid characteristics of quantum dots bound together by organic molecules.
The University of Toronto and King Abdullah University of Science & Technology have signed a licensing agreement in order to commercialize this technology, which also has other potential applications.
“The world – and the marketplace – need solar innovations that break the existing compromise between performance and cost,” said Ted Sargent, the author on the work and holder of the Canada Research Chair in Nanotechnology at the University of Toronto.
The researchers outline their work in the paper Collodial-quantum-dot photovoltaics using atomic-ligand passivation in the latest issue of Nature Materials.
Photo Credit: Pink Sherbet Photography and University of Toronto