The U of T researchers, led by Professor Ted Sargent, report the first efficient tandem solar cell based on colloidal quantum dots (CQD). "The U of T device is a stack of two light-absorbing layers – one tuned to capture the sun's visible rays, the other engineered to harvest the half of the sun's power that lies in the infrared," said lead author Dr. Xihua Wang.
"We needed a breakthrough in architecting the interface between the visible and infrared junction," said Sargent, a Professor of Electrical and Computer Engineering at the University of Toronto, who is also the Canada Research Chair in Nanotechnology. "The team engineered a cascade – really a waterfall – of nanometers-thick materials to shuttle electrons between the visible and infrared layers."
According to doctoral student Ghada Koleilat, "We needed a new strategy – which we call the Graded Recombination Layer – so that our visible and infrared light-harvesters could be linked together efficiently, without any compromise to either layer."
The team pioneered solar cells made using CQD, nanoscale materials that can readily be tuned to respond to specific wavelengths of the visible and invisible spectrum. By capturing such a broad range of light waves – wider than normal solar cells – tandem CQD solar cells can in principle reach up to 42 per cent efficiencies. The best single-junction solar cells are constrained to a maximum of 31 per cent efficiency. In reality, solar cells that are on the roofs of houses and in consumer products have 14 to 18 per cent efficiency. The work expands the Toronto team's world-leading 5.6 per cent efficient colloidal quantum dot solar cells.
"Building efficient, cost-effective solar cells is a grand global challenge. The University of Toronto is extremely proud of its world-class leadership in the field," said Professor Farid Najm, Chair of The Edward S. Rogers Sr. Department of Electrical & Computer Engineering.
Sargent is hopeful that in five years solar cells using the graded recombination layer published in today's Nature Photonics paper will be integrated into building materials, mobile devices, and automobile parts.
"The solar community – and the world – needs a solar cell that is over 10% efficient, and that dramatically improves on today's photovoltaic module price points," said Sargent. "This advance lights up a practical path to engineering high-efficiency solar cells that make the best use of the diverse photons making up the sun's broad palette."
The publication was based in part on work supported by an award made by the King Abdullah University of Science and Technology (KAUST), by the Ontario Research Fund Research Excellence Program, and by the Natural Sciences and Engineering Research Council (NSERC) of Canada. Equipment from Angstrom Engineering and Innovative Technology enabled the research.
To read the published paper in its entirety, please contact Takara Small, Communications & Media Relations Coordinator for the Faculty of Applied Science & Engineering, University of Toronto.
For more information, please contact:Takara Small
Takara Small | EurekAlert!
New test procedure for developing quick-charging lithium-ion batteries
07.12.2017 | Forschungszentrum Jülich
Plug & Play Light Solution for NOx measurement
01.12.2017 | Heraeus Noblelight GmbH
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years' time. An international research team working with Empa has now succeeded in producing nanotransistors from graphene ribbons that are only a few atoms wide, as reported in the current issue of the trade journal "Nature Communications."
Graphene ribbons that are only a few atoms wide, so-called graphene nanoribbons, have special electrical properties that make them promising candidates for the...
08.12.2017 | Event News
07.12.2017 | Event News
05.12.2017 | Event News
08.12.2017 | Life Sciences
08.12.2017 | Information Technology
08.12.2017 | Information Technology