Think those flat, glassy solar panels on your neighbour’s roof are the pinnacle of solar technology? Think again.
Researchers in the University of Toronto’s Edward S. Rogers Sr. Department of Electrical & Computer Engineering have designed and tested a new class of solar-sensitive nanoparticle that outshines the current state of the art employing this new class of technology.
Diagram of a quantum dot.
University of Toronto
This new form of solid, stable light-sensitive nanoparticles, called colloidal quantum dots, could lead to cheaper and more flexible solar cells, as well as better gas sensors, infrared lasers, infrared light emitting diodes and more. The work, led by post-doctoral researcher Zhijun Ning and Professor Ted Sargent, was published this week in Nature Materials.
Collecting sunlight using these tiny colloidal quantum dots depends on two types of semiconductors: n-type, which are rich in electrons; and p-type, which are poor in electrons. The problem? When exposed to the air, n-type materials bind to oxygen atoms, give up their electrons, and turn into p-type. Ning and colleagues modelled and demonstrated a new colloidal quantum dot n-type material that does not bind oxygen when exposed to air.
Maintaining stable n- and p-type layers simultaneously not only boosts the efficiency of light absorption, it opens up a world of new optoelectronic devices that capitalize on the best properties of both light and electricity. For the average person, this means more sophisticated weather satellites, remote controllers, satellite communication, or pollution detectors.
“This is a material innovation, that’s the first part, and with this new material we can build new device structures,” said Ning. “Iodide is almost a perfect ligand for these quantum solar cells with both high efficiency and air stability—no one has shown that before.”
Ning’s new hybrid n- and p-type material achieved solar power conversion efficiency up to eight per cent—among the best results reported to date.
But improved performance is just a start for this new quantum-dot-based solar cell architecture. The powerful little dots could be mixed into inks and painted or printed onto thin, flexible surfaces, such as roofing shingles, dramatically lowering the cost and accessibility of solar power for millions of people.
“The field of colloidal quantum dot photovoltaics requires continued improvement in absolute performance, or power conversion efficiency,” said Sargent. “The field has moved fast, and keeps moving fast, but we need to work toward bringing performance to commercially compelling levels.”
This research was conducted in collaboration with Dalhousie University, King Abdullah University of Science and Technology and Huazhong University of Science and Technology.
Senior Communications Officer
The Edward S. Rogers Sr. Department of Electrical & Computer Engineering
University of Toronto
Dominic Ali | newswise
Trojan Transit Rolling Out
27.03.2015 | University of Arkansas at Little Rock
Ultra-Thin Silicon Films Create Vibrant Optical Colors
25.03.2015 | University of Alabama Huntsville
In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...
The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.
As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...
When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.
The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe.
Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...
Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.
From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...
25.03.2015 | Event News
19.03.2015 | Event News
17.03.2015 | Event News
27.03.2015 | Agricultural and Forestry Science
27.03.2015 | Materials Sciences
27.03.2015 | Ecology, The Environment and Conservation