Recent advances in material technology could soon lead to more advanced solar cells that can be painted or printed onto a surface, such as thin films and roofing materials.

 A new class of solar-sensitive nanoparticle, developed by researchers at the University of Toronto’s Edward S. Rogers Sr. Department of Electrical & Computer Engineering, outperforms current versions of light-sensitive nanoparticles.

Post-doctoral researcher Zhijun Ning and Professor Ted Sargent have led the work on colloidal quantum dots, manufactured nanoparticles that generate electricity from sunlight. Their research could “lead to cheaper and more flexible solar cells, as well as better gas sensors, infrared lasers, infrared light emitting diodes and more.”

The dots are made from semiconductor materials. The newest research on colloidal quantum dots has addressed difficulties with n-type and p-type semiconductors, creating a more stable material that offers greater efficiency than past versions. With continued development, commercial applications of colloidal quantum dot technology could lead to “more sophisticated weather satellites, remote controllers, satellite communication, or pollution detectors.”

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 according to Sargent, the dots need continued improvement to reach commercial potential. “The field has moved fast, and keeps moving fast, but we need to work toward bringing performance to commercially compelling levels,” he said.
If perfected, the technology could broaden the photovoltaic market. According to the University, “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.”

Collaborators in the research include Dalhousie University, King Abdullah University of Science and Technology and Huazhong University of Science and Technology.

Similar research is under way at the National Institute for Nanotechnology located at the University of Alberta in Edmonton. According to reporter Travis Dhanraj, “They’re fine tuning the development of flexible, polymer-based solar cells…about the thickness of a human hair.”

Jillian Buriak, Professor and Senior Research Officer at the U of A and NINT, said “What we’re trying to do is to find a way to mass produce plastic-based solar cells.” The researchers said they’re hoping their research will be in use around the world as early as 2015.
“The ease of spraying solar cells from a can or rolling them out like newspaper, along with significant reductions in production costs, will allow third-world nations currently off the grid to access cheap, clean power,” Dhanraj noted.

Current mass-produced photovoltaic panels have seen robust growth in usage, with Germany currently generating about six per cent of its electric demand from photovoltaic panels. China is the world’s fastest-growing market, and is projected to take the lead in 2016. Total global capacity of photovoltaics was estimated at 139 gigawatts (GW) at the end of 2013, which covers the electricity needs of about 40 million households. According to the 2014 European Photovoltaic Industry Association (EPIA) report, global PV installations will grow by an estimated 35-52 GW in 2014.

New forms of photovoltaics could offer nonindustrialized nations and communities around the world more versatile, and potentially cheaper options for powering electrical devices.