We could power the planet for a year if we managed to collect all of the solar power from one hour of sunshine on Earth. Admittedly, Chemistry professor Zhifeng Ding isn’t quite there yet. But thanks to a Strategic Project Grant of $517,255 over three years from Natural Sciences and Engineering Research Council of Canada (NSERC), his work to develop more practical solar cells got a major boost.
Just two years ago, it was common to purchase solar cells with only 0.01 per cent efficiency. Today, the conversion rate of popular silicon cells hovers around 6 per cent.
However, Ding has developed a process where he is able to electrochemically deposit six thin film layers to produce solar cells running at a conversion rate of 10 per cent.
His current successes started a few years ago when a Western alumnus donated $70,000 for the research. That seed money was the basis for Ding to apply for funding from the Ontario Centre of Excellence and NSERC to match the existing funds by five times to $350,000.
That funding was enough to demonstrate thin film deposition was a workable concept.
His team applied for a U.S. patent which was approved in 2011.
“The good thing is that in China, now my previous collaborator, Professor Leo Lau, he’s leading the recent green energy standard in China,” Ding said. “He would like to collaborate with us further by licensing this patent.”
In February, the facilities in China were able to produce panels running at 10 per cent photo conversion. “This is the criterion for a production line and commercialization” Ding added. “I think we will do a great job with this commercialization of our intellectual property and then get further.”
In 2009, Ding also received NSERC support through the Idea to Innovation program to develop a flexible solar cell. Flexible solar cells have the advantage of being less likely to break during installation and withstand daily wear and tear.
Even with these advances, Ding’s group continue the search for further refinements.
The current six-layered cell uses some rare earth elements to boost the efficiency, but Ding said “gallium, indium and selenium are disappearing and are kind of expensive.”
The current strategy is to further reduce the cost, so now Ding is using four inexpensive and plentiful elements – copper, zinc, tin and sulphur, which his team has branded CZTS.
Although there are labs that can produce a solar cell that can run at 20 per cent efficiency, the cost of production for these cells are well above the current market price. Still, the competition is stiff to produce the next generation of cells with research labs in the United States, Japan and Germany doing significant work with access to broader resources than in Canada.
The key is finding cheaper ways of producing solar cells.
“In this way, we can enrich the free energy sources but at very low cost and get the conversion at 10 per cent,” Ding said. “We can do more engineering with the Strategic Grant. In the future, we possibly can reach 15 per cent with CZTS and it will do a good job.”
