“We’re not interested in fabricating the most efficient solar cell in the world,” says Dr. Siva Sivoththaman of the University of Waterloo. “We’re interested in fabricating the cheapest.”

That sort of market-oriented perspective shapes much of the research at the Centre for Photovoltaic Systems and Devices, where Dr. Sivoththaman is the director. He believes that photovoltaic technology will play an important role in reducing our dependence on fossil fuels. But for that to happen, solar power has to become significantly cheaper—and that’s going to require some technological breakthroughs.

In the search for more affordable solar cells, Dr. Sivoththaman and his colleagues are taking a broadbased approach. “If you want to make a real impact,” he says, “you need to influence every aspect of the technology. That means looking at materials, devices, systems and electronics. I like to say we have a comprehensive research facility that takes us from desktop to rooftop.” The 1400-square-metre lab—unique in the world for the range of its capabilities—is being funded in part by an investment from the Ontario Innovation Trust.

A key avenue of research focuses on silicon, the material that dominates 90 percent of today’s photovoltaic market. “Silicon is one of the most abundantly available materials on earth,” says Dr. Sivoththaman. “It’s the purification steps that make it so expensive. So we’re looking at fabricating photovoltaic devices with low cost silicon materials, and reduced numbers of purification steps.” Cheaper silicon makes solar cells less efficient, but the potential decrease in cost may far outweigh the loss in performance.

Scientists at the centre are also investigating the use of tiny silicon spheres for advanced photovoltaic devices. Alternative materials for future photovoltaics, including organic semi-conductors and exotic thin films, are also being researched. Nanotechnology is another focus, as it is in so many disciplines. By exploiting the bizarre “quantum effects” that hold sway at this atomic scale, it may be possible to sidestep what were once considered fundamental limits of solar cell performance. Dr. Sivoththaman is also creating “spectral-engineered” solar cells by deploying nano-scale structures onto the devices.

Even this kind of exotic research, however, is being driven by a very practical agenda. “Our primary focus,” says Dr. Sivoththaman, “is solar cells at an affordable price. What we want is to make a real impact.”