While solar cells are becoming more common across North America, we are far from making the most of this green energy source. One challenge is increasing the number of people who choose solar over other energy sources; the other is that the solar cells most commonly in use come with several significant problems.
The dominant kind of solar cell right now is silicon, which itself is quite difficult to manufacture and relatively expensive to produce. Moreover, the solar cells which result are more fragile than the industry would like: they can be shattered by something like a severe hail storm, which limits their appeal and use.
Among solar researchers, therefore, the big goal right now is to come up with something that is easier and cheaper to produce, and also more durable. One such candidate is what's called a colloidal quantum dot solar cell, which meets those goals—but comes with its own liability, At its current early stage of development, CQD cells are much less efficient than silicon solar cells.
Recently, however, researchers at the University of Toronto and the King Abdullah University of Science and Technology have made a breakthrough on that front, setting a record for producing the most efficient CQD cell ever.
Solar cells need to reach about 10 to 15 per cent efficiency in order to be commercially viable. As recently as 10 months ago CDQ cells were at about five per cent efficiency; now researchers, under the leadership of U of T engineering professor Ted Sargeant, have hit the 7 per cent mark—a 37 per cent increase in efficiency, and an important step along the way to make these much cheaper cells ready for the market. The results were published in the July 29, 2012 issue
of Nature Nanotechnology.
Writer: Hamutal Dotan
Source: Liam Mitchell, Communications & Media Relations Strategist, Faculty of Applied Science & Engineering, University of Toronto