Researchers at Toronto University have developed a solar cell that overcomes one of the problems of trying to increase efficiency rates for capturing energy from both visible and infrared wavelengths. The new cells are made using two layers of colloidal quantum dots (CQD) — nanoscale materials that can be tuned to respond to specific wavelengths of light. One layer responds to the visible region of the spectrum, and the other the invisible wavelengths.
In theory, the cells could produce efficiencies of up to 42 %, although so far the technology has only yielded 31 %. This is still much higher than most existing commercial solar panels, which typically have efficiencies of between 10 and 20%.
‘We needed a breakthrough in structuring the interface between the visible and infrared junctions,’ said research leader Professor Ted Sargent.‘The team engineered a cascade — really a waterfall — of nanometres-thick materials to shuttle electrons between the visible and infrared layers.’
He added: ‘The solar community — and the world — needs a solar cell that is more than 10 per cent efficient, and that dramatically improves on today’s photovoltaic module prices.
There is a possibility that this new kind of cell could be integrated into building materials, mobile devices and even car parts, turning them into generators that produce electricity at much higher efficiencies than existing technology.
