Solar cell could turn building materials into generators

A new kind of solar cell could turn building materials into generators that produce electricity at much higher efficiencies than existing technology.

Researchers at Toronto University have developed a solar cell that overcomes one of the problems of trying to capture energy from both visible and infrared light.

They hope in five years the cells could be integrated into building materials, mobile devices and car parts.

In theory, the cells could produce efficiencies of up to 42 per cent, although so far the technology has only yielded 31 per cent efficiency.

But this is still much higher than most existing commercial solar panels, which typically have efficiencies of between 10 and 20 per cent.

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 captures the visible part of the spectrum and the other captures the invisible part.

‘We needed a breakthrough in architecting the interface between the visible and infrared junction,’ said research leader Prof 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 price points.

‘This advance lights up a practical path to engineering high-efficiency solar cells that make the best use of the diverse photons making up the sun’s broad palette.’