‘Double-glazed’ solar panels promise new life for photovoltaics
Researchers at the University of Warwick have developed a ‘double glazed’ solar panel that use gas rather than a vacuum to collect electricity.
Developed by Dr Gavin Bell and Dr Yorck Ramachers from the university’s Physics department, the device is essentially a thin double-glazed window where the outer pane is transparent and conducts electricity.
The inner window is coated with a special material that acts as a source of electrons under illumination by sunlight, called a photocathode.
The two panes are separated by a safe inert gas, such as argon - exactly as is found in high quality double glazing windows.
When sunlight hits the device, electrons are knocked out of the photocathode and bounce through the gas to the outer pane without being absorbed or lost.
This is totally different from how electrons act in existing solar panels, and opens up the possibility of improving solar power generation methods.
The electrons are then collected and the electrical energy pumped into the grid, the university says. This can be done through a gas-filled gap rather than a vacuum which the researchers say is far more cost-effective for any practical device.
“It’s satisfying to find a new twist on ideas dating back to the start of the 20th century, and as a materials physicist it is fascinating to be looking for materials which would operate in an environment so different to standard photocathodes, “ said Bell.
The optimal material for the photosensitive layer still needs to be identified, and the researchers have proposed a range of candidate materials - including thin films of diamond, which would be very robust and long-lasting.
The transparency of the photocathode could be varied, leading to the possibility of tinted windows generating solar power.
The researchers would like the scientific community to think about potential optimal materials. “We think the materials challenge is really critical here so we wanted to encourage the materials science community to get creative,” said Bell.
“Our device is radically different from standard photovoltaics, and can even be adapted for other green technologies such as turning heat directly into electricity, so we hope this work will inspire new advances.”
In October researchers at Michigan State University said that widespread adoption of transparent solar materials mounted on windows, combined with rooftop panels, could almost meet US electricity demand.