A new 'double-glazing' solar power device --
which is unlike any existing solar panel and
opens up fresh opportunities to develop more
advanced photovoltaics -- has been invented by
University of Warwick researchers.
This unique approach, developed by Dr Gavin
Bell and Dr Yorck Ramachers from Warwick's
Department of Physics, uses gas -- rather than
vacuum -- to transport electrical energy,
The device is essentially a thin double-glazed
window. The outer pane is transparent and
conducts electricity. The inner window is coated
with a special material, which acts a source of
electrons under illumination by sunlight -- this
is 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 to how electrons act in
existing solar panels, and opens up the
possibility of improving solar power generation
methods -- whereas improvements in classic
photovoltaics are hard to come by.
The electrons are then collected and the
electrical energy pumped into the grid. This can
be done through a gas-filled gap rather than a
vacuum which would be far more cost-effective
for any practical device.
Dr Bell and Dr Ramachers re-investigated ideas
about the photoelectric effect dating back to
Nikola Tesla and Albert Einstein when they
considered whether these ideas could be used
for modern solar power generation -- leading to
the development of this new process.
Dr Gavin Bell, from the University of Warwick's
Department of Physics, commented:
"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."
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 Dr 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."