The optical rectenna, you could think of it
as like a radio antenna, only for the sun.
It's working off of very similar principles,
where we instead have very tiny antenna
that match the size of the energy coming
from the sun or visible light.
And when that energy is coupled into the antenna,
then another device is used to extract the energy
and turn it into electricity.
So making a rectenna is actually a pretty simple process,
which was part of the beauty of the discovery.
You basically take any type of conductive substrate,
and we can grow these carbon nanotubes
like a carpet-- vertical off the substrate.
We grow our nanotube.
We can formally coat them with something
that is an electrical insulator, then
we deposit another layer of metal on top
to create a so-called metal insulator or metal diode
structure.
And so that diode structure is important,
because it's the fastest diode in the world.
And it's the only diode that's fast enough to open and close
the gate at the speed of solar energy oscillating
in an antenna.
What gets me excited today is that we've done it.
That we've actually achieved the goal that
was six years in the making.
But that's enough to get me out of bed every day,
because I think if we achieve that goal,
we're going to make solar cells that
are twice as efficient of what we have today.
And that, to me, is an opportunity
to change the world in a very big way.