solar power is a key piece of most plans
for a carbon neutral energy future
while silicon-based solar cells are by
far the most common technology
one relative newcomer solar cells that
use perovskite crystals has been getting
better by leaps and bounds
at this rate perovskite solar cells
could become an attractive alternative
to silicon
in the near future or the two types of
solar cells could
join forces to take solar power to new
heights
perovskites are a class of materials
that have a cube-like and diamond-like
crystal structure
though the first perovskites were
discovered more than 180 years ago
they were only applied to solar cells
within the last two decades
they work the same way other
semiconductor based solar cells do
light from the sun excites electrons in
the material and those electrons
flow to conducting electrodes and
generate a current
in 2006 perovskite cells were about
three percent efficient
fast forward to 2020 and some
researchers were boasting
25 efficiency for comparison the first
silicon solar cells were created in a
lab as far back as 1940.
in the 80 years since then they've
matured steadily to the point where
they're now typically
15 to 20 percent efficient it's true
that silicon cells are getting cheaper
all the time but they're still
relatively expensive and difficult to
make
perovskite cells on the other hand can
be made with simpler manufacturing
processes like
printing the crystals onto a surface so
they have the potential
to be much cheaper wait it gets better
because perovskites are artificial they
can be designed to be most efficient
at certain wavelengths meaning they can
work in tandem with silicon in a solar
cell
to generate electricity from light that
silicon can't
use these tandem solar cells are already
a hair's breadth from
30 efficiency and still have room for
improvement
it's also possible to paint perovskite
crystals onto a surface
meaning you could literally paint your
house into a solar panel
you know provided your house's exterior
is made of materials that can conduct
the electricity the crystals generate
just
you know that caveat oh hey look at that
we are at the halfway point of the video
and everything i've said about the
technology thus far has been
glowing you know what that means right
there's a butt coming and here it is
perovskite solar cells have amazing
potential but they still face a few
challenges before they'll be
commercially viable
one major challenge is degradation while
silicon cells can last
25 years or more perovskites aren't
anywhere
close to that their performance drops
off in the span of months
rather than years the material is
fragile and degrades when exposed to
moisture
oxygen high heat and
light a solar cell that breaks down when
exposed to light
is shall we say less than ideal it's
also
difficult to make large perovskite cells
to maintain high efficiency
pinholes and impurities between the
grains can hinder the flow of current
and these problems get worse over larger
areas
these defects also give humidity and
oxygen a foothold to start breaking down
the material so
larger perovskite cells degrade faster
and finally there's the issue that a
major component of the crystals
themselves
is lead either the toxicity and
environmental concerns of using lead
will have to be addressed or researchers
will have to find an
alternative despite all that it's still
incredible
just how far perovskite solar cells have
come in such a short amount of time
the next generation of solar cells that
use perovskites and silicon
in tandem could be hitting the market as
soon as 2022
in terms of efficiency perovskites have
caught and surpassed the most
established solar power technology there
is in the span of just
15 years new breakthroughs in efficiency
lifespan and scalability are happening
all the time
if researchers can keep up that piece of
innovation the future of solar power
looks very bright indeed to learn more
about how exactly solar panels work
check out this illuminating lightspeed
episode here thanks so much for watching
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and i will see you next time on secret