Perovskite is one of the most common crystal structures found on the planet.
But common doesn’t mean boring.
While it was originally discovered as a mineral,
this amazing crystal shape shows up everywhere,
and is a common subject,
for cutting-edge scientific research.
For starters, Earth scientists are fascinated with it,
because even though it's the most abundant kind of mineral on the planet,
We hardly ever see it.
Most of it is buried deep within the earth’s mantle.
Perovskites make up 93 percent of the lower mantle’s mass,
and 38 percent of the total mass of the planet.
There are several different kinds of perovskite,
but they share a similar, dense crystalline structure.
In the mantle, silicate-perovskites are the most common;
the high density of these minerals
create the sharp boundary at a depth of 660 kilometers
that separates the less dense upper mantle,
from the more dense, perovskite-rich lower mantle.
Below 2600 kilometers,
the pressure crushes, silicate-perovskites into
a new mineral called post-perovskite.
Post-perovskite is mechanically weaker, but has a higher electrical conductivity
that allows pockets of the mineral to interact with Earth’s magnetic field.
Researchers theorize that all terrestrial planets bigger than Mars,
have a similar abundance of perovskites deep beneath their surface,
so mapping out these mineral transitions allows us
to not only learn more about the internal structure of our planet,
but other planets as well.
Perovskite’s knack for conductivity brings to the fore another quirk
that makes it the perfect target for research.
Metal-halide perovskites are a type of crystal that can act as a semiconductor.
So scientists are looking at how it can be incorporated into various technologies.
In 2009, researchers discovered that by shining light on perovskite,
they were able to induce a small electric charge,
creating a minuscule solar cell.
Since then, the efficiency of perovskite-based solar cells has increased to over 22 percent.
These panels generate electricity via a thin layer of Lead halide perovskite film
on top of a coating of conductive oxide.
One of the benefits to using perovskites in solar cells is their “defect-tolerance.”
Unlike silicon cells, where everything has to be aligned perfectly to work,
and any damage renders the entire device unusable,
perovskite cells can be simply layered onto a surface
and generate an electric charge,
making manufacturing easier and cheaper.
But while engineers are hopeful that perovskite could help to bring down the price of solar energy,
they have some downsides for now.
The perovskite cells are small, fragile, and degrade much faster
than conventional silicon crystal panels:
on the order of hours and days, instead of years.
If perovskite can take in light, could it also make it?
Researchers are looking into improving screens and LEDs,
Using lead halide perovskites as “quantum dot” nanocrystals
On a LCD TV screen, pixels are made up of 3 colors: red, green, and blue.
Tests with prototype perovskite pixels used a single kind of light source, blue LEDs,
with perovskite/polymer beads on top to control the color.
When the blue light shines through the beads, the color of the light that makes it through
comes out in a green or red hue.
While silicon quantum dot displays are out on the market already, they are very expensive.
So like solar panels, using halide perovskites
could bring down the cost of manufacturing immensely.
The colors created by this perovskite prototype,
exceeded some television and computer monitor standards
good enough for use in a future TV.
Even though each of these uses has some roadblocks to adoption,
the massive increase in research and studies about perovskite
means we’ll be seeing a lot of this crystal structure
in the years to come.