Defect Tolerance:
Perfect Imperfection
Seán
Kavanagh
Even though these atomic ‘mistakes’ may occur only
once for every billion normal atoms, like DNA, they
can significantly alter the resulting macroscopic
properties.
Just as a single genetic mutation can change your eye
colour from brown to blue, a tiny amount of defects
can kill device performance in a range of important
technologies, such as solar cells, batteries in electric
vehicles, pacemakers and iPhones, or even LEDs in
your TV and phone screens.
Scan me with your phone camera for
a 4 minute YouTube talk on this work!
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@Kavanagh_Sean_
[email protected]
a
Supervisor:
Prof David Scanlon (Chemistry)
Captions
a. Like genetic mutations in DNA, rare but
omnipresent ‘imperfections’ in materials can
cause major overall changes, such as preventing
the efficient conversion of sunlight to electricity in
solar cells.
b. Outline of a typical high-throughput screening
investigation, with a large input material search
space assessed using chemical rules and quantum
mechanical calculations to predict material
properties and performance. From this, a small
selection of promising defect-tolerant candidates
are obtained, for further experimental verification
and development in low-cost high-efficiency
devices.
Like the rare, random mutations in DNA which
facilitate evolution, all materials contain faults in the
arrangement of their atoms, known as ‘defects’.
These wonder materials could revolutionise the energy sector, making the dream of cheap
renewable energy a reality.
In our lab, we use quantum mechanical calculations to understand the atomic properties of
these materials and their defects, before then leveraging this understanding to search
unexplored chemical space for materials that fit this criteria.
Given that there are trillions of compounds and materials yet to be discovered, we are
hopeful that we will soon find the ‘needle in the haystack’ that exhibits defect tolerance and is
stable, non-toxic and earth-abundant.
The future is bright for solar technology!
Recently, an exciting new class of ‘defect-tolerant’ materials has emerged – which retain high
device efficiencies despite large concentrations of defects, allowing extremely cheap
manufacturing costs.
b
A missing atom here, an atom in the wrong place there.
Check out our recent review paper on this topic:
Huang, Y.-T.; Kavanagh, S. R.; Scanlon, D. O.; Walsh,
A.; Hoye, R. L. Z. Perovskite-Inspired Materials for
Photovoltaics and beyond; from Design to Devices.
Nanotechnology 2021, 32 (13), 132004.
doi.org/10.1088/1361-6528/abcf6d.