Advanced Science,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 20, 2025
Abstract
Lead‐free
halide
double
perovskites
provide
a
promising
solution
for
the
long‐standing
issues
of
lead‐containing
perovskites,
i.e.,
toxicity
Pb
and
low
stability
under
ambient
conditions
high‐intensity
illumination.
Their
light‐to‐electricity
or
thermal‐to‐electricity
conversion
is
strongly
determined
by
dynamics
corresponding
lattice
vibrations.
Here,
measurement
presented
in
prototypical
lead‐free
perovskite(Cs
2
NaInCl
6
).
The
quantitative
measurements
first‐principles
calculations
show
that
scatterings
among
vibrations
at
room
temperature
are
timescale
≈1
ps,
which
stems
from
extraordinarily
strong
anharmonicity
Cs
.
Further
degree
each
type
atom
quantitatively
characterized
single
crystal,
interatomic
forces,
demonstrate
this
synergistically
contributed
bond
hierarchy,
tilting
NaCl
InCl
octahedral
units,
rattling
+
ions.
Consequently,
crystalline
possesses
an
ultralow
thermal
conductivity
≈0.43
W
mK
−1
temperature,
weak
dependence
T
−0.41
These
findings
uncovered
underlying
mechanisms
behind
can
largely
benefit
design
optoelectronics
thermoelectrics
based
on
perovskites.
