The Journal of Physical Chemistry Letters,
Journal Year:
2025,
Volume and Issue:
unknown, P. 2072 - 2079
Published: Feb. 19, 2025
Two-dimensional
(2D)
materials
with
tunable
interlayer
interactions
hold
immense
potential
for
optoelectronic
and
photocatalytic
applications.
Understanding
the
dependence
of
carrier
dynamics
on
twist
angle
in
Janus
bilayers
is
essential,
as
it
directly
impacts
device
efficiency.
This
study
employs
time-dependent
density
functional
theory
(TD-DFT)
nonadiabatic
molecular
(NAMD)
to
investigate
twist-angle-dependent
MoSSe
type-II
band
alignment.
Simulations
reveal
ultrafast
charge
transfer
times
approximately
70
500
fs,
largely
independent
due
multiple
intermediate
states.
In
contrast,
electron-hole
recombination
depend
strongly
angles,
extending
up
133
ns
twisted
configurations
(21.8°
38.2°)
compared
57
high-symmetry
(0.0°
60.0°).
Structural
randomness
weakens
interactions,
reducing
coupling
coherence
time,
which
collectively
prolong
lifetimes.
These
findings
offer
valuable
guidance
designing
2D
high-efficiency
photovoltaics
long-durable
photocatalysts.
Chemistry of Materials,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 6, 2025
Metal
halide
perovskites
(MHP)
have
attracted
great
attention
in
the
photovoltaic
industry
due
to
their
high
and
rapidly
rising
power
conversion
efficiencies,
currently
over
25%.
However,
hybrid
organic-inorganic
MHPs
are
inherently
chemically
unstable,
limiting
application.
All-inorganic
perovskites,
such
as
CsPbI3,
many
merits,
but
stable
efficiency
is
lower,
around
18%,
a
larger
band
gap
causing
mismatch
with
solar
spectrum.
Choosing
α-CsPbI3
prototypical
system,
we
demonstrate
new
general
concept
of
dynamic
defects
that
fluctuate
between
deep
shallow
states,
increase
range
absorbed
photons,
without
accelerating
nonradiative
electron-hole
recombination.
In
deeper
energy
state,
narrow
allow
harvesting
light
longer
wavelengths.
Fluctuating
shallower
energies,
escape
photogenerated
charges
into
bands,
enabling
charge
transport
resulting
defect-mediated
upconversion
thermal
electricity.
Defect
covalency
participation
low-frequency
anharmonic
vibrations
decouple
trapped
from
free
carriers,
minimizing
carrier
losses.
Our
findings
defect
dynamics
unique
important
properties
MHPs,
can
be
used
optimize
for
efficient
optoelectronic
applications.
The Journal of Physical Chemistry Letters,
Journal Year:
2025,
Volume and Issue:
unknown, P. 1253 - 1260
Published: Jan. 26, 2025
Halide
perovskite
optoelectronic
devices
achieve
high
energy
conversion
efficiencies.
However,
their
efficiency
decreases
significantly
with
an
increase
in
temperature.
This
decline
is
likely
caused
by
changes
nonradiative
recombination
and
electron-phonon
coupling,
which
remain
underexplored.
When
the
lattice
temperature
increases,
anharmonicity
induces
level
fluctuation
band
gap
narrowing
modulating
interactions.
As
vibrations
intensify,
high-frequency
phonons
progressively
dominate
carrier
dynamic
processes
halide
perovskites,
thereby
strengthening
coupling
between
electronic
subsystem
phonons.
The
increased
overlap
of
electron
wave
functions
strengthens
non-adiabatic
accelerating
process.
On
basis
these
findings,
we
propose
introduction
appropriate
materials
heavy
atoms
at
B-site
X-site
to
modulate
mitigating
enhancing
solar
cell
performance.
Advanced Optical Materials,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 6, 2025
Abstract
The
ab
initio
nonadiabatic
molecular
dynamics
(NAMD)
approach
is
advanced
by
integrating
light–matter
interactions,
enabling
comprehensive
simulations
of
the
carrier
in
solid
materials
from
photoexcitation
to
relaxation.
Using
this
method,
excited
electron
and
hole
are
investigated
monolayer
MoSe
2
entangled
with
optical
field,
phonons
spin‐orbit
coupling
(SOC),
encompassing
valley
polarization
depolarization.
During
initial
0.6
ps
after
photoexcitation,
field
dominates,
leading
rapid
a
high‐polarization
plateau,
alongside
phonon‐assisted
intervalley
photoexcitation.
Subsequently,
electron‐phonon
interactions
SOC
starts
play
role
depolarization,
diminishing
zero
around
1.6
ps.
Hole
also
induced
it
depolarizes
more
slowly
than
electrons
without
an
but
becomes
dependent
on
when
laser
present.
This
work
provides
powerful
tool
for
studying
coherent
effects
fields,
phonons,
dynamics,
which
crucial
design
next‐generation
optoelectronic
devices.
The Journal of Physical Chemistry Letters,
Journal Year:
2025,
Volume and Issue:
unknown, P. 2072 - 2079
Published: Feb. 19, 2025
Two-dimensional
(2D)
materials
with
tunable
interlayer
interactions
hold
immense
potential
for
optoelectronic
and
photocatalytic
applications.
Understanding
the
dependence
of
carrier
dynamics
on
twist
angle
in
Janus
bilayers
is
essential,
as
it
directly
impacts
device
efficiency.
This
study
employs
time-dependent
density
functional
theory
(TD-DFT)
nonadiabatic
molecular
(NAMD)
to
investigate
twist-angle-dependent
MoSSe
type-II
band
alignment.
Simulations
reveal
ultrafast
charge
transfer
times
approximately
70
500
fs,
largely
independent
due
multiple
intermediate
states.
In
contrast,
electron-hole
recombination
depend
strongly
angles,
extending
up
133
ns
twisted
configurations
(21.8°
38.2°)
compared
57
high-symmetry
(0.0°
60.0°).
Structural
randomness
weakens
interactions,
reducing
coupling
coherence
time,
which
collectively
prolong
lifetimes.
These
findings
offer
valuable
guidance
designing
2D
high-efficiency
photovoltaics
long-durable
photocatalysts.
