The Journal of Physical Chemistry Letters,
Год журнала:
2025,
Номер
unknown, С. 4262 - 4269
Опубликована: Апрель 22, 2025
van
der
Waals
crystal
NbOCl2
has
attracted
considerable
interest
owing
to
its
spontaneous
parametric
downconversion
properties,
but
challenges
remain
due
degradation
and
reduced
optical
nonlinearity
under
ambient
conditions.
Here,
we
show
that
high-temperature
vacuum
annealing
can
recover
even
enhance
second
harmonic
generation
(SHG)
in
degraded
via
recrystallization.
During
degradation,
the
second-order
decreases,
accompanied
by
changes
structure
of
NbOCl2.
However,
after
annealing,
SHG
is
recovered
improved
as
a
result
recrystallization
nanosheets.
This
strategy
enables
realization
tunable
nonlinear
responses,
including
absorption.
By
combining
linear
absorption
spectroscopy,
transient
absorption,
transmission
electron
microscopy,
occurs
specific
temperatures,
leading
bandgap
modulation
altered
electronic
relaxation.
study
offers
new
approach
achieving
reversible
for
device
applications.
Advanced Functional Materials,
Год журнала:
2024,
Номер
34(16)
Опубликована: Янв. 4, 2024
Abstract
Second
harmonic
generation
(SHG)
as
an
essential
nonlinear
optical
effect,
has
gradually
shifted
its
research
trend
toward
the
integration
and
miniaturization
of
photonic
optoelectronic
on‐chip
devices
in
recent
years.
2D
layered
materials
(2DLMs)
open
up
a
new
paradigm
optics
due
to
their
large
second‐order
susceptibility,
atomically
thin
structure,
perfect
phase‐matching.
However,
2DLMs
are
facing
bottleneck
weak
SHG
conversion
efficiency
limit
caused
by
short
light–matter
interaction
lengths
at
nanoscale.
Moreover,
advances
integrated
based
on
rely
continuing
development
novel
strategies
with
tunable
efficient
responses.
Here,
this
review
provides
comprehensive
overview
progress
exploring
highly
responses
2DLMs.
Various
modulation
enhancement
for
response
extensively
studied
systematically
discussed,
which
can
be
classified
into
two
categories:
symmetry
breaking
light‐matter
enhancement.
remaining
challenges
outlooks
further
extending
realizing
practical
applications
characteristics
discussed.
Nano Letters,
Год журнала:
2024,
Номер
24(11), С. 3413 - 3420
Опубликована: Март 8, 2024
Two-dimensional
(2D)
NbOI2
demonstrates
significant
second-harmonic
generation
(SHG)
with
a
high
conversion
efficiency.
To
unlock
its
full
potential
in
practical
applications,
it
is
desirable
to
modulate
the
SHG
behavior
while
utilizing
intrinsic
lattice
anisotropy.
Here,
we
demonstrate
direction-specific
modulation
of
response
by
applying
anisotropic
strain
respect
orientations,
where
more
than
2-fold
enhancement
intensity
achieved
under
along
polar
axis.
The
strain-driven
evolution
attributed
strengthened
built-in
piezoelectric
field
(polar
axis)
and
enlarged
Peierls
distortions
(nonpolar
axis).
Moreover,
provide
quantifications
correlation
between
terms
susceptibility
tensor.
Our
results
effective
coupling
orientation-specific
through
order
2D
nonlinear
optical
crystals,
opening
new
paradigm
toward
development
functional
devices.
Journal of the American Chemical Society,
Год журнала:
2023,
Номер
145(44), С. 24416 - 24424
Опубликована: Окт. 26, 2023
An
unusual
O/F
ordered
d0
transition
metal
fluoroantimonite,
namely,
K2SbMoO2F7,
has
been
created
by
the
cationic
size
effect
of
alkali
metals.
It
features
largest
birefringence
0.220@550
nm
among
inorganic
antimonites
with
a
halogen
element,
which
is
an
order
magnitude
larger
than
disordered
A2SbMoO2F7
(A
=
Rb,
Cs).
These
three
new
compounds
exhibit
two
different
structures,
although
all
structures
were
made
[SbMoO2F7]2-
chains
formed
SbF5
square
pyramids
and
MoO2F4
octahedrons.
A
transparent
single
crystal
K2SbMoO2F7
dimensions
7.0
×
5.0
1.0
mm3
successfully
grown
aqueous
solution
volatilization
method.
The
UV-vis-MIR
transmission
spectrum
showed
that
can
display
excellent
transmittance
in
range
0.5-5.0
μm
6.0-9.8
μm,
indicating
its
application
potential
as
birefringent
material
mid
infrared
band.
This
work
offers
fresh
approach
to
design
synthesis
materials.
Journal of the American Chemical Society,
Год журнала:
2023,
Номер
145(43), С. 23842 - 23848
Опубликована: Окт. 20, 2023
Organic-inorganic
halide
perovskites
possess
unique
electronic
configurations
and
high
structural
tunability,
rendering
them
promising
for
photovoltaic
optoelectronic
applications.
Despite
significant
progress
in
optimizing
the
characteristics
of
organic
cations
inorganic
framework,
role
organic-inorganic
interactions
determining
optical
properties
has
long
been
underappreciated
remains
unclear.
Here,
by
employing
pressure
tuning,
we
realize
continuous
regulation
a
lead
perovskite,
MHyPbBr3
(MHy+
=
methylhydrazinium,
CH3NH2NH2+).
Compression
enhances
strengthening
Pb-N
coordinate
bonding
N-H···Br
hydrogen
bonding,
which
results
higher
distortion
framework.
Consequently,
second-harmonic-generation
(SHG)
intensity
experiences
an
18-fold
increase
at
1.5
GPa,
order-disorder
phase
transition
temperature
increases
from
408
K
under
ambient
to
454
industrially
achievable
level
0.5
GPa.
Further
compression
triggers
sudden
non-centrosymmetric
centrosymmetric
transition,
accompanied
anomalous
bandgap
0.44
eV,
stands
as
largest
boost
all
known
perovskites.
Our
findings
shed
light
on
intricate
correlations
among
interactions,
octahedral
distortion,
SHG
and,
more
broadly,
provide
valuable
insights
into
design
property
optimization
through
cation
engineering
ACS Nano,
Год журнала:
2024,
Номер
18(8), С. 6256 - 6265
Опубликована: Фев. 14, 2024
Self-intercalation
in
two-dimensional
(2D)
materials
is
significant,
as
it
offers
a
versatile
approach
to
modify
material
properties,
enabling
the
creation
of
interesting
functional
materials,
which
essential
advancing
applications
across
various
fields.
Here,
we
define
ic-2D
covalently
bonded
compounds
that
result
from
self-intercalation
metal
into
layered
2D
compounds.
However,
precisely
growing
with
controllable
phases
and
concentrations
fully
exploit
family
remains
great
challenge.
Herein,
demonstrated
controlled
synthesis
self-intercalated
H-phase
T-phase
Ta1+xS2
via
temperature-driven
chemical
vapor
deposition
(CVD)
viable
intercalation
concentration
spanning
10%
58%.
Atomic-resolution
scanning
transmission
electron
microscopy-annular
dark
field
imaging
Ta
atoms
occupy
octahedral
vacancies
located
at
van
der
Waals
gap.
The
nonperiodic
break
centrosymmetry
structure
Fermi
surface
properties
intrinsic
TaS2.
Therefore,
consistently
exhibit
spontaneous
nonlinear
optical
(NLO)
effect
regardless
sample
thickness
concentrations.
Our
results
propose
an
activate
NLO
response
centrosymmetric
achieving
modulation
wide
range
optoelectronic
family.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(32), С. 22469 - 22475
Опубликована: Авг. 1, 2024
Rational
design
of
structural
polarization
is
vital
for
modern
technologies,
as
it
allows
the
physical
properties
functional
materials
to
be
tailored.
An
effective
approach
governing
involves
utilization
stereochemical
lone-pair
electrons
(LPEs).
However,
despite
recognized
significance
LPEs
in
controlling
polarization,
there
remains
a
lack
understanding
regarding
quantitative
relationship
between
their
expression
and
extent
polarization.
Here,
by
using
pressure
continuously
tune
LPE
expression,
we
achieve
precise
control
quantification
which
brings
enhanced
second
harmonic
generation
(SHG)
molecular
crystal
SbI
Two-dimensional
ferroelectric
materials
can
generate
a
bulk
photovoltaic
effect,
making
them
highly
promising
for
self-powered
photodetectors.
However,
their
practical
application
is
limited
by
weak
photoresponse
due
to
transition
strength
and
wide
band
gap.
In
this
study,
we
construct
van
der
Waals
heterojunction
using
NbOI2,
which
has
significant
in-plane
polarization,
with
absorbing
MoSe2
layer.
We
observe
ultrafast
hole
transfer
from
NbOI2
within
0.4
ps
electron
in
the
opposite
direction
3.8
ps,
facilitating
efficient
charge
dissociation
extraction.
Applying
direct
current
electric
field
poling
modulates
domains
enhancing
effect.
This
results
one
of
highest
responsivities
photodetectors
(101.3
mA/W)
at
0
V
bias
alongside
excellent
polarization
sensitivity
(∼7.58).
work
advances
understanding
self-powering
mechanisms
via
effect
proposes
new
strategies
future
devices.
Abstract
It
is
substantially
challenging
for
non‐centrosymmetric
(NCS)
Hg‐based
chalcogenides
infrared
nonlinear
optical
(IR‐NLO)
applications
to
realize
wide
band
gap
(
E
g
>
3.0
eV)
and
sufficient
phase‐matching
(PM)
second‐harmonic‐generation
intensity
d
eff
1.0
×
benchmark
AgGaS
2
)
simultaneously
due
the
inherent
incompatibility.
To
address
this
issue,
work
presents
a
diagonal
synergetic
substitution
strategy
creating
two
new
NCS
quaternary
chalcogenides,
AEHgGeS
4
(AE
=
Sr
Ba),
based
on
centrosymmetric
(CS)
AEIn
S
.
The
derived
displays
excellent
NLO
properties
such
as
(≈3.04–3.07
eV),
large
PM
(≈2.2–3.0
),
ultra‐high
laser‐induced
damage
threshold
(≈14.8–15
suitable
Δ
n
(≈0.19–0.24@2050
nm),
making
them
highly
promising
candidates
IR‐NLO
applications.
Importantly,
second‐order
are
primarily
attributed
synergistic
combination
of
tetrahedral
[HgS
]
[GeS
functional
primitives,
supported
by
detailed
theoretical
calculations.
This
study
reports
first
materials
with
well‐balanced
comprehensive
(i.e.,
eV
puts
forward
design
avenue
construction
more
efficient
candidates.