A Combined Experimental and Computational Study on the Broadening Mechanism of the Luminescence in Narrow-Band Eu2+-Doped Phosphors
The Journal of Physical Chemistry C,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 1, 2025
In
this
work,
we
present
a
comprehensive
study
of
the
luminescence
relaxation
mechanism
and
associated
spectral
broadening
in
series
Eu2+-doped
narrow-band
phosphors.
It
is
highlighted
that
commonly
used
full-width
at
half-maximum
(fwhm)
no
longer
sensitive
measure
for
quantifying
emission
bandwidth
these
materials.
A
thorough
understanding
factors
contributing
to
narrow
requires
an
explicit
treatment
magnetic
structure
ground
emissive
excited
state
manifolds.
This
incorporating
spin–orbit
coupling
effects
using
wave
function-based
methods
such
as
complete
active
space
self-consistent
field
combined
with
second-order
N-electron
valence
perturbation
theory
(CASSCF/NEVPT2).
addition,
dynamics
calculations,
one
needs
consider
vibronic
interactions
on
basis
Franck–Condon
(FC),
Herzberg–Teller
(HT),
and,
when
necessary,
pseudo
Jahn–Teller
(PJT)
effects.
Our
analysis
underscores
controlling
synergistic
roles
"static"
"dynamic"
are
essential
accurately
assessing
band
systems.
We
show
results
can,
principle,
be
generalized
arbitrary
set
phosphor
candidates
can
potentially
aid
experimental
efforts
toward
developing
novel
phosphors
enhanced
luminescent
properties.
Language: Английский
Unraveling the Mechanism of Circularly Polarized Thermally Activated Delayed Fluorescence (CP-TADF) in Chiral Two-Coordinated Cu(I) Emitters: A Comprehensive Theoretical Exploration
Lingling Lv,
No information about this author
ZiYe Ning,
No information about this author
YanYing Zhang
No information about this author
et al.
Inorganic Chemistry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: March 21, 2025
The
circularly
polarized
thermally
activated
delayed
fluorescence
(CP-TADF)
processes
of
four
pairs
Cu(I)-based
chiral
enantiomers
were
calculated
by
employing
the
path
integral
approach
to
dynamics.
results
reveal
that
introduction
different
substituents
at
various
positions
on
planar
CzP
units
significantly
impacts
dissymmetry
factor
gCPL
CP
luminescence
(CPL).
Substituting
sixth
position
hydrogen
unit
with
-CN
or
-Cl
groups
increases
2.1
×
10-3
and
2.2
in
Sp-MAC-Cu-CNCzP-1
Sp-MAC-Cu-ClCzP,
respectively.
This
is
due
a
small
electric
transition
dipole
moment
|μ|
relatively
large
magnetic
|m|.
from
CT
excitation
spatially
separated
highest-occupied
molecular
orbital
(HOMO)
lowest-unoccupied
(LUMO)
transitions
S1
state,
leading
ΔE(S1
-
T1)
more
efficient
TADF.
Interestingly,
seventh-substituted
MAC-Cu-CNCzP-2
complex
exhibits
substantial
increase
0.346
eV,
which
consequently
leads
significant
decrease
kRISC
rate,
down
3.32
103
s-1,
indicating
further
reverse
intersystem
crossing
(RISC)
are
failed.
Thus,
design
CP-TADF
molecules,
key
lies
regulating
balancing
factors
affecting
both
TADF
CPL
properties.
Language: Английский
Investigating the Mechanism of Thermally Activated Delayed Fluorescence Induced by Different Conformations of a Two-Coordinate Copper(I) Complex
ZiYe Ning,
No information about this author
Lingling Lv,
No information about this author
YanYing Zhang
No information about this author
et al.
The Journal of Physical Chemistry A,
Journal Year:
2025,
Volume and Issue:
unknown
Published: June 4, 2025
The
investigation
of
thermally
activated
delayed
fluorescence
(TADF)
in
carbene-metal-amide
(CMA)
complexes
reveals
that
structurally
flexible
ligands
can
demonstrate
significant
TADF
characteristics.
A
series
four
conformationally
copper(I)
featuring
cyclic
alkyl
amino
carbene
(CAAC)
and
10H-phenothiazine-5,5-dioxide
(Ptz)
were
systematically
studied
using
quantum
chemical
calculations.
study
examines
the
impact
two
key
structural
parameters,
namely
torsion
angle
φ
(CAAC-Cu(I)-Ptz-1:
perpendicular;
CAAC-Cu(I)-Ptz-2
CAAC-Cu(I)-Ptz-3:
coplanar;
CAAC-Cu(I)-Ptz-4:
anticoplanar)
tilt
β
(near-planar
arrangement:
CAAC-Cu(I)-Ptz-3
>
CAAC-Cu(I)-Ptz-2),
on
photophysical
properties
conformations.
Geometrical
excited-state
analyses
indicate
CAAC-Cu(I)-Ptz-1,
CAAC-Cu(I)-Ptz-2,
CAAC-Cu(I)-Ptz-4
conformations
are
observed
to
have
similar
transitions,
but
their
angles
critically
influence
energy
gap
variations.
Specifically,
differences
between
excited
states
0.10
0.20
eV,
respectively,
due
distinct
spans.
Notably,
increased
diminishes
contribution
Cu,
with
lowest
triplet
state
(T1)
displaying
47%
ligand-to-ligand
charge
transfer
(LLCT)
28%
metal-to-ligand
(MLCT)
character.
combined
minimum
crossing
point
(MECP)
spin-orbit
coupling
(SOC)
elucidate
effect
reverse
intersystem
(RISC)
rates:
(0.41
eV
MECP
barrier)
CAAC-Cu(I)-Ptz-1
(SOC
=
4.35
cm-1)
confirmed
suppress
RISC
rates
(1.09
×
104
1.09
108
s-1,
respectively),
while
enhanced
achieved
through
reduced
barriers
strengthened
SOC
interactions
by
(1.68
109
3.87
respectively).
These
findings
highlight
vital
role
ligand
flexibility
CMA
emitters,
offering
valuable
guidance
for
designing
efficient
materials.
Language: Английский
Chiral Organometallic Complexes Derived from Helicenic N-Heterocyclic Carbenes (NHCs): Design, Structural Diversity, and Chiroptical and Photophysical Properties
Accounts of Chemical Research,
Journal Year:
2024,
Volume and Issue:
57(20), P. 2941 - 2952
Published: Oct. 3, 2024
ConspectusRecently,
helicene
derivatives
have
emerged
as
an
important
class
of
molecules
with
potential
applications
spanning
over
asymmetric
catalysis,
biological
activity,
magnetism,
spin
filtering,
solar
cells,
and
polymer
science.
To
harness
their
full
potential,
especially
emissive
components
in
circularly
polarized
organic
light-emitting
diodes
(CP-OLEDs),
generating
structural
chemical
diversity
understanding
the
resulting
photophysical
chiroptical
properties
are
crucial.
In
this
Account,
we
shed
light
on
engineering
combining
Language: Английский
Chiroptical activity of benzannulated N-heterocyclic carbene rhenium(i) tricarbonyl halide complexes: towards efficient circularly polarized luminescence emitters
Physical Chemistry Chemical Physics,
Journal Year:
2023,
Volume and Issue:
26(6), P. 4855 - 4869
Published: Nov. 14, 2023
The
work
describes
the
in-depth
experimental
and
computational
investigation
of
a
novel
series
enantiomerically
pure,
circularly
polarized
emitters
based
on
tris-carbonyl
Re(
i
)
complexes.
Language: Английский