Nanoscale,
Год журнала:
2024,
Номер
16(12), С. 6309 - 6314
Опубликована: Янв. 1, 2024
Graphene
quantum
dots
with
Coulomb
blockade
phenomenon
can
be
fabricated
through
electroburning.
The
alteration
in
magnetoconductance
at
the
peak
is
possibly
due
to
formation
of
Landau
levels
graphene
leads.
Nature Nanotechnology,
Год журнала:
2024,
Номер
19(7), С. 986 - 992
Опубликована: Март 25, 2024
Quantum
effects
in
nanoscale
electronic
devices
promise
to
lead
new
types
of
functionality
not
achievable
using
classical
components.
However,
quantum
behaviour
also
presents
an
unresolved
challenge
facing
electronics
at
the
few-nanometre
scale:
resistive
channels
start
leaking
owing
tunnelling.
This
affects
performance
transistors,
with
direct
source-drain
tunnelling
degrading
switching
ratios
and
subthreshold
swings,
ultimately
limiting
operating
frequency
due
increased
static
power
dissipation.
The
usual
strategy
mitigate
has
been
increase
device
complexity,
but
theory
shows
that
if
can
be
exploited
molecular-scale
electronics,
this
could
provide
a
route
lower
energy
consumption
boost
performance.
Here
we
demonstrate
these
experimentally,
showing
how
molecular
transistors
is
improved
when
channel
contains
two
destructively
interfering
waves.
We
use
zinc-porphyrin
coupled
graphene
electrodes
three-terminal
transistor
>10
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(6), С. 3651 - 3659
Опубликована: Фев. 1, 2024
The
search
for
long
molecular
wires
that
can
transport
charge
with
maximum
efficiency
over
many
nanometers
has
driven
electronics
since
its
inception.
Single-molecule
conductance
normally
decays
length
and
is
typically
far
below
the
theoretical
limit
of
G0
(77.5
μS).
Here,
we
measure
conductances
a
family
edge-fused
porphyrin
ribbons
(lengths
1–7
nm)
display
remarkable
behavior.
low-bias
high
across
whole
series.
Charging
molecules
in
situ
results
dramatic
realignment
frontier
orbitals,
increasing
to
1
(corresponding
current
20
μA).
This
behavior
most
pronounced
longer
due
their
smaller
HOMO–LUMO
gaps.
conductance-voltage
traces
frequently
exhibit
peaks
at
zero
bias,
showing
energy
level
resonance
Fermi
level.
work
lays
foundations
long,
perfectly
transmissive,
technological
potential.
Chemical Reviews,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 5, 2025
The
growing
interest
in
thermoelectric
energy
conversion
technologies
has
recently
extended
to
the
molecular
scale,
with
tunnel
junctions
emerging
as
promising
platforms
for
harvesting
from
heat
a
quantum-tunneling
regime.
This
Review
explores
advances
thermoelectricity
within
junctions,
highlighting
unique
ability
of
these
exploit
charge
tunneling
and
controlled
structure
enhance
performance.
Molecular
thermoelectrics,
which
bridge
nanoscale
material
design
applications,
utilize
mechanisms,
such
coherent
hopping
processes,
including
incoherent
pathways,
facilitate
conversion.
Complementing
mechanisms
is
an
array
high-precision
fabrication
techniques
single-molecule
break
large-area
liquid
metal-based
systems,
each
tailored
optimize
transfer
properties.
With
novel
strategies
incorporation
electron-dense
ligands,
customizable
anchor
groups,
advanced
junction
architectures,
hold
promise
addressing
challenging
targets
thermoelectricity.
focuses
on
theoretical
models,
experimental
methodologies,
principles
aimed
at
understanding
function
enhancing
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(31), С. 21476 - 21489
Опубликована: Июль 23, 2024
The
dynamics
of
electron
and
spin
transfer
in
the
radical
cation
photogenerated
triplet
states
a
tetramethylbiphenyl-linked
zinc-porphyrin
dimer
were
investigated,
so
as
to
test
relevant
parameters
for
design
single-molecule
valve
creation
novel
platform
photogeneration
high-multiplicity
states.
We
used
combination
multiple
techniques,
including
variable-temperature
continuous
wave
EPR,
pulsed
proton
electron-nuclear
double
resonance
(ENDOR),
transient
optical
spectroscopy.
conclusions
are
further
supported
by
density
functional
theory
(DFT)
calculations
comparison
reference
compounds.
low-temperature
cw-EPR
room-temperature
near-IR
spectra
monocation
demonstrate
that
is
spatially
localized
on
one
side
at
any
point
time,
not
coherently
delocalized
over
both
porphyrin
units.
EPR
298
K
reveal
rapid
hopping
between
sites
via
reversible
intramolecular
transfer.
hyperfine
interactions
modulated
can
be
quantified
using
ENDOR
This
allowed
simulation
with
two-site
exchange
model
provided
information
temperature-dependence
rate.
rates
range
from
about
10.0
MHz
200
53.9
K.
activation
enthalpies
Δ
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(47), С. 32206 - 32221
Опубликована: Ноя. 14, 2024
Long-range
charge
transport
(LRCT)
in
molecular
wires
is
crucial
for
the
advancement
of
electronics
but
remains
insufficiently
understood
due
to
complex
mechanisms
and
their
dependencies
on
structure.
While
short-range
typically
dominated
by
off-resonant
tunneling,
which
decays
exponentially
with
length,
recent
studies
have
highlighted
certain
structures
that
facilitate
LRCT
minimal
attenuation
over
several
nanometers.
This
Perspective
reviews
latest
progress
understanding
LRCT,
focusing
chemical
designs
enable
this
phenomenon.
Key
strategies
include
π-conjugation,
redox-active
centers,
stabilization
radical
intermediates,
support
through
such
as
coherent
resonant
tunneling
or
incoherent
hopping.
We
discuss
how
effects
structure,
temperature
influence
transport,
highlight
emerging
techniques
like
Seebeck
effect
distinguishing
between
mechanisms.
By
clarifying
principles
behind
outlining
future
challenges,
work
aims
guide
design
systems
capable
sustaining
efficient
long-distance
thereby
paving
way
practical
applications
beyond.
ACS Omega,
Год журнала:
2024,
Номер
9(9), С. 10610 - 10620
Опубликована: Фев. 22, 2024
A
combination
of
density
functional
theory
(DFT)
methods
and
quantum
transport
(QTT)
has
been
used
to
investigate
the
spectroscopic,
electronic,
thermoelectric
properties
carbon
nanohoop
molecules
with
different
molecular
templates.
The
connectivity
type,
along
inherent
strain,
impacts
behavior
creates
a
destructive
interference
(DQI),
which
proves
itself
be
powerful
strategy
enhance
these
molecules,
making
them
promising
candidates
for
applications.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(16)
Опубликована: Фев. 27, 2024
When
designing
a
molecular
electronic
device
for
specific
function,
it
is
necessary
to
control
whether
the
charge-transport
mechanism
phase-coherent
transmission
or
particle-like
hopping.
Here
we
report
systematic
study
of
charge
transport
through
single
zinc-porphyrin
molecules
embedded
in
graphene
nanogaps
form
transistors,
and
show
that
depends
on
chemistry
molecule-electrode
interfaces.
We
van
der
Waals
interactions
between
anchoring
groups
yield
characteristic
Coulomb
blockade
with
incoherent
sequential
hopping,
whereas
covalent
amide
bonds
give
intermediately
strongly
coupled
single-molecule
devices
display
coherent
transmission.
These
findings
demonstrate
importance
interfacial
engineering
circuits.
RSC Advances,
Год журнала:
2024,
Номер
14(21), С. 14704 - 14715
Опубликована: Янв. 1, 2024
Quantum
interference
(QI)
is
one
of
the
most
important
phenomena
that
affects
charge
transport
through
single
molecules.
The
effect
a
constructive
and
destructive
quantum
on
electronic,
thermoelectric
spectroscopic
properties
oligo(phenyleneethynylene)
based-molecular
junctions
has
been
investigated
using
combination
density
functional
theory
(DFT)
methods,
tight
binding
(Hückel)
modelling
(TBHM)
(QTT).
Molecules
with
carbonyl,
diphenyl,
ethane
ethynylferrocene
substituents
show
(DQI),
which
enhances
these
molecules
making
them
promising
materials
for
applications.
Chemical Science,
Год журнала:
2024,
Номер
15(26), С. 10207 - 10213
Опубликована: Янв. 1, 2024
Porphyrin-diazaporphyrin
hetero
oligomers
were
constructed
through
a
Suzuki–Miyaura
cross-coupling
reaction.
Hetero
nanotapes
exhibiting
strong
NIR
absorption
obtained
via
further
oxidation
of
these
oligomers.
The Journal of Physical Chemistry Letters,
Год журнала:
2024,
Номер
15(17), С. 4737 - 4744
Опубликована: Апрель 25, 2024
Porphyrin
nanoring
has
been
attracting
immense
attention
due
to
its
light
harvesting
capacity
and
potential
applications
in
optical,
catalysis,
sensor,
electronic
devices.
We
demonstrate
by
nonadiabatic
quantum
dynamics
simulations
that
the
photovoltaic
efficiency
can
be
enhanced
template
engineering.
Altering
hexadentate
(T6)
with
two
tridentate
templates
(2T3)
within
porphyrin
ring
(P6)
cavity
accelerated
electron
transfer
twice
suppressed
electron–hole
recombination
nearly
three
times.
The
atomistic
tight-binding
simulation
rationalized
different
localizations
of
charge
band
edge
states,
changes
coupling,
alteration
coherence,
involvement
diverse
electron–phonon
vibrational
modes.
Further
2T3
more
strongly
hold
P6
than
T6,
reducing
structural
fluctuation.
As
a
result,
coupling
becomes
weaker
suppresses
carrier
recombination.
Current
presents
engineering
strategy
enhance
exciton
lifetime
along
ultrafast
separation,
crucial
factors
for
applications.