Small,
Journal Year:
2023,
Volume and Issue:
20(18)
Published: Dec. 8, 2023
Abstract
Solution‐processable
near‐infrared
(NIR)
photodetectors
are
urgently
needed
for
a
wide
range
of
next‐generation
electronics,
including
sensors,
optical
communications
and
bioimaging.
However,
it
is
rare
to
find
with
>300
kHz
cut‐off
frequencies,
especially
in
the
NIR
region,
many
emerging
inorganic
materials
explored
comprised
toxic
elements,
such
as
lead.
Herein,
solution‐processed
AgBiS
2
high
frequencies
under
both
white
light
(>1
MHz)
(approaching
500
kHz)
illumination
developed.
These
due
short
transit
distances
charge‐carriers
ultrathin
photoactive
layer
photodetectors,
which
arise
from
strong
absorption
this
material,
that
film
thicknesses
well
below
120
nm
sufficient
absorb
>65%
visible
light.
It
also
revealed
ion
migration
plays
critical
role
photo‐response
speed
these
devices,
its
detrimental
effects
can
be
mitigated
by
finely
tuning
thickness
layer,
important
achieving
low
dark
current
densities
well.
outstanding
characteristics
enable
realization
air‐stable,
real‐time
heartbeat
sensors
based
on
strongly
motivates
their
future
integration
high‐throughput
systems.
Advanced Materials,
Journal Year:
2023,
Volume and Issue:
35(36)
Published: July 15, 2023
Organic
photodetectors,
as
an
emerging
wearable
photoplethysmographic
(PPG)
technology,
offer
exciting
opportunities
for
next-generation
photonic
healthcare
electronics.
However,
the
mutual
restraints
among
photoresponse,
structure
complexity,
and
fabrication
cost
have
intrinsically
limited
development
of
organic
photodetectors
ubiquitous
health
monitoring
in
daily
activities.
Here,
effective
route
to
dramatically
boost
performance
with
a
solution-processed
integration
circuit
application
is
reported.
Through
creating
ideal
metal-semiconductor
junction
interface
that
minimizes
trap
states
within
device,
solution-printed
field-effect
transistors
(OFETs)
are
achieved
ultrahigh
signal
amplification
efficiency
37.1
S
A-1
,
approaching
theoretical
thermionic
limit.
Consequently,
monolithic
OFET
photoconductor
enables
remarkable
photoresponse
signal-to-noise
ratio
by
more
than
four
orders
magnitude
from
5.5
4.6
×
105
which
able
meet
demand
accurately
extracting
physiological
information
PPG
waveforms.
This
work
offers
versatile
approach
greatly
enhance
photodetector
performance,
promising
revolutionize
technologies.
Advanced Materials,
Journal Year:
2024,
Volume and Issue:
36(19)
Published: Feb. 15, 2024
Abstract
Detecting
short‐wavelength
infrared
(SWIR)
light
has
underpinned
several
emerging
technologies.
However,
the
development
of
highly
sensitive
organic
photodetectors
(OPDs)
operating
in
SWIR
region
is
hindered
by
their
poor
external
quantum
efficiencies
(EQEs)
and
high
dark
currents.
Herein,
high‐sensitivity
SWIR‐OPDs
with
an
efficient
photoelectric
response
extending
up
to
1.3
µm
reported.
These
OPDs
utilize
a
new
ultralow‐bandgap
molecular
semiconductor
featuring
quinoidal
tricyclic
electron‐deficient
central
unit
multiple
non‐covalent
conformation
locks.
The
SWIR‐OPD
achieves
unprecedented
EQE
26%
under
zero
bias
even
more
impressive
41%
–4
V
at
1.10
µm,
effectively
pushing
detection
limit
silicon
photodetectors.
Additionally,
low
energetic
disorder
trap
density
active
layer
lead
significant
suppression
thermal‐generation
carriers
current,
resulting
excellent
detectivity
(
D
sh
*
)
exceeding
10
13
Jones
from
0.50
1.21
surpassing
12
1.30
bias,
marking
highest
achievements
for
beyond
date.
Validation
photoplethysmography
measurements,
spectrometer
prototype
0.35–1.25
range,
image
capture
1.20
irradiation
demonstrate
extensive
applications
this
SWIR‐OPD.
Advanced Functional Materials,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Sept. 23, 2024
Abstract
Upconversion
detectors
monolithically
combining
a
detection
unit
and
light
emitting
unit,
enables
visualization
in
compact
structure,
promising
great
advances
miniaturized
multifunctional
optoelectronics.
The
range
of
upconversion
usually
covers
broadband
spectrum,
limiting
their
use
spectroscopic
fields.
This
work
investigates
two
wavelength‐selective
made
with
organic
semiconductors
to
realize
narrowband
near‐infrared
(NIR)
dual
function.
Two
non‐fullerene‐based
NIR‐sensitive
bulk‐heterojunctions
(BHJs)
are
exploited
make
detectors,
achieving
peak
sensitivity
at
860
890
nm,
full
width
half
maximum
125
170
respectively.
Each
BHJ
comprises
donor
polymer
non‐fullerene
acceptor,
both
which
selectively
sensitive
NIR
light.
cumulative
analysis
the
optical
properties
absorber
current–voltage
characteristics
device
indicates
that
wavelength
selectivity
stems
mainly
from
wavelength‐dependent
absorption.
In
particular,
exhibit
electronic
dual‐readouts,
appealing
for
applications,
including
health
monitoring,
communication,
microbead
imaging,
paving
way
practical
applications.
Nature Communications,
Journal Year:
2022,
Volume and Issue:
13(1)
Published: Sept. 3, 2022
Inherently
narrowband
near-infrared
organic
photodetectors
are
highly
desired
for
many
applications,
including
biological
imaging
and
surveillance.
However,
they
suffer
from
a
low
photon-to-charge
conversion
efficiencies
utilize
spectral
narrowing
techniques
which
strongly
rely
on
the
used
material
or
nano-photonic
device
architecture.
Here,
we
demonstrate
general
facile
approach
towards
wavelength-selective
phtotodetection
through
intentionally
n-doping
500-600
nm-thick
nonfullerene
blends.
We
show
that
an
electron-donating
amine-interlayer
can
induce
n-doping,
resulting
in
localized
electric
field
near
anode
selective
collection
of
photo-generated
carriers
this
region.
As
only
weakly
absorbed
photons
reach
region,
devices
have
response
at
wavelengths
close
to
absorption
onset
blends
with
high
rejection
ratio.
These
spectrally
exhibit
zero-bias
external
quantum
~20-30%
900-1100
nm,
full-width-at-half-maximum
≤50
as
well
detectivities
>1012
Jones.
Science Advances,
Journal Year:
2023,
Volume and Issue:
9(23)
Published: June 7, 2023
One
of
the
key
challenges
facing
organic
photodiodes
(OPDs)
is
increasing
detection
into
infrared
region.
Organic
semiconductor
polymers
provide
a
platform
for
tuning
bandgap
and
optoelectronic
response
to
go
beyond
traditional
1000-nanometer
benchmark.
In
this
work,
we
present
near-infrared
(NIR)
polymer
with
absorption
up
1500
nanometers.
The
polymer-based
OPD
delivers
high
specific
detectivity
D*
1.03
×
1010
Jones
(-2
volts)
at
1200
nanometers
dark
current
Jd
just
2.3
10-6
ampere
per
square
centimeter
-2
volts.
We
demonstrate
strong
improvement
all
metrics
in
NIR
region
compared
previously
reported
due
enhanced
crystallinity
optimized
energy
alignment,
which
leads
reduced
charge
recombination.
value
1100-to-1300-nanometer
particularly
promising
biosensing
applications.
as
pulse
oximeter
under
illumination,
delivering
heart
rate
blood
oxygen
saturation
readings
real
time
without
signal
amplification.
Advanced Materials Technologies,
Journal Year:
2023,
Volume and Issue:
8(16)
Published: June 19, 2023
Abstract
The
performance
of
organic
photodetectors
is
steadily
improving,
and
the
specific
detectivity,
as
a
key
figure
merit,
has
reached
values
10
12
–10
13
Jones,
i.e.,
comparable
to
that
silicon
diodes
but
still
considerably
lower
than
intrinsic
limit.
As
with
other
semiconductor
devices,
electrical
state‐of‐the
art
photodiodes
(OPDs)
presently
determined
high
degree
by
presence
chemical
impurities
or
structural
defects
which
create
carrier
trapping
states
within
bandgap
active
layer.
This
review
aims
provide
comprehensive
timely
account
trap‐assisted
charge
generation
recombination
in
OPDs,
emphasis
on
impact
these
phenomena
photodetector
parameters
such
as,
noise
dark
current
density,
responsivity,
response
speed,
ultimately,
detectivity.
ACS Energy Letters,
Journal Year:
2023,
Volume and Issue:
8(6), P. 2641 - 2651
Published: May 17, 2023
Near-infrared
(NIR)
electron
acceptors
are
critical
components
for
constructing
organic
solar
cells
(OSCs).
Herein,
we
report
a
set
of
A-DA′D-A-type
with
end-groups
cyano-substituted
2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile
(CN-IC),
which
possesses
the
strongest
electron-withdrawing
ability
among
reported
to
date.
An
optical
bandgap
as
low
1.29
eV
was
obtained
CN-IC
end-groups,
is
decreased
by
0.12
respect
that
reference
acceptor.
Meanwhile,
deep-lying
frontier
molecular
orbital
energy
levels
were
maintained
in
these
acceptors.
These
advantages
endow
broad
light-harvesting
range
and
capacity
match
prevalent
polymer
donors.
Consequently,
OSCs
power
conversion
efficiency
18.1%
obtained.
results
suggest
huge
potential
NIR
Wearable electronics.,
Journal Year:
2024,
Volume and Issue:
1, P. 53 - 77
Published: May 13, 2024
With
the
evolution
of
Industry
4.0,
next-generation
wearable
devices
have
come
under
spotlight,
where
organic
electronics
are
playing
an
important
role
due
to
their
flexible
form
factor,
high
performance,
and
integration
capability.
Designed
conform
soft
dynamic
surfaces,
photodetectors
(OPDs)
integrated
arrays
stand
out
for
application
potential
in
non-invasive
biosensing
bio-imaging,
with
inherent
advantages
mitigating
motion
artifacts
–
a
notable
limitation
traditional,
rigid
photodetector
systems.
Leveraging
near-infrared
(NIR)
spectrum's
capability
deep
skin
penetration
minimal
scattering
human
tissues,
NIR
OPDs
especially
capable
precise
diagnostics
enhanced
signal
quality.
The
adaptable
factor
further
broadens
applications
human-environment
interaction,
marking
shift
towards
more
responsive
intelligent
technologies.
This
review
summarizes
latest
challenges
breakthroughs
OPDs,
emphasizing
effective
strategies
toward
high-performance
device
units
We
discuss
remaining
outlook
on
vast
reshaping
our
interaction
surroundings.
Science Advances,
Journal Year:
2024,
Volume and Issue:
10(23)
Published: June 5, 2024
Short-wavelength
infrared
(SWIR)
light
detection
plays
a
key
role
in
modern
technologies.
Emerging
solution-processed
organic
semiconductors
are
promising
for
cost-effective,
flexible,
and
large-area
SWIR
photodiodes
(OPDs).
However,
the
spectral
responsivity
(
R
)
specific
detectivity
D
*)
of
OPDs
restricted
by
insufficient
exciton
dissociation
high
noise
current.
In
this
work,
we
synthesized
an
small
molecule
with
coverage
0.3
to
1.3
micrometers
peaking
at
1100
nanometers.
The
photodiode,
optimized
dissociation,
charge
injection,
transmittance,
achieves
record
0.53
ampere
per
watt
*
1.71
×
10
13
Jones
1110
nanometers
under
zero
bias.
1
1.2
surpasses
that
uncooled
commercial
InGaAs
photodiode.
Furthermore,
semitransparent
all-organic
upconversion
devices
integrating
photodiode
realized
static
dynamic
SWIR-to-visible
imaging,
along
excellent
efficiency
spatial
resolution.
This
work
provides
alternative
insights
developing
sensitive
detection.