Carbon neutrality, energy savings, and lighting costs and quality have always led to urgent demand for lighting technology innovation. White light-emitting diodes (WLEDs) based on a single emissive ...layer (SEL) fabricated by the solution method have been continuously researched in recent years; they are advantageous because they have a low cost and are ultrathin and flexible. Here, we reviewed the history and development of SEL-WLEDs over recent years to provide inspiration and promote their progress in lighting applications. We first introduced the emitters and analysed the advantages of these emitters in creating SEL-WLEDs and then reviewed some cases that involve the above emitters, which were formed via vacuum thermal evaporation or solution processes. Some notable developments that deserve attention are highlighted in this review due to their potential use in SEL-WLEDs, such as perovskite materials. Finally, we looked at future development trends of SEL-WLEDs and proposed potential research directions.
An ideal anti-counterfeiting technique has to be inexpensive, mass-producible, nondestructive, unclonable and convenient for authentication. Although many anti-counterfeiting technologies have been ...developed, very few of them fulfill all the above requirements. Here we report a non-destructive, inkjet-printable, artificial intelligence (AI)-decodable and unclonable security label. The stochastic pinning points at the three-phase contact line of the ink droplets is crucial for the successful inkjet printing of the unclonable security labels. Upon the solvent evaporation, the three-phase contact lines are pinned around the pinning points, where the quantum dots in the ink droplets deposited on, forming physically unclonable flower-like patterns. By utilizing the RGB emission quantum dots, full-color fluorescence security labels can be produced. A convenient and reliable AI-based authentication strategy is developed, allowing for the fast authentication of the covert, unclonable flower-like dot patterns with different sharpness, brightness, rotations, amplifications and the mixture of these parameters.
The mimicking of classical conditioning, including acquisition, extinction, recovery, and generalization, can be efficiently achieved by using a single flexible memristor. In particular, the ...experiment of Pavlov's dog is successfully demonstrated. This demonstration paves the way for reproducing advanced neural processes and provides a frontier approach to the design of artificial‐intelligence systems with dramatically reduced complexity.
Simulating the human brain for neuromorphic computing has attractive prospects in the field of artificial intelligence. Optoelectronic synapses have been considered to be important cornerstones of ...neuromorphic computing due to their ability to process optoelectronic input signals intelligently. In this work, optoelectronic synapses based on all‐inorganic perovskite nanoplates are fabricated, and the electronic and photonic synaptic plasticity is investigated. Versatile synaptic functions of the nervous system, including paired‐pulse facilitation, short‐term plasticity, long‐term plasticity, transition from short‐ to long‐term memory, and learning‐experience behavior, are successfully emulated. Furthermore, the synapses exhibit a unique memory backtracking function that can extract historical optoelectronic information. This work could be conducive to the development of artificial intelligence and inspire more research on optoelectronic synapses.
Artificial optoelectronic synapses are considered to be essential cornerstones of visual‐related artificial intelligence. A two‐terminal optoelectronic synapse employing CsPbBr3 perovskite nanoplates, which implement electronic synaptic plasticity and photonic synaptic plasticity simultaneously, is fabricated. In‐depth research shows that these devices have a unique memory backtracking function that can extract historical optoelectronic information to emulate the biological synapse.
In this paper, we consider a fourth order parabolic equation with heat source function and homogeneous boundary conditions. We establish some sufficient conditions to guarantee that the solution
u
(
...x
,
t
)
blows up at finite time and obtain upper and lower bounds of the blow-up time by constructing the corresponding functionals. We generalize the heat source function and improve the proof of the critical inequality in the reference Philippin (Proc Am Math Soc 143(6):2507–2513, 2015).
Wearable solar textiles have currently emerged as excellent candidates for potential applications in next-generation wearable functional clothing. Here, we report a wearable ultra-lightweight polymer ...solar textile based on transparent electronic fabrics (e-fabrics). The transparent e-fabrics with a structure of polyester/Ag nanowires/graphene core-shell have been used as anodes, as well as transparent substrates, for solar textiles. The anode buffer layer and the bulk heterojunction layer were deposited by blade-coating them onto the e-fabrics. The fabricated solar textiles show a power conversion efficiency of 2.27%, a low areal density of 5.0mg/cm2, good endurance against mechanical deformations, and high compatibility with clothing. These results indicate that these novel solar textiles hold potential applications in the field of wearable self-powered portable electronics.
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•Wearable ultra-lightweight polymer solar textile based on transparent electronic fabrics (e-fabrics) is developed.•Transparent e-fabric has been used as anodes as well as transparent substrates for solar textile.•Solar textile shows a power conversion efficiency of 2.27%, good endurance against mechanical deformations, and high compatibility with clothing.•Solar textile shows a low areal density of 5.0mg/cm2.
In this paper, we investigate uniform decay estimate of the solution to the Petrovsky equation with memory
u
tt
+
Δ
2
u
-
∫
0
t
g
(
t
-
s
)
Δ
2
u
(
s
)
d
s
=
0
with initial conditions and boundary ...conditions, where
g
is a memory kernel function. The related energy has been shown to decay exponentially or polynomially as
t
→
+
∞
by the theorem established under the assumption
g
′
(
t
)
⩽
-
k
g
1
+
1
p
(
t
)
with
p
∈
(
2
,
∞
)
and
k
>
0
in the reference(J Funct Anal 254(5):1342–1372, 2008). Using the ideas introduced by by Lasiecka and Wang (Springer INdAM Series 10, Chapter, vol 14, pp 271–303, 2014), we prove the optimized uniform general decay result under the assumption
g
′
(
t
)
+
H
(
g
(
t
)
)
≤
0
, where the function
H
(
·
)
∈
C
1
(
R
1
)
is positive, increasing and convex with
H
(
0
)
=
0
, which is introduced for the first time by Alabau-Boussouira and Cannarsa (C R Acad Sci Paris Ser I 347:867–872, 2009) and studied systematically by Lasiecka and Wang (Springer INdAM Series 10, Chapter, vol 14, pp 271–303, 2014). The exponential decay result and polynomial decay result in the reference (J Funct Anal 254(5):1342–1372, 2008) are the special cases of this paper by choosing special
H
(
·
)
.
In this paper, we consider the initial boundary value problem of nonlinear evolution equation with hereditary memory, variable density, and external force term
{
|
u
t
|
ρ
u
t
t
−
α
Δ
u
−
Δ
u
t
t
+
∫
...−
∞
t
μ
(
t
−
s
)
Δ
u
(
s
)
d
s
−
γ
Δ
u
t
=
f
(
u
)
,
(
x
,
t
)
∈
Ω
×
R
+
,
u
(
x
,
t
)
=
0
,
(
x
,
t
)
∈
∂
Ω
×
R
+
,
u
(
x
,
0
)
=
u
0
(
x
)
,
u
t
(
x
,
0
)
=
u
1
(
x
)
,
x
∈
Ω
.
Under suitable assumptions, we prove the existence of a global solution by means of the Galerkin method, establish the exponential stability result by using only one simple auxiliary functional, and give the polynomial stability result.
Poly(9,9-dioctylfluorenyl-2,7-diyl)-alt(4,4′-(N-(4-butylphenyl)) (TFB), one of the most popular and widely used hole-transport layer (HTL) materials, has been successfully applied in high performance ...spin-coated quantum dots-based light-emitting diodes (QLEDs) due to its suitable energy level and high mobility. However, there are still many challenging issues in inkjet-printed QLED devices when using TFB as HTL. TFB normally suffers from the interlayer mixing and erosion, and low surface energy against the good film formation. Here, a novel environment-friendly binary solvent system was established for formulating quantum dot (QD) inks, which is based on mixing halogen-free alkane solvents of decalin and n-tridecane. The optimum volume ratio for the mixture of decalin and n-tridecane was found to be 7:3, at which a stable ink jetting flow and coffee-ring free QD films could be formed. To research the influence of substrate surface on the formation of inkjet-printed QD films, TFB was annealed at different temperatures, and the optimum annealing temperature was found to enable high quality inkjet-printed QD film. Inkjet-printed red QLED was ultimately manufactured. A maximum 18.3% of external quantum efficiency (EQE) was achieved, reaching 93% of the spin-coated QLED, which is the best reported high efficiency inkjet-printed red QLEDs to date. In addition, the inkjet-printed QLED achieved similar
T
75
operational lifetime (27 h) as compared to the spin-coated reference QLED (28 h) at 2,000 cd·m
−2
. This work demonstrated that the novel orthogonal halogen-free alkane co-solvents can improve the interfacial contact and facilitate high-performance inkjet printing QLEDs with high EQE and stability.
Nonexponential relaxations are universal characteristics for glassy materials. There is a well-known hypothesis that nonexponential relaxation peaks are composed of a series of exponential events, ...which have not been verified. In this Letter, we discover the exponential relaxation events during the recovery process using a high-precision nanocalorimetry, which are universal for metallic glasses and organic glasses. The relaxation peaks can be well fitted by the exponential Debye function with a single activation energy. The activation energy covers a broad range from
relaxation to
relaxation and even the fast
relaxation. We obtain the complete spectrum of the exponential relaxation peaks over a wide temperature range from 0.63
to 1.03
, which provides solid evidence that nonexponential relaxation peaks can be decomposed into exponential relaxation units. Furthermore, the contribution of different relaxation modes in the nonequilibrium enthalpy space is measured. These results open a door for developing the thermodynamics of nonequilibrium physics and for precisely modulating the properties of glasses by controlling the relaxation modes.
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