A versatile metal nanowiring platform enables the fabrication of Ag nanowires (AgNW) at a desired position and orientation in an individually controlled manner. A printed, flexible AgNW has a ...diameter of 695 nm, a resistivity of 5.7 μΩ cm, and good thermal stability in air. Based on an Ag nanowiring platform, an all‐NW transistors array, as well as various optoelectronic applications, are successfully demonstrated.
We report effective solution‐processed chemical p‐type doping of graphene using trifluoromethanesulfonic acid (CF3SO3H, TFMS), that can provide essential requirements to approach an ideal flexible ...graphene anode for practical applications: i) high optical transmittance, ii) low sheet resistance (70 % decrease), iii) high work function (0.83 eV increase), iv) smooth surface, and iv) air‐stability at the same time. The TFMS‐doped graphene formed nearly ohmic contact with a conventional organic hole transporting layer, and a green phosphorescent organic light‐emitting diode with the TFMS‐doped graphene anode showed lower operating voltage, and higher device efficiencies (104.1 cd A−1, 80.7 lm W−1) than those with conventional ITO (84.8 cd A−1, 73.8 lm W−1).
Anodic optimization: p‐Type chemical doping of graphene with trifluoromethanesulfonic acid (TFMS) leads to a flexible graphene anode with 70 % reduced sheet resistance and 0.83 eV increased surface work function with excellent air‐stability. An OLED with TFMS‐doped graphene anode exhibited lower operating voltage and higher efficiency than those with conventional ITO anode.
Highly efficient, simplified, solution‐processed thermally activated delayed‐fluorescence organic light‐emitting diodes can be realized by using pure‐organic thermally activated delayed fluorescence ...emitters and a multifunctional buffer hole‐injection layer, in which high EQE (≈24%) and current efficiency (≈73 cd A−1) are demonstrated. High‐efficiency fluorescence red‐emitting and blue‐emitting devices can also be fabricated in this manner.
Tailoring the interface energetics between a polymeric hole extraction layer (HEL) and a photoactive layer (PAL) in organic photovoltaics (OPVs) and organic–inorganic hybrid perovskite solar cells ...(PrSCs) is very important to maximize open circuit voltage (
V
oc
), power conversion efficiency (PCE), and device lifetime. In principle, when Fermi-level pinning and a vacuum level shift take place between the HEL and PAL, they give rise to an energy level offset between the HEL and the valence band maximum (VBM) (or the highly occupied molecular orbital (HOMO) in the case of organic photoactive materials) of the PAL and then
V
oc
loss. However, here we show that the
V
oc
loss at the interface can be overcome by universal energy level tailoring of a self-organized HEL (SOHEL) between the HEL and PAL irrespective of photoactive materials. A SOHEL composed of a conducting polymer and a perfluorinated ionomer (PFI) is effectively used to study the interface energetics in OPVs and PrSCs. We systematically tailored the interface energy level of the SOHEL to remove the energy offset at the interface and understand clearly the universal energy level alignment with the diverse photoactive materials of OPVs and PrSCs. The Fermi-level of the HEL is pinned to the midgap state of photoactive materials, which is about 0.6–0.7 eV above the VBM or HOMO. However, the interface energy state of the PFI-enriched surface layer of the SOHEL can be formed deeper below the Fermi-level by self-organized molecules so that it can match the top of the valence band of the photoactive materials. As a result, the energy offset at the interface between photoactive materials and the SOHEL can be significantly decreased to achieve high
V
oc
and PCE. Furthermore, our SOHEL significantly prolonged the stability of OPVs (half lifetime: 2.84 year) compared with pristine PEDOT:PSS (half lifetime: 0.2 year) under continuous irradiation of air mass-1.5 global simulated sunlight at 100 mW cm
−2
due to the diffusion-blocking ability of the self-organized PFI at the surface of SOHELs for impurities from indium tin oxide.
Covalent or Noncovalent? Systematic investigation of polymeric binders incorporating Meldrum's acid reveals most critical binder properties for silicon anodes in lithium ion batteries, that is ...self‐healing effect facilitated by a series of noncovalent interactions.
Organic–inorganic hybrid perovskites (OHPs) are promising emitters for light‐emitting diodes (LEDs) due to the high color purity, low cost, and simple synthesis. However, the electroluminescent ...efficiency of polycrystalline OHP LEDs (PeLEDs) is often limited by poor surface morphology, small exciton binding energy, and long exciton diffusion length of large‐grain OHP films caused by uncontrolled crystallization. Here, crystallization of methylammonium lead bromide (MAPbBr3) is finely controlled by using a polar solvent‐soluble self‐doped conducting polymer, poly(styrenesulfonate)‐grafted polyaniline (PSS‐g‐PANI), as a hole injection layer (HIL) to induce granular structure, which makes charge carriers spatially confined more effectively than columnar structure induced by the conventional poly(3,4‐ethylenedioythiphene):polystyrenesulfonate (PEDOT:PSS). Moreover, lower acidity of PSS‐g‐PANI than PEDOT:PSS reduces indium tin oxide (ITO) etching, which releases metallic In species that cause exciton quenching. Finally, doubled device efficiency of 14.3 cd A‐1 is achieved for PSS‐g‐PANI‐based polycrystalline MAPbBr3 PeLEDs compared to that for PEDOT:PSS‐based PeLEDs (7.07 cd A‐1). Furthermore, PSS‐g‐PANI demonstrates high efficiency of 37.6 cd A‐1 in formamidinium lead bromide nanoparticle LEDs. The results provide an avenue to both control the crystallization kinetics and reduce the migration of In released from ITO by forming OIP films favorable for more radiative luminescence using the polar solvent‐soluble and low‐acidity polymeric HIL.
Perovskite crystallization kinetics can be finely controlled using a self‐doped conducting polymer as the hole injection layer of perovskite light‐emitting diodes (PeLEDs). Polar solvent‐soluble self‐doped polyaniline facilitates crystallization control by impeding the solvent evaporation from cast perovskite precursor pseudo‐films. The finely controlled crystallization contributes to achieving granular nanograin structure, which can strengthen the exciton confinement for boosting luminescence efficiency of PeLEDs.
Organometal halide perovskite synaptic devices are fabricated; they emulate important working principles of a biological synapse, including excitatory postsynaptic current, paired‐pulse facilitation, ...short‐term plasticity, long‐term plasticity, and spike‐timing dependent plasticity. These properties originate from possible ion migration in the ion‐rich perovskite matrix. This work has extensive applicability and practical significance in neuromorphic electronics.
Gastric cancer is one of the most prevalent cancer types worldwide, and its resistance to cancer therapies, such as chemotherapy and radiotherapy, has made treating it a major challenge. Paeoniflorin ...(PF) is one potential pharmacological treatment derived from paeony root. However, in cancer, the molecular mechanisms and biological functions of PF are still unclear. In the present study, we found that PF exerts anti-tumor effects in vivo and in vitro and induces apoptotic cell death through ER stress, calcium (Ca
), and reactive oxygen species (ROS) release in gastric cancer cells. However, ROS inhibition by DPI and NAC blocks cell death and the PERK signaling pathway via the reduction of Nox4. Moreover, PF triggers a synergistic inhibitory effect of the epithelial-mesenchymal transition (EMT) process under radiation exposure in radiation-resistant gastric cancer cells. These findings indicate that PF-induced Ca
and ROS release overcomes radioresistance via ER stress and induces cell death under radiation in gastric cancer cells. Therefore, PF, in combination with radiation, may be a powerful strategy for gastric cancer therapy.
Novel hybrid composites of NH
-MIL-125(Ti) and ZnCr-layered double hydroxide nanosheets (ZnCr-LDH NSs) are developed for use as visible-light-active photocatalysts for hydrogen production based on ...water photolysis. The hybrid composites are obtained by growing NH
-MIL-125(Ti) in the presence of exfoliated ZnCr-LDH NSs using a solvothermal reaction. Hybridization of NH
-MIL-125(Ti) with exfoliated ZnCr-LDH NSs leads to significant effects on the morphology and optical properties of NH
-MIL-125(Ti). To find the optimum photocatalytic activity for hydrogen production by the hybrid composite photocatalysts, the content of ZnCr-LDH in this work is controlled. Compared to that of pristine NH
-MIL-125(Ti) and ZnCr-LDH, the hybrid composites exhibit an improved photocatalytic activity for hydrogen production under visible-light irradiation. In addition, the hybrid composite photocatalyst shows excellent photo-chemical stability. The improved photocatalytic activity is believed to benefit from the synergy of strong electronic coupling between NH
-MIL-125(Ti) and ZnCr-LDH NSs, expanded light absorption and band alignment to enhance the lifetime of photo-induced electrons and holes.
The small nanoparticle size and long-chain ligands in colloidal metal halide perovskite quantum dots (PeQDs) cause charge confinement, which impedes exciton dissociation and carrier extraction in ...PeQD solar cells, so they have low short-circuit current density J
, which impedes further increases in their power conversion efficiency (PCE). Here, a re-assembling process (RP) is developed for perovskite nanocrystalline (PeNC) films made of colloidal perovskite nanocrystals to increase J
in PeNC solar cells. The RP of PeNC films increases their crystallite size and eliminates long-chain ligands, and thereby overcomes the charge confinement in PeNC films. These changes facilitate exciton dissociation and increase carrier extraction in PeNC solar cells. By use of this method, the gradient-bandgap PeNC solar cells achieve a J
= 19.30 mA cm
without compromising the photovoltage, and yield a high PCE of 16.46% with negligible hysteresis and good stability. This work provides a new strategy to process PeNC films and pave the way for high performance PeNC optoelectronic devices.
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