Articles in 2022

This Perspective illustrates how theory and experiment can be combined to study the interfacial charge transfer between transition metal nanoparticles and oxide supports, the short- or long-range natures of interactions between them and the effects of oxide nanostructuring on the properties of supported metal particles. These studies deepen our understanding of the role of metal-oxide interactions in industrially relevant nanocomposites thus helping to design interfaces with unique properties for future applications

Charge carrier modulation in graphene by proximate ferroelectricity has attracted much attention, but it was rarely successful especially for oxide ferroelectrics mainly due to uncontrolled interfacial charge traps. In this work, the device operation of field–effect transistor comprising of graphene and ferroelectric single-crystal Pb(Mg_1/3Nb_2/3)O₃–PbTiO₃ was carefully analyzed for studying the direct or indirect coupling phenomena between charge carriers in graphene and nearby ferroelectricity.

Stickable light-emitting diodes (LEDs) were fabricated by selectively growing GaN micro-LEDs on a graphene sheet. Using the van der Waals interaction of the bottom graphene layer, the micro-LED/graphene heterostructures uniformly adhered to foreign graphene films. The transferred LEDs were fully operational and maintained good mechanical adhesion and electrical connections to the foreign graphene films under various bending conditions. Since the van der Waals integration method provides simple assembly processes of heterogeneous materials with negligible material compatibility issues, the LED/graphene heterostructure will be capable of integrating with various 2D devices.

The effects of nanomorphologies of acceptors on the environmental stability of donor:acceptor blends were investigated. Dispersed acceptors in mixed phase accelerate the photooxidation of donor, whereas aggregated acceptors stabilize the donor, both of phenomena coinciding for blends. Furthermore, photooxidation of donor leads to significant deterioration of hole transport, which shows strong correlation with efficiency loss in donor:acceptor organic solar cells.

We developed multi-bishelled cobalt-based nanospheres with each bi-shelled structure consisting of symmetric heterogeneous configuration. This architecture features sufficient heterointerfaces and a high density of active sites benefiting from interfacial electronic modulation. When they worked as OER electrocatalysts in CO₂ electrolysis, the electrochemical performance of Pd nanosheets (NSs) for CO₂ reduction can be significantly enhanced in terms of product selectivity and energy input.

Alkaline phosphatase (ALP) is one of the most extensively distributed enzymes existed in living species, which could act as crucial prognostic indicators for various diseases. Here, we present novel hybrid photonic alginate hydrogel microparticles for ALP detection. An intermediary chemical, the pyrophosphate ion (PPi), was introduced to trigger the phase transition of the copper alginate hydrogel, while ALP can react with PPi and suppress the process. This response can be converted into dual optical readouts, a fluorescence signal and a structural color signal. Quantitative determination of ALP was established based on this dual-indicator system with high accuracy and reliability.

We, for the first time, reveal that manipulation of microstructure enables the suppression of phase transformation and enhancement of long-term stability of Bi₂O₃-based ionic conductors. To investigate the microstructural influence on the stability, thin films with precisely defined grain structures are prepared. The conductivity of polycrystalline thin film decreased by 94.6% after approximately 20 h of operation, while the initial conductivity of epitaxial thin film remained almost constant during annealing for up to 100 h. This study provides novel insights for the development of highly conductive and durable solid electrolytes for next-generation energy applications.

Two-dimensional (2D) silicon sample consists of an airy hole array in a crystalline silicon thin film matrix was designed and fabricated with the property of phononic crystal. Significant suppression of hot carrier cooling was observed with lifetime prolongation by orders of magnitude. The present direct experimental evidence for hot carrier cooling suppression in 2D silicon phononic crystals and opens opportunities for promising applications.

Sialylated glycans (SGs), abundant in cell membranes, play decisive roles in regulating ion channels (e.g., NaV1.4, KV1.1, CaV1.2) in life system, only when the ion channels work stably and accurately can life activities proceed normally. Here we construct a biomimetic SG-modulated nanochannel based on a smart polymer design. Carbohydrate‒carbohydrate interaction triggers globule-to-coil transition of the polymer chains, which regulated the dynamic ion gating behavior of this nanochannel, resulting in a significant reduction in transmembrane ionic current. This device exhibits excellent specificity and sensitivity in response to α-2,6-linked sialyllactose, further realizing real-time monitoring of the sialylation reaction catalyzed by α2,6-sialyltransferase.

In this work, a high-T_c (~117 K) joined with a high-J_c (>10⁴ A/cm², 100 K) are reported in the CuBa₂Ca₃Cu₄O_10+δ (Cu-1234) superconductor. Studies have shown that the ordering vacancies and platelike 90° micro-domains serve as efficient microstructure pinning centers which suppress the vortex flux flow and enhance J_c. And plenty of holes with 2p_z symmetry owing to unique compressed [CuO₆] octahedrons decrease superconducting anisotropy and enhance the interlayer coupling that guarantee a high-J_c.

The photoactive α-phase FAPbI₃ perovskites can spontaneously transform into δ-FAPbI₃, which limits its use in photovoltaic device field. In this work, we show that the incorporation of the dimethylamine cation into FAPbI₃ significantly improves phase stability and photoelectric response of FAPbI₃ perovskite materials, while the inherent bandgap energy of the FAPbI₃ perovskite is maintained. A detailed ²H NMR analysis reveals the property optimization attributes to the increase of coupling interaction between organic cations and inorganic lattice.

We synthesized small-sized ion doped PEDOT-Ag quantum dot (S-PEDOT-Ag QD) composite film via one-step vapor phase polymerization (VPP) using a novel Ag(I) salt precursor. The films exhibit enhanced thermoelectric performance and good antibacterial activity at low Ag loadings. This facile approach provides new route to synthesize high performance conducting polymer–inorganic composite.

Physicochemical properties of three-dimensional hydrogels upregulate Smad2 and MAPKs signaling pathways during chondrogenesis.

This review focuses on the electron-phonon interactions in lead halide perovskite semiconductors, which dominate their optical and electronic properties by forming polarons. We describe the uniqueness of perovskite semiconductors in terms of long-range and short-range electron-phonon interactions. The formation of polarons profoundly affects the carrier effective mass, mobility, and various optoelectronic properties. These topics are explained with recent experimental data.

We show giant converse magnetoelectric effect in a multiferroic heterostructure consisting of ferromagnetic Heusler alloy Co₂FeSi and ferroelectric-oxide Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ for an electric-field control of magnetization vectors. In this system, the non-volatile and repeatable magnetization vector switchings in remanent states are also demonstrated. This approach can lead to a new solution to the reduction in the write power in spintronic memory architectures at room temperature.

An illustration of the optically controlled entanglement between a radical spin and a triplet state on an optically active moiety such as a phthalocyanine molecule. The optical excitations and the resulting strong exchange interactions, in combination with the recent spin manipulation in molecules at high temperature, imply this entangling mechanism has a great potential for room temperature quantum computing.

We formulated micromagnetic simulation models of nanocrystalline soft magnetic materials including effects of magnetostriction, and simulated motions of domain walls to clarify mechanism of energy dissipations in the nanocrystalline soft magnetic materials. The magnetostriction is nonuniformly distributed, and magnetic energy induced by external field is converted into elastic energy due to the magnetostriction. This energy consumption generates an excess loss in the nanocrystalline soft magnetic materials even there is no eddy current. The simulation results enable us to reduce the core loss in the nanocrystalline soft magnetic materials.

Single Sn vacancies are dominant in slow solidification speed, while multivacancies are dominant in high solidification speed SnSe crystals. The multivacancies also provide hole carrier to the crystal and are major p-type sources in high solidification speed SnSe crystals especially in polycrystalline SnSe.

Two-dimensional distorted orthorhombic GeS microribbons has been synthesized applying vapor-liquid-solid and vapor-solid mechanism-based chemical vapor transport. Polarized Raman and photoluminescence characterizations show the significantly angle-dependent intensity and anisotropic optical properties. Additionally, we probed the anisotropic electric properties by fabricating back-gate cross-shaped field effect transistors. In-plane direct current measurement demonstrated the charge carrier transport anisotropy and its anisotropic current ratio can be linearly adjusted by changing the gate voltage under dark and illumination conditions.

A novel technique is demonstrated for the fabrication of individually addressable, high-density, flexible pressure sensor arrays composed of 1D ZnO nanotubes on graphene. The individually addressable pixel matrix was fabricated by arranging the top and bottom electrodes of the sensors in a crossbar configuration. A high spatial resolution of 1058 dpi was achieved for a Schottky diode-based force/pressure sensor composed of piezoelectric ZnO nanotubes on a flexible substrate.