Research articles

Two-dimensional semiconductors are considered as field-effect transistors to overcome short channel effects and reduce the device size. As contacts to the metallic electrodes are decisive for the device performance, we study the electronic properties of contacts between Janus MoSSe and various two-dimensional metals. We demonstrate that weak interactions at these van der Waals contacts suppress Fermi level pinning and show that ohmic contacts can be formed for both terminations of Janus MoSSe, generating favorable transport characteristics.

A WO₃ nanoneedle film was developed for a gas sensor to detect low concentrations of acetone gas, which is a diabetes biomarker. The sensor exhibited a high response (19.72) to 10 ppmv acetone gas. The sensor also exhibited a high response (25.36) to 1 ppmv NO₂, which is related to asthma. The limits of detection for acetone and NO₂ gases were estimated to be 2.4 and 1.5 ppbv, respectively. The sensor exhibited superior ability to detect low concentrations of biomarker gases. The unique characteristics of the WO₃ nanoneedle film contributed to its high response rates.

In this work, 3D printing shape of memory polymer (SMP) based smart structures is conducted using a Digital light processing 3D printer and a customized resin in combination with liquid crystals. Lattice structures are fabricated and programmed to achieve tunable mechanical properties. The strain-sensing response is measured to demonstrate the utility of these lattice structures as smart patches for joint movement sensing. Changes in the electrical resistance are measured during the stretching and compression of the structure. The SMPs can be prepared conveniently and can potentially be used for various applications, such as smart tools, toys, and meta-material sensors.

Osmotic energy generation, using aramid nanofiber (ANF) semiconductor membranes for light-driven proton transport, displayed wavelength and intensity-dependent potential and current under unilateral illumination. The simultaneous application of illumination and pressure led to a five-fold voltage increase and a three-fold current increase. Density functional theory calculations and spectroscopic measurements confirmed ANF’s role in photoinduced proton transport. This research has significant implications for developing flexible, stable ANF membrane-based energy devices.

Ba_0.95La_0.05SnO₃ epitaxial films grown on (0001)-oriented Al₂O₃ with a BaZrO₃/MgO template bilayer exhibit lower sheet resistance by three orders of magnitude compared with template-free films. These epitaxial films with single-crystalline level properties, including high ultraviolet‒visible transmittance (~82%) and high electromagnetic shielding effectiveness (~18.6 dB at 10 GHz), can be used for the development of stable and inexpensive optoelectronic and energy applications of epitaxial BLSO films grown on Al₂O₃.

Controlling molecular spin quantum bits optically could help us reduce decoherence and raise the working temperature of quantum computing. Here we show theoretically exchange interactions and spin dynamics could be mediated by optically driven triplet state, leading to quantum gate operations. This indicates a great potential for radical as molecular building block for quantum circuits. A molecular quantum architecture, combining molecular network and nano-photonics, was also proposed. We thus expect the computational exploration of chemical database for molecular quantum computing. This work would therefore open up a new direction to use optical instruments and ‘Click Chemistry’ towards molecular quantum technology.

Inspired by Bouligand structure in the dactyl club of the mantis shrimp, direct ink writing is used to 3D print Bouligand composites reinforced with glass microfibres at controllable pitch angles. The Bouligand composites with a pitch angle of 40˚ exhibited a maximum energy absorption of 2.4 kJ/m², which was 140 % higher than the unidirectional composites. The topography of the fractured surface supplemented with numerical simulations revealed the combination of crack twisting and crack bridging mechanisms. These findings have implications for the microstructural design of engineered composites using direct ink writing for applications in aerospace, transportation, defense, etc.

In this work, by involving high-energy scanning X-ray diffraction strain mapping, we identify and distinguish between structural and elastic heterogeneity in the extremely rejuvenated metallic glasses under triaxial compression. Microindentation hardness hints at an unsymmetrical hardening/softening picture and further reveals the complementary effects of stress and structure modulation. Our results suggest that simultaneous stress and structural modulation can be used to enhance rejuvenation beyond the limits known to date, and may therefore aid in the design of MGs with enhanced ductility and strain-hardening capability.

III-V commercial optical semiconductor GaP crystalizes in either zincblende or wurtzite structure at ambient pressure. Zincblende GaP transforms into orthorhombic phase across a critical pressure during compression, accompanying piezochromic transition, metallization and superconductivity. Upon decompression, superconductivity could be preserved toward ambient pressure and displays broadening features due to amorphization. It reveals the presence of two high-pressure superconducting phases.

A molecular imaging-based strategy was proposed for precise diagnosing the depression through specifically visualizing the inflammation status associated with depressed brain. The inflammation-targeting MRI nanoprobe that can specifically target the inflamed vascular endothelial cells was constructed through attaching the ICAM-1 targeting peptides on biocompatible Fe₃O₄ nanoparticle. Through nanoprobe-based SWI, the spatial distribution of inflammation in depressed brain can be mapped in vivo. This strategy not only facilitate insight into the biological mechanism underlying depression, but also provide a target within the depressed brain for the further development of anti-inflammatory therapies.

We present a strategy for significantly increasing the H contents on catalysts for the HER in alkaline electrolyte solutions, which were generated by combining ruthenium with H_xYO_2−x on an oxygen vacancy-rich graphene system. This strategy greatly increased the hydrogen coverage on the RuYO_2−x/C catalyst to enhance the HER performance.

The rise of three-dimensional topological insulators as an attractive playground for the observation and control of various spin-orbit effects has ushered in the field of topological spintronics. To fully exploit their potential as efficient spin-orbit torque generators, investigating the efficiency of spin injection and transport at various topological insulator/ferromagnet interfaces is crucial. Here, using all-optical time-resolved magneto-optical Kerr effect magnetometry, we demonstrate efficient room-temperature spin pumping in Sub/BiSbTe_1.5Se_1.5(BSTS)/Co₂₀Fe₆₀B₂₀(CoFeB)/SiO₂ thin films characterized by the spin-mixing conductances of the interface and the spin diffusion length in BSTS, and obtain an ultrahigh interfacial spin transparency.

An interfacial co-assembly strategy for synthesizing gradient mesoporous hollow silica sheets is reported. The SO₄²⁻ and NH₄⁺ were aggregated by protonated amphiphilic polymer PVP and formed (NH₄)₂SO₄ crystals at the n-pentanol-water interface. Negatively charged silica oligomers can be confined on the (NH₄)₂SO₄ crystal surface by the Coulomb interaction of NH4⁺ and co-assembled with CTAB under the catalysis of ammonia molecules. After removing the (NH₄)₂SO₄ cores and CTAB template by washing and extraction, the first layer of mesoporous hollow silica was formed. Modulating the n-pentanol-water interface to n-hexane-water interface, n-hexane swelled CTAB micelle co-assembled with silica oligomers and formed the second layer of mesoporous silica with larger pore size. The finally obtained gradient mesoporous silica sheet shows remarkable gradient rejection rates for molecules with different sizes.

Precisely tunable high-entropy oxides (HEO) via controllable one-step combustion within a few seconds offers the rational design capability of optimal phases, structures and configurational entropy. The screened HEO-based anodes exhibit outstanding specific capacity (1165 mAh g⁻¹, 80.9% retention at 0.1 A g⁻¹_, and 791 mAh g⁻¹ even at 3 A g⁻¹), excellent rate capability, and stable cycling life (1252 mAh g⁻¹, 80.9% retention after 100 cycles at 0.2 A g⁻¹).

We observed a pressure-induced semiconductor-metal transition, which was followed by the emergence of superconductivity in the nonsymmorphic topological insulator KHgAs. The superconducting transition temperature reaches a maximum of approximately 6.6 K at 31.8 GPa, after which it slightly decreases up to 55 GPa. We identified the pressure-induced phase transitions and determined the structures of three high-pressure phases of KHgAs through structure prediction. Our findings establish the high-pressure phase diagram of the hourglass fermion compound KHgAs and demonstrate the potential coexistence of superconductivity with a topologically nontrivial feature protected by nonsymmorphic symmetries.

The low coercivity in Nd-Fe-B-based magnets, which is limited to around 20% of the anisotropy field (H_A) of the main phase, is a bottleneck for their usage at elevated temperatures. Herein, we overcome the limit and demonstrate a coercivity of 40% H_A by tuning the magnetism of grain boundaries, enabling their applications at elevated temperatures.

A two-dimensional array of magnetostrictive nanomagnets was used to demonstrate strong coupling between two different magnons (k_M1′ and k_M1′′) mediated by a phonon (k_ph). The coupling is strong, leading to the formation of a new quasi-particle – binary magnon-polaron. These two different magnons show 180° phase difference which is reminiscent of dark magnon modes. We show that it is possible to engineer this magnon-phonon coupling by choosing the frequency and wavelength of the acoustic wave to match the frequency and wavelength of the spin wave, the latter being controlled by a magnetic field.

The photodiode, FET, spintronic, piezoelectric, thermoplastic and molecular sensing applications of free-standing 2D GaN synthesized by sonochemical and Hummer’s method.

This work presents a design guide for anlog memristive devices for artificial synapses in neuromorphic computing. Ge implanted a-Si serves multiple fuctions to induce multifilamentary switching and prevent silicide formation. The linear synapse update behaviors were observed thanks to multi-filament formation, which was confirmed by TEM.

A facile and scalable approach was developed using ultrafine bubble (UFB)-assisted heteroagglomeration to fabricate high-concentration, impurity-free nanoceramic/metal composite powders for additive manufacturin. Individual ZrO₂ or Al₂O₃ nanoparticles up to ~10 wt% were homogeneously decorated on the surface of Ti-6Al-4V powders through the bridging effect of the negatively charged UFBs. The nanoceramics were completely decomposed and dissolved into the matrix upon laser irradiation; therefore, a unique Ti nanocomposite exhibiting both high strength and ductility was obtained.