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  • Nonuniform principal curvatures of air-water interfaces confer superdiffusive motion to single charge microgels attached onto the interface, and are responsible to bring microgel particles to common sites for cluster formation. The balance between various forces prior to cluster formation gives rise to a pseudoequilibrium state.

    • Wuguo Bi
    • Edwin K. L. Yeow
    ArticleOpen Access
  • Soft, transient silicon-based gas sensing system capable of detecting nitrogen oxides with remarkable sensitivity and selectivity is presented in this report. The results provide materials, device layouts, manufacturing process, and theorectical modeling illlustrating the capabilities and operational aspects. In vitro experiments demonstrate the possibilities for disposable environmental monitors and temporary biomedical implants.

    • Gwan-Jin Ko
    • Soo Deok Han
    • Suk-Won Hwang
    ArticleOpen Access
  • We present a promising technique for transparent flexible conducting oxide heteroepitaxial films: the direct fabrication of epitaxial molybdenum-doped indium oxide (IMO) thin films on a transparent flexible muscovite substrate. An n-type epitaxial IMO film is demonstrated with a mobility of 109 cm2 V−1 s−1, a figure of merit of 0.0976 Ω−1, a resistivity of 4.5 × 10−5 Ω cm and an average optical transmittance of 81.8% in the visible regime. IMO heterostructure not only exhibits excellent performance but also shows excellent mechanical durability. This study demonstrated an extraordinary achievement for the evolution and expansion of next-generation smart devices.

    • Chun-Hao Ma
    • En-Liang Chen
    • Ying-Hao Chu
    ArticleOpen Access
  • Ferromagnetic semiconductors are promising candidates for high-performance multifunctional spintronic devices due to the peculiar magneto-electric and magneto-optical properties. However, the low spin ordering temperature limits their applications. By using high pressure to stabilize the crystal structure and oxygen content, an oxygen-deficient perovskite SrCr0.5Fe0.5O2.875 was synthesized. This compound displays ferromagnetic behavior with a spin ordering temperature as high as 600 K. Benefiting from the semiconducting direct bandgap (~2.28 eV), a field-tunable green fluorescent effect is observed. This work opens up a new avenue for research on room-temperature multifunctional materials with coupled magnetic, electrical, and optical performance.

    • Bowen Zhou
    • Qing Zhao
    • Youwen Long
    ArticleOpen Access
  • The characteristics of I/Cl alloying structures in MAPbI3-xClx mixed-halide perovskites and their influences on the optoelectronic properties have been issues of long-standing controversy. In this work, by using on the time-dependent X-ray diffraction, 207Pb and 2H NMR, the authors investigated the I/Cl alloying structures and its long term stability in MAPbI3-xClx (x = 0.0 to 0.3) single crystals. It was found that Cl can substitute for I of the PbI3 inorganic lattice, leading to the tetragonal to cubic phase transition. Moreover, it revealed that the alloying structures of the MAPbI3-xClx crystals are metastable and may decompose over time.

    • Wen-Cheng Qiao
    • Jianming Yang
    • Ye-Feng Yao
    ArticleOpen Access
  • An imprinted four-fold magnetic anisotropy was observed in the amorphous ferromagnetic layer of FeRh/CoFeB heterostructures. The easy magnetization axes of the CoFeB layer are along the FeRh〈110〉 and FeRh〈100〉 directions for the epitaxially grown FeRh layer in the antiferromagnetic and ferromagnetic states, respectively. The fourfold magnetic anisotropy of the amorphous CoFeB layer is imprinted due to the interfacial exchange coupling between the CoFeB and FeRh moments from the magnetocrystalline anisotropy of the epitaxial FeRh layer, which may be applied to probe the magnetic structures of antiferromagnetic materials without using synchrotron methods.

    • Yali Xie
    • Qingfeng Zhan
    • Run-Wei Li
    ArticleOpen Access
  • We first shaped the critical role of Ge vacancies in GeTe on the crystal structure-thermoelectric properties relationship by combining first-principle calculations, Boltzmann transport equation, and experimental properties studies, leading to the stabilization of the metastable cubic structure, unfavorable band structure modification, and stable N-type conduction.

    • Zihang Liu
    • Naoki Sato
    • Takao Mori
    ArticleOpen Access
  • All-carbon memristive synapse is built through photo-reduction of a nanocomposite comprised of graphene oxide and N-doped carbon quantum dots. The analog-type resistive switching was demonstrated, which enabled the emulation of synaptic learning and pattern recognition with high accuracy. The all-carbon devices possess excellent transferability, flexibility and resistance to high temperature, showing the potential for the development of wearable neuromorphic computing system.

    • Ya Lin
    • Zhongqiang Wang
    • Yichun Liu
    ArticleOpen Access
  • A liquid-based neuromorphic device that can mimic the movement of ions in a nervous system is demonstrated by controlling Na+ movement in an aqueous solution. The liquid-based neuromorphic device consists of disodium terephthalate, Nafion, NaCl solution, and electrodes. The top and bottom electrodes work as pre- and post synaptic neurons, respectively, and the NaCl solution/Na2TP@Nafion works as a synapse. The device shows short-term and long-term plasticity such as EPSC, PPF, STDP, potentiation, and depression.

    • Dongshin Kim
    • Jang-Sik Lee
    ArticleOpen Access
  • Water of aqueous PEDOT:PSS solution was successfully exchanged with ethylene glycol or ethanol solvents using ultrafiltration method. This novel solvent exchange process enables uniform and conformal nano-coating of PEDOT:PSS on hydrophobic substrates without the addition of surfactants. This process can be widely used in fabrication of various sensors or electronic devices using conducting polymers.

    • Jung Joon Lee
    • Srinivas Gandla
    • Sunkook Kim
    ArticleOpen Access
  • 4D Printing Conduits: Electromagnitized carbon porous nanoccookies (NCs) under MF facilitate magneto-electrical conversion for growth factor release and cell simulation. Integrating four-dimensional (4D) printed technology, exposed NCs are able to enhances the cell adhesion and manifest directly electromagnetic stimulation to cells.

    • Jen-Hung Fang
    • Hao-Hsiang Hsu
    • Shang-Hsiu Hu
    ArticleOpen Access
  • It is still a mystery whether disorders could be beneficial for the superconductivity or not. In this work, it is surprising to find out that the carbon disordered 2D β-Mo2C crystal sheet shows a much stronger superconductivity than the carbon ordered 2D α-Mo2C crystal sheet, and the in-situ order-disorder transition from α-Mo2C to β-Mo2C induced by e-beam irradiation results in an enhanced superconductivity. Especially, the Tc variation trends of α-Mo2C and β-Mo2C are different under hydrostatic pressures. These results highlight the important role of disorders in the superconducting properties owing to the carbon distributions in Mo2C.

    • Yunjie Fan
    • Chuan Xu
    • Xiaoguang Li
    ArticleOpen Access
  • Understanding the correlation between atomic-scale structural/elastic fluctuations and local plastic rearrangements (shear transformation zone (STZ)) is essential to the widespread use of metallic glasses (MGs). We report a strategy to control the local stress state and enhance the shear stability of MGs. The enhanced degree of structural/elastic heterogeneities relates to the increased nonaffine thermal strain of the short- and medium-range order. We demonstrate that variations in the stress field around STZ affect their dynamics and percolation process, the progressive formation of shear bands, and, consequently, the macroscopic deformability of MGs. This work paves a new way for designing ductile MGs.

    • Xilei Bian
    • Daniel Şopu
    • Jürgen Eckert
    ArticleOpen Access
  • Quantum dot LED (light-emitting diode) optimization through the control of charge carriers’ kinetics is presented using impedance spectroscopy. The mobility of charge carriers through each one of the layers provide a path to estimate the transition time of each one of the charge carriers toward the emitting layer. By focusing on thickness optimization of electron transferring layer we can control the transition time of charge carriers and maximize radiative recombination.

    • Gary Zaiats
    • Shingo Ikeda
    • Prashant V. Kamat
    ArticleOpen Access
  • Our findings unearth the great importance of the size, core structure, and surface ligands in dictating the antibacterial activity of silver nanoclusters (AgNCs). Owing to the presence of amphiphilic ligands, AgNCs are more prone to adsorb the membrane and following endocytosis towards targeted bacterial cells, associated with membrane damage, as reflected by reinforced release of malondialdehyde (MDA). AgNCs bear strong peroxidase-like activity, coupled to massive production of reactive oxygen species (ROS). Altogether, these outstanding features of AgNCs resultantly elevated the bacteria-killing efficacy through impairing cell wall/membrane, promoting oxidative stress and attenuating pivotal cellular processes, e.g., ATP synthesis.

    • Yongjiu Chen
    • Liting Ren
    • Sijin Liu
    ArticleOpen Access
  • Speed-programmed melt electrospinning writing (sMEW) is used to create a hierarchically ordered biomimetic scaffold with long-range patterned and short-range porous architectures for cell growth in patterns with tunable cell density.

    • Yingchun Su
    • Zhongyang Zhang
    • Menglin Chen
    ArticleOpen Access
  • A sunlight management strategy in perovskite solar cells (PSCs) using silicon quantum dots (SiQDs) is proposed. Due to the reabsorption of visible light induced by SiQDs, the external quantum efficiency spectra of PSCs in a wide wavelength range of 360–760 nm is significantly improved, resulting in facilitated photocurrent collection and enhanced performance of SiQD-based PSCs.

    • Ying-Chiao Wang
    • Shao-Ku Huang
    • Kazuhito Tsukagoshi
    ArticleOpen Access