Nanoscience and technology articles within NPG Asia Materials

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  • Article
    | Open Access

    The modulation of interfacial coupling of (La0.67Sr0.33MnO3)n/(SrTiO3)n superlattices with n unit cells of SrTiO3 and n unit cells La0.67Sr0.33MnO3, offers an effective opportunity to control charge transfer and orbital hybridization. The easy axis of magnetic anisotropy rotates ~45° towards the out-of-plane direction from n = 10 to n = 2 at reduced temperature TRe = T/TS = 0.87 (TS is onset of magnetization). Orbital hybridization accompanying the charge transfer results in preferred occupancy of \(3d_{3z_{2} - r_{2}}\) orbital at the interface, and induces stronger electronic hopping integral and interfacial magnetic anisotropy along perpendicular direction, useful to tailor properties in device applications.

    • Bangmin Zhang
    • , Lijun Wu
    •  & Gan Moog Chow

  • Article
    | Open Access

    A thermoresponsive smart colorimetric patch was fabricated by embedding thermoresponsive plasmonic microgels in a stretchable hydrogel film. The stretchable and wearable colorimetric patches exhibited vivid color change, fast response time, outstanding thermal resolution, and high durability. Potential applications in wearable smart sensors and soft robotics were demonstrated through a spatial temperature scanner and a colorimetric thermometer for thermoresponsive actuators.

    • Ayoung Choe
    • , Jeonghee Yeom
    •  & Hyunhyub Ko

  • Article
    | Open Access

    Through combining nanochannel technique and host–guest interaction, a universal tuneable nanofluidic diode is fabricated. By changing different azobenzene derivatives, the system can achieve replaceable surface charges, and realize the light and pH dual stimuli responses. The system has potential applications in fields such as photosensitive nanofluidic devices, light-controlled drug transport, pH-activated drug release and devices for optical information storage.

    • Pei Liu
    • , Ganhua Xie
    •  & Liping Wen

  • Article
    | Open Access

    Amphiphilic Janus camptothecin-floxuridine (CF) conjugate was synthesized for engineering CF microbubbles (CF MBs) with ultrahigh drug-loading contents. CF MBs exhibited excellent capability to enhance ultrasound (US) imaging for identifying the location and size of the tumors, while it can be efficiently converted into CF NPs upon sonication, conducing to remarkably high drug tumor accumulation via sonoporation effect. Both camptothecin (CPT) and floxuridine (FUDR) could be released at an exact 1:1 ratio in the tumor microenvironment, achieving significantly improved therapeutic efficacy. Overall, the CF MBs combining with US technique will provide a step toward the application of targeted theranostics.

    • Xiaolong Liang
    • , Yunxue Xu
    •  & Zhifei Dai

  • Article
    | Open Access

    Silver indium sulfide (AgInS2) semiconductor nanoparticles are cadmium-free quantum dots emitting in visible to near infrared regions. The present study demonstrates the narrowing of their broad defect emission by coating AgInS2 core nanoparticles with amorphous indium sulfide or gallium sulfide shells. The new emission from the core/shell nanoparticles originating from the band-edge transition is substantially narrower (FWHM of 28.6 nm) than the defect emission of core nanoparticles (FWHM of 220 nm). The photoluminescence quantum yield is increased to 56% after giving several modifications to the synthetic procedures so that we can see the vibrant yellow emission under room light.

    • Taro Uematsu
    • , Kazutaka Wajima
    •  & Susumu Kuwabata

  • Article
    | Open Access

    A batch-by-batch free route for the continuous production black phosphorus nanosheets in a single-pass gas stream was designed, and the resulting nanosheets were directly employed in targeted chemo-phototherapy upon incorporating with doxorubicin, poly-l-lysine, and hyaluronic acid.

    • Bijay Kumar Poudel
    • , Jungho Hwang
    •  & Jeong Hoon Byeon

  • Article
    | Open Access

    Compared with unipolar transistors, ambipolar transistors, which can easily switch between n-type and p-type behavior by applying an electric field, are most promising candidates since they can effectively simplify circuit design and save the layout area in CMOS. In this study, we take a deep insight into the thickness dependent physical properties of WSe2, where the optical properties, electric field screening effect, and the ambipolar transport behavior are systematically studied. Furthermore, the investigation of ambipolar WSe2 transistors in analogue circuits exhibiting gate-controlled phase change directly explores its practical application in 2D communication electronics.

    • Zegao Wang
    • , Qiang Li
    •  & Mingdong Dong

  • Article
    | Open Access

    A rational way to explore economically feasible high-performance electrocatalyst for OER is developed by improving the reaction kinetics of rate-determining step via the hybridization with electron-withdrawing RuO2 nanosheet. Even with very low RuO2 content, self-assembled Ni–Fe-/Ni–Co-layered double hydroxide (LDH)–RuO2 nanohybrids show very small overpotentials of 207/276 mV at 10 mA cm−2 for oxygen evolution reaction with greatly improved current densities.

    • Nam Hee Kwon
    • , Minho Kim
    •  & Seong-Ju Hwang

  • Article
    | Open Access

    In this study, we investigate the effect of surface functional group of 2D materials on the hydrogen evolution reaction (HER) and it shows both band state (ΔGH) and the wettability of 2D catalyst influence on the onset potential. In particular, the COOH functionalized 2D materials demonstrate good catalytic effect and good stability during HER because the COOH moiety increases the polarization of the electrode related to wettability as well as reduces the hydrogen absorption energy of the Mo atom and S atom through proton transfer.

    • Hanleem Lee
    • , Sora Bak
    •  & Hyoyoung Lee

  • Article
    | Open Access

    The electrode based on ultradispersed sub-10 nm SnO2 nanocrystals anchored on graphene nanosheets can reversibly store Na ions through both a surface-controlled pseudocapacitive reaction and a diffusion-limited alloying reaction. The fabricated Na ion hybrid capacitor with ultradispersed sub-10 nm SnO2 nanocrystals anchored on graphene nanosheets as negative electrode exhibits superior electrochemical performance.

    • Panpan Zhang
    • , Xinne Zhao
    •  & Wei Huang

  • Article
    | Open Access

    GO can undergo significant physicochemical transformation in two simulated lung fluids–Gamble’s solution and artificial lysosomal fluid (ALF), as the organic acids in lung fluids cause reduction of GO. Biotransformation markedly inhibits the endocytosis of GO by scavenging macrophages. Notably, alterations in Gamble’s solution enhance the aggregation of GO in a layer-to-layer manner, resulting in GO precipitation and reduced interaction with cells, whereas changes in ALF lead to edge-to-edge aggregation of GO, enhancing the adhesion of large sheet-like GO aggregates on plasma membrane without cellular uptake.

    • Yu Qi
    • , Yun Liu
    •  & Wei Chen

  • Article
    | Open Access

    Platinum diselenide (PtSe2) is a newly discovered Group-10 transition metal dichalcogenide (TMD) which has unique electronic properties, in particular a semimetal-to-semiconductor transition. In this work, we have demonstrated the proposed vertically standing layered structure PtSe2 nanofilms based on hybrid heterojunction with high overall performance was realized for broadband light photodetection ranging from 200 nm to 1550 nm. The high-performance broadband photodetector will open up a new pathway for the development of next-generation two dimensional Group-10 materials based optoelectronic devices.

    • Longhui Zeng
    • , Shenghuang Lin
    •  & Yuen Hong Tsang

  • Article
    | Open Access

    A hybrid optofluidic technique was developed to achieve fluid transport with controllable modes and tunable strength. The switch of the optofluidic mode from buoyancy to thermocapillary convection is employed for three-dimensional manipulation. The strong confinement and torque in the convection are capable of trapping and rotating/spinning particles. The buoyancy convection provides a trapping circle to achieve collective trapping and vertical rotation/spin, while the thermocapillary convection offers a trapping lattice to achieve distributed trapping and horizontal rotation/spin. Further investigations in optofluidic arrangement, mixing, and synthesis will broaden its potential applications in the fields of lab-on-a-chip.

    • Jiapeng Zheng
    • , Xiaobo Xing
    •  & Sailing He

  • Article
    | Open Access

    Graphene is very promising for THz application, especially in the fields desiring fast THz imaging, like security screening, communication, biomedical and pharmacy control. However, current graphene-based THz detectors are severely hindered by its poor switching behavior, and lack of internal gain to boost up the responsivity in the framework of plasma-wave self-mixing or thermoelectric detections. A proper means to selectively trigger the photoelectric conversion is highly desirable for practical applications. This work offers alternative way for room temperature THz detection via manipulating the hot carriers either electrically and electromagnetically. Internal photoelectric gain is achieved via the bias-field effect, which leads to the giant enhancement of graphene-based detector’s responsivity over 200 V/W. Furthermore, switching behavior between photoconductive and photovoltaic modes can be given rise in a single device, being promising for scalable THz imaging.

    • Changlong Liu
    • , Lei Du
    •  & Wei Lu

  • Article
    | Open Access

    we present a novel paradigm that suppresses the reflection of light from a metallic surface by using an ultrathin CuO coating. This antireflection concept relies on the strong inference inside the ultrathin absorptive CuO coating. We derive the optimal conditions for minimum reflectance and expound how the film thickness impacts the reflectance. Almost zero reflectance can be obtained at wavelength of ca. 550 nm over a wide range of incident angles. This technology has the potential for many applications, especially viable for photoelctrochemical cells, which requires strong absorption and short carrier collection length.

    • Hongyan Liu
    • , Jingjing Peng
    •  & Yue Yan

  • Article
    | Open Access

    In this work, electrospun In2O3 nanowires with controllable Pt core were designed and prepared as an ultra-sensitive layer with good electron transmission ability as well as high surface area, and then SBA-15 molecular sieve was further integrated as a moisture filter layer. The as-design device was successfully used to detect trace acetone biomarker in exhaled breath, which could accurately distinguish the health people from diabetes in clinical samples.

    • Wei Liu
    • , Lin Xu
    •  & Hongwei Song

  • Article
    | Open Access

    As a new two-dimensional (2D) material, monolayer ruthenium oxide (RuO2) nanosheets (NSs) have distorted h-MX2 type crystal structures that lead to semiconducting properties and good optical transmittance. This study suggests that monolayer RuO2 can be useful in applications of flexible optoelectronics.

    • Dong-Su Ko
    • , Woo-Jin Lee
    •  & Jong Wook Roh

  • Review Article
    | Open Access

    Graphene has received enormous research interest in recent years owing to its intriguing structure and fascinating properties. Its high mechanical strength, flexibility and optical transparency make it a desire building block of 2D Janus materials. Through asymmetric surface modifications on target graphene derivatives, including hydrogenation and halogenation, grafting of organic molecules and polymers, and deposition of metal/metal oxides, different graphene-based Janus materials have been achieved with various shapes, sizes, and compositions. This review presents and discusses the development, fabricating strategies and applications of these 2D Janus materials, starting with the theoretical understanding of the behavior of Janus graphene.

    • Sze-Wing Ng
    • , Nuruzzaman Noor
    •  & Zijian Zheng

  • Article
    | Open Access

    An amphiphilic dendrimer engineered nanocarrier system (ADENS) possessing a unique hollow core/shell structure is developed, in which siRNA is incorporated in the hydrophilic cavity and paclitaxel is abundantly depoted in the hydrophobic interlayer. Then, the ADENS is modified by tumor microenvironment-sensitive polypeptides (TMSP). The TMSP-ADENS shows enhanced cellular uptake, tumor penetration and accumulation in a MMP-2/9-triggered mechanism. The TMSP-ADENS provides a potential strategy for effective co-delivery of siRNA and paclitaxel for anti-tumor therapy in a synergistic manner.

    • Xin Li
    • , A-ning Sun
    •  & Xian-rong Qi

  • Article
    | Open Access

    We present piezoresistive electronic skins with tunable force sensitivity and selectivity in response to multidirectional forces (normal, shear, tensile, bending) by engineering microstructure geometries (dome, pyramid, pillar). Microdome structures present the best force sensitivities for normal, tensile, and bending stresses. On the other hand, for shear stress, micropillar structures exhibit the highest sensitivity. As proof-of-concept demonstrations, the e-skins are used for wearable healthcare devices to precisely monitor various bio-signals including sound, human breath, and artery/carotid pulse pressures.

    • Jonghwa Park
    • , Jinyoung Kim
    •  & Hyunhyub Ko

  • Article
    | Open Access

    We suggest synaptic devices using cation migration along thickness direction in a new class of 2D layered materials. An electrochemically active metal, such as Ag and Cu, is used for the operation of the synaptic device and chromium thiophosphate (CrPS4) single crystal is used as an electrolyte material. Multi-stable resistive states, short-term plasticity, and long-term potentiation are observed by controlling external voltage pulse with height smaller than 0.3 V. Given that simple mechanical exfoliation can generate very thin CrPS4 layers, the vertical Ag/CrPS4/Au capacitor offers a promising inorganic synaptic device compatible with next-generation flexible neuromorphic technology.

    • Mi Jung Lee
    • , Sangik Lee
    •  & Bae Ho Park

  • Review Article
    | Open Access

    In this review, we overview the recent achievements in synthesis of high performance nacre-inspired macroscopic composites and divide them into different groups by standards of different dimensions, such as 1D nacre-inspired fibers, 2D nacre-inspired films and 3D nacre-inspired bulk composites. The methods to produce different dimensional nacre-inspired composites are also introduced and performance enhanced strategies for different dimensional nacre-inspired composites are summarized and explained in detail. Applications of high mechanical performance nacre-inspired composites are also summarized. A critical outlook for next-generation light-weight and high performance materials is proposed.

    • Hewei Zhao
    • , Zhao Yang
    •  & Lin Guo

  • Original Article
    | Open Access

    Inspired by the anti-stone phenomenon of normal renal tubule, we report that superhydrophilic nanohair hydrogel coating shows high anti-adhesion against mineral scales under flowing conditions. The experiment and theory simulation reveal the crucial role of superhydrophilicity and fluid-assisted motion of nanohair in the anti-scale property. Even at a high temperature of 80 °C, it still shows high anti-scale performance, which is much better than the flat hydrogel coating and commercial water pipe with polyvinylchloride surface. This study may provide a promising clue to design high anti-adhesion coatings for resisting mineral scales attachment in water management systems.

    • Tianzhan Zhang
    • , Yuefeng Wang
    •  & Shutao Wang

  • Original Article
    | Open Access

    Smart surface with tunable properties is vital for modern intelligent applications. Here we demonstrate a novel surface that enables fast surface changing based on a bioinspired micro-air-sacs network. The pneumatic smart surface allows for rapid and large-amplitude topography deformation through pneumatic control, and permits dynamic wettability switching between dominant and latent states. A smart surface with contrastive rose-petal-like and lotus-leaf-like wetting characters is presented and utilized as a droplet manipulator for in situ capture and release of water droplets on demand.

    • Jian-Nan Wang
    • , Yu-Qing Liu
    •  & Hong-Bo Sun

  • Original Article
    | Open Access

    NaCl-assisted APCVD technique to synthesize multi-stacked MoS2 crystals with different stacking orientations and shape has been developed. We found that the stacking orientation of multi-stacked MoS2 crystals shows the underlying variation in the crystalline phases, symmetry inversion, spin–orbit coupling and interlayer interactions through intensive optical study based on Raman spectroscopy, PL spectroscopy and nonlinear technique of FWM correlated SHG imaging technique. Our study based on the crystals with different shape and multiple stacking configurations provide a new avenue for the possibilities of future optoelectronic devices.

    • Sachin M Shinde
    • , Krishna P Dhakal
    •  & Jong-Hyun Ahn

  • Original Article
    | Open Access

    A simple and robust single-step in situ synthesis of carbon dots (C-dots) within a porous silicon oxide (PSiO2) matrix is reported. The resulting new hybrid guest–host material exhibits promising capabilities as a label-free dual-mode optical biosensor via modulation of both the optical reflectance associated with the PSiO2 matrix, as well as the C-dots’ fluorescence, and these two signals can be observed and collected simultaneously. The resulting sensing platform exhibits enhanced sensitivity, improved linear response, as well as a wider dynamic range in comparison to its single components.

    • Naama Massad-Ivanir
    • , Susanta Kumar Bhunia
    •  & Raz Jelinek

  • Original Article
    | Open Access

    A N-doped carbon nanotube catalyst containing a high concentration of single Fe atoms was prepared by a simple and scalable atomic isolation method, in which a metal isolation agent was introduced to isolate single Fe atoms and was then evaporated to produce abundant micropores that host single Fe atom active sites. As a result, the catalysts obtained showed excellent ORR performance, even better than that of commercial Pt/C catalysts in an acidic medium.

    • Jin-Cheng Li
    • , Zhi-Qing Yang
    •  & Hui-Ming Cheng

  • Original Article
    | Open Access

    Herein, an idea of creating MoS2/GO nanocomposites was brought about, which were constructed to integrate the merits for both materials with additional benefits and shield the mutual weaknesses. It turned out that MoS2/GO nanocomposites manifested beneficial multi-functionalities including favorable lung targeting, enhanced drug loading capacity, increased tumor killing efficacy and improved biosafety as well. This study would open a new path that may lead to desirable use of MoS2/GO nanocomposites in cancer therapeutics.

    • Yun Liu
    • , Jian Peng
    •  & Sijin Liu

  • Review
    | Open Access

    In this review, we highlight the recent progress in two rising areas: solar energy conversion through plasmon-assisted interfacial electron transfer and plasmonic nanofabrication. Localized surface plasmon resonance (LSPR) of plasmonic nanoparticles and nanostructures has attracted increasing attention because of their strong near-field enhancement by interacting with visible light. Recent studies have demonstrated the capability of such plasmonic systems in producing ‘LSPR-induced hot-electrons’ that are useful in photoenergy conversion and storage when combined with electron-accepting semiconductors. Concurrently, ‘hot-electron decay’ results in strong photothermal responses or plasmonic local heating. This heating has received renewed interest in photothermal manipulation of nanoparticles and molecules.

    • Akihiro Furube
    •  & Shuichi Hashimoto

  • Original Article
    | Open Access

    Well-defined and stable nanomicelles (20−30 nm in diameter) were demonstrated for the first time by the self-assembly of amphiphilic brush (comb-like) cyclic and tadpole-shaped copolymers based on a poly(glycidyl ether) backbone. In particular, the brush cyclic topology formed the most compact and most stable nanomicelles with an extremely narrow (pseudo-monodisperse) size distribution, which are unattainable by other conventional means. This study provides a unique opportunity for designing advanced functional high-performance amphiphile materials for micelles and facilitating their applications in various fields.

    • Brian J Ree
    • , Yusuke Satoh
    •  & Moonhor Ree

  • Original Article
    | Open Access

    Highly efficient voltage control of magnetic anisotropy has been demonstrated utlizing an ultrathin Ir-doped Fe layer in MgO-based magnetic tunnel junctions. Ir adoms are dispersed inside the ultrathin Fe layer through the interdiffusion process. Large spin–orbit interaction of Ir atoms having proximity-induced magnetism is attributed to the enhancement of the voltage-controlled magnetic anisotropy (VCMA) effect. High speed response of the VCMA effect was also confirmed by voltage-induced ferromagnetic resonance. The achieved properties first satisfy the required specification for the new type of magnetoresistive random access memory (MRAM) driven by voltage.

    • Takayuki Nozaki
    • , Anna Kozioł-Rachwał
    •  & Shinji Yuasa

  • Original Article
    | Open Access

    A skin-like stretchable multi-functional sensor array based on a combination of PU foam and MWCNT-PANI nanocomposite is demonstrated to simultaneously detect pressure, temperature and ammonia gas with high sensitivity. The integrated sensor array with printed liquid metal interconnections operates stably under applied strain due to its attachment to the skin and under a biaxial strain up to 50%.

    • Soo Yeong Hong
    • , Ju Hyun Oh
    •  & Jeong Sook Ha

  • Original Article
    | Open Access

    Nanostructural modifications, in particular nanoparticle (NP) additions, have been shown to have great success in improving energy-related material performance. We show how an economically viable method, namely metal organic deposition, can be used to obtain tunable small size (7 nm) and high number density NPs (8 × 1022 m−3) while maintaining the crystallinity of the perovskite-composite cuprate superconductor film matrix. Critical current density Jc(H) measurements demonstrate that the NPs are highly effective as pinning centers, decreasing vortex motion and fluctuation effects for all temperatures, magnetic field strengths and orientations measured. Our synthesis method can be applied to other perovskite-composite materials to improve their functionality.

    • Masashi Miura
    • , Boris Maiorov
    •  & Teruo Matsushita

  • Original Article
    | Open Access

    Iron oxides were designed to the rice-grain-shaped hollow structures with hierarchical pores and highly aligned nano/micro-structures using silk fibrous templates to impose multi-functional materials for the electrocatalysts for Li-O2 batteries and the adsorbents of organic pollutants.

    • Taek-Seung Kim
    • , Gwang-Hee Lee
    •  & Dong-Wan Kim

  • Original Article
    | Open Access

    Ultrathin Bi2Se3-CS-RGD NSs with excellent tumor-targeting ability and potent radiosensitization efficiency are constructed for imaging-guided cancer radiotherapy. The NSs in combination with X-ray irradiation inhibit HeLa cell growth by inducing G0/G1 cycle arrest and mitochondria-mediated intrinsic cell apoptosis, inhibiting TrxR and activating downstream ROS-mediated signaling pathways. Moreover, RGD coating enables the NSs to aggregate in the tumor regions quickly enabling efficient PAI of the entire tumor to facilitate radiotherapy of cervical cancer. Taken together, this study provides an effective and safe theranostic agent for next-generation cancer radiotherapy.

    • Zhenhuan Song
    • , Yanzhou Chang
    •  & Tianfeng Chen

  • Original Article
    | Open Access

    A new class of self-powered and flexible biomimetic NEMS flow sensor is developed that can detect minute fluid flows with ultrahigh sensitivity. The hydrogel-VACNT structure closely mimics the mechanical and material properties of the gelatinous cupula found in many biological flow sensors. This work illustrates how such a nature-inspired design when implemented in NEMS sensor through nanofabrication enhances the sensitivity of the flow sensor.

    • Meghali Bora
    • , Ajay Giri Prakash Kottapalli
    •  & Michael S Triantafyllou

  • Original Article
    | Open Access

    The redox half-reaction of wide bandgap silver chloride was utilised to promote the photo-emitted carriers from graphene and the photoresponsivity of the phototransistor, circumventing the limitation of semiconductor bandgap and facilitating the pronounced photoresponse to long wavelength photons far beyond the optical absorption edge of AgCl.

    • Ze Xiong
    • , Jiawei Chen
    •  & Jinyao Tang

  • Original Article
    | Open Access

    Ni ions can be aligned by a double-stranded DNA and form a Ni–DNA nanowire. By integrating with the semiconductor circuits it becomes a novel molecular device, which is the first real dual memelement that exhibits functionalities of novel resistor and capacitor with memory, and redox-induced negative differential resistance (NDR) properties. The working mechanism of this novel device is similar to the memcomputing in brain.

    • Hsueh-Liang Chu
    • , Jian-Jhong Lai
    •  & Chia-Ching Chang

  • Original Article
    | Open Access

    Electronic and geometric controlling the magnetization orientation of a material in nanoscale is key in developing spintronics, which correlates with tuning its magnetocrystalline anisotropy energy (MCAE). Although the MCAE of a Fe thin film is measured to oscillate with the film thickness and to vary with the amount of injected charges, switching the magnetization orientation electrically is desired. In this work, we provide a microscopic picture based on Fe quantum-well states and spin orbital coupling to explain experimental results (a), and thus predict that the magnetization orientation of a 5-ML Fe film can be switched electrically (b).

    • Ching-Hao Chang
    • , Kun-Peng Dou
    •  & Chao-Cheng Kaun

  • Original Article
    | Open Access

    A universal dual-electrochromic platform that could operate various advanced logic devices whose outputs visualized by the naked eye was constructed for the first time by introducing the electrochemical oxidation of 2, 2′ -azinobis (3-ethylbenzthiazoline-6-sulfonic acid) and electrodeposition of Prussian blue into one closed bipolar electrode system.

    • Qingfeng Zhai
    • , Daoqing Fan
    •  & Erkang Wang

  • Original Article
    | Open Access

    Here, we present a pressure-modulated heterojunction photodiode composed of n-type multilayer MoS2 and p-type GaN film by piezo-phototronic effect. Under the illumination of 365 nm incident light, strong photo-response is observed with a response time and recovery time of ~66 and 74 ms, respectively. Upon the pressure of 258 MPa, the photoresponsivity of this photodiode can be enhanced for about 3.5 times by piezo-phototronic effect arising from the GaN film. Due to the lowered junction barrier upon applying an external pressure (strain), more photo-generated carriers can successfully pass through the junction area without recombination, resulting in the enhancement effect.

    • Fei Xue
    • , Leijing Yang
    •  & Zhong Lin Wang

  • Original Article
    | Open Access

    Organic electronic synapses based on poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)/graphene quantum-dot (GQD) nanocomposites were fabricated by using a solution method. Current–voltage (I–V) curves for the devices under dual positive bias voltage sweeps and under dual negative bias voltage sweeps showed that the conductance with a pinched hysteresis gradually increased and gradually decreased, respectively, with increasing applied voltage which is a fingerprint of e-synapses. The current in the devices was found to decrease with increasing concentration of GQDs in the active layer, and the devices fabricated utilizing the ratio of PEDOT:PSS to GQDs of 1:0.4 showed the best performance among the e-synapses. The carrier transport and operating mechanisms of the e-synapses are described in this paper on the basis of both the I–V results and the trapping and escape of electrons from the GQDs. We believe that our letter contains significant results of interest to a broad spectrum of NPG Asia Materials readers.

    • Hwan Young Choi
    • , Chaoxing Wu
    •  & Tae Whan Kim

  • Original Article
    | Open Access

    Here, we utilize large-size scalable single-crystal 2D films to grow single crystalline inorganic semiconductors. Centimeter-scale hexagonal boron nitride (h-BN) films were synthesized on a single-crystal Ni(111) using chemical vapor deposition (CVD). Single-crystal GaN layers were directly grown on h-BN using metal–organic vapor phase epitaxy. The CVD-grown h-BN exhibited many atomic cliffs that enabled us to grow high-density GaN islands to be merged as homogeneous and flat GaN films. We also investigated the crystallinity and growth mechanism of the GaN films grown on CVD-grown h-BN using transmission electron microscopy and X-ray diffraction.

    • Kunook Chung
    • , Hongseok Oh
    •  & Gyu-Chul Yi

  • Original Article
    | Open Access

    We developed a simple but effective protocol to construct uniform FePO4 coating layer on various substrates. By controlling the precipitation kinetics, we were able to form uniform FePO4 nanoshells with its thickness precisely defined in nanometer accuracy. Specifically, a core-shell structured electrode material of MWCNTs@FePO4 was constructed, which showed promising potential as a cathode material for sodium ion battery as revealed by its high discharge capacity as well as the much improved rate capability.

    • Shu-Yi Duan
    • , Jun-Yu Piao
    •  & Li-Jun Wan

  • Original Article
    | Open Access

    A flash-evaporation printing technology is developed that employs freestanding carbon nanotubes as a flash evaporator. The target materials precoated on the flash evaporator are printed onto substrates by gas-phase transportation. This methodology offers a printable solution for hybrid perovskite thin films, and can also be used to print patterns and a wide variety of materials on large panels.

    • Haoming Wei
    • , Xingyue Zhao
    •  & Kaili Jiang

  • Original Article
    | Open Access

    Supramolecular polymeric materials constitute a unique class of materials held together by non-covalent interactions. Here we report a novel type of supramolecular rubber based on mixing of low molar mass, oligomeric, ABA-triblock copolyacrylates with oppositely charged outer blocks revealing unique mechanical properties. A broad set of materials is reported with systematic variations in triblock copolymer structures revealing insights in the mechanical properties and self-healing ability in correlation with the nanomorphology of the materials.

    • Lenny Voorhaar
    • , Maria Mercedes Diaz
    •  & Richard Hoogenboom

  • Original Article
    | Open Access

    Photodynamic therapy is a promising and effective strategy for being trialed for clinical application. However, poor targeting accumulation of traditional nanoprobes in tumor tissues has hindered its clinical use. Herein, ultra-small and highly stable Fe3O4@P-NPO/PEG-Glc@Ce6 nanoprobes were developed to improve the tumor-targeting efficiency and photodynamic therapeutic efficacy based on small size effect. The nanoprobes effectively prolong the residence time in the tumor region, reduce the accumulation in vital organs and significantly inhibit the growth of tumors in vivo. The successful application of small size effect in nanoprobes provides a new path for clinical therapies and translation in the near future.

    • Ting Yin
    • , Qian Zhang
    •  & Daxiang Cui

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