ORCID Profile
0000-0002-0618-1960
Current Organisations
Nanyang Technological University
,
University of the Chinese Academy of Sciences School of Microelectronics
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Publisher: AIP Publishing
Date: 20-12-2010
DOI: 10.1063/1.3530446
Abstract: We report the synthesis and characterization of an epitaxial heterostructure composed of multiferroic BiFeO3 and superconducting YBa2Cu3O7−δ thin films grown on (001) SrTiO3. Both the superconductivity of YBa2Cu3O7−δ and the ferroelectricity of BiFeO3 are retained in the heterostructure. Current density-electric field characteristics measured from 30 to 170 K suggest a Schottky-emission-like transport at the BiFeO3/YBa2Cu3O7−δ interface. Furthermore, the temperature dependence of the barrier height shows an anomalous enhancement at TC, indicating an intimate coupling between the multiferroic and the superconducting layers.
Publisher: American Chemical Society (ACS)
Date: 22-09-2010
DOI: 10.1021/JP1064209
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4NR01553C
Abstract: Pre-lithiation of a MoS 2 /OLC nano-urchin hybrid structure shows great potential in developing good performance lithium ion batteries with ultra-high initial coulombic efficiency.
Publisher: AIP Publishing
Date: 10-08-2009
DOI: 10.1063/1.3205122
Abstract: We investigate the optical properties of ultraviolet range emission from high quality tin oxide nanowires prepared by vapor-liquid-solid growth technique. Temperature dependent photoluminescence (PL) measurement is performed between 10 and 300 K. At low temperatures, the PL originates from radiative recombination of excitons bound to neutral donors, donor-acceptor pair transition and their associated longitudinal optical (LO) phonon replicas. The LO-phonon replicas up to third order with Huang–Rhys factor of 0.34 are observed. Evolution of the peaks and the origin of PL thermal quenching at high temperatures are discussed in detail.
Publisher: AIP Publishing
Date: 15-03-2010
DOI: 10.1063/1.3340930
Abstract: We report the correlated d0 ferromagnetism and photoluminescence in undoped single-crystalline ZnO nanowires synthesized by using a vapor transport method. We systematically tune the oxygen deficiency in the ZnO nanowires from 4% to 20% by adjusting the growth conditions, i.e., selecting different catalyst (Au or Ag) and varying the growth temperature. Our study suggests that oxygen vacancies induce characteristic photoluminescence and significantly boost the room-temperature ferromagnetism. Such undoped ZnO nanowires with tunable magnetic and optical properties are promising to find applications in multifunctional spintronic and photonic nanodevices.
Publisher: AIP Publishing
Date: 31-10-2011
DOI: 10.1063/1.3657412
Abstract: Room temperature ferromagnetism (RTFM) was observed in Li-N codoped ZnO thin films [ZnO:(Li, N)] fabricated by plasma-assisted molecular beam epitaxy, and p-type ZnO:(Li, N) shows the strongest RTFM. Positron annihilation spectroscopy and low temperature photoluminescence measurements indicate that the RTFM in ZnO:(Li, N) is attributed to the defect complex related to VZn, such as VZn and Lii-NO-VZn complex, well supported by first-principles calculations. The incorporation of NO can stabilize and enhance the RTFM of ZnO:(Li, N) by combining with Lii to form Lii-NO complex, which restrains the compensation of Lii for VZn and makes the ZnO:(Li, N) conduct in p-type.
Publisher: Elsevier BV
Date: 09-2009
Publisher: American Scientific Publishers
Date: 05-2015
Publisher: American Chemical Society (ACS)
Date: 07-06-2008
DOI: 10.1021/JP710837H
Publisher: American Chemical Society (ACS)
Date: 02-11-2011
DOI: 10.1021/JP204572V
Publisher: IOP Publishing
Date: 22-09-2008
DOI: 10.1088/0957-4484/19/43/435711
Abstract: Rational design of hybrid nanostructures through attaching nanowires with nanoparticles is an effective route to enhance the existing functionalities or to explore new ones. We carry out a systematic investigation on the photoluminescence of ZnO nanowire-Au nanoparticle hybrid nanostructures synthesized by attaching Au nanoparticles onto ZnO nanowires. Citrate-stabilized 40 nm Au nanoparticles effectively quench the green emission and enhance the UV emission of the ZnO nanowires, which is consistent with the wavelength-dependent generation of surface plasmon. The UV/green emission intensity ratio could be reversibly and reproducibly tailored by attaching/detaching Au nanoparticles. This enhancement of UV emission diminishes if the Au nanoparticles are coated with a polymer layer. We also find that the orange-red emission of the ZnO nanowires is related to the excess oxygen on the ZnO surface, and it is also tunable via annealing and surface modifications.
Publisher: American Physical Society (APS)
Date: 14-10-2011
Publisher: American Chemical Society (ACS)
Date: 02-07-2012
DOI: 10.1021/NL301226K
Abstract: As an important class of spintronic material, ferromagnetic oxide semiconductors are characterized with both charge and spin degrees of freedom, but they often show weak magnetism and small coercivity, which limit their applications. In this work, we synthesized Nd-doped ZnO nanowire arrays which exhibit stable room temperature ferromagnetism with a large saturation magnetic moment of 4.1 μ(B)/Nd as well as a high coercivity of 780 Oe, indicating giant magnetic anisotropy. First-principles calculations reveal that the remarkable magnetic properties in Nd-doped ZnO nanowires can be ascribed to the intricate interplay between the spin moments and the Nd-derived orbital moments. Our complementary experimental and theoretical results suggest that these magnetic oxide nanowires obtained by the bottom-up synthesis are promising as nanoscale building blocks in spintronic devices.
Publisher: AIP Publishing
Date: 11-01-2010
DOI: 10.1063/1.3291106
Abstract: We investigated the photoluminescence (PL) properties of ZnO nanowires with and without covering with polymethyl methacrylate (PMMA). Low temperature PL spectra of as-grown ZnO nanowires are dominated by near band edge (NBE) emission due to donor bound excitons and free-to-bound recombination (FB). FB emission persists till 300 K and together with free exciton emission governs the lineshape of the PL spectra. After covering with PMMA, the integral intensity of NBE emission increases about three times, indicating significantly improved excitonic emission efficiency. A model based on surface states and energy bands theory was proposed to interpret this emission enhancement.
Publisher: Elsevier BV
Date: 11-2010
Publisher: American Chemical Society (ACS)
Date: 03-04-2009
DOI: 10.1021/JP900026G
Publisher: AIP Publishing
Date: 06-01-2014
DOI: 10.1063/1.4861165
Publisher: Springer Science and Business Media LLC
Date: 22-11-2014
Abstract: Zn 1 - x Mn x O nanoparticles have been synthesized by hydrothermal technique. The doping concentration of Mn can reach up to 9 at% without precipitation or secondary phase, confirmed by electron spin resonance (ESR) and synchrotron X-ray diffraction (XRD). Room-temperature ferromagnetism is observed in the as-prepared nanoparticles. However, the room-temperature ferromagnetism disappears after post-annealing in either argon or air atmosphere, indicating the importance of post-treatment for nanostructured magnetic semiconductors.
Publisher: AIP Publishing
Date: 15-06-2009
DOI: 10.1063/1.3157842
Abstract: Although nanostructured SnO2 exhibited ultraviolet stimulated emission at room temperature, the low emission intensities and occurrence of gain saturation restricted them to be considered as luminescent materials for semiconductor lasers. In this letter, we find that a large ultraviolet excitonic gain can be obtained from SnO2 nanowires coated with an amorphous layer. Under effective pumping, ultraviolet coherent random lasing can be realized from randomly assembled SnO2 nanowires at room temperature.
Publisher: Springer Science and Business Media LLC
Date: 24-02-2023
DOI: 10.1038/S41467-023-36728-1
Abstract: Neuromorphic computing using nonvolatile memories is expected to tackle the memory wall and energy efficiency bottleneck in the von Neumann system and to mitigate the stagnation of Moore’s law. However, an ideal artificial neuron possessing bio-inspired behaviors as exemplified by the requisite leaky-integrate-fire and self-reset (LIFT) functionalities within a single device is still lacking. Here, we report a new type of spiking neuron with LIFT characteristics by manipulating the magnetic domain wall motion in a synthetic antiferromagnetic (SAF) heterostructure. We validate the mechanism of Joule heating modulated competition between the Ruderman–Kittel–Kasuya–Yosida interaction and the built-in field in the SAF device, enabling it with a firing rate up to 17 MHz and energy consumption of 486 fJ/spike. A spiking neuron circuit is implemented with a latency of 170 ps and power consumption of 90.99 μW. Moreover, the winner-takes-all is executed with a current ratio 4 between activated and inhibited neurons. We further establish a two-layer spiking neural network based on the developed spintronic LIFT neurons. The architecture achieves 88.5% accuracy on the handwritten digit database benchmark. Our studies corroborate the circuit compatibility of the spintronic neurons and their great potential in the field of intelligent devices and neuromorphic computing.
Publisher: American Chemical Society (ACS)
Date: 08-07-2010
DOI: 10.1021/NN1005396
Abstract: Although NiO is one of the canonical functional binary oxides, there has been no report so far on the effective fabrication of aligned single crystalline NiO nanowire arrays. Here we report a novel vapor-based metal-etching-oxidation method to synthesize high-quality NiO nanowire arrays with good vertical alignment and morphology control. In this method, Ni foils are used as both the substrates and the nickel source NiCl(2) powder serves as the additional Ni source and provides Cl(2) to initiate mild etching. No template is deliberately employed instead a nanograined NiO scale formed on the NiO foil guides the vapor infiltration and assists the self-assembled growth of NiO nanowires via a novel process comprising simultaneous Cl(2) etching and gentle oxidation. Furthermore, using CoO nanowires and Co-doped NiO as ex les, we show that this general method can be employed to produce nanowires of other oxides as well as the doped counterparts.
Publisher: AIP Publishing
Date: 19-05-2014
DOI: 10.1063/1.4879463
Publisher: AIP Publishing
Date: 06-09-2010
DOI: 10.1063/1.3485058
Abstract: We investigate the room temperature ferromagnetism in band gap tunable MgxZn1−xO (x≤0.22) alloy thin films and find that ferromagnetism is significantly enhanced in p-type MgxZn1−xO (x≥0.17) compared with the n-type counterparts (x≤0.15). Temperature-dependent photoluminescence measurements reveal the correlation between the p-type behavior, enhanced ferromagnetism, and zinc vacancies. First-principle calculations demonstrate that the formation energy of zinc vacancies decreases with the increasing Mg content and the zinc vacancies in MgxZn1−xO alloys stabilize the ferromagnetic coupling. Our results suggest a viable route to tune the magnetic properties of oxides through band gap and defect engineering.
Publisher: AIP Publishing
Date: 15-11-2010
DOI: 10.1063/1.3518470
Abstract: Arrays of regularly distributed CoO nano-octahedra are obtained by annealing Co nanowires at high temperatures. Both the size and the separation distance of the nano-octahedra can be controlled by tuning the annealing temperature. These self-assembled linear arrays of CoO nanocrystals result from the synergetic combination of the morphological transformation due to the intrinsic Rayleigh instability and the phase transformation due to the cobalt oxidation.
Publisher: Elsevier BV
Date: 04-2011
Publisher: AIP Publishing
Date: 28-11-2011
DOI: 10.1063/1.3665401
Publisher: Elsevier BV
Date: 08-2011
Publisher: American Physical Society (APS)
Date: 29-03-2010
Publisher: American Physical Society (APS)
Date: 04-01-2011
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5TC02936H
Abstract: K doped ZnO shows room temperature ferromagnetism from both theoretical and experimental studies. This ferromagnetism is mainly attributed to the formation of the Zn vacancy. The K dopants can stabilize the Zn vacancy by forming a defect complex and K substitution can induce magnetism via lattice distortion.
Publisher: IOP Publishing
Date: 25-02-2009
Publisher: AIP Publishing
Date: 06-2011
DOI: 10.1063/1.3609964
Abstract: To shed light on the mechanism responsible for the weak ferromagnetism in undoped wide band gap oxides, we carry out a comparative study on ZnO thin films prepared using both sol-gel and molecular beam epitaxy (MBE) methods. Compared with the MBE s les, the sol-gel derived s les show much stronger room temperature ferromagnetism with a magnetic signal persisting up to ∼740 K, and this ferromagnetic order coexists with a high density of defects in the form of zinc vacancies. The donor-acceptor pairs associated with the zinc vacancies also cause a characteristic orange-red photoluminescence in the sol-gel films. Furthermore, the strong correlation between the ferromagnetism and the zinc vacancies is confirmed by our first-principles density functional theory calculations, and electronic band alteration as a result of defect engineering is proposed to play the critical role in stabilizing the long-range ferromagnetism.
Publisher: AIP Publishing
Date: 06-2014
DOI: 10.1063/1.4882172
Abstract: The emission behavior of C-doped ZnO films, which were prepared by implantation of carbon into ZnO films, is investigated. Orange/red emission is observed for the films with the thickness of 60–100 nm. However, the film with thickness of 200 nm shows strong green emission. Further investigations by annealing bulk ZnO single crystals under different environments, i.e. Ar, Zn or C vapor, indicated that the complex defects based on Zn interstitials are responsible for the strong green emission. The existence of complex defects was confirmed by electron spin resonance (ESR) and low temperature photoluminescence (PL) measurement.
Publisher: AIP Publishing
Date: 08-07-2013
DOI: 10.1063/1.4813217
Publisher: American Physical Society (APS)
Date: 18-03-2013
Publisher: American Chemical Society (ACS)
Date: 27-02-2009
DOI: 10.1021/NN800808S
Abstract: We report the fabrication and characterization of ZnO nanowire memory devices using a ferroelectric Pb(Zr(0.3)Ti(0.7))O(3) (PZT) film as the gate dielectric and the charge storage medium. With a comparison to nanowire transistors based on SiO(2) gate oxide, the devices were evaluated in terms of their electric transport, retention, and endurance performance. Memory effects are observed as characterized by an eminent counterclockwise loop in I-V(g) curves, which is attributed to the switchable remnant polarization of PZT. The single-nanowire device exhibits a high (up to 10(3)) on/off ratio at zero gate voltage. Our results give a proof-of-principle demonstration of the memory application based on a combination of nanowires (as channels) and ferroelectric films (as gate oxide).
Publisher: American Chemical Society (ACS)
Date: 20-04-2010
DOI: 10.1021/NN1000996
Abstract: We report the fabrication of micro/nanoscale pits with facile shape, orientation, and size controls on an Si surface via an Au-nanoparticles-assisted vapor transport method. The pit dimensions can be continuously tuned from 70 nm to several mum, and the shapes of triangles, squares, and wire/hexagons are prepared on Si (111), (100), and (110) substrates, respectively. This reliable shape control hinges on the anisotropic diffusivity of Co in Si and the sublimation of cobalt silicide nanoislands. The experimental conditions, in particular the substrate orientation and the growth temperature, dictate the pit morphology. On the basis of this understanding of the mechanism and the morphological evolution of the pits, we manage to estimate the diffusion coefficients of Co in bulk Si along the 100 and 111 directions, that is D(100) and D(111). These diffusion coefficients show strong temperature dependence, for ex le, D(100) is ca. 3 times larger than D(111) at 860 degrees C, while they approach almost the same value at 1000 degrees C. This simple bottom-up route may help to develop new technologies for Si-based nanofabrication and to find potential applications in constructing nanodevices.
Publisher: American Chemical Society (ACS)
Date: 26-10-2010
DOI: 10.1021/JA106402P
Abstract: Single-crystalline CrSi(2) nanostructures with a unique hexagonal nanoweb morphology have been successfully synthesized for the first time. These nanowebs span 150-200 nm and are composed of nanowire segments with a thickness of 10-30 nm. It is proposed that surface charges on the {101̅0} sidewalls and the minimization of electrostatic energy induce the nanoweb formation. Calculations of the electrostatic energies were used to predict the transitions between different modes of bending, which agreed well with the experimental observations.
Publisher: AIP Publishing
Date: 23-04-2012
DOI: 10.1063/1.4707373
Abstract: The phenomenon of resistive switching (RS) has been demonstrated in several non-magnetic and some magnetic oxide systems, however the “magnetic” aspect of magnetic oxides has not been emphasized especially in terms of low field tunability. In our work, we examined the CoFe2O4/La0.66Sr0.34MnO3 all-magnetic oxide interface system for RS and discovered a very sharp (bipolar) transition at room temperature that can be gated with high sensitivity by low magnetic fields (∼0–100 mT). By using a number of characterizations, we show that this is an interface effect, which may open up interesting directions for manipulation of the RS phenomenon.
Publisher: AIP Publishing
Date: 10-05-2010
DOI: 10.1063/1.3428365
Abstract: We carry out a comparative study on resistive switching in Mn-doped ZnO thin films s les grown on Pt and Si show unipolar and bipolar switching behaviors, respectively. Fittings of the current-voltage curves and area dependence of the device resistance reveal the filamentary conduction in Pt/Mn:ZnO/Pt. On the other hand, the interfacial effect dominates in Pt/Mn:ZnO/Si, and its low resistance state exponentially relaxes toward the high resistance state in contrast to the good data retention in Pt/Mn:ZnO/Pt. Our results suggest that selecting electrodes dictates the resistive switching mechanism presumably by affecting the migration dynamics of oxygen vacancies.
Publisher: AIP Publishing
Date: 16-03-2009
DOI: 10.1063/1.3097029
Abstract: Cu 2 O nanowires are synthesized by reduction of CuO nanowires with hydrogen gas. Strong green photoluminescence dominated by band-edge emission is observed. Field effect transistors fabricated from in idual Cu2O nanowires present high on-off ratio (& ) and high mobility (& cm2/V s). Furthermore, the device demonstrates a fast photoelectric response to blue illumination in air at room temperature. In addition, anomalous ferromagnetism appears in Cu2O nanowires, which may originate from the defects in Cu2O nanowires. This work shows the application potentials of the Cu2O nanowires, especially in an electrical and photonic device.
Publisher: American Chemical Society (ACS)
Date: 06-02-2015
DOI: 10.1021/CM504261Q
Location: China
No related grants have been discovered for Guozhong XING.