Author
Shuit-Tong Lee
Other affiliations: University of British Columbia, Hong Kong University of Science and Technology, University of Western Ontario ...read more
Bio: Shuit-Tong Lee is an academic researcher from Soochow University (Suzhou). The author has contributed to research in topics: Silicon & Nanowire. The author has an hindex of 138, co-authored 1121 publications receiving 77112 citations. Previous affiliations of Shuit-Tong Lee include University of British Columbia & Hong Kong University of Science and Technology.
Topics: Silicon, Nanowire, OLED, Electroluminescence, Diamond
Papers published on a yearly basis
Papers
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TL;DR: The ability to reversibly adjust the SERS EF enables to reduce EF variations caused by external effects such as substrate-to-substrate differences and long-term-storage degradation, which improves the quantitative detection of analytes and might be a significant step forward in employing SERS for practical applications.
Abstract: There is a strong correlation between the surface enhanced Raman scattering (SERS) enhancement factor (EF), the excitation wavelength, and the feature properties (composition, size, geometry, and analytes). The prediction of the EF of specific substrates, crucial to the quantitative SERS detection, is however still very difficult. The present work presents smart liquid SERS substrates consisting of suspensions of Fe3O4/Au nanoparticles, which provide high spot-to-spot uniformity, reproducibility and good reversibility. The EF of these substrates can be reversibly tuned by applying an external magnetic field. The EF magnetic tuning is within 2 orders of magnitude per substrate in the range of 10(4)-10(7). The ability to reversibly adjust the SERS EF enables to reduce EF variations caused by external effects such as substrate-to-substrate differences and long-term-storage degradation. This improves the quantitative detection of analytes and might be a significant step forward in employing SERS for practical applications.
42 citations
TL;DR: P-type conductivity of polycrystalline cubic cubic boron nitride (cBN) films was achieved by implantation of beryllium ions.
Abstract: P-type conductivity of polycrystalline cubic boron nitride (cBN) films was achieved by implantation of beryllium ions The effects of implantation doses and annealing on the phase composition and electrical properties of cBN films were studied A reduction in resistivity by seven orders of magnitude was observed Hall measurement revealed a corresponding hole concentration of 61×1018cm−3 and mobility of 3cm2∕Vs The activation energy was estimated to be 020±002eV from the temperature dependence of resistance The electrical properties of Be-implanted films are comparable to that of Be-doped cBN single crystals synthesized by high-pressure and high-temperature method
42 citations
TL;DR: A dinuclear aluminum 8-hydroxyquinoline complex (DAlq3) with improved electron mobility was designed for organic light-emitting diodes in this paper, which was determined via transient electroluminescence (EL).
Abstract: A dinuclear aluminum 8-hydroxyquinoline complex (DAlq3) with improved electron mobility was designed for organic light-emitting diodes. The electron mobility in DAlq3 was determined via transient electroluminescence (EL) from bilayer devices with structure of indium tin oxide (ITO)/N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB)/DAlq3/Mg:Ag. It was found that the electron mobility in DAlq3 is between 3.7–8.4×10−6 cm2/Vs at electric fields ranging between 1.2×106 and 4.0×106 V/cm, which is a factor of two higher than that in Alq3. The DAlq3 also shows a higher EL efficiency of 2.2 cd/A (1.2 Lm/W), as compared to Alq3 with an EL efficiency of 2.0 cd/A (1.0 Lm/W), which is attributed to more balanced electron and hole recombination due to the improved electron mobility of DAlq3.
41 citations
TL;DR: In this paper, two host materials, DBTSF2 (DBT and spirobifluorene (SF) blocks, were designed and synthesized, incorporating dibenzothiophene and SF blocks, and their thermal, electrochemical and photo-physical properties were fully characterized.
41 citations
TL;DR: Investigation reveals that LUMO energy is a helpful aid in predicting the alkaline stability of imidazolium cations and indicates that alkyl groups are the most suitable substituents for the N3 position of imdazolia cations.
Abstract: Imidazolium cations are promising candidates for preparing anion-exchange membranes because of their good alkaline stability. Substitution of imidazolium cations is an efficient way to improve their alkaline stability. By combining density functional theory calculations with experimental results, it is found that the LUMO energy correlates with the alkaline stability of imidazolium cations. The results indicate that alkyl groups are the most suitable substituents for the N3 position of imidazolium cations, and the LUMO energies of alkyl-substituted imidazolium cations depend on the electron-donating effect and the hyperconjugation effect. Comparing 1,2-dimethylimidazolium cations (1,2-DMIm+) and 1,3-dimethylimidazolium cations (1,3-DMIm+) with the same substituents reveals that the hyperconjugation effect is more significant in influencing the LUMO energy of 1,3-DMIms. This investigation reveals that LUMO energy is a helpful aid in predicting the alkaline stability of imidazolium cations.
41 citations
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TL;DR: This work reviews recent progress in graphene research and in the development of production methods, and critically analyse the feasibility of various graphene applications.
Abstract: Recent years have witnessed many breakthroughs in research on graphene (the first two-dimensional atomic crystal) as well as a significant advance in the mass production of this material. This one-atom-thick fabric of carbon uniquely combines extreme mechanical strength, exceptionally high electronic and thermal conductivities, impermeability to gases, as well as many other supreme properties, all of which make it highly attractive for numerous applications. Here we review recent progress in graphene research and in the development of production methods, and critically analyse the feasibility of various graphene applications.
7,987 citations
TL;DR: The theoretical charge capacity for silicon nanowire battery electrodes is achieved and maintained a discharge capacity close to 75% of this maximum, with little fading during cycling.
Abstract: There is great interest in developing rechargeable lithium batteries with higher energy capacity and longer cycle life for applications in portable electronic devices, electric vehicles and implantable medical devices. Silicon is an attractive anode material for lithium batteries because it has a low discharge potential and the highest known theoretical charge capacity (4,200 mAh g(-1); ref. 2). Although this is more than ten times higher than existing graphite anodes and much larger than various nitride and oxide materials, silicon anodes have limited applications because silicon's volume changes by 400% upon insertion and extraction of lithium which results in pulverization and capacity fading. Here, we show that silicon nanowire battery electrodes circumvent these issues as they can accommodate large strain without pulverization, provide good electronic contact and conduction, and display short lithium insertion distances. We achieved the theoretical charge capacity for silicon anodes and maintained a discharge capacity close to 75% of this maximum, with little fading during cycling.
6,104 citations
TL;DR: The beltlike morphology appears to be a distinctive and common structural characteristic for the family of semiconducting oxides with cations of different valence states and materials of distinct crystallographic structures, which could be an ideal system for fully understanding dimensionally confined transport phenomena in functional oxides.
Abstract: Ultralong beltlike (or ribbonlike) nanostructures (so-called nanobelts) were successfully synthesized for semiconducting oxides of zinc, tin, indium, cadmium, and gallium by simply evaporating the desired commercial metal oxide powders at high temperatures. The as-synthesized oxide nanobelts are pure, structurally uniform, and single crystalline, and most of them are free from defects and dislocations. They have a rectanglelike cross section with typical widths of 30 to 300 nanometers, width-to-thickness ratios of 5 to 10, and lengths of up to a few millimeters. The beltlike morphology appears to be a distinctive and common structural characteristic for the family of semiconducting oxides with cations of different valence states and materials of distinct crystallographic structures. The nanobelts could be an ideal system for fully understanding dimensionally confined transport phenomena in functional oxides and building functional devices along individual nanobelts.
5,677 citations
TL;DR: The state of the art, future directions and open questions in Raman spectroscopy of graphene are reviewed, and essential physical processes whose importance has only recently been recognized are described.
Abstract: Raman spectroscopy is an integral part of graphene research. It is used to determine the number and orientation of layers, the quality and types of edge, and the effects of perturbations, such as electric and magnetic fields, strain, doping, disorder and functional groups. This, in turn, provides insight into all sp(2)-bonded carbon allotropes, because graphene is their fundamental building block. Here we review the state of the art, future directions and open questions in Raman spectroscopy of graphene. We describe essential physical processes whose importance has only recently been recognized, such as the various types of resonance at play, and the role of quantum interference. We update all basic concepts and notations, and propose a terminology that is able to describe any result in literature. We finally highlight the potential of Raman spectroscopy for layered materials other than graphene.
5,673 citations
TL;DR: This paper presents a meta-analysis of the chiral stationary phase transition of Na6(CO3)(SO4)2, a major component of the response of the immune system to Na2CO3.
Abstract: Ju Mei,†,‡,∥ Nelson L. C. Leung,†,‡,∥ Ryan T. K. Kwok,†,‡ Jacky W. Y. Lam,†,‡ and Ben Zhong Tang*,†,‡,§ †HKUST-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China ‡Department of Chemistry, HKUST Jockey Club Institute for Advanced Study, Institute of Molecular Functional Materials, Division of Biomedical Engineering, State Key Laboratory of Molecular Neuroscience, Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China Guangdong Innovative Research Team, SCUT-HKUST Joint Research Laboratory, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
5,658 citations