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Shuit-Tong Lee

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
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Journal ArticleDOI
TL;DR: In this article, the lower hole mobility in crystalline NPB films is attributed to the improved device performance, leading to a better carrier balancing in the NPB/AlQ 3 interface.

44 citations

Journal ArticleDOI
TL;DR: In this paper, a carbon photocatalyst with abundant carbon defects created by removing the nitrogen atoms from a N-doped precursor was presented, which then work as oxidation sites for O2 generation.
Abstract: Hydrogen production from overall water splitting by photocatalyst is an ultimate clean and renewable energy strategy. Recent developments show that carbon based materials are considerable photocatalysts for overall water splitting under visible light because of their high activity, high stability, low-cost, easy fabrication and structural diversity. However, it still lacks a systematic study and deep understanding on the working mechanism of the carbon based photocatalysts. Herein, we show the fabrication of a carbon photocatalyst with abundant carbon defects created by removing the nitrogen atoms from a N-doped precursor. The active defects bond with water molecules during the photocatalytic reaction, which then work as oxidation sites for O2 generation. We also demonstrate an accessible strategy to produce more defects to observably enhance the photocatalytic activity (around 10 times) as well as to select between the 2-electron/2-electron and the 4-electron pathway water splitting. The synthesized photocatalyst is efficient in photocatalytic visible-light overall water splitting with an optimum H2 and O2 production of 2.54 and 1.25 μmol h−1, respectively. Moreover, the quantum efficiency and solar to hydrogen (STH) efficiency were measured to be 2.04% for wavelength λ = 420 ± 20 nm and 0.1% using AM 1.5 G, respectively.

43 citations

Journal ArticleDOI
TL;DR: Compared to MCEE commonly performed in aqueous HF solution, the present pseudo gas phase etching offers exceptional simplicity, flexibility, environmental friendliness, and scalability for the fabrication of three-dimensional silicon nanostructures with considerable depths.
Abstract: Inspired by metal corrosion in air, we demonstrate that metal-catalyzed electroless etching (MCEE) of silicon can be performed simply in aerated HF/H2O vapor for facile fabrication of three-dimensional silicon nanostructures such as silicon nanowires (SiNW) arrays. Compared to MCEE commonly performed in aqueous HF solution, the present pseudo gas phase etching offers exceptional simplicity, flexibility, environmental friendliness, and scalability for the fabrication of three-dimensional silicon nanostructures with considerable depths because of replacement of harsh oxidants such as H2O2 and AgNO3 by environmental-green and ubiquitous oxygen in air, minimum water consumption, and full utilization of HF.

43 citations

Journal ArticleDOI
TL;DR: In this article, the performance of polymeric electroluminescent (EL) devices using glycerol-modified poly(styrene sulfonate)-doped poly(3,4-ethylene dioxythiophene) (GPEDOT) films as anodes have been fabricated.
Abstract: Poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT)-based polymeric electroluminescent (EL) devices using glycerol-modified poly(styrene sulfonate)-doped poly(3,4-ethylene dioxythiophene) (GPEDOT) films as anodes have been fabricated. By comparing the devices made with unmodified commercial PEDOT anode, glycerol doping effectively reduces the operating voltage. At a current density of 60 mA/cm2, the operating voltage for device with 0.28 g/ml GPEDOT anode greatly reduces to 7.8 V; while that for device with unmodified PEDOT anode is about 9.9 V. This is mainly attributed to the significant enhancement of conductivity by incorporating a suitable amount of glycerol into polymeric PEDOT layer. It was further found that the conductivity of PEDOT film increases with the concentration of glycerol doping. Therefore, this highly conductive polymeric anode can be finely tuned to have an optimized conductivity such that a better balance of electron and hole currents, and thus a better device efficiency, can be achieved.

43 citations

Journal ArticleDOI
TL;DR: In this article, microwave plasmas were employed to synthesize single- or double-layer graphene sheets on copper foils using a solid carbon source, polymethylmetacrylate.
Abstract: Microwave plasmas were employed to synthesize single- or double-layer graphene sheets on copper foils using a solid carbon source, polymethylmetacrylate. The utilization of reactive plasmas enables the graphene growth at reduced temperatures as compared to conventional thermal chemical vapor deposition processes. The effects of substrate temperature on graphene quality were studied based on Raman analysis, and a reduction of defects at elevated temperature was observed. Moreover, a facile approach to incorporate nitrogen into graphene by plasma treatment in a nitrogen/hydrogen gas mixture was demonstrated, and most of the nitrogen atoms were verified to be pyridinelike in carbon network.

43 citations


Cited by
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Journal ArticleDOI
11 Oct 2012-Nature
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

Journal ArticleDOI
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

Journal ArticleDOI
09 Mar 2001-Science
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

Journal ArticleDOI
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

Journal ArticleDOI
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