A5103136458- ZnO doping and properties
- Ga2O3 and related materials
- Gas Sensing Nanomaterials and Sensors
- Copper-based nanomaterials and applications
- Quantum Dots Synthesis And Properties
- Hematopoietic Stem Cell Transplantation
- Advanced Photocatalysis Techniques
- Nanowire Synthesis and Applications
- Perovskite Materials and Applications
- GaN-based semiconductor devices and materials
- Conducting polymers and applications
- Acute Lymphoblastic Leukemia research
- Electronic and Structural Properties of Oxides
- Mesenchymal stem cell research
- Periodontal Regeneration and Treatments
- Neonatal Respiratory Health Research
- TiO2 Photocatalysis and Solar Cells
- Adipose Tissue and Metabolism
- Immune cells in cancer
- Organic Electronics and Photovoltaics
- Chronic Myeloid Leukemia Treatments
- Health and Medical Research Impacts
- Polymer Surface Interaction Studies
- Dendrimers and Hyperbranched Polymers
- Respiratory Support and Mechanisms
Chinese University of Hong Kong
1997-2025
University of Hong Kong
2004-2023
Centre Hospitalier de l’Université de Montréal
2023
University of Waterloo
2012
City University of Hong Kong
2007-2010
Hong Kong University of Science and Technology
2006
Prince of Wales Hospital
2002
Royal College of Physicians
1976
King's Fund
1976
ZnO nanorod arrays were fabricated using a hydrothermal method. The nanorods studied by scanning electron microscopy, photoluminescence (PL), time-resolved PL, X-ray photoelectron spectroscopy, and positron annihilation spectroscopy before after annealing in different environments at temperatures. Annealing atmosphere temperature had significant effects on the PL spectrum, while all cases diffusion length decay times increased. We found that, defect emission can be significantly reduced 200...
Defects in three different types of ZnO nanostructures before and after annealing under conditions were studied. The atmosphere temperature found to strongly affect the yellow orange-red defect emissions, while green emission was not significantly affected by annealing. emissions exhibited a strong dependence on excitation wavelength, with some observable only at low temperatures for certain wavelengths. samples prepared hydrothermal method is likely due presence OH groups, instead commonly...
We prepared ZnO nanostructures using chemical and thermal evaporation methods. The properties of the fabricated were studied scanning electron microscopy, x-ray diffraction, photoluminescence, paramagnetic resonance (EPR) spectroscopy. It was found that luminescence in visible region has different peak positions samples by exhibited green due to surface centers, while methods yellow which not affected modification. No relationship between emission g∼1.96 EPR signal, sample with strong signal.
Abstract ZnO tetrapod nanostructures have been prepared by the evaporation of Zn in air (no flow), dry and humid argon flow, nitrogen flow. Their properties investigated using scanning electron microscopy (SEM), X‐ray diffraction (XRD), photoluminescence (PL) excitation (PLE) spectroscopies (at different temperatures), paramagnetic resonance (EPR) spectroscopy at –160 °C room temperature. It is found that fabrication conditions significantly influence EPR PL spectra obtained. While a g =...
ZnO commonly exhibits luminescence in the visible spectral range due to different intrinsic defects. In order study defect emissions, photoluminescence from nanostructures prepared by methods (needles, rods, shells) was measured as a function of excitation wavelength and temperature. Under at 325nm, needles exhibited orange-red emission, rods yellow while shells green emission. Obvious color change orange observed for with increasing wavelengths, nanorods (yellow) showed smaller shift...
ZnO tetrapod nanostructures were prepared by evaporating Zn metal under humid argon flow. After the fabrication, Mn diffusion doping was performed at two different temperatures (600 and 800 °C). The samples characterized scanning electron microscopy, transmission x-ray fluorescence, diffraction (XRD), superconducting quantum interference device magnetometer, photoluminescence. Diffusion resulted in increase of size tetrapods, but no new peaks found XRD spectrum. doped structures to be...
We demonstrated a simple and low-cost fabrication of ZnO p-n homojunction. The junction consists n-type nanowires array by hydrothermal method covered with p-type Al, N co-doped film sol-gel method. exhibits good rectification characteristics, reverse leakage current ratio ∼5 μA ∼150 at bias 3 V, respectively. is operated as photodetector when light radiation shined on the glass-side device. shows peak responsivity 384 nm UV-visible (R384 nm/R550 nm) ∼70 an operating −3 V.
Different ZnO nanostructures (tetrapods, shells, rods, and highly faceted rods) were characterized by photoluminescence (PL) time-resolved PL measurements. It was found that different exhibit very optical properties in terms of defect emission decay times the spontaneous emission. No correlation between intensities positions. The short UV are most likely due to nonradiative defects correlated with crystalline quality do not contribute visible Neither nor intense emissions rule out...
ZnO nanoneedles were fabricated by thermal evaporation of Zn nanoparticles at 800 °C and atmospheric pressure. The samples showed strong ultraviolet photoluminescence weak orange defect luminescence. Time-resolved (TRPL) was measured using the Kerr-gated fluorescence technique in order to probe ultrafast carrier dynamics exciton-exciton scattering electron hole plasma (EHP) regimes. In both regimes, decay time is very fast (∼1ps). Even though no structure detected time-integrated spectra EHP...
ABSTRACT Purpose Recent research (Li et al. 2021) suggests an upregulated expression and activation of H1 receptors on macrophages in the tumor microenvironment, concomitant H1‐antihistamine use is associated with improved overall survival patients lung skin cancers receiving immunotherapy. Therefore, we retrospectively evaluated impacts cancer during Methods All who had received at least one dose immune checkpoint inhibitors (ICIs) from July 1, 2014 to October 31, 2019 were identified Hong...
Dye-sensitized solar cells based on perpendicular titania nanotube arrays were fabricated. Titania prepared by anodization of Ti foil. The cell performance as a function length and method was investigated. Short circuit current density efficiency increased with the length. Device also affected method, spacer layer thickness, annealing conditions. With optimized device structure procedure, short 3.28mA∕cm2 could be achieved under AM 1.5 simulated irradiation.
ZnO tetrapod nanowires were fabricated by evaporation of Zn in a N2 gas flow. Stimulated emission with threshold was observed and the linewidths individual modes range 0.7–0.9 nm. Time-resolved measurements have been performed at different excitation powers. With an increase pump power, transition from exciton stimulated to electron–hole plasma regime can be clearly observed. Both decay times under 10 ps.
Vertically aligned ZnO nanowire (NW) arrays have been synthesized selectively on patterned aluminum-doped zinc oxide (AZO) layer deposited silicon substrates without using any metal catalysts. The growth region was defined by conventional photolithography with an insulating template. Careful control of the types template materials and conditions allows good alignment selectivity for NW arrays. Sharp ultraviolet band-edge peak observed in photoluminescence spectra reveals optical qualities....
Well-aligned ZnSe nanowires and nanorods can be grown on epilayers different GaAs substrates, with without catalyst, by metal–organic chemical vapor deposition. Gold particles affect the number density, growth direction, morphology of resulting nanostructures. In absence gold hexagonal grow along <111> directions (see Figure). Growth defects may nucleation sites nanorods.
Stimulated emission from single ZnO tetrapod nanowires was studied by time-resolved photoluminescence (TRPL) spectroscopy. The samples were excited a 300 fs pulse and the spectra collected as function of time. exhibit change in position shape peak with time evolution for different pump excitation fluences. exhibited blue shift increasing fluence, while all fluences red peaks obtained. Possible reasons observed behaviour are discussed.
Therapy‐related myelodysplastic syndrome (t‐MDS) is a very rare complication of allogeneic bone marrow transplantation (BMT). A woman with T acute lymphoblastic leukaemia (T‐ALL) received an BMT from donor the β‐thalassaemic trait. Five years after BMT, red cell indices returned to normal initial conversion microcytosis, implying autologous haematopoietic regeneration. Seven thrombocytopenia developed and examination confirmed t‐MDS, characteristic karyotype 46,XX,inv(3)(q21;q26),...