Li Jiaun Lin

Bio: Li Jiaun Lin is an academic researcher from Industrial Technology Research Institute. The author has contributed to research in topics: Wurtzite crystal structure & Photoluminescence. The author has an hindex of 4, co-authored 4 publications receiving 618 citations.

Enhanced Resonant Raman Scattering and Electron-Phonon Coupling from Self-Assembled Secondary ZnO Nanoparticles

Abstract: Self-assembled secondary ZnO nanoparticles, recognized with the agglomeration of crystalline subcrystals, are successfully synthesized by a simple sol-gel method. TEM images display that one artificial cluster behaves in a single-crystal-like wurtzite structure because subcrystals coagulate as the same crystal orientation. Moreover, from the resonant Raman scattering, the as-grown sample exhibits phonon red shift; meanwhile, the coupling strength between electron and longitudinal optical phonon, determined by the ratio of secondto first-order Raman scattering cross sections, diminishes compared with the samples after postannealing at

The substrate effect on the in-plane orientation of vertically well-aligned ZnO nanorods grown on ZnO buffer layers

Abstract: Vertically well-aligned ZnO nanorods were synthesized without employing any metal catalysts on various substrates including glass, Si(111), 6H-SiC(0001) and sapphire (0001), which were pre-coated with c-oriented ZnO buffer layers, by simple physical vapour deposition. The alignments of the ZnO nanorods on the different substrates depend on the crystallographic alignments of the pre-coated ZnO buffer layers. The ZnO nanorods grown on glass and Si(111) are vertically aligned but randomly oriented in the in-plane direction. In contrast, the vertically aligned ZnO nanorods on 6H-SiC(0001) and sapphire (0001) show an in-plane alignment with azimuthally sixfold symmetry, which indicates the epitaxial relationship between ZnO and the substrate. Similarly, photoluminescence measurements show the distinct appearance of ZnO nanorods on different substrates. Besides the UV band, which was attributed to the recombination of free excitons near the band edge, defect-related visible emissions were also observed for the samples grown on both glass and Si(111) substrates. However, the ZnO nanorods exhibit only strong band edge emission peaks with no noticeable deep level emissions when grown on the 6H-SiC(0001) and sapphire (0001) substrates, which confirms the good crystalline and optical quality of the epitaxial ZnO nanorods.

Towards a definition of inorganic nanoparticles from an environmental, health and safety perspective

Abstract: The regulation of engineered nanoparticles requires a widely agreed definition of such particles. Nanoparticles are routinely defined as particles with sizes between about 1 and 100 nm that show properties that are not found in bulk samples of the same material. Here we argue that evidence for novel size-dependent properties alone, rather than particle size, should be the primary criterion in any definition of nanoparticles when making decisions about their regulation for environmental, health and safety reasons. We review the size-dependent properties of a variety of inorganic nanoparticles and find that particles larger than about 30 nm do not in general show properties that would require regulatory scrutiny beyond that required for their bulk counterparts.

ZnO with Different Morphologies Synthesized by Solvothermal Methods for Enhanced Photocatalytic Activity

Abstract: ZnO materials with a range of different morphologies have been synthesized via a simple solvothermal method with different solvents. Zinc acetylacetonate was used as the zinc source in such solvothermal syntheses for the first time. XRD data showed that single-phase ZnO with the wurtzite crystal structure was obtained for all the solvents used. FE-SEM imaging showed that ZnO with cauliflower-like, truncated hexagonal conical, tubular and rodlike, hourglass-like, nanorods, and spherical shapes were produced when THF, decane, water, toluene, ethanol, and acetone were used as the solvent, respectively. The TEM data showed that the crystalline ZnO had different growth habits in the different solvents. The optical properties of the as-prepared ZnO materials were investigated by UV−vis absorption and room temperature photoluminescence. Photodegradation of phenol was used as a model reaction to test the photocatalytic activity of the ZnO samples. ZnO samples with different morphologies and crystal growth habits ...