Lihuan Zhang

Bio: Lihuan Zhang is an academic researcher from Peking University. The author has contributed to research in topics: Vapor–liquid–solid method & Crystal twinning. The author has an hindex of 1, co-authored 1 publications receiving 18 citations.

Twinning-induced kinking of Sb-doped ZnO nanowires

Abstract: Sb-doped ZnO nanowires with kinking structures have been synthesized by a catalyst-free thermal evaporation method with the addition of Sb2O3. Transmission electron microscopy (TEM) observations revealed that the kinks of the nanowires are induced by twinning structures. , twins and heavy stacking faults in the (0001) plane were observed in these kinked nanowires. High-resolution TEM and energy dispersive x-ray spectroscopy showed that there exists an Sb-rich segregation layer in the twin boundaries of some nanowires. A formation mechanism of the kinked nanowires was proposed. The optical property of the synthesized nanowires was investigated by room-temperature photoluminescence.

Curved carbon nanotubes: From unique geometries to novel properties and peculiar applications

Abstract: Incorporating pentagons and heptagons into the hexagonal networks of pristine carbon nanotubes (CNTs) can form various CNT-based nanostructures, as pentagons and heptagons will bend or twist the CNTs by introducing positive and negative curvature, respectively. Some typical so-made CNT-based nanostructures are reviewed in this article, including zero-dimensional toroidal CNTs, and one-dimensional kinked and coiled CNTs. Due to the presence of non-hexagonal rings and curved geometries, such nanostructures possess rather different structural, physical and chemical properties from their pristine CNT counterparts, which are reviewed comprehensively in this article. Additionally, their synthesis, modelling studies, and potential applications are discussed.

Modulation of Thermal Conductivity in Kinked Silicon Nanowires: Phonon Interchanging and Pinching Effects

Abstract: We perform molecular dynamics simulations to investigate the reduction of the thermal conductivity by kinks in silicon nanowires. The reduction percentage can be as high as 70% at room temperature. The temperature dependence of the reduction is also calculated. By calculating phonon polarization vectors, two mechanisms are found to be responsible for the reduced thermal conductivity: (1) the interchanging effect between the longitudinal and transverse phonon modes and (2) the pinching effect, i.e a new type of localization, for the twisting and transverse phonon modes in the kinked silicon nanowires. Our work demonstrates that the phonon interchanging and pinching effects, induced by kinking, are brand new and effective ways in modulating heat transfer in nanowires, which enables the kinked silicon nanowires to be a promising candidate for thermoelectric materials.

Modulation of thermal conductivity in kinked silicon nanowires: phonon interchanging and pinching effects

Abstract: We perform molecular dynamics simulations to investigate the reduction of the thermal conductivity by kinks in silicon nanowires. The reduction percentage can be as high as 70% at room temperature. The temperature dependence of the reduction is also calculated. By calculating phonon polarization vectors, two mechanisms are found to be responsible for the reduced thermal conductivity: (1) the interchanging effect between the longitudinal and transverse phonon modes and (2) the pinching effect, that is, a new type of localization, for the twisting and transverse phonon modes in the kinked silicon nanowires. Our work demonstrates that the phonon interchanging and pinching effects, induced by kinking, are brand-new and effective ways in modulating heat transfer in nanowires, which enables the kinked silicon nanowires to be a promising candidate for thermoelectric materials.

Controlled synthesis of kinked ultrathin ZnS nanorods/nanowires triggered by chloride ions: a case study.

Abstract: Colloidal synthesis of kinked ultrathin ZnS nanorods/nanowires with mixed phases using tiny Ag2S nanocrystals as catalysts is reported. It is found that chloride ions can induce the controlled morphology transition from straight to kinking. The synthetic parameters modulating the growth of kinked ZnS nanorods/nanowires are systematically investigated. Chloride ions introduced in the reaction can generate more proportion of wurtzite phase by slowing the nucleation and growth rates during the growth of one-dimensional (1D) ZnS nanorods/nanowires. The formation of kinked morphology is responsible for the increased domains of mixed stacking and twinning in single 1D nanostructures. The present recipe on controlled synthesis of 1D kinked nanorods/nanowires provides a model of crystal growth control, and these unique 1D nanostructures may also offer new opportunities to fabricate nanodevices with special functions.

A Review of Thermal Transport in Low-Dimensional Materials Under External Perturbation: Effect of Strain, Substrate, and Clustering

Abstract: Due to their exceptional electrical, thermal, and optical properties, low-dimensional (LD) materials are very promising for many applications, such as nanoelectronic devices, energy storage, energy conversion, and thermal management. The thermal performance of LD materials is often an important consideration in these applications. Although freestanding LD materials exhibit interesting thermal properties, they are almost never used in such a form. Instead, they are often integrated into a certain environment; for example, in a composite material or on a substrate. Due to the large surface-to-volume ratio of LD materials, the environment usually has a strong impact on the thermal transport properties of these materials. The thermal behavior of the LD materials can be completely different from the freestanding form. The effect of environmental perturbation on thermal transport properties has recently attracted a lot of research interest. In this article, we aim to provide a comprehensive review of ho...