The growth of different-dimensional structural materials and their semiconducting properties

随着信息技术的不断进步，信息表达和处理方式逐渐趋向高速度、高密度、高可靠的方向发展。低维纳米材料作为一种具有全新结构的材料，其微小的尺度正符合了当今信息社会对电子器件集成度日益增长的要求。而当材料进入低维小尺度时，往往表现出许多独特的效应，例如相变特性，电子输运现象，电导涨落和库仑阻塞等，为开发具有新原理、新结构的固态电子、光电子器件提供了广阔的发展空间。近年来，各种制备和表征技术的持续进步，以及组装工艺的日臻完善，推动着低维纳米材料由研发制备向器件应用的方向发展。同时，也对其结构性质、形成机制等方面的研究提出了更高的要求。就目前的发展形势来看，各种类型的低维材料在可控制备、结构表征、器件应用...As the development of information technology, the information expression and process tend gradually to high speed and reliability. Low-dimensional materials with their novel structures are consistent with the increasing integrity requirements of electronic devices in current information society. Moreover, as the materials reduce into low-dimensional region, many unique effects emerge, involving ph...学位：工学博士院系专业：物理与机电工程学院物理学系_微电子学与固体电子学学号：1982008015051

微电磁光开关的结构设计与性质模拟

基于微电磁光开关的工作原理,设计了MEMS电磁反射型光开关.采用ANSYS 9.0有限元软件分析结合Mathematica数值计算研究了微电磁光开关所需的电磁力、磁芯线圈的磁场分布、悬臂梁受电磁力的形变状态,从而获得磁芯线圈的匝数、悬臂梁位置、悬臂梁与平面磁芯线圈接触区域等结构参量.九江市杰出青年基金项目(No.2018042)厦门大学校长基金项目(No.20720190055

基于有限元模拟与数值计算的微电磁继电器结构设计与性质研究

运用ANSYS有限元模拟、Mathematica数值计算与OriginPro8.6图像处理等软件对多重弯曲的平面磁芯线圈电磁场分布以及活动电极在电磁场中所受电磁力情况进行仿真分析,从而合理设计励磁电流、活动电极材料、结构尺度、活动电极与固定电极的位置间距等.国家自然科学基金面上项目(No.61674124);;厦门大学校长基金项目(No.20720160122

Beam transformation in laser processing

激光光束形状和能量分布直接限定了激光加工的应用。为满足不同的激光加工要求,必须对激光光束进行光束变换。应用旋转棱镜和组合光学系统能够实现实心和环状光束之间的相互变换。从几何光学角度对旋转棱镜组合光学系统进行了理论分析和实验。通过调整正负旋转棱镜的间距d,获取不同形状和能量分布的激光光束。实验结果表明,基于旋转棱镜组合光学系统的光束变换技术,有效地实现了多种形式的光束变换,提高了激光束的利用率,在激光加工领域中具有广泛的应用前景。The shape and quality of laser beam directly define its applications in the laser processing.For different requests of laser processing,the input beam always needs to be transformed.The transformation between the solid beam and annular beam can be realized by the axicon-based optical devices.The optical system is analyzed based on the geometry optical theory.By adjusting the separation of the positive and negative axicon,different shapes and the energy distributions are gained.It is shown that the axicon-based beam transformations raise the use factor of laser and have wide application prospect in laser processing field.福建省科学技术厅资助项目(2005HZ1020

Control Growth of Mono-and Bilayer Graphene Films and the Modulation of Graphene Conductivity

石墨烯二维材料有着优异的物理、化学特性,在多个科学领域展现出广阔的应用前景.采用化学气相沉积方法在Cu-nI合金表面制备了二维石墨烯薄膜并揭示其生长机制;研究生长时间、温度等对石墨烯覆盖度和晶格质量的影响.通过优化生长条件,成功制备了大面积单层及具有强烈层间耦合作用的Ab堆叠双层石墨烯薄膜.进一步运用表面沉积技术在单层石墨烯上构建零维Au团簇和二维Au薄膜,研究其对石墨烯电导特性的影响;并结合第一性原理计算,揭示Au的形态及覆盖度影响石墨烯电导特性的规律.据此制作了石墨烯场效应晶体管器件,通过精确控制Au的覆盖度,实现石墨烯电导类型和载流子浓度的有效调控,拓展了其在微电子领域的应用.A hot wall chemical vapor deposition(CVD)system is used to synthesize two-dimensional graphene films on Cu-Ni alloy foils.Growth parameters are modulated to investigate their effects on graphene coverage.By understanding the growth mechanism and optimizing growth parameters,large-area uniform monolayer and strong coupling bilayer graphene are successfully achieved.Based on the monolayer graphene,Au nanoparticles and films are deposited respectively,displaying a size-dependent electronic characteristic:isolated Au nanoparticles produce n-type doping of graphene,while continuous Au films produce p-type doping.First-principle calculations suggest that different doping properties of Au-graphene system are induced by interactions between grapheme and different Au configurations.Accordingly,graphene field effect transistors(FET)are fabricated,with the in situ measurements suggesting the tunable conductivity type and level by well controlling the Au configurations.国家自然科学基金(11304257;91321102;61227009); 福建省自然科学基金(2014J01026

Simulating the magnetic field and mechanical properties of electromagnetic microrelay

运用有限元分析ANSYS和Mathematica软件对平面线圈的电磁场分布、悬臂梁与固定电极之间的电磁力、悬臂梁应力分布和受力形变等进行了理论分析和仿真模拟,为线圈结构、悬臂梁位置、悬臂梁与线圈距离的设计提供理论依据.Using the finite element analysis software ANSYS and Mathematica,theoretical simulation and analysis were performed to study the electromagnetic field distribution within the planar coil,the electromagnetic force between cantilever and fixed electrode,and the electromagnetic force distribution and deformation of the cantilever.Accordingly,the coil structure,the location of the cantilever and the distance between cantilever and the coil were designed.国家自然科学基金面上项目（No.61674124）; 厦门大学校长基金项目（No.20720160122