多种衬底上AlN一维纳米结构阵列的大面积可控制备及其掺杂与器件应用研究

Well-aligned arrays of AlN nanostructures will be synthesized on different substrates by metalorganic chemical vapor deposition (MOCVD) method using metal nanoparticles as the catalyst. By controlling the synthesis conditions, such as the size and density of catalyst nanoparticles, the ratio between the reaction and carrier gas, pressure of the reaction chamber, reaction temperature, and growth time, the size, density, composition, and morphology of the AlN nanostructure arrays will be controlled. Large-area AlN nanostructure arrays on certain substrates such as silicon, gallium nitride, sapphire, ITO, and so on, will be fabricated according to the device applications. During the growth of AlN nanostructure arrays, vapor form doping sources will be introduced into the reaction chamber to realize the in-situ doping of AlN nanostructures. The relationship between doping conditions and conductive properties, such as electrical transport type and conductive level, will be investigated. Controllable doping method to realize p-type and n-type conductivity in the same AlN nanostructure array will be developed, and tunable electrical transport properties including conductivity, doping concentration, and carrier mobility of AlN nanostructure arrays will be achieved finally. Based on the doped AlN nanostructure arrays, functional devices, such as ultraviolet light-emitting diodes, laser diodes, and ultraviolet photo-detectors, will be fabricated by filling organics, ozone etching, metal evaporation, and rapid-annealing. The properties related to device applications will be fully investigated. The influence of the morphology, size, and doping concentration of AlN nanostructure arrays on the electrical, optical, and optoelectronic properties of the devices will be studied. This project will open up opportunities for developing functional devices based on AlN nanostructure arrays.

通过金属有机物化学气相沉积法，采用金属纳米催化剂诱导生长氮化铝（AlN）一维纳米结构阵列，通过调控制备条件，如催化剂的尺寸和密度、反应气氛配比、压力、反应温度、生长时间等参数，实现纳米材料的尺寸、密度、成分以及形貌的控制；在特定衬底(硅、氮化镓、蓝宝石、ITO等)上制备大面积AlN一维纳米结构阵列的宏观样品，其尺寸达到器件应用要求。采用气氛掺杂法，在纳米材料制备过程中，对其进行原位掺杂。研究掺杂源、掺杂条件与导电类型、导电水平等性能的关系。发展在同一AlN纳米结构中实现p型和n型电导的控制掺杂方法，实现其导电性能可调。采用有机物填充、臭氧刻蚀、金属电极蒸镀、快速退火等工艺，构筑基于掺杂AlN一维纳米结构阵列的功能器件，如紫外发光二极管和紫外探测器。系统研究器件的各项性能参数，阐明阵列形貌、尺寸、掺杂浓度与器件传导、发光以及光电响应之间的关系，为发展AlN纳米材料功能器件探索途径。

固体紫外光源诸如紫外发光二极管在微电子制造技术、高密度光存储、生物医学研究、环境净化等领域有着重要的应用前景。氮化铝因具有6.2 eV的禁带宽度被认为是制备紫外发光二极管和探测器的优选材料。目前，由于AlN的高绝缘性，且制备的晶体缺陷密度过高，使其功能器件的发展停滞不前。已有研究表明，一维纳米结构因具有独特的一维形貌，易于获得低缺陷密度的单晶结构。然而，基于AlN一维纳米结构功能器件的研究报道甚少。基于此，本项目执行过程中已建立了一种催化剂诱导生长AlN一维纳米结构阵列的可控制备方法，阐明了催化剂的尺寸和密度、反应气氛配比、生长温度等对纳米结构阵列的尺寸、分布密度及形貌的影响。并通过优化制备条件获得具有宏观尺寸（1x1 cm）、分布均匀的阵列样品。并系统研究了掺杂条件,如掺杂源、掺杂气氛流速等对AlN 一维纳米结构阵列的掺杂类型和掺杂浓度的影响，发展出在AlN 一维纳米结构阵列中实现p 型和n 型电导的可控掺杂方法，实现了纳米阵列导电性能的基本可调。在实现AlN一维纳米结构阵列可控掺杂的基础上，构筑了基于AlN一维纳米结构单体和阵列的场效应管和p-n节二极管原型，系统研究了掺杂条件与导电性能的关系和影响规律，为发展基于AlN一维纳米结构阵列的功能器件奠定了重要的实验基础。