Size-Selective and Epitaxial Synthesis of GaN, InN, and InxGa1-xN Quantum Dots on Graphite and MoS2 (0001) Surfaces using the Electrochemical/Chemical Method

本项目致力于通过三步电化学法合成InxGa1-xN量子点。铟和镓从水溶液中共沉积，形成具有已知平均组成的InxGa1-x纳米颗粒，然后电化学氧化InxGa1-x纳米颗粒形成(InxGa1-x)203。第三步是用氮化物置换(InxGa1-x)203中的氧化物，氮化物来自反应源，如氨、肼或肼，形成InxGa1-xN量子点和副产物(气态水和氢)。步骤1和步骤2在室温下进行，将寻找步骤3的条件，以便在低于400℃的温度下有效地进行置换过程。该方法包括如上所述的InxGa1-xN量子点的合成、结构表征和光学表征。将研究合成参数，以更好地了解所涉及的过程，并控制颗粒的单分散性。光谱学将被用来指导InxGa1-xN量子点的合成，这些量子点在能带处发光。然后，这些量子点的发光和吸收特性将与中子活化分析确定的铟的摩尔分数相关联。该项目解决了材料科学中具有很高潜在技术相关性的主题领域的基础研究问题。这项研究将在基础水平上为电子/光子器件的新方面贡献基本的材料科学知识。从研究中获得的基本知识和理解将有助于提高先进器件和电路的性能，为设计和生产改进的材料和材料组合提供基本的理解和基础。在这些研究中将解决各种基本问题，拟议的实验还将开发一种技术上重要的发射材料，它能够跨越大部分可见光光谱。该计划的一个重要特点是通过在一个具有根本意义和技术意义的领域对学生进行培训，将研究和教育结合起来。***

This project addresses the synthesis of InxGa1-xN quantum dots(QDs) via a three step electrochemical process. Indium and gallium are co-deposited from aqueous solutions to form nanoparticles of InxGa1-x having a known, average composition followed by electrochemical oxidation of InxGa1-x nanoparticles to form (InxGa1-x)203. The third step involves displacement of the oxide from (InxGa1-x)203 with nitride derived from a reactive source such as ammonia, hydrazine, or hydrazoic acid to form InxGa1-xN QDs and byproducts (gaseous water and hydrogen). Steps 1 and 2 occur at room temperature, and conditions for step 3 will be sought permitting the displacement process to occur efficiently at temperatures below 400C. The approach includes synthesis, as outlined above, and structural characterization and optical characterization of InxGa1-xN QDs. Synthesis parameters will be studied to achieve greater understanding of the processes involved, and to control the particle size mono-dispersity. Optical spectroscopy will be used to guide the synthesis of InxGa1-xN QDs which are luminescent at the bandedge. The PL and absorption properties of these QDs will then be correlated with the indium mole fraction determined using neutron activation analysis. %%%The project addresses basic research issues in a topical area of materials science having high potential technological relevance. The research will contribute basic materials science knowledge at a fundamental level to new aspects of electronic/photonic devices. The basic knowledge and understanding gained from the research is expected to contribute to improving the perform-ance of advanced devices and circuits by providing a fundamental understanding and a basis for designing and producing improved materials, and materials combinations. A variety of fundamental issues are to be addressed in these investigations, and the proposed experiments will also develop a technologically important emissive material which is capable of spanning a large part of the visible spectrum. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. ***