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

本计画系以三步电化学方法合成InxGa 1-xN量子点。 从水溶液中共沉积铟和镓以形成具有已知平均组成的InxGa 1-x纳米颗粒，随后电化学氧化InxGa 1-x纳米颗粒以形成（InxGa 1-x）2 O3。 第三步涉及用衍生自反应源（例如氨、肼或叠氮酸）的氮化物置换来自（InxGa 1-x）203的氧化物以形成InxGa 1-xN QD和副产物（气态水和氢气）。 步骤1和2在室温下进行，步骤3的条件将寻求允许置换过程在低于400 ℃的温度下有效地进行。 该方法包括如上所述的合成，以及InxGa 1-xN QD的结构表征和光学表征。 将研究合成参数，以更好地理解所涉及的过程，并控制粒度单分散性。 光谱学将用于指导InxGa 1-xN量子点的合成，其在带边发光。 这些量子点的PL和吸收特性将与使用中子活化分析确定的铟摩尔分数相关。 该项目解决了材料科学领域的基础研究问题，具有很高的潜在技术相关性。 该研究将为电子/光子器件的新方面提供基础材料科学知识。 从研究中获得的基本知识和理解，预计将有助于提高先进器件和电路的性能，通过提供一个基本的理解和基础，设计和生产改进的材料，材料组合。 在这些研究中要解决各种基本问题，拟议的实验还将开发一种技术上重要的发射材料，这种材料能够跨越可见光谱的很大一部分。 该计划的一个重要特点是通过在一个基本和技术上重要的领域对学生进行培训来整合研究和教育。 ***

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. ***