In-situ characterization of MOVPE growth dynamics and of diffusion mechanisms in nitrides and their influence on optoelectronic properties of InGaN/AlGaN/GaN quantum structures

不均匀的铟浓度是目前尚未解决的主要科学问题，严重阻碍了InGaAlN材料体系生长的技术进步。该项目的目标是对金属有机气相外延 (MOVPE) 生产的 InGaN/GaN 的生长和分解有一个基本的了解，从而优化制造蓝色和绿色 LED 和激光二极管的 InGaN/AlGaN 量子结构的生长参数。特别是，我们希望阐明 AlInGaN 晶格中铟扩散依赖于外部参数（特别是温度）和内部影响的微观机制，例如晶格应变场和生长时刻（和温度）时的缺陷类型和浓度，这些除了压电场之外对于生长的基本理解也很重要。此外，它们也是影响氮化物器件（LED、激光器和晶体管）技术的关键未知因素。

Non-uniform indium concentration is the major unsolved scientific problem strongly impeding technological progress in the growth of the InGaAlN materials system. The goal of the project is to gain a fundamental understanding of the growth and decomposition of InGaN/GaN produced by metalorganic vapor phase epitaxy (MOVPE), thus enabling optimization of the growth parameters for fabrication of InGaN/AlGaN quantum structures of blue and green LEDs and laser diodes. In particular, we want to elucidate the microscopic mechanisms of indium diffusion in the AlInGaN lattice in dependence on external parameters (especially temperature) and internal influences, such as lattice strain fields and defect type and concentrations at the moment (and temperature) of growth, which beside piezoelectric fields are important for the fundamental understanding of growth. Also, they are crucial unknown factors with implication on the technology of nitride devices- LEDs, lasers and transistors.