基于飞秒激光的高Al组分氮化物薄膜和量子结构的新型光学表征方法研究

Deep ultraviolet solid light source because of its advantages as the green environmental protection, wavelength tuning, low voltage, power consumption and so become a new research hot spot in nitride materials, but the high density of dislocation, p-type AlGaN doping, resulting in the luminescence efficiency is low. This project starts from the optical testing method of AlGaN materials with femtosecond laser wavelength tunable and adjustable power by dual wavelength resonance analysis of barrier trap luminescence and variation of luminescence properties with temperature and power; pulse carrier localization effect using ultrashort femtosecond laser; then by establishing the relationship between localization and model analysis between the luminous efficiency; through the time-resolved fluorescence spectroscopic study of threading dislocations and point defects on the impact of the luminous efficiency, through the establishment of epitaxial process of point defects on the luminescence efficiency of AlGaN based influence; through the use of temperature change of carrier recombination dynamics model and the rate equation of power optimization method, improve the internal quantum efficiency of the precision; using femtosecond laser energy the height of the convergence, localization of Annealing on AlGaN material, improve the efficiency of the activation of Mg. Through the study of this project, is expected to achieve new breakthrough in theory the relationship of localization and dislocation density, access to high quality AlN and AlGaN and deep UV device internal quantum efficiency test model.

深紫外固态光源以其绿色环保、波长易调谐、电压低、功耗小等优点成为新的氮化物材料研究热点，但其位错密度高、p型AlGaN掺杂困难，导致其发光效率低下。本项目从AlGaN材料的光学测试方法入手，利用飞秒激光的波长可调谐以及功率可调的优点通过双波长分析阱垒发光和阱的共振发光特性随温度和功率的变化规律；利用飞秒激光器的超短脉冲研究载流子局域化效应；然后通过建立模型分析局域化与发光效率之间的关系；通过时间分辨荧光光谱研究穿透位错和点缺陷对发光效率的影响，通过外延工艺确立点缺陷对AlGaN基材料发光效率的影响；通过采用变温变功率方法优化载流子复合动力学模型和速率方程，提高内量子效率测试精度；利用飞秒激光能量的高度会聚，对AlGaN材料进行定位退火，改善Mg的激活效率。通过本项目的研究，有望实现局域化与位错密度关系的理论新突破，获得高质量的AlN和AlGaN材料以及深紫外器件的内量子效率测试模型。

本项目从AlGaN材料的光学测试方法入手，利用飞秒激光的波长可调谐以及功率可调的优点,通过双波长分析阱垒发光和阱的共振发光特性随温度和功率的变化规律,获得了内量子效率的优化测量方法；通过建立模型分析了局域化与发光效率之间的关系；通过时间分辨荧光光谱研究了穿透位错和点缺陷对发光效率的影响；通过采用变温变功率方法优化了载流子复合动力学模型和速率方程，提高了内量子效率测试精度；利用飞秒激光能量的高度会聚，对AlGaN材料进行定位加工，改善了Mg的激活效率；通过侧壁粗化技术，提升了LED的光提取效率。通过本项目的研究，实现了局域化与位错密度关系的理论新突破，获得了高质量的AlN和AlGaN材料以及深紫外器件的内量子效率测试模型。