利用红外反射光谱研究了蓝宝石衬底上用金属有机物化学气相淀积方法生长的稀磁半导体GaMnN材料的晶格振动特性.并成功地将改进的遗传算法应用于其红外反射光谱洛伦兹振子模型参数的提取.通过与GaN薄膜的洛伦兹振子模型参数的对比研究发现,GaN掺入Mn后,ωTO向高频方向移动,γ,ε∞和εs均增加,而ωLO基本保持不变.文中同时分析和讨论了Mn对晶格振动特性的影响及介电函数变化的机理.
The lattice vibrations of diluted magnetic semiconductor GaMnN epitaxial films grown on sapphire substrates by metalorganic chemical vapor deposition have been investigated using infrared reflectance spectroscopy. The revised genetic algorithm was successfully used to extract the Lorentz oscillator model parameters of GaMnN from infrared reflectance spectra. Comparing the Lorentz oscillator model parameters of GaMnN with those of GaN, it was found that ωTO moved to higher frequencies, γ, ε∞ and εs increased, but the ωTO was almost not changed. The effects of Mn on the properties of lattice vibration and the mechanisms of variations of the dielectric function were also analyzed and discussed in this paper.