论文部分内容阅读
本文报道（0001）晶向蓝宝石衬底上金属有机化学气相淀积（MOCVD）方法生长的单晶六角GaN薄膜室温光学性质．由光吸收谱和488umAr+激光激发的光调制反射光谱（PR）确定的禁带宽度分别为3．39和3．400eV，从光吸收谱得到了GaN薄膜的折射率随光谱能量的变化关系．对PR谱的调制机理进行的分析，发现信号来自缺陷作用下的表面电场调制．应用喇曼光谱研究了GaN薄膜中的声子模，通过对LO声子-等离激元的耦合模散射峰的研究，得到了材料中的载流子浓度和等离激元阻尼常数．
This paper reports the optical properties of (0001) single crystal hexagonal GaN films grown by metalorganic chemical vapor deposition (MOCVD) on sapphire substrates at room temperature. The bandgaps determined by the light absorption spectra and the 488umAr + laser-excited light modulation reflectance spectra (PR) were 3.39 and 3.400eV, respectively. The refractive index of the GaN films with respect to the spectral energy was obtained from the light absorption spectra. The analysis of the modulation mechanism of PR spectrum shows that the signal comes from the surface electric field modulation under the defect. The Raman spectra were used to study the phonon modes in the GaN thin films. The carrier concentration and the plasmon damping constant in the materials were obtained by studying the coupled mode scattering peaks of LO phonon-plasmons.