基于MOVPE和MBE法生成的GaN薄膜的反射、透射光谱测量

Reflection and transmission spectra measurement of GaN thin film generated by means of MOVPE and MBE procedures

使用紫外-可见光分光光度计,研究用金属有机物气相外延(MOVPE)方法生成在蓝宝石衬底上的GaN薄膜的反射光谱、透射光谱以及用分子束外延(MBE)方法生成在碳化硅衬底上GaN薄膜的反射光谱,结果表明,所测的GaN薄膜和体材料的光学吸收边出现在364 nm附近,对应的禁带宽度为3.41 eV.在两种不同衬底上,薄膜的反射谱由于材料晶格常数和热膨胀系数的不同有所差别.

The reflection and transmission spectra of GaN thin film grown on the sapphire substrate by using metal-organic vapor phase epitaxy were investigated with ultraviolet visible spectrophotometry. At the same time the reflection spectrum of GaN thin film grown on the SiC layer by means of molecular beam epitaxy was also studied. The results showed that the optic absorption edge took place at wave-length of 364 nm, corresponding to the direct band gap of 3, 41 eV in width. The reflection spectra of the thin films on the both different substrates were different due to the difference in lattice constant and thermal expansion coefficient of the materials.