MOCVD制备InN薄膜的光学性质

Optical Properties of InN Films Grown by MOCVD

利用吸收光谱、光致发光谱、喇曼散射光谱和椭圆偏振光谱一系列光学手段,对采用金属有机物气相沉积法(MOCVD)制备的InN薄膜的光学性质进行了系统研究.吸收光谱和光致发光谱的结果清晰地证明了高质量InN薄膜的光学带隙宽度为0.68eV,接近于现阶段主要报道值0.7eV.喇曼散射光谱实验说明窄光学带隙主要源于较低的背景电子浓度.利用椭圆偏振光谱不仅得到了纤锌矿InN临界点跃迁能量的值E0,同时首次得到了在0.65～4.0eV能量范围内复折射率实部n,虚部k的色散曲线.

By means of optical absorption, photoluminescence （PL）, and ellipsometric spectra, metal organic chemical vapor deposition （MOCVD） grown InN films are investigated. Through absorption and PL measurements,it is proven that the band gap of the high quality InN is 0.68eV,which agrees with the recently reported value of ~0.7eV. By analysis of the Raman scattering spectrum,the comparatively low background concentration of electrons results in a smaller band gap value. The transition energy E0 of wurtzite InN at critical point F0 is determined by ellipsometric spectra. In addition, the complex re- fractive index n ＋ ik of InN in the energy range from 0.65 to 4. 0eV is obtained for the first time.