【摘要】 采用椭圆偏振光谱技术研究了射频磁控溅射生长非晶态碲镉汞(amorphous Hg1-xCdxTe,amorphous MCT,a-MCT)薄膜的光学性质,发现非晶态碲镉汞薄膜的介电函数谱特征与晶态碲镉汞材料的明显不同,表现出与其他非晶态半导体材料类似的"波包"结构特征。基于修正的FB模型在1.0～4.0eV的能量范围内对实验结果进行了拟合分析,得到了不同组分非晶态碲镉汞薄膜的光学带隙随组分关系。通过与单晶碲镉汞光学带隙随组分变化关系的对比研究,结果表明碲镉汞的结构从晶态向非晶态转变过程中,材料的光学待续发生了明显的"蓝移"。更多还原

【Abstract】 Spectroscopic ellipsometry(SE) measurement results for the optical constants of amorphous Hg1-xCdxTe(amorphous MCT,a-MCT) films prepared by RF magnetron sputtering deposition were pre-sented.Dielectric-function spectra ε(ω) is very different between a-MCT and c-MCT,typically like other amorphous semiconductors.The measured data are analyzed by a developed model on the basis of FB model and Adachi’s suggestion.Results are in reasonable agreement with the experimental data over the entire range of photon energy(1.0 to 4.0 eV),energy gap of a-MCT films were obtained with different composi-tions,a remarkable blue-shift of energy gap were found when crystalline MCT transform into amorphous MCT.更多还原