【摘要】 采用分子束外延(MBE)方法在BaF2(111)衬底上生长了不同Mn组分的Pb1-xMnxTe(0≤x≤0.012)稀磁半导体薄膜.通过波长为3.0~11.0μm中红外透射谱的分析并应用透射光谱上干涉峰峰值的位置计算获得了Pb1-xMnxTe薄膜的折射率,由最小平方根拟合得到折射率的一阶Sellmeier色散关系.在吸收边附近,通过直接跃迁吸收系数与光子能量的关系外推得到其光学带隙.结果表明,在中红外区域其折射率随着Mn含量的增加而减小,其光学带隙则随着Mn含量的增加而增大,在温度T=295K时,随着Mn含量x由0变化到0.012,其光学带隙Eg由0.320eV增加到0.370eV.更多还原

【Abstract】 Dilute magnetic semiconductor Pb1-xMnxTe(0≤x≤0.012)thin films were grown on BaF2(111) substrates by using molecular beam epitaxy(MBE).The refractive indices and dispersions in wavelength range of 3.0~11.0μm for Pb1-xMnxTe films were attained by the measurement of mid-infrared transmission spectra and the analysis of peak positions of interference fringes and using the least-square fitting the first-order Sellmeier dispersion relation.Optical band gap energies were obtained by extrapolating the absorption of direct transition at absorption edge.The results show that as Mn content in Pb1-xMnxTe films increases the optical band gap becomes wider and the refractive index decreases.The optical band gap increases from 0.320eV to 0.370eV(295 K) as the Mn content x increases from 0 to 0.012.更多还原