分子束外延Pb_(1-x)Eu_xTe材料的红外透射谱研究

INFRARED TRANSMISSION SPECTRA OF MBE-GROWN Pb_(1-x)Eu_xTe FILMS

在2.5～25μm范围内测量了分子束外延(MBE)Pb_(1-x)Eu_xTe薄膜材料(x=0,0.011,0.032,0.045)的室温红外透射谱,得到了折射率的色散关系及禁带宽度与组份x的关系,首次报道了禁带宽度与光学介电常数的经验公式,讨论了本文结果与其它报道的不同之处。

The transmission spectra of Pb_(1-x)Eu_xTe(0≤x≤0.045)film grown by MBE have been measured over the wavelength range 2.5～25μm at 300K. The dispersion of the refractive index and the dependence of the energy gap on the Eu content x have been obtained. The refractive index of Pb_(1-x)Eu_xTe decreases with x. The energy gap of Pb_(1-x)Eu_xTe is a linear function of x and increases as dE/dx=2.3eV for x≤0.045. The empirical relation between fundamental absorption edge and the optical dielectrio constant is reported for the first time.