HgSe:Fe的红外光谱和自由载流子散射

INFRARED SPECTRA AND SCATTERING MECHANISM OF FREE CARRIERS IN HgSe:Fe

测量了掺Fe浓度为1.5×10^(18)～7×10^(19)cm^(-3)的HgSe:Fe样品在中红外波段内的室温透过率和反射率,由此看出Fe浓度大于或小于4×10^(18)cm^(-3)时吸收系数,迁移率和吸收截面的性质明显不同,用Fe的空间有序化模型解释了实验结果。

The infrared absorption and reflectivity spectra of five samples of HgSe: Fe with Fe concentration ranging from 1.5×10^(18) to 7×10^(19)cm^(-3) have been measured at room temperature in the region 400～2000 cm^(-1). The material parameters, such as E_f, N_e, m_f~* and m_s~* have been evaluated from the measured spectra. It is found that the absorption coefficient and mobility as well as absorption cross section undergo an evident change in their dependence on Fe concentration when the concentration exceeds 4×10^(18)cm^(-3), indicating that the absorption and transport theories based upon a random distribution of scattering are not valid in this ease, and the space ordering model of the ionized donors of Fe might be of help to give a satisfactory account for the experimental results.