OPTICAL INFORMATION TECHNOLOGIES, ELEMENTS, AND SYSTEMS MOBILITY OF MINORITY CARRIERS IN As-DOPED p-MCT FILMS GROWN BY MOLECULAR BEAM EPITAXY in situ

摘要

Temperature dependences of the Hall coefficient and magnetoresistance in heteroepitaxial structures of p-Cd{sub}xHg{sub}(1-x)Te (MCT) of X{sub}(CdTe) = 0.22-0.23, grown by molecular beam epitaxy on (013)GaAs substrates are investigated. The main electrophysical parameters, namely, concentration and mobility of electrons and holes, are obtained by multicarrier fitting and "mobility spectrum" techniques. It is found that at temperatures of 125-165 K, electron mobility in As-doped p-Cd{sub}xHg{sub}(1-x)Te is 1.5-2 times lower than in p-Cd{sub}xHg{sub}(1-x)Te whose conductance is determined by mercury vacancies. However, due to the higher lifetime the electron diffusion length calculated by Einstein formula is 2-2.5 times higher in the As-doped p-Cd{sub}xHg{sub}(1-x)Te than in the vacancy material. The lower mobility in the As-doped material is probably a result of an additional mechanism of scattering on neutral As atoms and growth defects.