Electron Mobility in Aluminum Antimonide

Abstract

The temperature dependence of the electron mobility in tellurium-doped aluminum antimonide is calculated assuming combined polar optical, acoustical mode, and ionized impurity scattering. The separate mobilities for each mechanism are calculated using effective mass components (which have been given by the authors in a previous publication) in a many-valley model having [100] symmetry. It is found that the dominant scattering mechanism at room temperature is polar optical mode. However, it appears likely that acoustical mode scattering is non-negligible. The calculated temperature dependence of the mobility is found to be in reasonable agreement with the measured mobility behavior of a sample with known compensation. The calculations give a room-temperature lattice mobility of 250 cm2/V·sec. A lower observed Hall mobility than that calculated for temperatures above room temperature in the same sample is attributed to the onset of intra- and intervalley scattering by nonpolar optical modes, and possible nonparabolicity of the band minima.