Semi-classical electronic transport properties of ternary compound AlGaAs₂: role of different scattering mechanisms

Using Rode's iterative method, we have investigated the semi-classical transport properties of the n-type ternary compound AlGaAs₂. Four scattering mechanisms have been included in our transport calculation, namely, ionized impurity, piezoelectric, acoustic deformation and polar optical phonon (POP). The scattering rates have been calculated in terms of ab initio parameters. We consider AlGaAs₂ to have two distinct crystal geometries, one in tetragonal phase (space group: ), while the other one having body centered tetragonal crystal structure (space group: ). Higher electron mobility has been observed in the body centered tetragonal phase, thereby making it more suitable for high mobility device application, over the tetragonal phase. In order to understand the differences in electron mobility for these two phases, curvatures of the E-k dispersion of the conduction bands for these phases have been compared. At room temperature, the dominant contribution in electron mobility was found to be provided by inelastic POP scattering. We have also noted that mobility is underestimated in relaxation time approximation compared with the Rode's iterative approach. (paper)