EFFECT OF ANISOTROPIC TUNNELING THROUGH COULOMB BARRIERS ON THE ELECTRON-CAPTURE IN SEMICONDUCTORS

The capture rate of hot electrons by negatively charged gold centers in n-Ge at T equals 77 K is considered for the anisotropic model. Making use of the adiabatic approximation, the angular dependence of the electron tunneling factor through the Coulomb barrier surrounding the center is determined. It is found that, for the anisotropic case, the tunneling factor is determined mainly by the smaller transverse effective mass of the electron. The obtained anisotropic tunneling factor is then used in studying the field dependence of the capture rate when the main mechanism of energy relaxation is due to electron scattering by acoustic phonons. A comparison with the isotropic case is given.