THE IMPACT OF RADIATION DEFECTS ON THE MECHANISMS OF ELECTRON SCATTERING IN SINGLE CRYSTALS n-Ge

The irradiation of sample single crystals n-Ge was carried on the M-30 microtron. The parameters of such a microtron allow to form beams of accelerated electrons with energies in the range of 1-25 MeV. The analysis of the results of electronic irradiation shows that in the forbidden zone of germanium an energy level (E-c - 0, 27) eV is formed owing to the A-center. The energy position of the A-center depends on the magnitude of internal stresses in the lattice. This in turn affects the scattering of electrons on deep centers. On the basis of the Hall effect measurements the temperature dependences of the Hall mobility for irradiated n-Ge single crystals of various streams of electrons with the energy of 10 MeV were obtained. For the investigated streams of electron irradiation, the conductivity type of germanium did not changed. Theoretical calculations show that besides the scattering of electrons on ions shallow donors, acoustic, optical and intervalley phonons, substantial contribution to the value of the Hall mobility of irradiated single crystals of n-Ge is brought by mechanisms of electron scattering on the regions of disordering and a large scale potential created by the fluctuations of the concentration of the charged defects. The uncharacteristic effect of increase of the Hall mobility at high temperatures for irradiated single crystals of n-Ge with the change of charge state of A-center at the expense of its thermal ionization by explained. Also, the magnitude of internal mechanical stresses in the lattice germanium depends on the charge state of A-center. Therefore, some discrepancy between theoretical and experimental dependences of the Hall mobility can be explained by the additional influence of electron scattering mechanisms on the regions of elastic deformation around the deffects created by radiation and deep levels of A-centers.