Small-field D.C. conduction in n-type germanium in the presence of large microwave field

Abstract

Small-field D.C. conduction inn-type germanium in the presence of large microwave field is theoretically studied assuming a Maxwellian distribution function for the carriers. Scattering by intra-valley acoustic and optical phonons and by equivalent inter-valley phonons have been taken into account, but the effect of non-equivalent inter-valley scattering has been neglected. The small-field D.C. conductivity is found to be appreciably different from the D.C. conductivity corresponding to the r.m.s. value of the microwave field and nearly frequency-independent up to a frequency of 35 Gc/s. The anisotropy in its values is also found to be of the same order as in the values of the high-field D.C. conductivity. The calculated values show close agreement with the experimental results in the field range 1 to 3 kV cm^-1 and for frequencies between 2.85 to 35 Gc/s.