Electric conductivity of heavily doped compensated n-type germanium, produced by neutron doping

In the temperature range P=400+-1.4 K investigated was electric conductivity of heavily doped compensated germanium of n type produced by neutron alloying with main impurity concentration Napproximately(5+-7)x1017 cm-3 and compensations 0 < or approximately k < or approximately 0.98. Charge transfer is established to occur at high temperatures according to delocalized states. It is described by the Boltzmann kinematic equation. With the temperature decrease at k > 0.9 the transition takes place to tunnelling fluctuation potential barriers the greatest size of which is determined by a screening radius Rsub(s)=βNsup(-1/3)(1-k)sup(-2/3), where β=0.1. At lesser k values, potential fluctuations are clear from the point of view of tunnelling. In T <= 10 +- 20 K area on a dielectric side of metal-isolator transition, specific resistance rhoinfinityexp(const/T)sup(1/2). This law is explained within the framework of a jump conduction model with variable jump length in quasi-slit g=g2(epsilon - μ)2 for localized states near the Fermi level μ. which should be related to the Coulomb interaction of localized carriers. It is established, that approaching the transition the localization radius near the Fermi level and factor g2 increase, while the Coulomb interaction weakens and quasi-slit collapses