Electrical Properties of Neutron-Transmutation-Doped Germanium

摘要

Electrical properties of neutron-transmutation-doped germanium (NTD Ge) and nearly uncompensated gallium-doped germanium have been measured as functions of net-impurity concentration (2 x 10 exp 15 cm exp -3 less than or equal to N/sub A/ - N/sub D/ less than or equal to 5 x 10 exp 16 cm exp -3 ) and temperature (0.3 K less than or equal to T less than or equal to 300 K). The method of impurity conduction as a function of carrier concentration and compensation was investigated in the low temperature hopping regime. For nearest neighbor hopping, the resistivity is expected to vary as rho = rho sub 0 exp( delta /T) while Mott's theory of variable range hopping predicts that rho = rho sub 0 exp( delta /T)/sup 1/4/ in the low temperature limit. In contrast, our results show that the resistivity can best be approximated by rho = rho sub 0 exp( delta /T)/sup 1/2/ in the hopping regime down to 0.3 K. (ERA citation 08:049552)