The growth of n-type GaSb by metal-organic chemical vapour deposition: effects of two-band conduction on carrier concentrations and donor activation

摘要

n-type GaSb has been prepared by metal-organic chemical vapour deposition with tellurium donors using diethyltelluride as the dopant precursor. The maximum carrier concentration achieved was 1.7 x 10~(18) cm~(-3), as measured by van der Pauw-Hall effect measurements, for an atomic tellurium concentration of 1.8 x 10~(19) cm~(-3). The apparent low activation of tellurium donors is explained by a model that considers the effect of electrons occupying both the Γ and L bands in GaSb due to the small energy difference between the Γ and L conduction band minima. The model also accounts for the apparent increase in the carrier concentration determined by van der Pauw-Hall effect measurements at cryogenic temperatures.