The calculation of electron-transport properties of direct-gap semiconductors has been generalized to include arbitrary electron degeneracy as well as scattering by ionized impurities and heavy holes. Conduction-band nonparabolicity and electron wave-function admixture are retained throughout the calculation of drift mobility and thermoelectric power. Extensive comparison of the results with experiment confirms the present description over wide ranges of temperature and ionized-impurity concentration. Effects of multivalley conduction due to electron transfer into $L_{1c}$ satellite valleys appear in InSb above 700 °K (just below the melting point at ∼ 780 °K) and in InP above 800 °K. The lowest satellite valleys of InAs are sufficiently remote from the conduction-band edge at $L_{1c}$ that the results are expected to be accurate up to the melting point at ∼ 1200 °K.

• Received 15 December 1970

DOI:https://doi.org/10.1103/PhysRevB.3.3287