Optische Bestimmung der Nichtparabolizität des dritten Valenzbandes von Germanium

Abstract

Measurements of the optical absorption of free holes in germanium produced by direct intraband transitions in the valence band have been made at temperatures of 300–390 °K. The experimental method of the photoabsorption was used which enables the absorption spectra to be determined at intrinsic material without an influence of the absorption edge due to interband transitions between the valence band and the conduction band. An analysis of the spectra gives an experimental determination of the shape of the non parabolic split-off valence band. By comparison withKane's theory a marked difference is found but good agreement with calculations fromFawcett is achieved.

The temperature dependence of the shape of the split-off band is discussed concerning the optical absorption measurements on “hot holes” in high electric fields with respect of the non-equilibrium energy distribution of the carriers.