Optical verification of the valence band structure of cadmium arsenide

Optical absorption measurements were performed on thin single crystalline samples of Cd₃As₂ at temperatures of 300 K and 10 K. At low temperature the interband absorption coefficient shows clearly two steps due to direct transitions from the heavy hole and light hole valence bands to the conduction band. The absorption coefficient can be interpreted quantitatively in an isotropic inverted Kane band model with a modified heavy hole band with its maximum shifted from the Λ-point.