Optical absorption of thin Hg1-xCdxTe epitaxial layers

The absorption coefficient near the fundamental absorption edge of Hg 1-x Cd x Te has been measured. The transition from the exponential tail of the absorption edge to the square root law deduced for direct interband transition within the Kane-band structure is used to determine the gap energy. It was found that the absorption coefficient at the gap energy is weakly temperature dependent within 2000 cm -1 < alpha (E g )<4000 cm -1 .