Narrow gap HgCdTe absorption behavior near the band edge including nonparabolicity and the Urbach tail

An analytical model describing the absorption behavior of HgCdTe is developed that simultaneously considers the contributions from nonparabolic conduction and light hole bands as calculated by a 14×14 matrix k∙p method as well as the Urbach tail. This model is capable of smoothly fitting experimental absorption coefficient curves over energies ranging from the Urbach tail region to the intrinsic absorption region up to 300meV above the band gap. Comparisons to the experimental results give good agreement.