Ionization energy levels in C-doped InxGa1-xN alloys.

The InxGa1-xN alloys present levels as a result of the intentional (doped) or unintentional (contamination) introduction of C atoms into the host semiconductor. The III-V nitride semiconductors and their alloys usually crystallize in the wurtzite structure although the zinc blende structure has also been grown. We obtained the InxGa1-xN:C ionization energies from first-principles calculations of the two ordered wurtzite and zinc blende structures using different exchange and correlation terms. In accordance with the experimental results, the ionization levels could give rise, on some occasions, to a metallic impurity band. [ABSTRACT FROM AUTHOR]