Energy Gap Decrease in Cation Multidoped Aluminum Oxide

Abstract

The electronic structure of metal‐doped α‐Al2O3 with the disordered distribution of multi‐d‐ (Zr, Nb or/and Mo) and s‐ (Mg) impurities in the aluminum sublattice under the variation of their concentrations have been calculated using the coherent potential approximation method. Herein, an energy gap reduction due to appearance of new isolated occupied or empty Zr, Nb, and Mo d bands near the conduction band bottom of undoped α‐Al2O3 is shown. New multi d‐ and s‐doped α‐Al2O3 dielectrics with energy gap values of 7.1, 5.6, and 4.3 eV are found. Four multi‐d‐doped α‐Al2O3 semiconductors , , , and with energy gap values of 0.2–0.4 eV can be considered as promising materials for optoelectronic devices.