Band Gaps of HoxSc1−xN, HoxY1−xN, and YxSc1−xN Semiconductor Alloys

The electronic structure of ternary alloys of ScN, YN and HoN semiconductors has been studied with density functional theory calculations. The linear dependence of a band gap on an alloy content was predicted for these systems within the MBJGGA approach. The range of indirect band gaps EgΓ−X available in Sc- and Y-based nitrides, starting from 0.89 and 1.09 eV, respectively, can be extended up to 1.3 eV thanks to alloying with HoN. The lack of band gap bowing found with the use of the special quasirandom structures for the YxSc1−xN systems is inconsistent with previous reports in the literature. The results presented in this work not only encourage further experimental efforts in band gap engineering in rare-earth nitrides, but also emphasize general requirements for theoretical studies on the electronic structure of this family of materials, which minimize the artificial band gap bowing found for the rock-salt nitride systems in previous studies.