Abstract
In InN, a genuine band gap opening observed after hydrogenation has been explained by means of the “solitary cation” model, a multi-H complex in which the central cation, In*, is fully separated from the structure [Pettinari et al., Adv. Funct. Mater. 25, 5353 (2015)]. Similar effects of H on the host band gap have been observed in In-rich alloys. Paying attention to these materials, we have theoretically investigated the In* properties against three kinds of disorder, structural, compositional, and configurational, all of them possibly occurring in alloys. As a first major result we have found that a same, general solitary-cation model and mechanism explain the effects of hydrogenation on the electronic properties of both InN and In-rich alloys. Even more interestingly, in these alloys, both the energetics of the In* solitary cations and their effects on the band gap result to be thoroughly independent of their atomic neighborhood, in particular, of the number and spatial distribution of their cation neighbors. Significantly, this implies that band-gap opening effects can be safely predicted in whatever hydrogenated In-rich nitride alloy containing different In companions (e.g., B, Al, or Ga) as well as in InN-containing, unconventional compounds (e.g., ZnO-InN), thus offering novel opportunities for material engineering.
- Received 21 June 2017
- Revised 13 September 2017
DOI:https://doi.org/10.1103/PhysRevMaterials.1.064606
©2017 American Physical Society