Abstract
Diffusion mediated by native point defects does not generally occur in semiconductors at room temperature (RT) because of high activation energies. However, recently observed plastic deformation in AlGaN/GaN structures in the presence of strain and electric fields was attributed to diffusive processes. Here, we report first-principles calculations showing that strain has little effect, but RT mass transport is enabled by near-zero formation energy of triply negative cation vacancies and a concomitant electric-field-induced lowering of migration energy. Similar phenomena are predicted to occur in other large-gap materials.
- Received 16 May 2011
DOI:https://doi.org/10.1103/PhysRevB.84.214109
©2011 American Physical Society