Tunable Band Gaps of In$_x$Ga$_{1-x}$N Alloys: From Bulk to Two-Dimensional Limit

12 Dec 2017  ·  Wang V., Wu Z. Q., Kawazoe Y., Geng W. T. ·

Using first-principles calculations combined with a semi-empirical van der Waals dispersion correction, we have investigated structural parameters, mixing enthalpies, and band gaps of buckled and planar few-layer In$_x$Ga$_{1-x}$N alloys. We predict that the free-standing buckled phases are less stable than the planar ones... However, with hydrogen passivation, the buckled In$_x$Ga$_{1-x}$N alloys become more favorable. Their band gaps can be tuned from 6 eV to 1 eV with preservation of direct band gap and well-defined Bloch character, making them promising candidate materials for future light-emitting applications. Unlike their bulk counterparts, the phase separation could be suppressed in these two-dimensional systems due to reduced geometrical constraints. In contrast, the disordered planar thin films undergo severe lattice distortion, nearly losing the Bloch character for valence bands; whereas the ordered planar ones maintain the Bloch character yet with the highest mixing enthalpies. read more

PDF Abstract
No code implementations yet. Submit your code now

Categories


Materials Science Mesoscale and Nanoscale Physics