Effect of Tensile Strain in GaN Layer on the Band Offsets and 2DEG Density in AlGaN/GaN Heterostructures
Abstract
We have addressed the existing ambiguity regarding the effect of process-induced strain in the underlying GaN layer on AlGaN/GaN heterostructure properties. The bandgaps and offsets for AlGaN on strained GaN are first computed using a cubic interpolation scheme within an empirical tight-binding framework. These are then used to calculate the polarization charge and two-dimensional electron gas density. Our bandstructure calculations show that it is not possible to induce any significant change in band offsets through strain in the GaN layer. The charge-density calculations indicate that such strain can, however, modulate the polarization charge and thereby enhance the 2DEG density at the AlGaN/GaN hetero-interface substantially, by as much as 25% for low Al mole fraction.
- Publication:
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arXiv e-prints
- Pub Date:
- December 2017
- DOI:
- 10.48550/arXiv.1712.03419
- arXiv:
- arXiv:1712.03419
- Bibcode:
- 2017arXiv171203419D
- Keywords:
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- Physics - Applied Physics
- E-Print:
- 3 pages, 4 figures