We propose a new method to calculate polarization induced interfacial charges in semiconductor heterostructures using classical electrostatics applied to real-space band diagrams from first principles calculations and apply it to GaN/AlN heterostructures with ultrathin AlN layers (4-6 monolayers). We show that the calculated electric fields and interfacial charges are independent of the exchange-correlation functionals used (local-density approximation and hybrid functionals). We also find the calculated interfacial charge of (6.8 +/- 0.4) x 10^13 cm-2 to be in excellent agreement with experiments and the value of 6.58 x 10^13 cm-2 calculated from bulk polarization constants, validating the use of bulk constants even for very thin films.
@article{arxiv.1104.4149,
title = {First principles calculation of polarization induced interfacial charges in GaN/AlN heterostructures},
author = {Rohan Mishra and Oscar D. Restrepo and Siddharth Rajan and Wolfgang Windl},
journal= {arXiv preprint arXiv:1104.4149},
year = {2011}
}
Comments
3 pages, 2 figures; submitted to Applied Physics Letters