Dresden 2014 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 37: Posters: Plasmonics, Electronic Structure and Spin-Orbit Interaction, Semiconductor and Insulator Surfaces, Nanostructures
O 37.49: Poster
Dienstag, 1. April 2014, 18:30–22:00, P2
Density functional study of GaN(0001)/AlN(0001) high electron mobility transistor structures — Jakub Sołtys1, Maria Ptasińska1, •Jacek Piechota1, and Stanisław Krukowski1,2 — 1ICM, University of Warsaw, Pawińskiego 5a, 02-106 Warsaw, Poland — 2Institute of High Pressure Physics, Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland
AlN/GaN high electron mobility transistor (HEMT) structures were theoretically investigated using the density functional theory (DFT). An existence of two-dimensional electron gas (2DEG), generated by strong polarization fields at the AlN/GaN interface, was confirmed by abinitio calculations. The potential profiles were analyzed for the HEMTs with different number of AlN layers, indicating that very thin AlN barrier could not provide a high density of carriers and good confinement of 2DEG. It was shown that for six AlN layers (thickness about 13Å), no electron gas is present as shown by the potential profile. In the investigated electronic structure, the band states associated with the two-dimensional electron gas were identified. It was shown that for a thicker AlN barrier, the occupancy of this states is higher, that is consistent with the available experimental data.