Dresden 2011 – scientific programme

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O: Fachverband Oberflächenphysik

O 36: Poster Session II (Metals; Nanostructures at surfaces; Surface or interface magnetism; Spin-Orbit Interaction at Surfaces; Electron and spin dynamics; Surface dynamics; Methods; Theory and computation of electronic structure)

O 36.123: Poster

Tuesday, March 15, 2011, 18:30–22:00, P4

GaN/AlN Structures with Two Dimensional Electron Gas: A Density Functional Theory Study — Jakub Sołtys¹, Michał Łopuszyński¹, •Jacek Piechota¹, and Stanisław Krukowski^1,2 — ¹Interdisciplinary Centre for Materials Modelling, University of Warsaw, ul. Pawińskiego 5a, 02-106 Warszawa, Poland — ²Institute of High Pressure Physics, Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142 Warsaw, Poland

GaN is a promising material because of its properties: it can be used in high-temperature, high-frequency and high-power device applications. It has been shown that the GaN/AlN/GaN junction with ultra-thin AlN layer can be prepared and significant improvement in some crucial parameters over GaN/AlGaN is attained. In our work we present density functional study of the AlN/GaN high electron mobility transistor (HEMT) structure. It was shown that two dimensional electron gas (2DEG) is present at the AlN/GaN interface. Analysis of potential profiles and band structures for different thickness of AlN barier allow us to assess how the barrier affects 2DEG.. It was demonstrated that for too thin AlN barrier 2DEG is not well confined. However, for a thicker AlN barrier, the occupancy of this states is higher, and this result is consistent with the available experimental data [Dabiran et.al., Appl. Phys. Lett. 93 082111 (2008)].