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Title: Contribution of alloy clustering to limiting the two-dimensional electron gas mobility in AlGaN/GaN and InAlN/GaN heterostructures: Theory and experiment

The influence of alloy clustering on fluctuations in the ground state energy of the two-dimensional electron gas (2DEG) in AlGaN/GaN and InAlN/GaN heterostructures is studied. We show that because of these fluctuations, alloy clustering degrades the mobility even when the 2DEG wavefunction does not penetrate the alloy barrier unlike alloy disorder scattering. A comparison between the results obtained for AlGaN/GaN and InAlN/GaN heterostructures shows that alloy clustering limits the 2DEG mobility to a greater degree in InAlN/GaN heterostructures. Our study also reveals that the inclusion of an AlN interlayer increases the limiting mobility from alloy clustering. Moreover, Atom probe tomography is used to demonstrate the random nature of the fluctuations in the alloy composition.
Authors:
;  [1] ;  [2] ; ; ;  [3]
  1. Electrical and Computer Engineering Department, University of California, Santa Barbara, California 93106 (United States)
  2. Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305 (United States)
  3. Materials Department, University of California, Santa Barbara, California 93106 (United States)
Publication Date:
OSTI Identifier:
22305752
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 13; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALLOYS; ALUMINIUM COMPOUNDS; ALUMINIUM NITRIDES; ATOMS; ELECTRON GAS; ELECTRON MOBILITY; FLUCTUATIONS; GALLIUM NITRIDES; GROUND STATES; INCLUSIONS; INDIUM COMPOUNDS; RANDOMNESS; SCATTERING; SIMULATION; TOMOGRAPHY; TWO-DIMENSIONAL CALCULATIONS; WAVE FUNCTIONS