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The role of dislocation-induced scattering in electronic transport in GaxIn1-xN alloys

Donmez, Omer and Gunes, Mustafa and Erol, Ayse and Arikan, Cetin M and Balkan, Naci and Schaff, William J (2012) 'The role of dislocation-induced scattering in electronic transport in GaxIn1-xN alloys.' Nanoscale Research Letters, 7 (1). p. 490. ISSN 1556-276X

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<jats:title>Abstract</jats:title> <jats:p>Electronic transport in unintentionally doped Ga<jats:sub>x</jats:sub>In<jats:sub>1-x</jats:sub>N alloys with various Ga concentrations (<jats:italic>x</jats:italic> = 0.06, 0.32 and 0.52) is studied. Hall effect measurements are performed at temperatures between 77 and 300 K. Temperature dependence of carrier mobility is analysed by an analytical formula based on two-dimensional degenerate statistics by taking into account all major scattering mechanisms for a two-dimensional electron gas confined in a triangular quantum well between Ga<jats:sub>x</jats:sub>In<jats:sub>1-x</jats:sub>N epilayer and GaN buffer. Experimental results show that as the Ga concentration increases, mobility not only decreases drastically but also becomes less temperature dependent. Carrier density is almost temperature independent and tends to increase with increasing Ga concentration. The weak temperature dependence of the mobility may be attributed to screening of polar optical phonon scattering at high temperatures by the high free carrier concentration, which is at the order of 10<jats:sup>14</jats:sup> cm<jats:sup>−2</jats:sup>. In our analytical model, the dislocation density is used as an adjustable parameter for the best fit to the experimental results. Our results reveal that in the samples with lower Ga compositions and carrier concentrations, alloy and interface roughness scattering are the dominant scattering mechanisms at low temperatures, while at high temperatures, optical phonon scattering is the dominant mechanism. In the samples with higher Ga compositions and carrier concentrations, however, dislocation scattering becomes more significant and suppresses the effect of longitudinal optical phonon scattering at high temperatures, leading to an almost temperature-independent behaviour.</jats:p>

Item Type: Article
Uncontrolled Keywords: GaxIn1-xN – In-rich GaxIn1-xN – Mobility – Electronic transport – PACS: 72.10.Fk – 72.20.Fr
Subjects: Q Science > QA Mathematics > QA75 Electronic computers. Computer science
Divisions: Faculty of Science and Health > Computer Science and Electronic Engineering, School of
SWORD Depositor: Elements
Depositing User: Elements
Date Deposited: 09 Jan 2015 21:38
Last Modified: 06 Jan 2022 14:39

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