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High carrier concentration induced effects on the bowing parameter and the temperature dependence of the band gap of GaxIn1−xN

Donmez, O and Gunes, M and Erol, A and Arikan, M C and Balkan, Naci (2011) 'High carrier concentration induced effects on the bowing parameter and the temperature dependence of the band gap of GaxIn1−xN.' Journal of Applied Physics, 110 (10). p. 103506. ISSN 0021-8979

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Abstract

The influence of intrinsic carrier concentration on the compositional and temperature dependence of the bandgap of GaxIn1-xN is investigated in nominally undoped samples with Ga fractions of x = 0.019, 0.062, 0.324, 0.52, and 0.56. Hall Effect results show that the free carrier density has a very weak temperature dependence and increases about a factor of 4, when the Ga composition increases from x = 0.019 to 0.56. The photoluminescence (PL) peak energy has also weak temperature dependence shifting to higher energies and the PL line shape becomes increasingly asymmetrical and broadens with increasing Ga composition. The observed characteristics of the PL spectra are explained in terms of the transitions from free electron to localized tail states and the high electron density induced many-body effects. The bowing parameter of GaxIn1-xN is obtained from the raw PL data as 2.5 eV. However, when the high carrier density induced effects are taken into account, it increases by about 14% to 2.9 eV. Furthermore, the temperature dependence of the PL peak becomes more pronounced and follows the expected temperature dependence of the bandgap variation.

Item Type: Article
Uncontrolled Keywords: Hall effect, III-V semiconductors, bending, electron density, energy gap, gallium compounds, indium compounds, localised states, photoluminescence, wide band gap semiconductors
Subjects: Q Science > QC Physics
Divisions: Faculty of Science and Health > Computer Science and Electronic Engineering, School of
Depositing User: Clare Chatfield
Date Deposited: 19 Jan 2015 11:12
Last Modified: 19 Jan 2015 11:12
URI: http://repository.essex.ac.uk/id/eprint/9049

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