Ga kinetics in plasma-assisted molecular-beam epitaxy of GaN(112¯2): Effect on the structural and optical properties - CEA - Commissariat à l’énergie atomique et aux énergies alternatives Access content directly
Journal Articles Journal of Applied Physics Year : 2008

Ga kinetics in plasma-assisted molecular-beam epitaxy of GaN(112¯2): Effect on the structural and optical properties

L. Lahourcade
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  • PersonId : 859296
J. Renard
B. Gayral
E. Monroy

Abstract

GaN directly deposited on m-sapphire by plasma-assisted molecular-beam epitaxy settles into two main crystalline orientation domains: GaN﴾112¯2﴿ and GaN{101¯3}. The dominant phase is GaN﴾112¯2﴿ with <112¯3¯>GaN║ <0001>sapphire and <11¯00>GaN║ <112¯0>sapphire in-plane epitaxial relationships. Deposition of GaN on top of an AlN﴾112¯2﴿ buffer layer and growth under slightly Ga-rich conditions reduce GaN{101¯3} precipitates below the detection limits. Studies of Ga adsorption demonstrate that it is possible to stabilize up to one Ga monolayer on the GaN﴾112¯2﴿ surface. The presence of this monolayer of Ga excess on the growth front reduces the ﴾112¯2﴿ surface energy and hence minimizes the surface roughness. Photoluminescence from two-dimensional GaN﴾112¯2﴿ layers is dominated by a near-band-edge emission, which is assigned to excitons bound to stacking faults, present with a density around 3x105 cm−1.
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Dates and versions

cea-00372565 , version 1 (01-04-2009)

Identifiers

  • HAL Id : cea-00372565 , version 1

Cite

L. Lahourcade, J. Renard, B. Gayral, E. Monroy, Marie-Pierre Chauvat, et al.. Ga kinetics in plasma-assisted molecular-beam epitaxy of GaN(112¯2): Effect on the structural and optical properties. Journal of Applied Physics, 2008, 103, pp.093514. ⟨cea-00372565⟩
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