Initial stages of the epitaxial growth of AlN on GaN (111)-(2 x 2) surface: Ab-initio studies
Por:
Moreno J.C., Camacho-Garcia J.H., Ponce-Pérez R., Sánchez-Ochoa F., Romero de la Cruz M.T., Cocoletzi G.H.
Publicada:
1 feb 2019
Resumen:
Initial stages of the aluminium nitride epitaxial growth on the gallium
nitride (1 1 1)-(2 x 2) surface have been investigated by
first-principles total-energy calculations. Studies have been performed
within the periodic density functional theory as implemented in the
PWscf code of the quantum espresso package. The electron-ion
interactions are treated according to the pseudopotential approach. The
exchange-correlation energies are treated within the generalized
gradient approximation according to Perdew-Burke-Ernzerhof
parameterization. First we investigate the Al adsorption on the surface
at high symmetry sites with results showing the T4 site as the most
stable geometry. The aluminium (Al) coverage varies from 1/4 to 1
monolayer. The Al incorporation into the GaN atomic structures occurs by
displacing the first layer Ga atoms, with Ga becoming the new adatom to
be adsorbed on the surface at high symmetry sites having the T4-2 as the
most favorable structure. Surface formation energies (SFE) are
calculated; according to results the AlN bilayer formation on top of the
surface is the most favorable structure. Moreover the Ga chain on the Al
terminated surface may be formed with SFE energy value similar to the Al
layer under a Ga layer. Electronic properties have been investigated by
calculating the density of states (DOS) and projected density of states
(PDOS) of the most favorable structures. At the Fermi level the density
of states displays no energy gap indicating that surfaces are metallic.
Filiaciones:
Moreno J.C.:
Univ Autonoma Puebla, Fac Ingn Quim, Puebla 72570, Mexico
Universidad Autónoma de Puebla, Facultad de Ingeniería QuímicaPuebla 72570, Mexico
Camacho-Garcia J.H.:
Univ Autonoma Puebla, Fac Ingn Quim, Puebla 72570, Mexico
Universidad Autónoma de Puebla, Facultad de Ingeniería QuímicaPuebla 72570, Mexico
Ponce-Pérez R.:
Univ Autonoma Puebla, Inst Fis, Apartado Postal J-48, Puebla 72570, Mexico
Univ Autonoma Coahuila, Fac Ciencias Quim, Saltillo 25280, Coahuila, Mexico
Universidad Autónoma de Puebla, Instituto de Física, Apartado Postal J-48Puebla 72570, Mexico
Universidad Autónoma de Coahuila, Facultad de Ciencias Químicas, Ing. J. Cárdenas Valdez, Republica, Saltillo, Coahuila 25280, Mexico
Sánchez-Ochoa F.:
Univ Nacl Autonoma Mexico, Inst Fis, Apartado Postal 20-364, Mexico City 01000, DF, Mexico
Universidad Nacional Autónoma de México, Instituto de Física, Apartado Postal 20-364, Cd. de México, 01000, Mexico
Romero de la Cruz M.T.:
Univ Autonoma Coahuila, Fac Ciencias Fis Matemat, Unidad Camporredondo, Edif A, Saltillo 25000, Coahuila, Mexico
Universidad Autónoma de Coahuila, Facultad de Ciencias Físico Matemáticas, Unidad Camporredondo, edif. A, Saltillo, Coahuila 25000, Mexico
Cocoletzi G.H.:
Univ Autonoma Puebla, Inst Fis, Apartado Postal J-48, Puebla 72570, Mexico
Universidad Autónoma de Puebla, Instituto de Física, Apartado Postal J-48Puebla 72570, Mexico
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