ACTA

First-Principles Investigation of Structural and Electronic Properties of the B_xGa_{1 - x}N, B_xAl_{1 - x}N, Al_xGa_{1 - x}N and B_xAl_yGa_{1 - x - y}N Compounds

L. Djoudi^{a, b}, A. Lachebi^a, B. Merabet^a and H. Abid^a
^aApplied Materials Laboratory, Research Center, Sidi Bel Abbes University, 22000, Algeria
^bUniversity of Tissemsilt, Institute of Science and Technology, 38000, Algeria

Received: January 17, 2012; in final form August 4, 2012

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The structural and electronic properties of the B_xGa_{1 - x}N, B_xAl_{1 - x}N, Al_xGa_{1 - x}N and B_xAl_yGa_{1 - x - y}N compounds were studied using the full-potential linearized augmented plane wave method, within the generalized gradient approximation. We have compared the Al and B compositions dependence on the ground state properties: lattice parameters, bulk moduli and their pressure derivative, and band gap energies. The lattice parameters are found to change linearly for Al_xGa_{1 - x}N, exhibit a downward bowing for both B_xAl_{1 - x}N and B_xGa_{1 - x}N, and has a very small deviation when Al is added and a large deviation when B is incorporated for B_xAl_yGa_{1 - x - y}N. The calculated band gap variation for the ternaries shows that the B_xGa_{1 - x}N has a phase transition from direct-gap to indirect-gap for high boron contents (x > 0.75). As for B_xAl_{1 - x}N, a direct-gap is found in the boron content range 0.07 < x < 0.83. For Al_xGa_{1 - x}N and B_xAl_yGa_{1 - x - y}N compounds, they have been found to be direct-gap materials. The results show that the B_xGa_{1 - x}N, B_xAl_{1 - x}N, Al_xGa_{1 - x}N and B_xAl_yGa_{1 - x - y}N materials may well be useful for optoelectronic applications.

DOI: 10.12693/APhysPolA.122.748
PACS numbers: 71.15.Mb, 71.20.-b, 71.20.Nr, 71.55.Eq