First-Principles Investigation of Structural and Electronic Properties of the BxGa1 - xN, BxAl1 - xN, AlxGa1 - xN and BxAlyGa1 - x - yN Compounds
L. Djoudia, b, A. Lachebia, B. Merabeta and H. Abida
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 BxGa1 - xN, BxAl1 - xN, AlxGa1 - xN and BxAlyGa1 - x - yN 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 AlxGa1 - xN, exhibit a downward bowing for both BxAl1 - xN and BxGa1 - xN, and has a very small deviation when Al is added and a large deviation when B is incorporated for BxAlyGa1 - x - yN. The calculated band gap variation for the ternaries shows that the BxGa1 - xN has a phase transition from direct-gap to indirect-gap for high boron contents (x > 0.75). As for BxAl1 - xN, a direct-gap is found in the boron content range 0.07 < x < 0.83. For AlxGa1 - xN and BxAlyGa1 - x - yN compounds, they have been found to be direct-gap materials. The results show that the BxGa1 - xN, BxAl1 - xN, AlxGa1 - xN and BxAlyGa1 - x - yN 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