Post-growth hydrogen incorporation in In-rich InxGa1-xN (x>0.4) alloys strongly modifies the optical and structural properties of the material: A large blue-shift of the emission and absorption energies is accompanied by a remarkable broadening of the interatomic distance distribution, as probed by synchrotron radiation techniques. Both effects vanish at a finite In-concentration value (x0.5). Synergic x-ray absorption measurements and first-principle calculations unveil two different defective species forming upon hydrogenation, one due to the high chemical-reactivity of H, the other ascribed to mere lattice damage. In the former species, four H atoms bind to as many N atoms, all nearest neighbors of a same In atom. The stability of this peculiar complex, which is predicted to behave as a donor, stems from atomic displacements cooperating to reduce local strain.

Identification of four-hydrogen complexes in In-rich InxGa1-xN (x>0.4) alloys using photoluminescence, x-ray absorption, and density functional theory

Giubertoni, Damiano;
2012

Abstract

Post-growth hydrogen incorporation in In-rich InxGa1-xN (x>0.4) alloys strongly modifies the optical and structural properties of the material: A large blue-shift of the emission and absorption energies is accompanied by a remarkable broadening of the interatomic distance distribution, as probed by synchrotron radiation techniques. Both effects vanish at a finite In-concentration value (x0.5). Synergic x-ray absorption measurements and first-principle calculations unveil two different defective species forming upon hydrogenation, one due to the high chemical-reactivity of H, the other ascribed to mere lattice damage. In the former species, four H atoms bind to as many N atoms, all nearest neighbors of a same In atom. The stability of this peculiar complex, which is predicted to behave as a donor, stems from atomic displacements cooperating to reduce local strain.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11582/128401
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