Postgrowth hydrogen incorporation in In-rich InxGa1−xN (x>0.4) alloys strongly modifies the optical and structural properties of the material: A large blueshift 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 In_{x}Ga_{1−x}N (x>0.4) alloys using photoluminescence, x-ray absorption, and density functional theory / M. De Luca;G. Pettinari;G. Ciatto;L. Amidani;F. Filippone;A. Polimeni;E. Fonda;F. Boscherini;A. Amore Bonapasta;D. Giubertoni;A. Knübel;V. Lebedev;M. Capizzi. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - STAMPA. - 86:(2012), pp. 201202.201202-1-201202.201202-5. [10.1103/PhysRevB.86.201202]
Identification of four-hydrogen complexes in In-rich In_{x}Ga_{1−x}N (x>0.4) alloys using photoluminescence, x-ray absorption, and density functional theory
AMIDANI, LUCIA;BOSCHERINI, FEDERICO;
2012
Abstract
Postgrowth hydrogen incorporation in In-rich InxGa1−xN (x>0.4) alloys strongly modifies the optical and structural properties of the material: A large blueshift 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.