Effects of hydrogen irradiation on optical quality of GaN(x)As(1-x) alloys grown by gas source molecular beam epitaxy are studied by photoluminescence (PL) and PL excitation spectroscopies. A strong blue shift of the alloy band gap towards the value of a reference. N-free GaAs samples is revealed. Substantial improvements in the optical quality of the structures induced by hydrogen, due to a reduction of band edge potential fluctuations, is also demonstrated. The effect is tentatively attributed to the preferential trapping of hydrogen atoms at the lattice sites with the highest N compositions, which leads to the neutralization of electronic states contributing to the band tail states as well as to the improvement in strain uniformity. (C) 2003 Elsevier B.V. All rights reserved.
Role of hydrogen in improving optical quality of GaNAs alloys / M., Izafard; I. A., Buyanova; W. M., Chen; Polimeni, Antonio; Capizzi, Mario; C. W., Tu. - In: PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES. - ISSN 1386-9477. - STAMPA. - 20:3-4(2004), pp. 313-316. (Intervento presentato al convegno 11th International Conference on Narrow Gap Semiconductors tenutosi a BUFFALO, NY nel JUN 16-20, 2003) [10.1016/j.physe.2003.08.025].
Role of hydrogen in improving optical quality of GaNAs alloys
POLIMENI, Antonio;CAPIZZI, Mario;
2004
Abstract
Effects of hydrogen irradiation on optical quality of GaN(x)As(1-x) alloys grown by gas source molecular beam epitaxy are studied by photoluminescence (PL) and PL excitation spectroscopies. A strong blue shift of the alloy band gap towards the value of a reference. N-free GaAs samples is revealed. Substantial improvements in the optical quality of the structures induced by hydrogen, due to a reduction of band edge potential fluctuations, is also demonstrated. The effect is tentatively attributed to the preferential trapping of hydrogen atoms at the lattice sites with the highest N compositions, which leads to the neutralization of electronic states contributing to the band tail states as well as to the improvement in strain uniformity. (C) 2003 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
