Université Montpellier 2, Groupe d'Étude des Semiconducteurs, UMR-CNRS 5650, Case Courrier 74, 34095 Montpellier Cedex 5, France
We report the growth of indium-rich InGaN alloys by metal-organic vapour phase epitaxy, using ammonia, trimethylgallium and trimethylindium as precursors. Compared to indium nitride, our alloy samples present substantial photoluminescence robustness with temperature. The analysis of the optical properties of these samples versus temperature indicates the existence of two non radiative recombination channels: one with a thermal activation temperature of 77 K and another one with an activation temperature ranging from 300 K for InN up to 640 K for In0.72Ga0.28N. The latter competes with the former at low temperatures whilst the former rules the optical properties at ambient conditions.
(Received September 11 2008)
(Accepted December 11 2008)
(Online publication January 31 2009)