Optical properties of low-dimensional systems based on group-III nitride ternary and quaternary alloys.
CNRS - Universite Montpellier 2 (GES), Place Eugene Bataillon, Montpellier 34095, France
In low-dimensional systems based on hexagonal group-III nitrides, the optical recombination of electron-hole pairs is tributary to the complex interplay of internal electric fields and of the localisation of carriers, at the scale of a few nanometers. A microscopic model is proposed that accounts for these intricate influences and for the resulting remarkable scaling law that was observed by time-resolved photoluminescence (TRPL) in a variety of InGaN/GaN quantum well and quantum dot systems: once plotted in a reduced-time scale, the photoluminescence decay keeps a constant, nonexponential shape. The time-dependent screening of the internal field by high densities of electron-hole pairs is analysed. The paper also presents TRPL results proving that it is possible, by using quaternary alloys, to produce quantum structures for which the internal electric field is minimized.
Presentation: invited oral at E-MRS Fall Meeting 2003, Symposium A, by Pierre LEFEBVRE
See On-line Journal of E-MRS Fall Meeting 2003
Submitted: 2003-06-02 15:58 Revised: 2009-06-08 12:55