Photoluminescence properties of Be-doped GaAs/(Al0.2Ga 0.8)0.51In0.49P heterostructures subjected to annealing processes Conference Paper uri icon

abstract

  • The photoluminescence (PL) properties of Be-doped GaAs/(Al0.2Ga0.8)0.51In0. 49P heterostructures doped at different beryllium concentrations were studied as a function of temperature. The analysis of 15 K-PL spectra showed strong transitions below both the GaAs and AlGaInP band edges associated with Be acceptor levels (A0,X), shallow impurities (A,X) and a low energy broad signal possibly related to oxygen deep levels (O,DL). We observed that the PL emission around the GaAs band edge changed according to the changes in the underlying AlGaInP layer. For instance, in low doped samples, the (A0,X) line dominates the GaAs PL spectrum, while for heavy doped samples the (A,X) transition becomes more important. When thermal treatments are applied, the intensity of (A0,X) increases while (A,X) diminishes suggesting Be-diffusion between GaAs and AlGaInP layers. In PL measurements performed as a function of temperature, we observed that the experimental data perfectly fits the empirical Varshni equation. When the most doped sample was annealed at 450 °C the (O,DL) transition dominates the PL spectra along with defect lines indicating disorder effects in the AlGaInP films. © 2005 Elsevier B.V. All rights reserved.

publication date

  • 2005-01-01