Preparation of devices by liquid phase epitaxy with application to the achievement of a visible laser in GaAlAs

The effect of introducing Sn and Ge doping on the liquidus-solidus curves is studied for the case of epitaxy in GaAlAs. The proposed theory combined with the equations for epitaxial layer deposit kinetics has enabled the SPELLAS (simulation of liquid epitaxy processes for producing lasers) program to be set up. This program helps and completely simulates the production of multilayers by liquid-phase epitaxy according to several technologically important choices. In particular, we shall show the advantage of using a precursor substrate for a first deposition. An example of its application will be described for the preparation of visible lasers in GaAlAs. A laser structure emitting at 706 nm with a threshold current density of 4.3 kA/cm2 and an efficiency of ηD=20% has thus been made.