Preparation of Laser Diodes on Wide Band-Gap Materials
Original Publication Date: 1980-Jan-01
Included in the Prior Art Database: 2005-Feb-13
Laser diodes emitting in the visible spectrum can only be obtained with appreciable p- and n-doping of crystals with sufficiently wide band-gaps, such as II-VI or III-V compounds. Wide band-gap materials of good crystalline quality usually cannot be prepared with both types of doping, due to the phenomenon of vacancy formation that results in self-compensation of one or both types of dopants. A new preparation method uses doping by ion implantation, followed by rapid laser annealing to restore the crystalline quality of the damaged surface layer. This allows one to achieve simultaneously a fair crystal quality and the required doping profiles, as the fast epitaxial recrystallization that follows the laser irradiation occurs in conditions that are far from thermodynamic equilibrium.