QUANTUM-WELL LASERS WITH CARBON-DOPED CLADDING LAYERS GROWN BY SOLID SOURCE MOLECULAR-BEAM EPITAXY

Data are presented which demonstrate that very high quality carbon (C) doped epilayers for the fabrication of AlGaAs-GaAs and AlGaAs-GaAs-InGaAs quantum well (QW) lasers can be grown by solid source molecular beam epitaxy (MBE) using a resistively heated graphite filament as a p-type dopant source. Broad area lasers fabricated from this material exhibit very low threshold current densities (66 A/cm(2) for a 2-mm-long single QW AlGaAs-GaAs-InGaAs laser emitting at 980-nm wavelength). It is also shown that lasers with carbon doped cladding layers grown on either n(+) or p(+) substrates exhibit similar low threshold current densities. These C-doped lasers are expected to have improved long term reliability compared to conventional Be-doped laser structures.