Reliability of carbon doped MOCVD grown InGaAs/AlGaAs high power laser diodes

InGaAs/AlGaAs SQW and DQW broad waveguide separate confinement laser heterostructures with carbon p-doping have been investigated. For this purpose carbon-doping of GaAs and AlGaAs layers grown by low pressure MOCVD, using triethylgallium, trimethylaluminium and arsine as growth precursors and carbon tetrachloride as p-type dopant precursor, were studied. Doping level dependence on technology parameters (growth temperature, growth rate, V/III ratio) was established. Broad waveguide heterostructures design and optimization of active area growth conditions have been fulfilled to obtain high power operation of laser diodes with low transverse divergence. Broad area laser diodes were manufactured and analyzed. The 100 μm wide stripe laser diodes demonstrated more than 5W CW output power. Slope efficiency varied from 0.8 to 1.1 W/A. The results were compared with similar laser diodes based on Zn-doped heterostructures. The LDs have been tested during 5000 hours at output power 1.5 W at RT. The LDs demonstrated less than 3% fall power at a constant drive current. The LDs with the same geometry and Zn-doping P-clad and p+contact demonstrated more significant fall 5-6% at the same test conditions. The optimal p-type dopant precursor for high power laser diodes was discussed.