Improved Regrowth Interface of AlGaInAs/InP-Buried-Heterostructure Lasers by In-Situ Thermal Cleaning

The influence of in-situ thermal cleaning on the regrowth interface quality of 1.3-μm wavelength AlGaInAs/InP-buried-heterostructure (BH) lasers grown by organo-metallic vapor-phase epitaxy was investigated. The surface recombination velocity estimated from below threshold electroluminescence measurements was used to quantitatively study regrowth interface quality. The relationship between surface recombination velocity and lasing properties was supported by theory. In this way, we could validate the use of surface recombination velocity as a measure of interface quality. In-situ thermal cleaning at 650°C for 45 min under PH₃ atmosphere resulted in operational BH lasers (1.6 μm stripe width) with a differential quantum efficiency of 66% and an internal quantum efficiency of approximately 76%.