Characteristics of InGaAs quantum dots grown on tensile-strained GaAs_(1-x)P_x

摘要

InGaAs quantum dots (QDs) embedded in tensile-strained GaAs_(1-x)P_x (x=0.0-0.45) barrier layers are grown using low-pressure metal-organic chemical-vapor deposition. Variable-temperature photoluminescence (PL) measurement demonstrates that the lowest-energy QD transition can be blueshifted up to 90 nm compared with similar structures utilizing GaAs barriers. Temperature-dependent PL measurements and atomic force microscopy surface imaging show that the InGaAs QDs grown on GaAsP exhibit reduced height, which is consistent with shorter-wavelength emission. Preliminary results from broad stripe (100 μm wide) diode lasers utilizing two stacks of InGaAs QDs embedded in GaAs_(0.82)P_(0.18) barriers exhibit a 30% reduction in threshold current density compared with similar laser structures which have GaAs barriers.