DLTS study of deep levels in GRIN–SCH–SQW GaAs/AlGaAs laser diode structures grown by MBE

Abstract Deep level transient spectroscopy has been used to measure the electrical activity of deep levels present in graded refractive index separate confinement heterostructure single quantum well laser diodes grown by molecular beam epitaxy. We report the use of untypical sequences of filling pulses to show that the main minority trap at ΔE B =0.78 eV acts as an effective non-radiative recombination center. Changes observed in the trap concentration, depending on growth conditions of the structures, can be a reason why photoluminescence intensities measured in the structures increase for higher substrate temperature and are in excellent correlation with threshold currents of lasers made of the structures.