Improvement of photoluminescence and electroluminescence characteristics of MBE-grown In0.53Ga0.47As/In-0.53(Ga0.6Al0.4)(0.47)As quantum well laser structure with InGaAlAs digital alloys by thermal annealing

Abstract

We investigated the effect of rapid thermal annealing, (RTA) on the photoluminescence (PL) and electroluminescence of the In0.53Ga0.47As/In-0.53 (Ga0.6Al0.4)(0.47)As multiple quantum well (MQW) laser structure with InGaAlAs barrier layers provided by the digital-alloy technique. The SiO2- (Si3N4-) capped samples followed by the RTA exhibited a significant improvement of PL intensity without any appreciable shifts in PL peak energy for settings of up to 750 degreesC (800 degreesC) for 45 s. This improvement is attributed to the annealing of nonradiative defects in InAlAs layers of digital-alloy InGaAlAs and partially those near the heterointerfaces of the digital-alloy layers. The InGaAs/InGaAlAs MQW laser diodes fabricated on the samples annealed at 850 degreesC show a hugely improved lasing performance.