Effect of InAs insertion layer on the structural and optical property improvement of InGaAs/InAlAs multiple quantum wells

A 100 periods In0.53Ga0.47As/In0.52Al0.48As multiple quantum wells (MQWs) with and without 2 ML InAs insertion layers (ISLs) were grown on semi-insulating GaAs (001) substrates by molecular beam epitaxy (MBE). The stress-strain was weakened by inserting two monolayers of InAs between the In0.53Ga0.47As well layer and the In0.52Al0.48As barrier layer. High-resolution transmission electron microscopy (HRTEM) was investigated to visually characterize the crystal quality of MQW structures with and without InAs ISLs. The effect of structural and optical properties of the In0.53Ga0.47As/In0.52Al0.48As MQWs by InAs-inserting were characterized by X-ray diffraction (XRD) and photoluminescence (PL) spectra. The research shows that the introduction of the 2 ML InAs ISLs can eliminate the strain and reduce the average dislocation density from 2.4×108 cm−2 to 1.4×108 cm−2 in the InGaAs/InAlAs MQWs structure, then control the interface between InGaAs and InAlAs, and finally realize the improvement of the quantum well structural and optical properties with the PL intensity increased by one order of magnitude. Our studies have great significance to the fabrication of GaAs-based multiple quantum well optoelectronic devices, which promote the further development of high-performance versatile optoelectronic applications. •Introduce the InAs insertion layer to grow high-quality InGaAs/InAlAs MQWs on lattice-mismatched GaAs substrates.•By inserting InAs layers, the strain is reduced, resulting in an improvement in the crystal and optical quality of the MQWs.•XRD and PL characterised the InAs ISL effect on strain reduction, improved crystal quality and enhanced PL intensity in MQWs.