Microstructural and optical properties of strain compensated InxGa1−xAs/InyAl1−yAs multiple quantum wells Original Research Article

Transmission electron microscopy (TEM) and photocurrent (PC) measurements were carried out to investigate the microstructural and excitonic transitions in In0.52Ga0.48As/In0.55Al0.45As multiple quantum wells (MQWs). TEM images showed that high-quality 11-period strain-compensated In0.52Ga0.48As/In0.55Al0.45As MQWs had high-quality heterointerfaces. Based on the TEM results, a possible crystal structure for the In0.52Ga0.48As/In0.55Al0.45As MQWs is presented, and their strains are compensated. The results for the PC data at 300 K for several applied electric fields showed that several excitonic transitions shifted to longer wavelengths as the applied electric field increased. These results indicate that the strain-compensated In0.52Ga0.48As/In0.55Al0.45As MQWs hold promise for electroabsorption modulator devices.