Transmission electron microscopy (TEM) and photocurrent (PC) measurements w
ere carried out to investigate the microstructural and excitonic transition
s in In0.52Ga0.48As/In0.55Al0.45As multiple quantum wells (MQWs). TEM image
s 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 i
s 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 in
creased. These results indicate that the strain-compensated In0.52Ga0.48As/
In0.55Al0.45As MQWs hold promise for electroabsorption modulator devices. (
C) 2001 Elsevier Science Ltd. All rights reserved.