Superposition of light-hole and heavy-hole bandgaps in InGaAsInAlAs strained quantum-well structures

✍ Scribed by I.J. Fritz; J.F. Klem; T.M. Brennan; J.R. Wendt; T.E. Zipperian

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 521 KB
• Volume: 10
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1016/0749-6036(91)90156-l

✦ Synopsis

We present calculations and data on superposltlonlng of light-and heavy-hole band-edge states in InxGal.xAs/InyAll.yAs multiple strained quantum-well structures.

This superposltloning, produced by tailoring the built-in biaxial tensile strain in the InGaAs quantum wells, may improve performance of electro-optic devices operating near bandgap. We have used electric-fleld dependent photocurrent and electroreflectance spectroscoples to characterize two samples with bandgaps near 1.5 pm. Of these samples, one has coincident bandgaps at zero applied electric field, whereas the other requires a field of -2 x 105 V/cm for superpositioning.

Our observed transition energies agree with modeling based on phenomenological deformation-potential theory coupled with two-band envelope-function calculations.