Optical investigation of strain-balanced superlattices

✍ Scribed by F.J. McGow; R.W. Martin; M. Hopkinson

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 63 KB
• Volume: 25
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1999.0668

✦ Synopsis

A series of strain-balanced GaInAs/AlInAs superlattices were investigated using optical spectroscopy. Three sets of excitonic Landau levels could be resolved in magneto-absorption spectra enabling estimates to be made for the reduced effective masses of the first and second electron to heavy hole (0.040 ± 0.001m e and 0.034 ± 0.002m e ) and the first electron to light hole (0.053 ± 0.002m e ) excitons. Enhancement in the light hole in-plane effective mass, relative to the heavy hole, is shown to result from the tensile strain in the quantum wells. Temperature-dependent photoluminescence measurements of these samples show evidence of thermal excitation of carriers between the first light and heavy hole states. The activation energy of this process compares well with the separation of the first heavy and light holes confined levels found from low-temperature absorption measurements in two structures with energy splitting of ∼40 meV and <10 meV respectively.