AVS 46th International Symposium
    Surface Science Division Tuesday Sessions
       Session SS-TuP

Paper SS-TuP15
Raman-scattering Study of In(As,Sb)/InSb Superlattices

Tuesday, October 26, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: L. Artús, Institut Jaume Almera (CSIC), Spain
Authors: B. Marcos, Institut Jaume Almera (CSIC), Spain
R. Cuscó, Institut Jaume Almera (CSIC), Spain
R.A. Stradling, Imperial College, U.K.
L. Artús, Institut Jaume Almera (CSIC), Spain
Correspondent: Click to Email
InAs@sub 1-x@Sb@sub x@ alloys display the smallest bandgap in the III-V group for x=0.6. By growing In(As,Sb)/InAs superlattices even smaller effective bandgaps can be obtained, making these layer structures very interesting for applications to mid- and far-infrared semiconductor lasers and light-emitting diodes operating at wavelengths from 4 to beyond 10 µm. In a previous paper@footnote 1@ we reported a Raman-scattering study of the optical phonon modes of InAsSb/InAs strained-layer superlattices(SSL) for different Sb compositions, but to our knowledge no study has been reported so far on the phonons of the other end system SSLs, namely the InAsSb/InSb SSLs. In the present work we report Raman measurements on InAsSb/InSb SSLs for several As concentrations below 20%. The InAsSb alloy displays a two-mode behaviour,@footnote 2@ and consequently the InSb-like and InAs-like LO modes of the alloy are expected. In fact, despite the low As concentration of the alloy, in the (Z|XY|-Z) Raman spectra we could observe not only the InSb-like LO mode of the alloy but also the InAs-like LO mode. The strain-induced relative shift of this peak is well accounted for by elastic strain calculations. In the (Z|XX|-Z) configuration an additional peak is observed below the InSb-like LO mode of the alloy that can be tentatively assigned to interface modes. @FootnoteText@ @footnote 1@ L. Artús, R. A. Stradling, Y. B. Li, S. J. Webb, W. T. Yuen, S. J. Chung, and R. Cuscó, Phys. Rev. B 54, 16 373 (1996). @footnote 2@ Y. B. Li, S. S. Dosanjh, I. T. Ferguson, A. G. Norman, A. G. de Oliveira, R. A. Stradling, and R. Zallen, Semicond. Sci. Technol. 7, 567 (1992).