Conduction- and Valence-Band Energies in Bulk InAs1−xSbx and Type II InAs1−xSbx/InAs Strained-Layer Superlattices

• Published in: Journal of electronic materials 2013-05, Vol.42 (5), p.918-926
• Main Authors: Lin, Youxi, Wang, Ding, Donetsky, Dmitry, Shterengas, Leon, Kipshidze, Gela, Belenky, Gregory, Svensson, Stefan P., Sarney, Wendy L., Hier, Harry S.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronics and Microelectronics; Exact sciences and technology; Instrumentation; Materials Science; Optical and Electronic Materials; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Photoluminescence; Physics; Solid State Physics
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-013-2528-9

The energy gaps were studied in two types of structures: unrelaxed bulk InAs 1− x Sb x layers with x  = 0.2 to 0.46 grown on metamorphic buffers and type II InAs 1− x Sb x /InAs strained-layer superlattices (SLS) with x  = 0.225 to 0.296 in the temperature range from T  = 13 K to 300 K. All structures were grown on GaSb substrates. The longest wavelength of photoluminescence (PL) at low temperatures was observed from bulk InAs 0.56 Sb 0.44 with a peak at 10.3  μ m and full-width at half-maximum (FWHM) of 11 meV. The PL data for the bulk InAs 1− x Sb x materials of various compositions imply an energy gap bowing parameter of 0.87 eV. A low-temperature PL peak at 9.1  μ m with FWHM of 13 meV was observed for InAs 0.704 Sb 0.296 /InAs SLS. The PL spectrum of InAs 0.775 Sb 0.225 /InAs SLS under pulsed excitation revealed a second peak associated with recombination of electrons in the three-dimensional (3D) continuum with holes in the InAs 0.775 Sb 0.225 . This experiment determined the conduction-band offset in the InAs 0.775 Sb 0.225 /InAs SLS. The energies of the conduction and valence bands in unstrained InAs 1− x Sb x and their bowing with respect to the Sb composition are discussed.