GROWTH AND CHARACTERIZATION OF SERPENTINE SUPERLATTICES IN THE GASB-ALSB SYSTEM

We report the growth of GaSb/AlSb serpentine superlattices (SSLs) on vicinal GaAs and GaSb substrates. Cross-sectional transmission electron microscopy confirms the SSL structure and shows excellent lateral uniformity, better than previous arsenide-SSLs. Photoluminescence (PL) measurements indicate a good-quality lateral superlattice with a spectral linewidth between 13 and 15 meV. Polarization-dependent PL measurements give a normalized linear polarization around 60%, the strongest that has been seen for SSL structures. Preliminary estimates suggest much better segregation between the Ga-rich and Al-rich regions than arsenide-SSLs, with the change in aluminum concentration DELTAx almost-equal-to 0.35.