Résumé
We studied the Ga-free InAs/InAsSb type-II superlattice (T2SL) period, thickness and antimony composition, in order to define an optimized structure suitable for detection of the full mid-wavelength infrared domain (MWIR). The SL structures were fabricated by MBE on n-type GaSb substrates and exhibited cut-off wavelengths between 5μm and 5.5μm at 150K. The growth procedure used to achieve strain-balanced structures is reported and first structural and optical results, made of high-resolution Xray diffraction pattern, AFM image scan, photoluminescence (PL) and time resolved photoluminescence measurements (TRPL), are presented and analyzed.