Résumé
InAs/InAsSb (Ga-free) type II superlattice (T2SL) is a promising candidate for mid wave infrared (MWIR) detection using III-V materials with minority carrier lifetime over 2µs [1, 2]. However, in order to achieve a MWIR compatible cut-off wavelength, a large period of more than 5 nm and a valence band offset between InAs and InAsSb of around 150 meV are required [3]. This results in localization of holes between significant periodic potential barriers which directly affects the dark current and quantum efficiency of detector. InGaAsSb quaternary material is an interesting candidate which offers an additional degree of freedom in T2SL bands engineering with versatile gap values and positions. These materials have been well studied in the GaSb rich part driven by 2.x µm GaSb based laser manufacturing [4]. Nevertheless, there are few studies in the InAs rich part, and gap values and positions are less known [5]. It's also not clear for what composition quaternary material quality became unacceptable for good performances compound manufacturing [6].</p><p>This work focuses on the study of InAs rich quaternary bulk and quaternary based T2SL. The quality of these molecular beam epitaxy grown materials was evaluated through X-Rays Diffraction, photoluminescence, optical absorption, Hall effect and minority carrier lifetime measurements. A 18bands KP model has been used to perform bulk and SL gap simulations. Finally, a barrier structure containing this new T2SL was grown and promising electrical performances of less than 10 -7 A.cm -² dark current density for a cut-off wavelength of 4.5 µm at 130 K were obtained.