Optimization of InAs/GaSb type-II superlattice interfaces for long-wave (∼8 μm) infrared detection

• Published in: Journal of crystal growth 2009-03, Vol.311 (7), p.1901-1904
• Main Authors: Khoshakhlagh, A., Plis, E., Myers, S., Sharma, Y.D., Dawson, L.R., Krishna, S.
• Format: Article
• Language: English
• Subjects: A1. Interfaces; A1. Superlattices; A3. Antimonides; A3. Molecular beam epitaxy; B3. Infrared devices; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of crystal growth; physics of crystal growth; Methods of deposition of films and coatings; film growth and epitaxy; Molecular, atomic, ion, and chemical beam epitaxy; Physics; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2008.11.027

Optimization of various growth parameters for type-II 13 MLs InAs/7 MLs GaSb strained layer superlattices (SLSs) ( λ cut-off ∼8 μm at 300 K), grown by solid source molecular beam epitaxy, has been undertaken. This includes a systematic study to investigate the influence of the effect of the growth temperature and the thickness of an InSb layer formed at the GaSb-on-InAs interface on the properties of the superlattice. We present optical and structural characterization of these SLS structures, using high-resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM) and cross-sectional scanning transmission electron microscope (STEM). Optimized growth parameters were then used to grow a 2-μm-thick active region for a SLS detector designed to operate in the long-wave infrared (LWIR) region, which demonstrated full-width half-maximum (FWHM) of 16 arcsec for the first SLS satellite peak and nearly zero lattice mismatch between zero-order SLS peak and GaSb substrate.