InAs/GaSb type-II superlattice structures and photodiodes grown by metalorganic chemical vapor deposition

Abstract

We report on the characterization and performance of epitaxial structures and photodiodes based on InAs/GaSb type-II superlattices grown by metalorganic chemical vapor deposition. Interfacial layers were introduced at the superlattice interfaces to compensate the tensile strain and hence to improve the overall material quality of the superlattice structures. The optimal morphology and low strain was achieved via a combined interfacial layer scheme with InAsSb+InGaSb layers. Using this scheme, a p-i-n photodiode structure with a 360-period InAs/GaSb superlattice was grown on a GaSb substrate, which operates at 78 K with a cut-off wavelength of ∼8 μm and a peak responsivity of 0.6 A/W at ∼6 μm.

Causes and elimination of pyramidal defects in GaSb-based epitaxial layers

“…Additionally, a rougher starting surface has been associated with increased decomposition of metastable layers. [16][17][18][19] Studies that do exist have reported high densities of mesoscopic defects, often pyramidal in shape, 20,21 at typical densities of 10 4 to 10 5 cm À2 . 15 However, there are a lack of studies of the morphology of GaSb buffer layers grown by molecular beam epitaxy (MBE).…”

Epitaxial growth and characterization of InAs/GaSb and InAs/InAsSb type-II superlattices on GaSb substrates by metalorganic chemical vapor deposition for long wavelength infrared photodetectors

“…There are few reports on the growth and characterization of MOCVD-grown InAs/GaSb T2SLs [18,19] as well as InAs/InAsSb T2SLs [15,20]. The authors have investigated the viability of short-period InAs/GaSb T2SL growth by MOCVD on GaAs and GaSb substrates [21,22] and have demonstrated an InAs/GaSb T2SL photodiode with a cut-off wavelength of l$8 mm [23,24]. The next step is to explore the feasibility of the T2SL photodiodes employing InAs/InAsSb SLs in comparison with InAs/GaSb T2SLs grown by MOCVD.…”

Effect of growth temperature on surface morphology and structure of InAs/GaSb superlattices grown by metalorganic chemical vapor deposition

“…However, the growth of InAs/GaSb SLs with high crystalline quality and good optical properties by metalorganic chemical vapor deposition (MOCVD) remains a great challenge. The difficulties arise not only from the lattice mismatch between InAs and GaSb [9,10], but also from the special V-group precursor of trimethylantimony (TMSb) and interdiffusion near the interfaces where no common atoms exist. Previous report has shown the arsenic-for-antimony and indiumfor-gallium exchanges by using cross-sectional scanning tunneling microscopy [11].…”