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

The effect of growth temperature on the surface morphology and crystalline structure of InAs/GaSb type-II superlattices (SLs) grown on (100) GaSb substrates by metalorganic chemical vapor deposition (MOCVD) was investigated by in-situ reflectance measurement, atomic force microscopy, high-resolution x-ray diffraction and Raman scattering spectroscopy. All the data show that the structural properties of the SL samples are very sensitive to the growth temperatures. The optimal SL growth temperature in our MOCVD is 520 °C. Only 20 °C lower of the temperature resulted in rough surfaces from the beginning of SL epitaxy and 20 °C higher resulted in the composition of the mixing interfaces far from expected and consequently deteriorated structure. Room temperature absorption from 2 to 8 μm has been realized by our samples.

► InAs/GaSb superlattices were grown with ternary alloy interfaces by MOCVD.
► The interfaces and crystalline quality were very sensitive to the growth temperature.
► The optimized growth temperature was determined to be 520 °C.
► Room temperature absorption from 2 to 8 μm has been realized.