RESUMO
BACKGROUND: In x Ga1-x Sb is an important material that has tunable properties in the infrared (IR) region and is suitable for IR-device applications. Since the quality of crystals relies on growth conditions, the growth process of alloy semiconductors can be examined better under microgravity (µG) conditions where convection is suppressed. AIMS: To investigate the dissolution and growth process of In x Ga1-x Sb alloy semiconductors via a sandwiched structure of GaSb(seed)/InSb/GaSb(feed) under normal and µG conditions. METHODS: In x Ga1-x Sb crystals were grown at the International Space Station (ISS) under µG conditions, and a similar experiment was conducted under terrestrial conditions (1G) using the vertical gradient freezing (VGF) method. The grown crystals were cut along the growth direction and its growth properties were studied. The indium composition and growth rate of grown crystals were calculated. RESULTS: The shape of the growth interface was nearly flat under µG, whereas under 1G, it was highly concave with the initial seed interface being nearly flat and having facets at the peripheries. The quality of the µG crystals was better than that of the 1G samples, as the etch pit density was low in the µG sample. The growth rate was higher under µG compared with 1G. Moreover, the growth started at the peripheries under 1G, whereas it started throughout the seed interface under µG. CONCLUSIONS: Kinetics played a dominant role under 1G. The suppressed convection under µG affected the dissolution and growth process of the In x Ga1-x Sb alloy semiconductor.
