| GaInAsSb semiconductor alloy is an important material for mid and far-IR laser devices. However most of its properties are still unknown and despite today's epitaxy techniques, GaInAsSb still represents a challenge due to the difficulty of controlling the composition during the growth of mixed arsenic and antimony compounds. In this work, we have employed a novel growth technique referred to as beam modulated epitaxy and demonstrated its advantages respect to conventional molecular beam epitaxy. By use of this technique, good quality GaInAsSb layers were obtained over the whole GaSb lattice matched composition and from their photoluminescence the GaInAsSb bandgap fit parameters retrieved. To perform such fit, a mathematically consistent extension of the Thompson-Wolley interpolation was developed. Such interpolation technique is then extended to fit the measurements of the composition dependent band offsets of GaInAsSb and to present for the first time, the valence band offset coefficients of this alloy. |
