Dependence of the groundstate interband optical transition in InAs-GaSb superlattices on the width of the GaSb layers

We have investigated the optical characteristics of a set of InAs-GaSb superlattice structures (SLS) which have InAs layers with a fixed width of 25 {\AA} and GaSb layers whose width varies from stucture to structure over the range 25 {\AA} to 100 {\AA}. Photoluminescence measurements were carried out over the range 10K -- 100K on the SLS. Using photodiodes fabricated from the SLS, measurements of the photocurrent-excitation energy spectrum and the time-resolved photoconductivity were carried out at 78K. The observed dependence of the relative oscillator strength of the SLS band-edge transition on the GaSb layer width will be compared with theory$^{1}$. The effect of defects on the the optical and transport properties of the SLS and the dependence of this effect on the GaSb layer width will be discussed.