VALENCE-BAND MODULATION IN INGAAS INALAS SUPERLATTICES WITH TENSILELYSTRAINED WELLS GROWN ON INGAAS QUASI-SUBSTRATE ON GAAS/

We have studied structural and optical properties of strained InGaAs/I nAlAs superlattices grown on an InGaAs quasi-substrate on GaAs by X-ra y diffraction measurement, photoluminescence and photocurrent spectros copy. The measurements were performed for two sample groups: one was W annier-Stark type superlattices (SLs) with thin barriers and the other was quantum confined Stark effect type SLs with relatively thick barr iers. In each group, we have obtained ample evidence for modulation ef fects on the SLs' band structure by tensile strain, which is controlle d by the lattice constant of the InGaAs quasi-substrate.