Quantitative investigation of intrinsic shear strain and asymmetric interface conditions in semiconductor superlattices.

We introduce a convenient and nondestructive method for the quantitative study of symmetry-related factors in low-dimensional semiconductor structures. By experimentally monitoring the intrinsic valence-bands mixing effect (VBME) and its variation with external strain modulation, together with the application of effective-mass theory, intrinsic shear strain and asymmetric interface conditions can be simultaneously determined in InGaAs/InAlAs superlattices. The observed shear strain is of the order of 10 − 3 . Further analysis reveals that the VBME induced by asymmetric interface conditions is weaker than that induced by intrinsic shear strain. In addition, they exhibit a compensating relationship in the studied superlattices. The proposed method can be generalized for quantitative investigation of symmetry-related factors in many other semiconductor nanostructures in the framework of k ⋅ p perturbation theory. [ABSTRACT FROM AUTHOR]