Strain states in semipolar III-nitride semiconductor quantum wells.

Strain states in wurtzite III-nitride semiconductor quantum wells (QWs) are investigated. X-ray diffraction (XRD) reciprocal space mapping using semipolar [formula] and [formula] InGaN/GaN QWs as test samples demonstrates that the projections of reciprocal lattice vectors of unstrained GaN and pseudomorphically strained InGaN on the interface agrees, indicating continuity of layers across the interface. High resolution transmission electron microscopy supports the XRD analysis. Based on the experimental results, strain tensor elements are extracted for arbitrary crystalline orientation. Furthermore, expansion of the model to arbitrary crystal structures is suggested. [ABSTRACT FROM AUTHOR]