Abstract
We have investigated the polarization dependence of the near-band-edge photoluminescence and photoreflectance spectra in nonpolar (A-plane) ZnO films under strong biaxial compressive strain. We show that anisotropic strain and the orientation of the nonpolar plane play an important role in determining the polarization selectivity and properties of excitonic transitions. We identified four distinct band-edge transitions at 3.449, 3.420, 3.386, and 3.326eV. They were identified as E2 and E1 free excitons, E1 excitons bound to a donor, and free-electron-to-bound-hole transition, respectively. Unlike previously reported results on relatively thick nonpolar films, the E1 exciton (lowest energy) was mainly polarized to E⊥c and weakly polarized to E∥c under strong biaxial compressive strain in the 100nm thick film. The E2 exciton (next higher energy) was exclusively polarized to E∥c. The localization energy of DX is 34meV, which is much larger than that in polar ZnO, and the DX was not thermally delocalized even at room temperature.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
