Initial Growth Behavior in Catalyst-Free-Grown Vertical ZnO Nanorods on c-Al2O3, as Observed Using Synchrotron Radiation X-ray Scattering

초록

In this study, synchrotron radiation X-ray diffraction analysis is used to investigate the initial growth dynamics of metal-organic vapor-phase epitaxy-grown ZnO nanorods on c-Al<inf>2</inf>O<inf>3</inf> substrates. A two-dimensional area detector with a grazing-incidence geometry enables projected reciprocal space mapping (RSM) using coordinate transformation of diffraction images. The projected RSM reveals multiple heteroepitaxial relationships between ZnO and Al<inf>2</inf>O<inf>3</inf>, including the dominant relationship of ZnO(101̅0)∥Al<inf>2</inf>O<inf>3</inf>(21̅1̅0). Evolution of internal strain is revealed by an additional study on diffraction images and θ-2θ scans. Surface topology from atomic force microscopy estimates the growth rate, supported by the Scherrer equation analysis of the θ-2θ diffraction. © 2023 American Chemical Society.