Growth direction and morphology of ZnO nanobelts revealed by combining in situ atomic force microscopy and polarized Raman spectroscopy

Abstract

Control over the morphology and structure of nanostructures is essential for their technological applications, since their physical properties depend significantly on their dimensions, crystallographic structure, and growth direction. A combination of polarized Raman _PR_ spectroscopy and atomic force microscopy _AFM_ is used to characterize the growth direction, the presence of point defects and the morphology of individual ZnO nanobelts. PR-AFM data reveal two growth modes during the synthesis of ZnO nanobelts by physical vapor deposition. In the thermodynamics-controlled growth mode, nanobelts grow along a direction close to _0001_, their morphology is growth-direction dependent, and they exhibit no point defects. In the kinetics-controlled growth mode, nanobelts grow along directions almost perpendicular to _0001_, and they exhibit point defects.