Asymmetrical quantum dot growth on tensile and compressive-strained ZnO nanowire surfaces

ZnO nanowire was bent in a high-resolution transmission electron microscope (HRTEM). The growth process of tensile and compressive stress-induced asymmetrical ZnO quantum dots (QDs) on bent ZnO nanowire (NW) surface was observed in situ at the atomic scale. The positionally resolved atomic-level strain distribution along the radial directions was mapped directly from the atomic-level strained HRTEM images of the bent ZnO NW. The size, growth rate and density of the QDs can be significantly affected by the strain type and magnitude. These results are helpful in controlling the fabrication of ZnO QDs.