Growth and optical properties of ZnO microwells by chemical vapor deposition method

The well-like ZnO nanostructures were obtained by chemical vapor deposition method. The uniform and dense ZnO slim nano-columns were grown along the circle to form a microwell. The growth mechanisms, such as 1D linear, 2D screw dislocation and step growth are discussed. These observations provide some insight into the growth kinetics in vapor–solid growth process. The fabrication of ZnO microwell morphology provided a direct experimental evidence for explaining the 1D growth mechanism based on the axial screw dislocation. Photoluminescence (PL) microscopy showed the surface-related optical properties. The green light emission enhancement revealed that the ZnO microwells have waveguide properties. The abnormal enhancement of integrated PL intensity of deep-level emission with temperature increase showed abundant surface state existence.