A novel BiOCl film with flowerlike hierarchical structures and its optical properties.

A novel BiOCl film with flowerlike hierarchical structures has been fabricated for the first time by dipping Bi film in a mixed solution of H(2)O(2) and HCl. This method presents the advantages of a simple technique, template-free, uniform and controllable morphology, as well as easy mass production. Each flowerlike hierarchical structure is composed of several dozen ultra-thin single-crystal nanopetals which grow along the 110 directions in the tetragonal structure. The layered growth of nanopetals is related to the more marked anion polarization along the c axis and layered stacking of various atoms (Cl-Bi-O-Bi-Cl). The growth mechanism of the BiOCl hierarchical structure is preferred to be a nucleation-dissolution-recrystallization process. A Raman shift originating from laser-induced compressive stress is observed. Photoluminescence (PL) spectra of the BiOCl film show principal green emission, indicating potential applications in optoelectronic devices.