Synthesis and band gap of ZnO particles with hexagonal bilayer structure

The unique water/PVP (polyvinylpyrrolidone)/n-pentanol interface has been developed to prepare the ZnO particles with hexagonal bilayer structure. By modifying the interface through varying the amount of PVP and water, one can readily tune the particle size and change the particle shape from hexagonal bilayer to capped potlike to hemispherical features. The study of the growth dynamics and extinction spectra suggests that the bilayer structure arises from the selective adsorption of PVP on the ZnO crystallographic planes. Both the photoluminescence and extinction spectra show that the band gap of the hexagonal bilayer ZnO particles shrinks with increasing particle size. (c) 2007 American Institute of Physics.