Figure 7.

The as-prepared SiO2 hollow octahedra: a low and b high magnification SEM image, c TEM image. d PL spectra of (a) ZnO and (b) ZnO/SiO2 core/shell structures obtained under an ultraviolet excitation at 350 nm

Wu et al. Nanoscale Research Letters 2010 5:1779-1787   doi:10.1007/s11671-010-9711-1