Figure 4.

a Spatial mapping of corresponding Raman intensities of the E2 peak ranging from 417 to 448 cm−1; b series of Raman spectra taken along the growth direction of a single ZnONW. The E2 phonon peak shifts to a lower frequency and broadens as a result of the nano-sized effect

Gandhi et al. Nanoscale Research Letters 2009 5:581-586   doi:10.1007/s11671-009-9509-1