Figure 3.

(a) Typical Raman spectra of bare ZnO and Au-ZnO NRs measured at room temperature using 532 nm laser excitation. The height and width (FWHM) variations of the E₂^high mode of ZnO measured in-situ with increasing temperatures are shown in (b) and the linear relationship of the FWHM with increasing temperatures is shown in (c). The relationship of FWHM of E₂^high mode of ZnO in the presence and absence of Au NPs with different laser (532 nm) incident powers is shown in (d), where T represents the temperature at the Au-ZnO NRs surface estimated from the corresponding FWHM values.