Raman scattering and photoluminescence studies of ZnO nanowhiskers assembled as flowers in the presence of fullerene

Probing surface states in C60decorated ZnO microwires: detailed photoluminescence and cathodoluminescence investigations

“…18,24,57 Also in that case, a slight redshi of the peak position of the broad band was observed by increasing the C 60 content from #5 to #20 ooding, 8 although less pronounced than that in the present case, which again can be attributed to a higher contribution of the surface-related green emission when compared to the orange component. Additionally, comparing the present results with other results found in the literature for ZnO/C 60 composites, it is possible to infer that the decrease in the intensity of the green emission seems to be a common trend, as also reported by Baibarac et al 58 In their work, the authors coated ZnO nanowhiskers with C 60 molecules and found that the intensity of the broad band decreases with the C 60 addition. Moreover, they observed that in the case of the ZnO nanowhiskers alone, the PL signal decreased when the measurements were carried out in vacuum ($5.4 Â 10 À5 mbar), attributing this behaviour to the removal of physically adsorbed entities on the surface of the semiconductor, reducing the number of trapping centres of electrons and holes.…”

“…This decrease was not observed in the composites, suggesting the absence of such surface recombination centres, which are expected to be replaced by the chemical attachment of the C 60 molecules onto ZnO. 58 Nevertheless, it is important to take into account that the behaviour of the ZnO luminescence centres in the presence of different carbon structures may differ from the one presented here, depending on the type of interaction that is established between the carbon and the ZnO structures and the subsequent alignment of the energy levels of both materials, namely the defect-related ones. Furthermore, the origin and locations of the defects found in the semiconductor will also play an important role.…”

“…This decrease was not observed in the composites, suggesting the absence of such surface recombination centres, which are expected to be replaced by the chemical attachment of the C 60 molecules onto ZnO. 58 …”

Dual Transduction of H2O2 Detection Using ZnO/Laser-Induced Graphene Composites

“…Therefore, the presence of LIG in close contact with ZnO enhances the population of the excitonic levels of the semiconductor and/or the surface defects located in the UV energy range, at the same time that LIG contributes to the passivation of part of the defects that originate the green emission, leading to the reduction in its intensity. The reduction or even suppression of the green spectral component has been observed in other ZnO structures when in contact with C 60 molecules [13,14,92] or Ag micro/nanoparticles [75]. In these cases, charge transfer from surface defects of the ZnO to such materials was found to be the cause for the decrease in the radiative processes [13,14,75].…”