Figure 6
Mechanisms of the photocurrent generation in the TiO2-Au bilayer.
(a) Hot electron injection, for which the rough Au film absorbs photons of different wavelengths to generate hot electrons, whose potential levels of excited states are high enough to overcome the potential barrier to be injected into the TiO2 layer. (b) Plasmonic resonance energy transfer, for which the plasmonic resonance of Au nanostructures generates intense electric fields in the TiO2 layer and excites the electrons of TiO2 to the conduction band. For the energy’s point of view, the photon energy excites the Au electrons, which falls back and transfers the energy to the TiO2 electrons via the intense electric field near the plasmonic hot spots.
