Improvement of Plasmon-Enhanced Photocurrent Generation by Interference of TiO2 Thin Film

In this study, we demonstrated an improvement in the plasmon-enhanced photocurrent generation due to Fabry-Perot interference of titanium dioxide (TiO2) thin-film electrodes loaded with Au nanoislands (Au-NIs). TiO2 thin films with thicknesses of 215-274 nm, which show obvious Fabry-Perot interference, were deposited via atomic layer deposition (ALD) onto silica glass and were modified by the deposition of Au-NIs onto their surface. Anodic plasmon-enhanced photocurrent generation was observed over the Au-NIs-loaded TiO2 thin-film photoelectrodes. The incident photon to current efficiency (IPCE) action spectra correlated strongly with the Au-NIs plasmon resonance and exhibited a strong dependence on the thickness of the TiO2 thin film. The photocurrent conversion efficiency increased when the transmission constructive interference wavelength overlapped with the Au-NIs plasmon resonance band. This work provides a simple and applicable approach for the further design of low-cost and lightweight plasmon-enhanced energy conversion devices.