Coupling plasmonic nanoparticles with TiO₂ nanotube photonic crystals for enhanced dye-sensitized solar cells performance

In order to break through the limit of low power conversion efficiency (PCE) of dye-sensitized solar cell (DSSC) with single photon management architecture in photoanode, herein, we propose a novel architecture, composed of a TiO₂ nanotube photonic crystal (TiO₂ NTPC) layer and in-suit deposited Au plasmonic nanoparticles (Au NPs), as photoanode for DSSC applications. The designed photoanode is expected to significantly increase the light harvesting in DSSCs, due to the synergistic effect of the photonic crystal (PC) effect originates from TiO₂ NTPC and the surface plasmon resonance (SPR) effect from Au NPs. This synergistic effect of the newly designed photoanode and its functionality in DSSCs are discussed by both experimental and simulated results. Moreover, when the SPR band of Au NPs has been tailored to best match with the bandgap of TiO₂ NTPC, the maximum enhancement in power conversion efficiency (PCE, 44.7%), which exceeds the sum enhancement producing by coupling individual TiO₂ NTPC (22.1%) or Au NPs (18.0%), has been achieved by introducing the designed Au NPs/TiO₂ NTPC photoanode, yielding a PCE of 5.63% in the NT-based DSSCs. The work presented here provides new insights into the design and application of SPR/PC coupling architectures for high efficient light management and synergistically enhanced light harvesting in photovoltaic devices.