Highly efficient plasmonic dye-sensitized solar cells with silver nanowires and TiO2 nanofibres incorporated multi-layered photoanode

Abstract

The effect of incorporating silver nanowires (Ag NWs) and TiO2 nanofibers (NFs) into a tri-layer photoanode of dye sensitized solar cells (DSSCs) have been investigated. Ag NWs with diameter 60–90 nm and length of 1–2 μm were synthesized via polyol reduction method. TiO2 nanofibers (NFs) with diameter 80–120 nm were prepared by electrospinning. The DSSC with tri-layer photoanode made with a composite of TiO2 P25, Ag NWs and TiO2 NFs sandwiched between two TiO2 P25 layers exhibited power conversion efficiency of 9.74% and open circuit voltage (Voc), short circuit current density (Jsc) and fill factor (FF) of 727.4 mV, 19.8 mA cm−2 and 67.6% respectively under the irradiance of 100 mW cm−2. The efficiency of the reference DSSC with TiO2 P25/P25/P25 tri-layer photoanode of the same thickness was found to be 6.69%. The efficiency enhancement of the DSSC with Ag NWs and TiO2 NF incorporated composite, tri-layer photoanode compared to the reference DSSC is 45.6%. This is evidently due to the enhancement in short-circuit photocurrent density (Jsc) by (a) localized surface plasmon resonance effect by Ag NWs and (b) increased light harvesting by multiple scattering events by the presence of TiO2 NFs.