A DSSC with an Efficiency of ∼10 %: Fermi Level Manipulation Impacting the Electron Transport at the Photoelectrode‐Electrolyte Interface

Abstract

AbstractIn the literature, many studies pertain to gold (Au) nanoparticles, (NPs) incorporated dye‐sensitized solar cells (DSSCs) were reported due to the beneficial effect of the surface plasmon polaritons originating from the Au NPs on the DSSC performance. Thiolated Au quantum dots and dye based DSSCs was explored recently, wherein the Au cluster act both as sensitizer and voltage booster by enhancing the quasi‐Fermi level of TiO2. There is a knowledge gap on effect of thiolated Au NPs on DSSC performance. In this study, we have demonstrated Fermi level equilibration between the TiO2 and thiolated Au NPs. Thiolated Au NPs blocks the back electron transfer at the thiolated Au NPs‐electrolyte interface thereby improving the open circuit voltage and efficiency of DSSCs. We have also shown beneficial effect of WO3–TiO2–thiolated Au NPs interface in enhancing the DSSC performance significantly in comparison to that of sole TiO2 based DSSC. For the DSSC cell: FTO/WO3/TiO2‐Au‐thiolated/N719, an efficiency of 9.9 % is achieved (JSC = 17.4 mA cm−2, VOC = 0.820 V and FF=0.70).