Fence Constructed at a Semiconductor/Electrolyte Interface Improving the Electron Collection Efficiency of the Photoelectrode for a Dye-Sensitized Solar Cell

Abstract

Charge recombination and transfer at the TiO/dye/electrolyte interface play a crucial role in dye-sensitized solar cells (DSSCs). Here, a fine-controlled gold nanoparticle (Au NP) via electrodeposition incorporated into a porous TiO photoanode and dodecanethiol molecules as an assembled monolayer capping on Au NPs was designed and prepared. The "fence-like" structure of gold thiol molecules at the TiO/dye/electrolyte interface can not only insulate the electrolyte to suppress recombination but also make full use of the plasmon-enhanced light absorption of Au NPs. The photoanodes were characterized by X-ray photoelectron spectroscopy, UV-vis absorption, and Mott-Schottky analyses. Compared to pure TiO, the DSSC with an interface "fence" structure achieved an efficiency (η) of 8.17%, increasing by 10.4%. The enhancement results are essentially attributed to the increase of the light-harvesting and electron collection properties, accompanying a slight promotion in the Fermi level. Furthermore, after dodecanethiol molecule treatment, the Au NPs with an intensified near-field effect also acted as electron sinks to store more electrons and exhibited a well electron-transport performance from electrochemical impedance spectroscopy analysis.

A detailed investigation on the performance of dye-sensitized solar cells based on reduced graphene oxide-doped TiO2 photoanode

“…The photoanodes have a significant impact on the performance of DSSCs [4][5][6][7]. Based on the working mechanism of DSSCs, increasing the transmission rate of photogenerated electrons and reducing the recombination of electrons inside the photoanode are effective means to improve the photoelectric conver-photoanodes are critical for high-performance DSSCs [11][12][13].…”