A Combined Effect of Plasmon Energy Transfer and Recombination Barrier in a Novel TiO₂/MgO/Ag Working Electrode for Dye-Sensitized Solar Cells

Abstract

Novel TiO2/MgO/Ag composite electrodes were applied as working electrodes of dye-sensitized solar cells (DSSCs). The TiO2/MgO/Ag composite films were prepared by dip coating method for MgO thin films and photoreduction method for Ag nanoparticles. The MgO film thicknesses and the Ag nanoparticle sizes were in ranges of 0.08–0.46 nm and 4.4–38.6 nm, respectively. The TiO2/MgO/Ag composite films were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The TiO2/MgO/Ag composite electrodes were sensitized by immersing in a 0.3 mM of N719 dye solution and fabricated for conventional DSSCs.J-Vcharacteristics of the TiO2/MgO/Ag DSSCs showed that the MgO film thickness of 0.1 nm and the Ag nanoparticle size of 4.4 nm resulted in maximum short circuit current density and efficiency of 8.6 mA/cm2and 5.2%, respectively. Electrochemical Impedance Spectroscopy showed that such values of short circuit current density and efficiency were optimal values obtained from plasmon energy transfer by 4.4 nm Ag nanoparticles and recombination barrier by the ultrathin MgO film.

Ag-Doped TiO2Nanotube Arrays Composite Film as a Photoanode for Enhancing the Photoelectric Conversion Efficiency in DSSCs

“…Although the introduction of one-dimensional TiO 2 nanostructure can greatly improve the electron transfer rate, the TiO 2 nanomaterial has its own weakness, that is, poor light-harvesting ability and dye adsorption [22]. Studies have shown that some metal nanoparticles can improve the energy level structure of the TiO 2 nanomaterials and enhance the ability of light absorption [23]. Wang et al found that TiO 2 powder mixed with Er 3+ showed a higher photocatalytic activity, compared with the pure TiO 2 powder [24].…”

PtSn/GO Co-Catalyst for Quasi-Solid-State Dye Sensitized Solar Cells

“…The TiO 2 electrodes were screen printed from a TiO 2 paste (Dyesol) 3 times on a fluorine-doped-tin-oxide (FTO) glass substrate (2x3 cm 2 in size) and sintered at 450°C for 30 min. A 200-mesh was used to obtain TiO 2 layers having area of 0.5 x 1.2 cm 2 and a thickness of approximately 14 µm [6]. Then, the TiO 2 films were dipped in a magnesium acetate solution with a concentration of 1x10 -3 M at 40°C for 30 seconds.…”

“…To avoid leakage and volatilization of liquid electrolytes, composite poly(ethylene oxide) PEO/TiO 2 /KI/I 2 electrolyte in acetronitrile with ethanol additive demonstrated an increase in ionic conductivity of the solid polymer electrolyte [5]. In order to decrease electron-hole recombination and increase light absorption at working electrodes, a 0.1 m thick MgO layer was dip coated and 4.4 nm Ag nanoparticles were photoreduced onto the conventional porous TiO 2 layer, respectively [6]. Without expensive apparatus, optimization of materials for the photoanode, the electrolyte and the CEs of the DSSCs should enable reasonable energy-conversion performances.…”