Aggregated mesoporous nanoparticles for high surface area light scattering layer TiO2 photoanodes in Dye-sensitized Solar Cells

Abstract

Hierarchically structured aggregates, consisting of TiO2 nanoparticles were produced via one-step solvothermal syntheses with a mixed solvent system containing both acetic acid and ethanol. Two of the resulting structures, one ~700 nm and the other ~300 nm in diameter, were found to be comprised of 8.5 nm and 10.5 nm anatase crystals, and possess specific surface areas of 138 and 106 m2 g−1 respectively. These particles were incorporated into Dye-sensitized Solar Cells (DSCs) as high surface area scattering layers, along with a layer of a transparent material. Solar-to-electric conversion efficiencies (PCE) of 9.1% and 8.2% were recorded using these aggregated particles as compared to those of commonly used large particles scattering layer 7.4%.

Effective MgO-doped TiO2 nanoaerogel coating for crystalline silicon solar cells improvement

“…Hence, the particles did not impair the light benefits on the original ARC layer, whereas the incident light was forward scattered into the cell through the TiO 2 ‐based NPs. Furthermore, the aerogels with mesoporous microstructure potentially allow more incident light to transmit through the pore and shine onto the ARC layer over a large angular range, increasing the optical path length of photons in the cell, thereby enhancing the light harvesting . The drastic reduction of reflectance in the range of 250 to 350 nm is due to the absorption of high‐energy incident photons mainly in the short‐middle wavelength UV region.…”

“…When Mg 2+ ions are doped into the TiO 2 nanoaerogels, various types of crystal defects and vacancies are created to compensate the charge neutrality in TiO 2 crystal, contributing to further enhancement in the UV photocatalytic reactivity . In addition, the smaller NPs with higher surface‐to‐volume ratio may probably induce more photons to be absorbed at the short‐middle wavelength UV region for photo‐current conversion …”

“…There are many reports about the effects of TiO 2 ‐based NPs on the enhanced performance of PV devices, but less research is now carried out on c‐Si solar cells . Herein, we report on the potential application of TiO 2 and magnesium oxide (MgO)‐doped TiO 2 NPs to improve the conversion efficiency of commercial single junction mono‐Si solar cells.…”

“…An alternative strategy is to obtain high surface area of TiO 2 particles with microporous or mesoporous structures because the porous texture on the TiO 2 NPs opens up the possibility for light diffusion on the interface of semiconductor and promotes rapidly the photogenerated‐electron transfer to the conduction band of TiO 2 NPs. Moreover, the high surface area and porous structure allow multiple reflections of incident light and provide a good scattering effect, which enhances the light harvesting capability of TiO 2 across a wide wavelength …”

“…Moreover, the high surface area and porous structure allow multiple reflections of incident light and provide a good scattering effect, which enhances the light harvesting capability of TiO 2 across a wide wavelength. [23][24][25] There are many reports about the effects of TiO 2 -based NPs on the enhanced performance of PV devices, 23,25,26 but less research is now carried out on c-Si solar cells. 27,28 Herein, we report on the potential application of TiO 2 and magnesium oxide (MgO)-doped TiO 2 NPs to improve the conversion efficiency of commercial single junction mono-Si solar cells.…”