Multi-Functionality of Macroporous TiO₂ Spheres in Dye-Sensitized and Hybrid Heterojunction Solar Cells

Abstract

Micron-sized macroporous TiO2 spheres (MAC-TiO2) were synthesized using a colloidal templating process inside emulsions, which were then coated on a nanocrystalline TiO2 light absorption film to prepare a bilayered photoanode for liquid-based dye-sensitized solar cells (DSSC) and hybrid heterojunction solid-state solar cells. MAC-TiO2 layers can enhance light scattering as well as absorption, because their pore size and periodicity are comparable to light wavelength for unique multiple scattering and a porous surface can load dye more. Moreover, due to the bicontinuous nature of macropores and TiO2 walls, electrolyte could be transported much faster in between the TiO2 spheres rather than within the small TiO2 nonporous architectures. Electron transport was also facilitated along the interconnected TiO2 walls. In DSSCs with these MAC-TiO2 scattering layers, efficiency was higher than conventional DSSCs incorporating a commercial scattering layer. The unique geometry of MAC-TiO2 results in strong improvements in light scattering and infiltration of hole-transporting materials, thereby the MAC-TiO2-based solid-state device showed comparatively higher efficiency than the device with conventional nanocrystalline TiO2.

Performances Enhancement in Perovskite Solar Cells by Incorporating Plasmonic Au NRs@SiO2 at Absorber/HTL Interface

“…The interfacial transfer and recombination behavior of the separated electrons and holes was detected by electrochemistry impedance spectroscopy (EIS), as seen in Figure a. The charge recombination process occurring at TiO 2 /perovskite/HTM heterojunction can be characterized as recombination resistance R rec , corresponding to the main arc in Nyquist plot at the middle frequency . A large R rec means a decreased recombination process at TiO 2 /perovskite/HTM heterojunction.…”

Ta-doped hierarchical TiO 2 spheres for dye-sensitized solar cells

“…[19] Recently, TiO 2 hierarchical spheres were regarded as a promising material for DSSCs since their hierarchical structure has the advantages of high surface area, abundant macropores, and reduced electron path. [20][21][22][23] Furthermore, the structure of TiO 2 hierarchical spheres is beneficial for the filling of quasi-solid-state electrolyte, which can help to solve the problems of difficult sealing, risk of leakage and contamination caused by liquid electrolyte.…”

Graphene oxide nanosheets as an effective template for the synthesis of porous TiO2 film in dye-sensitized solar cells

“…Significantly, the porous TiO 2 film photoelectrode is one of the most key factors that affect the overall light-to-electricity conversion efficiency [8,[16][17][18][19][20][21]. Usually, template approach has been widely demonstrated to be one of the most efficient methods for the preparation of porous TiO 2 film [17,[22][23][24][25][26][27][28][29][30]. Especially, template method by using various organic components as the pore-forming agent is a controllable strategy for the preparation of various porous inorganic materials [23,[25][26][27][28][29][30].…”