Green‐Engineered All‐Substrate Mesoporous TiO₂ Photoanodes with Superior Light‐Harvesting Structure and Performance

Abstract

Electrophoretic deposition (EPD) is employed successfully in a suspension of multicomponent TiO2 nanoparticulates of different sizes and morphologies to engineer a very robust bifunctional electrode structure for dye-sensitized solar cell (DSSC) applications that shows excellent light-harvesting and photoelectrochemical performance. Aqueous-synthesized anatase nanocrystallites and sub-micrometer-sized "sea urchin"-like rutile aggregates are formulated in a stable isopropanol suspension without resorting to binders or charging agents. Interestingly, extremely robust films are obtained because of the high surface reactivity, electrophoretic mobility, and unique morphology of the rutile aggregates. DSSCs built with the newly configured bifunctional electrode yielded a record efficiency (8.59 %) for EPD-fabricated devices without resorting to mechanical compression. Such green-engineered mesoporous electrode structures can be built on both metallic and plastic substrates and can find applications in various energy and environmental fields.

Steady‐State, Scalable Production of Mesoporous Rutile and Brookite Particles and Their Use in Energy Conversion and Storage Cells

“…The left semicircle corresponding to high frequencies represents the charge transfer processes at FTO/TiO 2 interface, and Pt counter electrode/electrolyte, ( R CE ). The middle semicircle at intermediate frequencies represents charge transport resistance in TiO 2 film ( R t ), and recombination resistance at the TiO 2 /dye/electrolyte interface ( R rec ), and the third semi‐circle at low frequencies represents the Nernst diffusion resistance within the electrolyte . In the two EIS spectra in Figure 6 (d) the third semicircle only appears for the cell with the scattering layer, and can be attributed to the presence of two layers of drastically different size particles, which affects electrolyte diffusion in the film .…”

“…The middle semicircle at intermediate frequencies represents charget ransport resistance in TiO 2 film (R t ), and recombination resistance at the TiO 2 /dye/electrolyte interface (R rec ), and the third semi-circle at low frequencies represents the Nernstd iffusion resistance within the electrolyte. [33,34] In the two EIS spectra in Figure 6(d) the thirds emicircle only appears for the cell with the scattering layer,a nd can be attributedt ot he presenceo ft wo layers of drastically different size particles, which affects electrolyte diffusion in the film. [35] Electrochemical parameters based on equivalent circuit model were fitted with Z-view and their values are given in Ta ble 2.…”

A hierarchical homogeneous core–shell structure of TiO2 hollow microspheres for high efficiency dye-sensitized solar cells

“…To attain higher efficiency DSSCs, many works have been performed, which mainly have included the improvement of specific surface area, electron transport and light-scattering effects. In recent years, many researchers have focused attention on improving light-scattering ability [5][6][7][8][9][10][11]. Scattering layers of various structures, such as mesoporous spheres [6,7], microplates [5], hollow spheres [8][9][10] and multi-hollow spheres [11], involving upper scattering layers and scattering centers, have been effectively utilized to enhance light-harvesting efficiency, thus improving the performance of DSSCs.…”

Effect of Particle Size on the Performance of TiO2 Based Dye‐Sensitized Solar Cells

“…Various semiconductors such as TiO 2 , ZnO,SnO 2 , Nb 2 O 5 , and SrTiO 3 etc have been used as DSSC photoanode materials and demonstrated significant photovoltaic performances . Using porous Titanium‐di‐oxide (TiO 2 )and perovskite absorbing layer high power conversion efficiency could be achieved and various ways to improve the photovoltaic performances of DSSCs have continuously been explored by researchers, such as the development of dyes with broad absorption band,, increasing the surface area of the porous layer, increasing the light‐harvesting properties by introducing a scattering layer and controlling of the particles size of semiconductors (TiO 2 or ZnO) etc. Increasing the surface area of the porous layer with large semiconductor oxide structures resulted in significantly improved performance of DSSCs …”