Double-layered TiO 2 cavity/nanoparticle photoelectrodes for efficient dye-sensitized solar cells

• Published in: Frontiers of materials science 2023, Vol.17 (1), p.230638
• Main Authors: Li, Zhen, Yu, Libo
• Format: Article
• Language: English
• Subjects: cavity; dye sensitized solar cell; light scattering; titanium dioxide
• ISSN: 2095-025X; 2095-0268
• DOI: 10.1007/s11706-023-0638-8

TiO 2 nanoparticles (NPs) in the size of ~25 nm, namely P25, are very common material as the electron collecting layer in dye-sensitized solar cells (DSSCs). However, the light-scattering improvement of TiO 2 NP photoelectrodes is still a challenge. Here, we built TiO 2 cavities on the top of the TiO 2 NP layer by using carbonaceous microspheres as the template, forming the TiO 2 cavity/nanoparticle (C/NP) photoelectrode for the application in DSSCs. The cavity amount in the TiO 2 C/NP photoelectrode was controlled by adjusting the weight ratio of carbonaceous microspheres. SEM results confirm the successful formation of the double-layered TiO 2 C/NP electrode. J ‒ V tests show that the optimized TiO 2 C/NP electrode prepared with 25 wt. % carbonaceous microspheres contributes to remarkable improvement of the short-circuit current density ( J sc) and the power conversion efficiency (PCE). The best photovoltaic performance solar cell with the PCE of 9.08 % is achieved with the optimized TiO 2 C/NP photoelectrode, which is over 98 % higher than that of the TiO 2 NP photoelectrode. Further investigations of UV-vis DRS, IPCE, OCVD, and EIS demonstrate that the competition between light scattering effect and charges recombination in this TiO 2 C/NP photoelectrode is responsible for the PCE enhancement.