Developing Hybrid TiO2–Multiwalled Carbon Nanotubes Photoanodes for Dye-Sensitized Solar Cells

Abstract

Dye-sensitized solar cells (DSSCs) are one of the prominent research fields of solar energy that have been recently studied by scientists among different disciplines. One of the manners for the production of effective DSSCs is greatly dependent on improving the properties of the TiO₂ structure. Resistance against diffusion of photoexcited charge carriers through interconnected TiO₂ nanoparticles is one of the main obstacles for achieving greater efficiency. Charge transfer resistances that originate from imperfections and surface trap states between TiO₂ nanoparticles deteriorate the electron transport process. This study addresses the issues of charge transfer resistance and trap states, hindering the performance parameters of a solar cell. To mitigate these problems, the TiO₂ paste including TiCl₃ blocking layer and TiCl₄ post-treatment is incorporated with multiwalled carbon nanotubes (MWCNTs). Herein, different amounts of MWCNTs (0, 0.025, 0.05, 0.1, 0.15, and 0.2 wt%) are added into TiO₂ pastes. The impact of the changing weight ratios of MWCNTs on the DSSC performance parameters was investigated. When compared with the undoped sample (0 wt%), it has seen that J_SC and power conversion efficiency (PCE) are boosted by 114% and 58.4%, correspondingly, for the sample containing 0.1 wt% of MWCNT. The results indicate that the J_SC and PCE of the DSSC with an ideal amount of MWCNT can be upgraded to 22.63 mA cm⁻² and 7.21%, respectively.