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

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 JSC 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 JSC and PCE of the DSSC with an ideal amount of MWCNT can be upgraded to 22.63 mA cm-2 and 7.21%, respectively.