Incorporation of multiwalled carbon nanotubes into TiO₂ nanowires for enhancing photovoltaic performance of dye-sensitized solar cells via highly efficient electron transfer

Multiwalled carbon nanotube (MWCNT)-embedded TiO₂ nanowires (NWs) were synthesized by a combination of electrospinning and calcination processes. We examined the effect of the MWCNT mass fraction in the MWCNT-TiO₂ composite NW-based photoelectrode on the photovoltaic properties of the resulting dye-sensitized solar cells (DSSCs). The MWCNT (5wt%)-TiO₂ composite NW-based DSSC fabricated in this study showed a significantly improved short circuit current density and power conversion efficiency (PCE) compared to pure TiO₂ NW (i.e., MWCNT 0wt%)-based DSSCs (the values increased from 2.91±0.15 to 10.72±0.21mA/cm² and from 1.44±0.10% to 5.03±0.35%, respectively). This improvement was due to an increase in rapid electron transfer and suppression in charge recombination caused by MWCNTs embedded in the TiO₂ matrix NWs. These specially designed MWCNT-TiO₂ composite NW-based photoelectrodes have great potential as an effective charge transfer medium to inherently enhance the photovoltaic performance of DSSCs.