Effect of single-walled carbon nanotube in PbS/TiO2 quantum dots-sensitized solar cells

Single-walled carbon nanotubes (SWNTs) layers formed on indium-doped tin oxide (ITO) electrodes for enhanced photoconversion efficiency of PbS/TiO₂ quantum dots (Q dots)-sensitized photoelectrochemical solar cells (PECs). The short-circuit current of Q dots-sensitized PECs with SWNTs layers increased under illumination, and the dark current of the PECs was also reduced without illumination. Furthermore, the electron lifetimes of PbS/TiO₂/SWNTs in open-circuit voltage decay is higher than that of PbS/TiO₂ films at the same voltage. As a result, the power conversion efficiency of PbS/TiO₂ on ITO increased 35.6% in the presence of SWNTs due to the improved charge-collecting efficiency and reduced recombination process.