TiO } Nanofibers Doped With NiS as Photoanode to Improve the Photovoltaic Conversion Efficiency of Dye-Sensitized Solar Cells

Nickel sulfide (NiS) particles with a hollow microsphere structure were prepared by a hydrothermal method. NiS/titanium dioxide nanofibers (NiS/TiO _{\text{2}} NFs) were prepared by the addition of NiS into TiO _{\text{2}} nanofibers (NFs) through electrospinning. There were two methods to modify the photoanodes of dye-sensitized solar cells (DSSCs). One was a mixture of NiS particles into a TiO _{\text{2}} layer of photoanode. The other was to cement NiS/TiO _{\text{2}} NFs onto the TiO _{\text{2}} layer of the photoanode. The DSSCs with the two kinds of modified photoanodes were compared with the DSSCs without modification. The results prove that the DSSC with NiS/TiO _{\text{2}} NFs photoanode has photovoltaic conversion efficiency (PCE) of 5.63%. It is 40.75% higher than that of the DSSCs without modification. It is due to the increased specific surface area of the hollow microsphere structure of NiS and the NiS/TiO _{\text{2}} NFs provide higher porosity to increase the dye adsorption. NiS can also reduce the transmission resistance in the DSSCs.