Nanostructured Nitrogen Doping TiO Nanomaterials for Photoanodes of Dye-Sensitized Solar Cells - Low-cost Nanomaterials: Toward Greener and More Efficient Energy Applications - page 62

Fig. 5 XPS spectra of N-A-15: a survey; b Ti 2p; c O1s; d N1s [ 42 ]

3 Applications of N-doped TiO 2 into the DSCs

The porous semiconductor photoanode is an important part that influences the
performance of DSCs. From the view of DSCs' photoanodes, the efficiency losses
origin from photogenerated electron losses such as electron recombination during
their transport to the substrate. The traps mainly come from the surface and lattice
defect of TiO 2 . Therefore, TiO 2 after nitrogen modifying is expected to decrease
the electron losses. Our group and other researchers introduce N-doped TiO 2 to
improve the performance of DSCs.

3.1 Effect of N-doping on the Overall Energy Conversion
Efficiency

In our previous works, we reported highly efficient DSCs based on N-doped TiO 2
electrode (N-doped DSCs). The N-doped DSCs achieved a significant improve-
ment in the energy conversion efficiency compared with the DSCs using P25
electrodes. Results show that N-doped TiO 2 electrodes could enhance the incident
photo-to-current conversion efficiency (IPCE) and the overall conversion effi-
ciency of the DSCs. Afterwards; we optimized the N-doped DSCs system, yielding
a high efficiency of 10.1 % [ 55 ]. With careful evaluation of DSCs based on