Synthesis of N-doped TiO2 particles from aquaethylenediaminetitanium(IV) hydroxide complex and their optical properties on dye-sensitized solar cells

To promote the photoelectric conversion efficiency of solar cell, N-doped TiO₂ particles are introduced as working electrodes in dye-sensitized solar cells. The N-doped TiO₂ particles (N–en–TiO₂) are easily synthesized from Ti(NH₂CH₂CH₂NH₂) _x (H₂O) _y ]zOH (aquaethylenediaminetitanium(IV) hydroxide) complex using a modified sol–gel process. The produced N–en–TiO₂ particles show rice-shapes of 25–50 nm and their band-gaps become to be shorter than that of TiO₂. The N–en–TiO₂ particles are applied to working electrode layers in dye-sensitized solar cells, and on comparing the performances of pure TiO₂ and N–en₂–TiO₂–DSCs, the latter shows good performance with a solar energy conversion efficiency of ~5.54 % versus the former of 4.21 % respectively with a notable photocurrent enhancement. Particularly, the N–en₂–TiO₂–DSCs exhibit relatively low charge transfer resistance at counter electrode and electron transfer resistance from dye/TiO₂/photoanode, slower recombination times, faster electron transport times, and higher electron diffusion coefficients than non-doped TiO₂–DSCs.