Enhancing dye-sensitized solar cell efficiency by anode surface treatments

In this study, titanium substrates treated with HF solution and KOH solution sequentially forming micro- and nano-structures were used for the fabrication of flexible dye-sensitized solar cells (DSSCs). After wet etching treatments, the titanium substrates were then exposed to the O ₂ plasma treatment and further immersed in titanium tetrachloride (TiCl ₄ ) solution. The process conditions for producing a very thin TiO ₂ blocking layer were studied, in order to avoid solar cell current leakage for increasing the solar cell efficiency. Subsequently, TiO ₂ nanoparticles were spin-coated on Ti substrates with varied thickness. The dye-sensitized solar cells on the titanium substrates were subjected to simulate AM 1.5 G irradiation of 100 mW/cm ² using backside illumination mode. Surface treatments of Ti substrate and TiO ₂ anode were found to play a significant role in improving the efficiency of DSSC. The efficiencies of the backside illumination solar cells were raised from 4.6% to 7.8% by integrating these surface treatments.