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 (TiCl4) solution. The process conditions for producing a very thin TiO2 blocking layer were studied, in order to avoid solar cell current leakage for increasing the solar cell efficiency. Subsequently, TiO2 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 TiO2 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. (C) 2014 Elsevier B. V. All rights reserved.