An 80 nm thick zinc aluminate thin film was deposited on a glass substrate via radio-frequency (rf) magnetron sputtering and heat treated to analyze changes in the wetting angles due to a surface modification. The thin films were modified from hydrophilic to hydrophobic by a simple thermal treatment. The surface modification from a heat treatment increased the wetting angles up to 111°, which was explained by the relationship with the excess surface area. The wetting angles of the annealed thin films decreased with increasing exposure time under ambient conditions, which was attributed to the oxygen vacancies in the films that were introduced during deposition. The annealed thin films were treated by ionized oxygen via oxygen plasma. After the oxygen plasma treatment, the decreased wetting angles were maintained at ~95° for 11 days.

Photo electrode is an important component for DSSC. DSSCs electrical characteristics and efficiencies fabricated with different TiO2 photo electrodes thickness and modified phoro electrode surface area were studied. 11 ㎛ TiO2 photo electrode shows a 4.956% efficiency. The highest short circuit current density was a 9.949 mA/cm2. Efficiencies and short circuit current density increased as tape casting thickness decreased. Modified surface area of the photo electrode by needle stamp processing were studied. 200 times needle stamp processing on photo electrodes shows a highest 5.168% efficiency. Also the short circuit current density was a 10.261 mA/cm2.

Nano-structured one-dimensional Na2Ti6O13 particles were synthesized by a molten salt process. Effects of processing parameters on the microstructure and band gap energy of the Na2Ti6O13 powder were studied in this paper. For the synthesis of the Na2Ti6O13 particles, two different raw materials of tubular shaped Na-titanate (Na-TiNT) and spherical shaped TiO2 were utilized. Synthesizing with the raw material of Na-TiNT, around 70nm thick 1D-Na2Ti6O13 with the bandgap energy of 3.5 eV was obtained at 810℃. Below 810℃ or without the presence of NaCl, 1D-Na2Ti6O13 was in a relatively short in length and agglomerated state. With the processing temperature increased, the thickness of the 1D-Na2Ti6O13 was also observed to be increased. On the other hand, when TiO2 was employed as a raw material, the mixed amount of Na2CO3 played an important role in transforming the morphology and phase of the raw material, affecting the bandgap energy of the synthesized product. Specific surface area of the synthesized 1D-Na2Ti6O13 was significantly affected by the raw and mixed materials as well as processing temperature. When Na-TiNT was processed at 810℃ with NaCl, the specific surface area of the 1D-Na2Ti6O13 showed the best value of 30.63 m2/g.