2.2. DSSC makingTo prepare a screen-printable paste, ethyl cellulose and -terpineol were mixed in ca. 20 ml ethanol solution, which wasstirring to completely dissolve ethyl cellulose in ethanol. 0.25 g TiO2 mesoporous spheres, TiO2 nano particles, or P25 were mixed in theabove solution, and was stirring for ca. 10 min, which were stillfollowed by 10 min ultrasonic dispersion.