Hello all friends , I wanna make a DSSC , i need to make TiO2 as Semiconductor ,from which sources can i make it?.

I have a research to make Dye-Sensitized Solar Cell-DSSC and i should make every materials by myself in Lab. how can i make TiO2 and from which sources ? to be more cheap and easy . and what is an alternative material for Iodide ( electrolyte ) in DSSC? thank you for replying and for sharing your knowledge about. :)