High density, non-porous anatase titania thin films for device applications

TEM studies have been performed on 50 nm thick monolayer films of sol-gel derived anatase titania (TiO 2 ). It is found that a dense polycrystalline structure, having low porosity and consisting of nanocrystallites ranging from 5-20 nm in diameter, is the result of a sintering process involving temperature ramping up to 550 °C. Ohmic conduction is believed to be due to almost flat band conditions caused by partial depletion of carriers from the crystallites.