Atomic layer deposition of photocatalytic TiO(2) thin films from TiF(4) and H(2)O

作者：Pore Viljami^*; Kivela Tiina; Ritala Mikko; Leskela Markku

来源：Dalton Transactions, 2008, (45): 6467-6474.

DOI：10.1039/b809953g

Titanium dioxide (TiO(2)) thin films were grown by atomic layer deposition (ALD) at 300-500 degrees C using TiF(4) and H(2)O as precursors. The films were characterized by FESEM, EDX, UV/Vis and XRD techniques. Two glass types, soda lime and borosilicate, were used as the substrate materials. It was found that the type of the glass substrate had a very strong influence on the growth and properties of the resulting films. At substrate temperatures of 400 and 500 degrees C, the growth rates on borosilicate were 0.8 and 1.0 angstrom per cycle, respectively, and the films were mainly anatase. With the same deposition conditions on soda lime, rutile phase was formed and the growth rates were 1.1 and 1.5 angstrom per cycle, respectively. Growth saturation was confirmed for both glass substrates at 400 degrees C by varying the pulse lengths of the precursors. Both anatase and rutile films prepared at 400-500 degrees C possessed photocatalytic activity in degrading stearic acid under UV and visible light, whereas the films prepared at 300 degrees C had virtually no activity. All the films, including those prepared at 300 degrees C, turned superhydrophilic under UV light.

• 出版日期2008