TiO2 thin films doped by Ce, Nb, Fe, deposited onto ITO/glass substrates

Optical transmittance studies were carried out on some doped titanium dioxide thin films, obtained by r.f. magnetron reactive sputtering, using glass and ITO/glass substrates. We have observed that, while TiO2 films have a good transparency till about 2000 nm, the ensemble TiO2 and ITO (indium tin oxide) films gives a decrease of the optical transmittance in near infraread region, being still transparent in the visible range. The mentioned decrease depends on the dopant used. This is an important observation, since TiO2 films are already used as coatings for many buildings. So, for economic reasons, the necessary energy used for the inside cooling of the air can be reduced, by getting a good visible transparent window, together with a NIR shielding.