Double Functional Films With Shielding-Ultraviolet And Transparent Conduction By Radio-Frequency Magnetron Sputtering

CeO₂-TiO₂ films have high reflective index and excellent shielding-Ultra violet properties, as well as SnO₂:Sb films have good electric-conductivity and excellent optical properties. Considering these good properties, the double functional films deposited on glass substrates by radio-frequency(R.F.) magnetron sputtering show ultraviolet-shielding and transparent conduction, which is the unique and creative idea in the experimental research.In the thesis, SnO₂:Sb(6% mol) targets and a series of CeO₂-TiO₂ targets with different molar ratio of CeO₂ to TiO₂ were prepared .CeO₂-TiO₂ films and SnO₂:Sb(6% mol) films were deposited on glass substrates by R.F magnetron sputtering. In the same way, CeO₂-TiO₂/SnO₂:Sb(6% mol) films and SnO₂:Sb(6% mol)/CeO₂-TiO₂ films were made. The influence of different Ce/Ti molar ratio on the shielding-ultraviolet (UV) properties was deeply and systemically studied. CeO₂-TiO₂/SnO₂:Sb(6%mol) films and SnO₂:Sb(6% mol)/CeO₂-TiO₂ films were compared by shielding-ultraviolet(UV) and infrared reflection properties. The films were characterized by all kinds of testing analytic ways. The results show as following:1) The shielding-ultraviolet properties of CeO₂-TiO₂ films are better than pure CeO₂ film and pure TiO₂ film. XRD analysis indicates structure of CeO₂-TiO₂ film, when Ce:Ti=0.5:0.5 and 0.6:0.4, appear amorphousphases, which play an important role in shielding UV. XPS analysis shows there are Ce³⁺, Ce⁴⁺and Ti⁴⁺on the surface of the films. TEM analysis indicates thin film is composed of CeO₂ (CaF₂ type), TiO₂ (Rutile) and transition phase CeO_1.6·2TiO₂. TiO₂ and CeO₂ were first produced in film production process, other than CeO_1.6·2TiO₂. CeO₂-TiO₂ films, CeO₂ film and TiO₂ film are indirect optical gaps. By optical gaps calculation and analysis, the result of optical gaps shows: Eg(CeO₂-TiO₂)2)2).2) CeO₂-TiO₂/SnO₂:Sb(6%mol) double films show high shielding-Ultra violet(UV)(>99 % ), high visible light transmission (>75%) and good conductivity. The sheet resistance of the double films is about 70⁹0Ω/â–¡ , its electrical resistivity is about 3.2³.6×10^-3Ω·cm.3) Both double films show high shielding-Ultraviolet(>99%) and high visible light transmission (>75%) whether CeO2-TiC>2 films are deposited as the inner film or the outer film. But seeing from the infrared reflectional rate(wavenumber 400-4000cm"1), the infrared reflectional rate of CeO2-TiO2 /SnO2:Sb(6%mol) films are higher than that of SnO2:Sb(6% mol)/CeO2-TiO2 films. Especially in wavenumber 400-2000 cm"1, the former of infrared reflectional rate is above 50%, but the later is only above 23%. Therefore CeO2-TiO2/SnO2:Sb(6%mol)double films show the properties of ultraviolet-shielding and transparent conduction without significant absorption of visible light.