Repozytorium publikacji - Politechnika Gdańska

Optical, photo-electrochemical, crystallographic and morphological properties of TiO2 thin films prepared by high power impulse magnetron sputtering at low substrate temperatures (<65 ◦C) without post-deposition thermal annealing are studied. The film composition-anatase, rutile or amorphous TiO2-is adjusted by the pressure (p ∼ 0.75-15 Pa) in the deposition chamber. The different crystallographic phases were determined with grazing incidence x-ray diffractometry. The surface morphology and size of TiO2 grains/clusters were imaged with atomic force microscopy. Basic plasma parameters were determined by means of the time-resolved Langmuir probe technique. The power density influx on the substrate was estimated from calorimetric probe measurement. The data from calorimetric probe measurements and time-resolved Langmuir probe served as input parameters for the calculation of influx contributions of particular species. The band-gap energy Eg depends on the film composition and crystallographic phase. Optical parameters (refractive index n + ik, transmittance T , reflectance R and absorbance A) are measured as functions of photon energy in theUV-Vis range by spectroscopic ellipsometry. For the rutile and anatase films agreement with the respective bulk phase is found. Incident photon-current conversion efficiency determined by photo- electrochemical measurements reached the highest values (0.312) for the anatase film.

Autorzy

• Vítězslav STRAňáK,
• Martin Čada,
• Marion Quaas,
• Stephan Block,
• dr hab. inż. Robert Bogdanowicz link otwiera się w nowej karcie ,
• Štěpán Kment,
• Harm Wulff,
• Rainer Hippler,
• Zdeněk HUBIčKA,
• Milan TICHý