Déposition par Pulvé Risation Cathodique Radio Fréquence et Caracté Risation Électronique, Structurale et Optique de Couches Minces du Dioxyde de Titane

[摘要] Deposited titanium oxide thin films are used as optical protector films for several materials and as energy converters for solar cells. In this work, titanium oxide thin films are deposited on c-Si and glass substrates by reactive radiofrequency sputtering. All the deposits are grown at ambient temperature and the sputtering gas is a mixture of oxygen and argon with an overall pressure of10−2mbar. The oxygen partial pressure ratios varies from 5% to 20%.Characterization of deposited films is made by grazing incidence X-ray diffraction (GIXD), grazing incidence X-ray reflection (GIXR), X-ray photoemission spectroscopy (XPS) and optical transmission spectroscopy. The characterization results reveal that deposited films of TiO2 are polycrystalline and present both rutile and anatase phases. The chemical composition of raw films in Ti:O ratio is equal to 1:2.02, and the titanium at surface is completely oxidized. In fact, the Ti2p core level behavior shows that the oxidization state of Ti is equal to+4.The specularily reflected intensity according to incidence angle of the X-ray on TiO2/glass structure shows one critical angle attributed to the TiO2 film equal to 0.283º. This angle value involves film density between rutile and anatase phases. The optical characterization shows that TiO2 thin films obtained are transparent in visible range, and have a refraction index value equal to 2.45 and when extrapolated to infrared range, it is equal to 2.23. Thevalue of gap energy (3.35 eV) is deduced from variation of absorption coefficient versus incident radiation energy.

[学科分类] 电子、光学、磁材料