Photoactivated Properties of TiO2 Films Prepared by Magnetron Sputtering

Abstract

This article reports on photoactivity of sputtered TiO2 films induced by UV irradiation. TiO2 films were prepared by dc pulsed reactive magnetron sputtering using a dual magnetron operated in bipolar mode and equipped with Ti targets. The photoactivity of TiO2 films, characterized by the water droplet contact angle (WDCA) on the film surface after UV irradiation, was evaluated and discussed in detail. The structure of TiO2 film was measured using X‐ray diffraction and surface morphology using AFM. A sharp decrease in WDCA to ∼10° has been observed for optimal sputtering conditions. Possibility of low‐temperature sputtering (<90°) of photoactive TiO2 films on heat sensitive substrates has been introduced.

High-rate low-temperature dc pulsed magnetron sputtering of photocatalytic TiO2films: the effect of repetition frequency

“…This finding is in a good agreement with previous reported results [21,25]. The TiO 2 films prepared at f r = 350 kHz exhibited best hydrophilicity; the WDCA a on their surfaces decreases rapidly after 20 min of the UV irradiation to a ir 20min = 9°.…”

“…Recent results have shown that the low-T sputtering of the crystalline hydrophilic TiO 2 films with the anatase structure can be realized in the oxide mode [6,21]. A systematic investigation of the correlations between the deposition process parameters and the properties of the TiO 2 films showed that an increase of repetition frequency f r from 100 to 350 kHz at constant values of p T = 0.9 Pa, I da1,2 = 3 A and d s-t = 100 mm results in a significant increase of the film deposition rate a D in both the metallic (p O2 = 0 Pa) and oxide mode (0.15 Pa) of sputtering, see Fig.…”

“…The films were deposited on unheated microscope glass slides (26 · 26 · 1 mm 3 ) and unheated polycarbonate (PC) substrates (26 · 26 · 3 mm 3 ). The TiO 2 films with a constant thickness h % 1,000 nm were prepared in order to avoid a strong influence of the film thickness h on their properties [6,21].…”

“…The high photoactivity of the films sputtered at very low p O2 in the transition mode of sputtering is a result of their very high surface roughness that increases in the transition mode of sputtering with decreasing p O2 ; for more details see Refs. [21,28].…”

Recent developments in TiO2 as n- and p-type transparent semiconductors: synthesis, modification, properties, and energy-related applications

“…The films were deposited on unheated microscope glass slides (26 9 26 9 1 mm 3 ) and unheated polycarbonate (PC) substrates (26 9 26 9 3 mm 3 ). TiO 2 films with a constant thickness t & 1000 nm were prepared to avoid a strong influence of the film thickness on the properties [104,105]. Figure 7 presents the time evolution of the pulse waveforms of the current (I d ) and voltage (U d ) in the dual magnetron discharge generated in the oxide mode of sputtering (P O 2 = 0.15 Pa) at different values of the repetition frequency f r , an average discharge current I da 1, 2 of 3 A, and P T of 0.9 Pa.…”