Effect of Na diffusion from glass substrate on the microstructural and photocatalytic properties of post-annealed TiO2 films synthesised by reactive sputtering

Synthesis and characterization of mixed phase anatase TiO2 and sodium-doped TiO2(B) thin films by low pressure chemical vapour deposition (LPCVD)

“…14. Here we propose three steps for the TiO 2 (B) formation: (1) Na + ions migrate to the surface of the substrate during the pre-heat treatment process; 38 (2) owing to higher negative charge of non-bridging oxygen units of TiO 2 than SiO 2 , the Na + ions prefer to diffuse from the surface of the substrate into the nascent TiO 2 lms leaving a Na-depleted zone in the region of glass neighboring the TiO 2 lm; 39 (3) a seeding intermediate phase is formed and this decomposes at temperature so forming TiO 2 (B) needles and leaving Na + ions to continuously migrate to the upper surface of the thin lm. Further into the lm and in the absence of signicant amounts of Na, the titania deposits and forms anatase instead of TiO 2 (B) depending on the reaction temperature.…”

Crystalline Si photovoltaic modules based on TiO2-coated cover glass against potential-induced degradation

“…It has been reported that Na + diffused from the soda lime glass reacts with TiO 2 thin lm coating on the glass substrate, producing either sodium titanate or a brookite phase. [18][19][20][21][22] Therefore, our results suggest that the TiO 2 lm reacts with Na + diffused from the front cover glass by applying minus high voltage. As a result, the diffusion of Na + from the cover glass to the Si cell was prevented, resulting in the suppression of remarkable degradation by PID.…”

Effect of SiNx diffusion barrier thickness on the structural properties and photocatalytic activity of TiO2 films obtained by sol–gel dip coating and reactive magnetron sputtering

“…In this paper, we studied the effect of the SiN x thickness on thin TiO 2 layers coated by either a soft chemistry (sol-gel) or physical (reactive sputtering) method. In earlier work, we studied the concentration of Na + ions as a function of the SiN x diffusion barrier thickness using extremely sensitive surface analysis techniques (X-ray photoelectron spectroscopy (XPS) and sputtered neutral mass spectrometry (SNMS)) [5,6,13]. Aubry et al showed that the concentration of Na + ions increases with a decrease of the SiN x diffusion barrier of thickness less than 150 nm [13].…”