Low Pressure CVD of Electrochromic WO₃at 400°C

Abstract

Monoclinic tungsten trioxide coatings were deposited on fluorine doped tin dioxide glass substrate using a low pressure chemical vapor deposition system at 400 • C. Morphology analysis indicated the agglomeration of grains for 50 sccm O 2 flow rate, while for higher flow rates, the growth of islands which tend to coalescence to form a continuous film is observed. The electrochemical performance for the as-grown coating using 75 sccm O 2 flow rate was similar with the one for 100 sccm presenting stability up to 500 scans. The samples indicated Li + intercalated charge of 16 mC cm −2 , time response of 43 s and a coloration efficiency of 38 cm −2 C −1 .

Inducing Crystallinity of Metal Thin Films with Weak Magnetic Fields without Thermal Annealing

“…On the other hand, the thin film deposited without a magnetic field had a thickness of 0.1 micron. In contrast, Tungsten, a paramagnetic metal, exhibited crystallization after 45 min in ambient atmosphere, corresponding to peak intensity achieved by annealing at 400 degrees as reported previously [26,27]. Figure 2 represents the following two W phases: (a) higher peak W3O (00-041-1230) and (b) smaller peak at 44.2 degrees representing beta W (03-065-6453).…”

“…We can conclude with certainty that no atmospheric oxygen was integrated into the thin film trough vaporization/ionization reaction. Furthermore, higher intensity of W3O compared to pure W is likely related to tungsten target cleaning [28], which In contrast, Tungsten, a paramagnetic metal, exhibited crystallization after 45 min in ambient atmosphere, corresponding to peak intensity achieved by annealing at 400 degrees as reported previously [26,27]. Figure 2 represents the following two W phases: (a) higher peak W 3 O (00-041-1230) and (b) smaller peak at 44.2 degrees representing beta W (03-065-6453).…”

“…Since we worked well below W melting and boiling points, oxygen could not be purged from the material, causing contamination, and we can therefore, explain oxidation of W as other authors did. While preparing W and W 3 O thin films, they observed that a low oxidized tungsten phase existed from the beginning of thin film growth [27] which could not be related to oxygen contamination in the chamber. We can conclude with certainty that no atmospheric oxygen was integrated into the thin film trough vaporization/ionization reaction.…”

Electrical Resistivity of Ni–Fe Wires Coated with Sn Using low-Pressure Chemical Vapor Deposition

“…Controlling the resistivity of alloy wires by depositing metals on their surface through low-pressure chemical vapor deposition (LPCVD) can be a good alternative to high-temperature melting. During LPCVD, the chemical reaction occurs at pressures below the atmospheric pressure (usually less than 10 Torr) [7][8][9][10][11][12][13][14][15]. Therefore, LPCVD can activate chemical reactions between metals and alloy wires at temperatures lower than those used for high-temperature melting.…”

Novel Spark Method for Deposition of Metal Oxide Thin Films: Deposition of Hexagonal Tungsten Oxide

“…Various methods have been used for the deposition of the thin films of metal oxides, including Chemical Vapor Deposition, Pulsed Laser Deposition, Sputtering, Hydrothermal Synthesis, Atomic Layer Deposition, Electrodeposition, Anodization techniques, and Sol‐Gel . More recently, a new deposition approach has been reported, the Spark Method, which is very attractive because it is a low cost and simple physical method, without the need of dangerous chemical precursors that can be easily used for large scale manufacturing.…”