Nikirin V. Processes of ion modification and synthesis of thermochromic films of vanadium and tungsten oxide.

The paper presents the results of studies of the processes occurring in magnetron synthesis of vanadium oxide films. The physical mechanisms and technological conditions which provide for the formation of certain vanadium oxide phases have been determined. A new method for the two-step synthesis of films, which enables creating films with different functionalities had been proposed. Only amorphous VOx film (1.8 < x < 2.2) with single nanocrystalline inclusions are suitable for controlled crystallization and crystal modification with a further low-temperature annealing. Annealing allows for preferential conditions for the growth of certain structural vanadiya oxide phases. A model that describes the processes of phase and structural transformations in the films at different stages of their formation has been proposed. Using the original method we was able to synthesize two types of vanadium oxide films with high functional parameters: 1) powerful thermochromic effect (change in optical transmission up to 50 times), and 2) high (7%), temperature coefficient of resistance. Also, a study of the structure and parameters of electrochromic WO3 and NiO films was carried out. On the basis of these films a working electrochromic system has been created and its degradation reasons were determined. Ion implantation and annealing in various ambients have been used to modify the films, allowing purposefully change the component structure and optimize the development of materials technology. It is shown that use of ionic liquids as electrolytes in electrochromic devices is promising because it significantly increases the life of the system.