What are thin film coatings?
Thin -layer coatings are extremely thin layers of material located on the surface of the substrate. They may vary in thickness from several micrometers, or a million meters, to less than 1 nanometer or a billion meter. Thin -layer coatings can be made of various substances, including silicon, ceramics and arsenic Gallia. They are usually used in optical devices such as photovoltaic cells used to produce solar energy, for electronics and tool components and other devices that require resistance to surface damage.
The composition of the thin -layer coating depends on its purpose. Thin -layer coatings used in photovoltaic cells to generate solar energy are made of semiconductive materials such as silicon and arsenide Gallium. These materials can convert energy from light into electricity when incoming light photons are excited by the electrons of the semiconductor material to a higher energy level. These coatings are also used in electronics such as integrated circuits. TY these layers can be incredibly thin and some thin -layer coatings have layers that have only one atom thick. Thus, a thin -layer coating may contain a complex internal structure of different layers in an extremely small space.
Thin -layer ceramics are used in applications that require wear resistant or corrosion materials. For example, cutting tools can have a significantly extended work life if they are made with a thin ceramic outer layer at the tip to protect the rest of the blade from wear. Devices that use reactive chemicals, such as fuel cells, can use thin -layer ceramics to detain them due to relative chemical inerty of ceramic film.
Other use of thin -layer coatings include rechargeable lithium batteries that can be made with a cathode composed of a thin film of lithium and metal oxides to form batteries that are much less ODFiner and flexible than conventional batteries. The mirrors contain a thin metal film, usually made of aluminum in modern mirrors, behind the glass to form a reflective surface. Thin aluminum film coatings are also used in a package of many modern consumer goods, especially food, to increase the durability of lecturers and make a package shinier and more evident. Aluminum movies are also used as insulation, especially for applications that require flexibility and portability, and are incorporated into things such as space suits, firefighter protective equipment and emergency insulating blankets for shock victims.
Thin -layer coatings are applied to the surface through one of several techniques referred to as a thin film deposition. Most of these methods are categorized as either chemical deposition, in which the thin film is the Applied chemical reaction between the surface and the liquid called a precursor or a physical deposition in which the film is applied by mechanical, thermal orelectrical means. The methods of chemical deposition include plating, which uses a liquid precursor solution containing dissolved metal ions and the deposition of chemical steam, in which the surface reacts with gaseous compounds.
Physical deposition methods are performed in a vacuum chamber containing a substrate and a substance. The latter particles are knocked down by various means such as heating, laser pulses or electrical arches, and creates steam that forms a film on the substrate. There are also methods that use both physical and chemical processes and neatly do not fit into any category, such as reactive spraying and epitaxes of molecular beam.