There are a wide variety of thin film materials. Selected metals are popular choices because they are malleable and are easily manufactured into thin sheets. With the science of nanotechnology, the manipulation of atom and molecules, unstable liquid and gaseous elements can also be used as efficient materials.
Mirrors make use of thin film, and in this type of application, metals like aluminum, silver, and copper are used. Tin is mixed in when silver is used to make the latter bond with the glass surface. More modern and economical processes use liquid metals as thin film materials. Silver nitrate, for example, is diluted with other chemicals, poured on a surface, and let dry, resulting in a mirror.
More modern devices also make use of thin films, such as solar panels, high-powered telescopes, and even memory chips. These technologies require thin films to be applied so accurately and smoothly that more advanced compounds are developed to make for an even coating. Copper indium gallium (di)selenide (CIGS) is one of the most popular thin film materials, especially for solar panels, as they can absorb solar power. Crystalline silicone is also a standard component for solar panels.
A liquid-based solution has been researched as a possible material for thin film. Nanofibers and other liquids form a mixture that, when agitated, can coat a surface in just mere seconds. This solution can produce thin film materials that are more affordable, more environment-friendly, and easier to apply.
Selecting from various thin film materials can depend on the technique of applying the thin film, whether it is of a chemical or a physical deposition. In chemical deposition, liquids or vapors experience a chemical change when they interact with a surface, resulting in an even coating of thin film. One common example of this is electroplating, a process that uses an electric field to coat an object with metal ions. The physical deposition, on the other hand, only changes the state of a material, usually turning it into solid. Sputter deposition is an example of this, wherein the solid surface ejects few of its atoms to a plasma, forming a thin film.
Aside from the thin film materials, the surface, or target materials, is also an important element. Glass is the standard target material, as it bonds well with many elements. Other materials such as ceramic, metal foil, and plastic are coming out as possible surfaces for thin films because they are less expensive than glass.
