Thin film devices is a research field and technological concept concerned with the design, fabrication, characterization, and application of functional structures constructed from one or more material layers with thicknesses typically ranging from nanometers to micrometers. This area investigates the unique physical, chemical, and electronic properties exhibited by materials at reduced dimensions and interfaces, and leverages precise deposition techniques to create components and systems with specific performance characteristics, driving innovation in areas like microelectronics, photovoltaics, displays, and sensors.