Terbium(III,IV) oxide is widely used as a phosphor material in green-emitting applications for television screens, fluorescent lamps, and display technologies, due to its ability to emit green light when excited by electrons or ultraviolet radiation. It serves as a key component in solid oxide fuel cells (SOFCs) owing to its mixed ionic and electronic conductivity, enhancing oxygen ion transport and improving cell efficiency at lower operating temperatures. Additionally, it is employed in oxygen sensors and electrochemical devices requiring high oxygen mobility. The compound shows promise in catalytic applications, particularly in oxidation reactions and environmental remediation processes. Its unique redox properties make it suitable for advanced materials in energy storage and conversion technologies. It is also utilized in ceramic materials for electronics that demand thermal and electrical stability.