sekundääriemissio

Sekundääriemissio, also known as secondary emission, refers to the process by which a material emits light after it has been excited by an initial source of light. This phenomenon is commonly observed in various materials, including phosphors, luminescent materials, and certain types of glass. The process begins when the material absorbs energy from an external light source, causing its electrons to move to a higher energy state. Once the external light source is removed, the electrons gradually return to their original state, releasing the excess energy in the form of light. This emitted light is typically of a different wavelength than the initial exciting light, a property known as Stokes shift. Sekundääriemissio is utilized in various applications, such as in fluorescent lamps, where a phosphor coating on the inner surface of the tube converts ultraviolet light from a mercury vapor lamp into visible light. It is also employed in television screens and computer monitors, where phosphors are used to produce the colors on the display. The efficiency and duration of sekundääriemissio depend on the specific material used and its chemical composition. Some materials exhibit persistent luminescence, where the emitted light can last for minutes or even hours after the initial excitation. This property is utilized in applications such as glow-in-the-dark materials and emergency signage.