Luminescence

Luminescence is emission of light by a substance not resulting from heat; it is thus a form of cold-body radiation. It can be caused by chemical reactions, electrical energy, subatomic motions, or stress on a crystal. This distinguishes luminescence from incandescence, which is light emitted by a substance as a result of heating. Historically, radioactivity was thought of as a form of "radio-luminescence", although it is today considered to be separate since it involves more than electromagnetic radiation. The term 'luminescence' was introduced in 1888 by Eilhard Wiedemann.
UV-photoluminescence in the microbiological diagnostics

The dials, hands, scales, and signs of aviation and navigational instruments and markings are often coated with luminescent materials in a process known as "luminising".

  • Hannover Messe: New transparent luminous pigments provide high temperature stable protection against counterfeiting

    Research scientists at INM have developed luminous particles that can also withstand high temperatures. When activated by UV light or x-rays, they glow orange red.

  • Industrial product and component labeling for extreme process conditions

    Researchers at Fraunhofer IKTS developed a robust solution for the individual labeling of components and products. It withstands extreme environmental influences, can be applied within seconds and read-out reliably. Therefore, the new development is suitable for the integration into industrial plants.

  • Invisible tags: Physicists at TU Dresden Write, Read and Erase Using Light

    A luminescent tag, contactless printed onto a plastic foil. The light emitting layer is thinner than a human hair. The imprint can be erased and replaced by another pattern. M. Gmelch and H. Thomas, TU Dresden

    A team of physicists headed by Prof. Sebastian Reineke of TU Dresden developed a new method of storing information in fully transparent plastic foils. Their innovative idea was now published in the renowned online journal “Science Advances”. Prof. Reineke and his LEXOS team work with simple plastic foils with a thickness of less than 50 µm, which is thinner than a human hair. In these transparent plastic foils, they introduce organic luminescent molecules. In the beginning, these molecules are in an inactive, dark state. By locally using ultraviolet irradiation, it is possible to turn this dark state into an active, luminescent one.