Lumenje

Lumenje is a term used in materials science to denote a class of luminescent materials that exhibit persistent luminescence, or afterglow, long after an excitation source has been removed. The term is not fully standardized and can appear in different research contexts to refer to various compounds that show long-lived emission.

In general, lumenje materials are inorganic hosts doped with luminescent ions, such as lanthanides or transition metals. The dopants create electronic traps within the crystal lattice, allowing charge carriers to be stored and later released as light. The emitted color and duration of the afterglow depend on the choice of host lattice and dopant, as well as the concentration and distribution of traps.

Synthesis and properties: Lumenje compounds are typically prepared by solid-state reactions, coprecipitation, or hydrothermal methods, with careful control over crystal quality, particle size, and dopant levels. Their afterglow behavior can range from a few milliseconds to several hours at ambient temperature. The performance is influenced by factors such as trap depth, host rigidity, and environmental stability, including moisture sensitivity and thermal quenching.

Applications and limitations: Potential uses include safety and emergency signage, display backlighting, and certain bioimaging or sensing applications where slow, visible light emission is advantageous. Limitations include fading of the afterglow over time, dependence on temperature, and, in some cases, concerns about the availability or toxicity of certain dopants or host materials.

Etymology and relation: The name lumenje blends the Latin lumen, meaning light, with a suffix used in naming conventions for materials. It is related to the broader category of persistent phosphors and phosphorescent materials, though its usage remains informal in parts of the literature.