electroluminescent

Electroluminescent refers to materials or devices that emit light in response to an electric field or current. The emitted photons arise from radiative processes within a phosphor material or an organic emissive layer when charge carriers gain energy from the applied field and recombine.

In inorganic electroluminescent (EL) devices, a phosphor layer (often zinc sulfide doped with copper or manganese) is sandwiched between dielectric layers and conductive electrodes. Under high-voltage alternating current, the electric field excites dopant centers in the phosphor, producing light. This architecture yields thin, rugged panels used for backlighting in displays, signage, instrument panels, and glow surfaces. Variants include AC-driven EL panels and EL wires.

Organic electroluminescence includes organic light-emitting diodes (OLEDs). In OLEDs, electrons and holes are injected from opposite electrodes into organic emissive layers where they form excitons that emit photons when they decay. OLEDs can be driven by direct current and can be fabricated on flexible substrates, enabling bright displays and lighting panels with a wide color range. Color is determined by the organic emitters and device architecture.

Applications and considerations vary: EL devices can provide uniform surface illumination with relatively simple driving schemes and good ruggedness. Inorganic EL tends to be durable with longer lifetimes but often requires higher driving voltages and may age due to phosphor degradation. OLEDs offer high efficiency and tunable color but can have shorter operational lifetimes and require effective encapsulation to guard against moisture. Electroluminescent technology supports signage, backlighting, decorative lighting, and the development of flexible display systems.