Engineered structure for high brightness solid-state light emitters

Abstract

Electroluminescent (EL) light emitting structures comprises one or more active layers comprising rare earth luminescent centers in a host matrix for emitting light of a particular color or wavelength and electrodes for application of an electric field and current injection for excitation of light emission. The host matrix is preferably a dielectric containing the rare earth luminescent centers, e.g. rare earth doped silicon dioxide, silicon nitride, silicon oxynitrides, alumina, dielectrics of the general formula SiAlON, or rare earth oxides. For efficient impact excitation, corresponding drift layers adjacent each active layer have a thickness related to a respective excitation energy of an adjacent active layer. A stack of active layers emitting different colors may be combined to provide white light. For rare earth species having a host dependent emission spectrum, spectral emission of the stack may be tuned by appropriate selection of a different host matrix in successive active layers.