SOLID STATE LIGHTING DEVICE WITH REDUCED LUMINOUS FLUX DROP AT ELEVATED TEMPERATURE

摘要

A solid state light emitting device includes a solid state light emitter and a lumiphoric material that are selected for use with one another to provide light emissions with improved (i.e., reduced) thermal droop A solid state emitter having a short peak emission wavelength (e.g., in a visible range at or below 440 nm) seemingly less than optimal at room temperature for use with a particular lumiphor can trigger more efficient stimulation of lumiphor emissions at high temperatures. Enhanced epitaxial structures also inhibit decrease of radiant flux by LEDs at elevated temperatures.

主权项

1. A solid state lighting device comprising a lumiphoric material having a peak emission wavelength in a yellow range arranged to receive and be excited by light emissions of at least one electrically activated solid state light emitter having a peak emission wavelength in a range of from 428 nm to 440 nm at a solid state light emitter temperature of 25° C., wherein the lumiphoric material comprises a peak excitation wavelength that exceeds the peak emission wavelength of the at least one electrically activated solid state light emitter by at least 20 nm.