Patent ID: 7838889
Filing Date: 2010-11-23
Classification: C09K,H05B

Abstract:
1. A solid-state area illumination system, comprising: a. a plurality of LED devices, each LED device formed on a separate substrate and each LED device emitting differently colored light at different angles relative to the substrate; wherein each color of light has a frequency distribution including a peak and full width half maximum and wherein the peak frequencies of each color of light differ by at least the smallest of the full width half maximums of the frequency distributions of emitted light; b. a support for positioning each of the plurality of LED devices at a plurality of orientations relative to an area of illumination upon a surface, so that any point within the area of illumination will receive multiple colors of light from more than one of the LED devices at different angles; wherein each LED device comprises one or more light-emitting elements, each light-emitting element including multiple sizes of core/shell quantum-dot emitters formed in a common polycrystalline semiconductor matrix layer, each different size of quantum-dot emitter in each light-emitting element having a peak emission frequency and emission bandwidth, each light-emitting element further including a single succession of parallel layers, the single succession of parallel layers forming different optical microcavities having different respective optical path lengths at different angles with respect to the normal to the surface of the layers in the single succession of layers, wherein an emission bandwidth of each population of quantum-dot emitters in each light-emitting element is tuned to a frequency response of one of the optical microcavities of that light-emitting element.