| 摘要 |
The present invention provides a phosphor-converted LED device comprising one or more phosphor thin films that convert primary light emitted by the LED into one or more other wavelengths of light to produce light of a particular color. Each phosphor thin film comprises dopant ions that are statistically spatially distributed in such a manner that the phosphor conversion of the primary light is predictable and controlled by the concentration of the dopants and by the thickness of the thin film. Therefore, variations in the color of the light produced by phosphor- converted LED devices can be eliminated, thereby enabling uniformity in the quality of the colored light produced to be ensured. In accordance with one embodiment of the present invention, a single phosphor thin film is comprised by the LED device. The thin film converts a portion of the primary emission into yellow light while allowing a portion of the primary blue light to pass through the thin film. The primary light and the yellow light combine to produce white light. Alternately, a plurality of phosphor thin films, each of which emits a different color of light, may be comprised in the LED device. Each of the thin films converts a portion of primary radiation into a particular color of light, e.g., red or green light. The red light, green light and the unconverted primary light combine to form white light. Alternatively, one of the thin films completely absorbs the primary radiation and converts it into blue light. This converted blue light then functions as the primary light that undergoes phosphor conversion via one or more other phosphor thin films to produce white light. One or more thin films may be used in this manner to perform phosphor conversion to produce light of colors other than white, such as green light.
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