White light-emitting diode and preparation method thereof

Abstract

The invention provides a chip-level white light-emitting diode and a preparation method thereof. A yellow light excitation layer formed by a quantum well is formed on the upper surface or the lower surface of a normal blue light quantum well; partial blue light emitted from the blue light quantum well excites the yellow light excitation layer to emit a yellow light; and a white light is formed after mixing, so that a white light chip free of fluorescent powder is achieved. According to the chip-level white light-emitting diode, the blue light is emitted by an active layer under electric injection; the emitted blue light excites a yellow light quantum well to emit the yellow light; matching with the active layer is mainly considered during current injection; and the amount of the blue light emitted from the active layer reaches the maximum value for the best. Meanwhile, the yellow light quantum well is high in absorption conversion efficiency and not easy to saturate; the color temperature of the white light formed after mixing does not deviate along with an increase of the injected current.

Description

technical field [0001] The invention relates to the field of semiconductor lighting, in particular to a chip-level white light emitting diode and a manufacturing method thereof. Background technique [0002] At present, the technical routes of using LEDs to realize white light sources are as follows: The first is to use red, green, and blue LEDs to mix and output white light. Due to the different attenuation speeds of LEDs of different colors, the control circuit is complicated and costly. High; the second is to use single-color LEDs with phosphors to achieve white light output, such as using blue LEDs to excite yellow phosphors, or ultraviolet LEDs to excite tri-primary phosphors. However, the stability of phosphors and the control of color temperature are both It is technically difficult and has high requirements for the packaging process. The third is to use a single chip without phosphors to achieve white light, which is expected to overcome the defects of the above tec...

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Problems solved by technology

However, this technology relies on point defects in the material, and the luminescence of point defects is easy to saturate under high current, which eventually leads to an increase in the color temperature of white light as the injection current increases.

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