White light LED excited by ultraviolet and preparation method thereof

Abstract

The invention provides a white light LED excited by ultraviolet. The white light LED comprises an ultraviolet LED chip, green fluorescent glass and a nano-patterned substrate coated with red quantum dots which are arranged in order, the green fluorescent glass is arranged at the upper portion of a light-emitting surface of the ultraviolet LED chip, and the nano-patterned substrate coated with thered quantum dots is arranged at the green fluorescent glass. The ultraviolet LED chip excites the green fluorescent glass and the red quantum dots to obtain white light to improve the color renderingindex of the white light LED; and the green fluorescent glass is employed to avoid a phenomenon that the LED is used for a long time and is aged so that an organic polymer turns yellow, improve the heat stability of the LED and solve the problem that the organic polymer can be influenced by a phosphor layer; and moreover, the nano-patterned substrate coated with the red quantum dots is employed toinhibit full reflection at an interface so as to improve the light extraction efficiency of the LED.

Description

technical field [0001] The invention relates to the technical field of white light LEDs, and more particularly, to a white light LED excited by ultraviolet rays and a preparation method thereof. Background technique [0002] In the packaging process of white light LEDs, blue light InGaN chips are usually used to excite YAG yellow phosphor to obtain white light, but the color reproduction of this white light LED is poor and is easily affected by the thickness of the phosphor layer. In addition, the phosphor particles are mixed with organic polymers, and then the mixture is coated on the LED package. The coating layer of the mixture prepared by this method not only has poor thermal stability, but also has poor thermal stability under long-term thermal radiation and ultraviolet irradiation. , prone to aging and yellowing, resulting in reduced luminous efficacy and reliability of white LEDs. Moreover, in the existing fluorescent glass, the difference in refractive index between...

AI Technical Summary

Problems solved by technology

[0002] In the packaging process of white light LEDs, blue light InGaN chips are usually used to excite YAG yellow phosphor to obtain white light, but the color reproduction of this white light LED is poor, and it is easily affected by the thickness of the phosphor layer.

In addition, the phosphor particles are mixed with organic polymers, and then the mixture is coated on the LED package. The coating layer of the mixture prepared by this method not only has poor thermal stability, but also has poor thermal stability under long-term thermal radiation and ultraviolet irradiation. , prone to aging and yellowing, resulting in reduced luminous efficacy and reliability of white LEDs

Moreover, in the existing fluorescent glass, there is a large difference in the refractive index between the air and the glass interface, which leads to the enhancement of the total emission effect at the interface, which is not conducive to the light output of the LED.

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