A kind of LED epitaxial structure and preparation method thereof

Abstract

The invention provides an LED epitaxial structure and a preparation method thereof. A compound current spreading layer is provided on the side of the active layer away from the N-type semiconductor layer, wherein the compound current spreading layer includes a plurality of hole supply layers. and a periodic unit composed of a hole barrier layer, and the hole supply layer is used as the contact surface of the recombination current spreading layer; further, the forbidden band width of the hole supply layer is less than or equal to the empty The forbidden band width of the hole barrier layer. The recombination current spreading layer provides holes through the hole supply layer, and forms an effective hole barrier height through the hole barrier layer, thereby increasing the P-type doping concentration and increasing the material in this region. valence band, thereby effectively improving the horizontal expansion capability of the current.

Description

technical field [0001] The invention relates to the field of light emitting diodes, in particular to an LED epitaxial structure and a preparation method thereof. Background technique [0002] In recent years, III-V nitrides have been widely used in the fields of electronics and optics due to their excellent physical and chemical properties (large band gap, high breakdown electric field, and high electron saturation mobility). Among them, blue-green and ultraviolet light-emitting diodes based on GaN / AlGaN-based materials have made great progress in the fields of lighting, display, curing, and killing. With the gradual expansion of LED applications, the market's requirements for LED performance are getting higher and higher, and a series of technologies such as positive and flip chips under high current density are often caused by thermal effects caused by current crowding, resulting in decreased efficiency and uneven brightness. The problem has become a hot spot in the curre...

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Problems solved by technology

However, the increase in the thickness of the ohmic contact layer directly affects the photon extraction efficiency of the device, especially in the ultraviolet band (UVB~UVC), because the ohmic contact layer is usually made of GaN material, which seriously absorbs ultraviolet light, thereby reducing the luminous efficiency.

When increasing the thickness of ITO or increasing the P-Finger, there is also the problem of light absorption or light blocking, which affects the light extraction efficiency of the chip, which in turn leads to the problem of low luminous efficiency.

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