GaN based LED epitaxial wafer of graphical substrate and method for preparing same

Abstract

The invention provides a GaN based LED epitaxial wafer of a graphical substrate and a method for preparing the same. In the GaN based LED epitaxial wafer of the graphical substrate, the substrate of the epitaxial wafer comprises a distributed DBR reflecting layer which has a layering structure formed by periodical alternative growth of two transparent materials with different refractive indexes, and the DBR reflecting layer having the layering structure forms at least two graphical structures, which are spaced, on the substrate; a window area is formed between the graphical structures, and the GaN epitaxial layer can be epitaxially grown from the window area; because the growing direction of the crystals is vertical to the original motion direction of dislocations, and a mask layer blocks the majority of motion of the extended dislocations, so that the epitaxial growth of the invention can greatly reduce the density of the extended dislocations in the epitaxial layer, and improve the crystal quality of the GaN epitaxial film; and simultaneously, because the DBR reflecting layer structure on the graphical substrate is the layering structure formed by the periodical alternative growth of two materials with different refractive indexes, the light transmitted downward by an active area can be reflected to the upper surface of the output light and the light outputting efficiency of the LEDs is greatly improved.

Description

technical field [0001] The invention relates to the field of compound semiconductor epitaxial wafers, in particular to an epitaxial wafer with a patterned substrate GaN-based LED. [0002] The invention also relates to a method for preparing an epitaxial wafer with a patterned substrate GaN-based LED. Background technique [0003] Light-emitting diode (LED) is a kind of solid-state light-emitting device that can directly convert electrical energy into visible light and radiant energy. It has the advantages of long working life, high luminous efficiency, no pollution, light weight, and small size. Widely used in indoor and outdoor large-screen display, backlight display, lighting, decoration, traffic lights and other fields. The GaN material system is the most mature material for preparing blue, green, purple and ultraviolet LEDs. The research on GaN materials began in the 1930s. In 1991, someone in the industry discovered that the method of using a low-temperature growth G...

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Problems solved by technology

[0008] The above-mentioned existing methods only improve a certain performance of the LED, or improve the quality of GaN crystal, or improve the light extraction efficiency of GaN-based LED, and cannot improve the poor quality of GaN epitaxial crystal and GaN luminescence at the same time. The problem of low light extraction efficiency of the device

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