Light emitting diode with sandwich-type current blocking structure

Abstract

The invention discloses a light emitting diode with sandwich-type current blocking structure, comprising a sapphire substrate and a light emitting epitaxial layer, wherein the light emitting epitaxial layer is extended outwards on the sapphire substrate and is composed of an n-GaN layer, an active layer and a p-GaN layer; a first transparent conducting oxide layer is formed above the p-GaN layer;a transparent insulating layer is positioned on the first transparent conducting oxide layer and inwards retracts by 1-50 micrometers in relation to the first transparent conducting oxide layer; a second transparent conducting oxide layer covers the transparent insulating layer, outwards expands in relation to the transparent insulating layer and is electrically connected with the first transparent conducting oxide layer; a p electrode is connected with the second transparent conducting oxide layer; and an n electrode is connected with the n-GaN layer. The ''inward retraction'' positioning ofthe transparent insulating layer ensures that the current transmission mode of the first transparent conducting oxide layer is transverse transmission with certain resistance from inside to outside; thus more injected current is distributed in the outer ring area of a chip, the lighting intensity of the area is far more than that of the central area of the chip; and light extraction efficiency isimproved because the extraction probability of the photon side surface of the outer ring area of the chip is higher.

Description

technical field [0001] The invention relates to a gallium nitride-based light-emitting diode, in particular to a light-emitting diode with a sandwich-type current blocking structure. Background technique [0002] At present, gallium nitride (GaN)-based light-emitting diodes (LEDs) have been widely used in the fields of mobile phone keys, indications, displays, backlights, and lighting. The traditional gallium nitride-based light-emitting diode chip adopts a double-electrode horizontally distributed positive structure. The basic structure is to make a transparent electrode on the light-emitting epitaxial layer as an ohmic contact layer and a current spreading layer; then, on the transparent electrode. Metal electrodes (p-electrodes) are arranged for wire bonding. However, the existence of the metal electrode will cause the light emitted in the active layer to be blocked and absorbed, thereby reducing the light extraction efficiency of the LED chip. [0003] In order to avoi...

AI Technical Summary

Problems solved by technology

Therefore, the gallium nitride-based light-emitting diodes with a current blocking structure produced according to the existing technology, because the current distribution is more concentrated in the local area near the center of the chip, resulting in a lower probability of side light emission, which ultimately affects the light extraction efficiency of the light-emitting diode.

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