LED device

Abstract

The invention relates to a light emitting diode device, which comprises at least one light emitting diode unit. Each of the light emitting diode units comprises a first light emitting diode, a second light emitting diode and a multilayer structure, wherein the thickness of the multilayer structure is smaller than or equal to 30 nanometers, and the multilayer structure is located between the first light emitting diode and the second light emitting diode and used as a tunnel junction. The multilayer structure is free of doping, or p-type doping is smaller than a first doping density of a p-side nitride semiconductor layer of the first light emitting diode, or n-type doping is smaller than a second doping density of an n-side nitride semiconductor layer of the second light emitting diode.

Description

technical field [0001] The invention relates to a light-emitting diode device, in particular to a stacked light-emitting diode device with a multi-layer structure. Background technique [0002] In order to improve the luminous efficiency of a light emitting diode (LED), one of the methods is to stack two or more light emitting diodes by using a tunnel junction. Stacked LEDs emit more light than a single LED, thus increasing brightness. The use of the tunnel junction can also enhance the spreading of the current, so that more carriers in the active layer can be recombined. In addition, stacked LEDs have fewer electrode contacts than the same number of single LEDs, which not only saves space, but also reduces the resulting electromigration problem. [0003] One of the traditional methods for forming tunnel junctions is to use heavy doping technology, such as US Patent No. 6,822,991, entitled "Light Emitting Devices Including Tunnel Junctions", in which indium gallium nitride...

AI Technical Summary

Problems solved by technology

When poling to make a tunnel structure (such as a single layer of indium gallium nitride), the concentration of indium (In) should be quite high (such as greater than 20%), and the thickness should be thick (such as at least 10 nanometers), the formed tunnel The tunnel structure has the disadvantage of light absorption, and the stress will be concentrated on the interface (such as the GaN / InGaN interface), so that the growth temperature of the upper LED in the stacked LED should not be too high, otherwise the stress will cause tunneling failure as the temperature increases

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