CN101399302B

CN101399302B - Light emitting diode

Info

Publication number: CN101399302B
Application number: CN2007101516900A
Authority: CN
Inventors: 吴易座
Original assignee: Everlight Electronics Co Ltd
Current assignee: Everlight Electronics Co Ltd
Priority date: 2007-09-26
Filing date: 2007-09-26
Publication date: 2010-12-15
Anticipated expiration: 2027-09-26
Also published as: CN101399302A

Abstract

A light-emitting diode at least comprises a substrate, N-type and P-type semiconductor layers, an ohmic contact layer, a light-emitting layer, a metal layer and an electrode. The ohmic contact layer and the metal layer are arranged in the N-type semiconductor layer, and the metal layer is directly contacted with the N-type semiconductor layer, thereby increasing the degree of the uniform distribution of the current introduction into the N-type semiconductor layer, effectively upgrading the light-emitting efficiency of the light-emitting diode and reducing the resistance of the light-emitting diode.

Description

Light-emitting diode

Technical field

The present invention relates to a kind of light-emitting diode, and particularly a kind of light-emitting diode that an ohmic contact layer (0hmic contact layer) and a metal level are set in n type semiconductor layer.

Background technology

Known light-emitting diode is generally to be longer than on the insulating substrate, for example sapphire (sapphire) base material.Because insulating substrate is also non-conductive,, be beneficial to the conduction of electricity so positive and negative electrode must be made in simultaneously the surface of the compound semiconductor epitaxial layer of tool conductivity.Yet because the conductivity of compound semiconductor epitaxial layer is than metal difference, thus cause current density inhomogeneous easily, and influence the luminous uniformity and the luminous efficiency of the light-emitting area of light emitting diode construction.

With reference to Fig. 1, it illustrates the constructed profile of known a kind of light-emitting diode.Light-emitting diode 100 has comprised base material 110, n type semiconductor layer 120 at least, luminescent layer 130, p type semiconductor layer 140, the first ohmic contact layers 151, the second ohmic contact layers 152, metal level 160, the first electrodes 171 and second electrode 172.

The relative position at cause first electrode 171 and second electrode, 172 places is also underlapped, and second ohmic contact layer 152 is also unequal with the area of metal level 160, makes win electric current distribution 181 and second electric current distribution 182 present crooked and uneven distribution.

Above-mentioned phenomenon will cause luminescent layer 130 higher near the current density of the part of second electrodes 172, and lower away from the current density of the part of second electrode 172.Therefore, cause the non-uniform light of luminescent layer 130, the luminous efficiency of light-emitting diode 100 still has naturally needs improved space.

Therefore, provide one not need significantly to change manufacturing process, increase simple in structure, and the good light-emitting diode of luminous efficiency is crucial.

Summary of the invention

The object of the present invention is to provide the better light-emitting diode of a kind of luminous efficiency.

According to above-mentioned purpose, the present invention proposes a kind of light-emitting diode.According to a preferred embodiment of the present invention, comprise base material, N type and p type semiconductor layer, ohmic contact layer, luminescent layer, metal level and electrode at least.

Light-emitting diode has a base material.One first n type semiconductor layer is set on base material, one first ohmic contact layer is set on first n type semiconductor layer, one the first metal layer is set on first ohmic contact layer, one second n type semiconductor layer is set on the first metal layer, one luminescent layer is set on second n type semiconductor layer, one p type semiconductor layer is set on luminescent layer, one second ohmic contact layer is set on p type semiconductor layer, one second metal level is set on second ohmic contact layer, on the first metal layer and second metal level, an electrode is set respectively.Wherein, this luminescent layer falls within the projected area of this first metal layer, falls into the areal extent of this first metal layer fully, and the projected area that falls within this second metal level falls into the areal extent of second metal level fully.

Be made up of and embodiment said structure, embodiments of the invention are compared with known technology and are had following advantage:

1. directly contact with n type semiconductor layer because of metal level, and the more known light-emitting diode of contact area is bigger, this kind structure can make electric current evenly import whole n type semiconductor layer, because of also comprising a metal level in the P type semiconductor bedded structure, so the distance of two groups of metal interlevels is effectively shortened, and more improves the degree that electric current is uniformly distributed in luminescent layer.

2. the distance of two groups of metal levels in the shortening light-emitting diode can effectively promote the luminous efficiency of light-emitting diode, with the resistance that reduces light-emitting diode.

For enabling further to understand feature of the present invention and technology contents, see also following about detailed description of the present invention and accompanying drawing, yet accompanying drawing only provide with reference to and the explanation usefulness, be not to be used for the present invention is limited.

Description of drawings

Fig. 1 illustrates the constructed profile according to known a kind of light-emitting diode.

Fig. 2 illustrates the constructed profile according to a kind of light-emitting diode of a preferred embodiment of the present invention.

Wherein, Reference numeral:

100: light-emitting diode 110: base material

120:N type semiconductor layer 130: luminescent layer

151: the first ohmic contact layers of 140:P type semiconductor layer

Ohmic contact layer 160 in 152: the second: metal level

172: the second electrodes of 171: the first electrodes

182: the second electric current distribution of 181: the first electric current distribution

200: light-emitting diode 210: base material

221: the first n type semiconductor layers of 220:N N-type semiconductor N bedded structure

Ohmic contact layer 223 in 222: the first: the first metal layer

N type semiconductor layer 230 in 224: the second: luminescent layer

240:P N-type semiconductor N bedded structure 241:P type semiconductor layer

243: the second metal levels of 242: the second ohmic contact layers

252: the second electrodes of 251: the first electrodes

262: the second electric current distribution of 261: the first electric current distribution

Embodiment

With reference to Fig. 2, it illustrates the constructed profile according to a kind of light-emitting diode of a preferred embodiment of the present invention.Light-emitting diode 200 has comprised base material 210, N type semiconductor bedded structure 220, luminescent layer 230 and P type semiconductor bedded structure 240 at least.

N type semiconductor bedded structure 220 comprises first n type semiconductor layer 221, first ohmic contact layer 222, the first metal layer 223 and second n type semiconductor layer 224.

P type semiconductor bedded structure 240 comprises p type semiconductor layer 241, second ohmic contact layer 242, with second metal level 243.

First n type semiconductor layer 221 is set on base material 210, first ohmic contact layer 222 is set on n type semiconductor layer 221, on first ohmic contact layer 222, the first metal layer 223 is set, second n type semiconductor layer 224 is set on the first metal layer 223, on second n type semiconductor layer 224, luminescent layer 230 is set, p type semiconductor layer 241 is set on luminescent layer 230, second ohmic contact layer 242 is set on p type semiconductor layer 241, second metal level 243 is set on second ohmic contact layer 242, first electrode 251 and second electrode 252 are set on the first metal layer 223 and second metal level 243 respectively.

Wherein, the material of first ohmic contact layer 222 and second ohmic contact layer 242 is nickel gold (NiAu) alloy or tin indium oxide (Indium Tin Oxide; ITO) compound.The material of the first metal layer 223, second metal level 243, first electrode 251 and second electrode 252 has comprised gold, silver, copper, aluminium, nickel or tungsten.

First ohmic contact layer 222 is in order to promote the conductivity of the first metal layer 223, first n type semiconductor layer 221 and second n type semiconductor layer 224.

Though the relative position at first electrode 251 and second electrode, 252 places is also underlapped, but the relative position of the first metal layer 223 and second metal level 243 is overlapping, and luminescent layer 230 falls within the projected area of the first metal layer 223, fall into the areal extent of the first metal layer 223 fully, the projected area that falls within second metal level 243 falls into the areal extent of second metal level 243 fully, in the present embodiment, luminescent layer 230 is identical and overlapping with the area of second metal level 243, makes the electric current distribution 261 of winning can present vertical distribution uniformly with second electric current distribution 262.

And vertical equally distributed current density can make that the luminescent layer 230 between second n type semiconductor layer 224 and p type semiconductor layer 241 is luminous uniformly, and does not have the situation that the known configurations luminous efficiency is not showing.

In addition, in the embodiments of the invention, the first metal layer 223 and second metal level 243 in that the both sides of luminescent layer 230 are provided with only have a metal level to compare with known configurations, and the resistance of light-emitting diode 200 is obviously lower.

Certainly; the present invention also can have other various embodiments; under the situation that does not deviate from spirit of the present invention and essence thereof; those of ordinary skill in the art work as can make various corresponding changes and distortion according to the present invention, but these corresponding changes and distortion all should belong to the protection range of the appended claim of the present invention.

Claims

1. a light-emitting diode is characterized in that, comprises at least:

One base material;

One N type semiconductor bedded structure, this N type semiconductor bedded structure is arranged on this base material, and this N type semiconductor bedded structure comprises one first n type semiconductor layer, one first ohmic contact layer, a first metal layer and one second n type semiconductor layer, this first ohmic contact layer covers on this first n type semiconductor layer, this the first metal layer covers on this first ohmic contact layer, and this second n type semiconductor layer exposes this first metal layer of part;

One luminescent layer, this luminescent layer are arranged on this second n type semiconductor layer;

One P type semiconductor bedded structure, this P type semiconductor bedded structure is arranged on this luminescent layer, and this P type semiconductor bedded structure comprises one second ohmic contact layer and one second metal level at least, this second ohmic contact layer is arranged on this luminescent layer, and this second metal level is arranged on this second ohmic contact layer;

First electrode is arranged on the surface of the first metal layer of this exposure; And

Second electrode, be arranged on this second metal level, wherein, this luminescent layer falls within the projected area of this first metal layer, fall into the areal extent of this first metal layer fully, the projected area that falls within this second metal level falls into the areal extent of second metal level fully.

2. light-emitting diode according to claim 1 wherein also comprises a p type semiconductor layer, and this p type semiconductor layer is arranged between this second ohmic contact layer and this luminescent layer.

3. light-emitting diode according to claim 1, wherein the material of this first ohmic contact layer and this second ohmic contact layer is the nickel billon.

4. light-emitting diode according to claim 1, wherein the material of this first ohmic contact layer and this second ohmic contact layer is the tin indium oxide compound.

5. light-emitting diode according to claim 1, wherein this first metal layer and this second metal level comprise gold, silver, copper, aluminium, nickel or tungsten.

6. light-emitting diode according to claim 1, wherein the material of this first electrode and this second electrode comprises gold, silver, copper, aluminium, nickel or tungsten.