KR20160014343A - Light emitting device and lighting system - Google Patents

Abstract

The present embodiment relates to a light emitting device, a method for manufacturing the light emitting device, a light emitting device package, and a lighting system. According to an embodiment, the light emitting device may comprise: a first-conductivity-type semiconductor layer; an active layer formed on the first-conductivity-type semiconductor layer; and an AlzGa(1-z)N layer (wherein, 0<=z<=1) formed on the active layer. According to an embodiment, the light emitting device may comprise an InxAlyGa(1-x-y)N-based superlattice layer (wherein, 0<=x<=1, 0<=y<=1) formed between the active layer and the AlzGa(1-z)N layer.

Description

[0001] LIGHT EMITTING DEVICE AND LIGHTING SYSTEM [0002]

Embodiments relate to a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and an illumination system.

A light emitting device is a p-n junction diode in which electric energy is converted into light energy, and elements of Group III and Group V can be generated by combining on the periodic table. LEDs can be implemented in various colors by controlling the composition ratio of compound semiconductors.

When a forward voltage is applied to a light emitting device, the electrons in the n-layer and the holes in the p-layer are coupled to emit energy corresponding to the energy gap between the conduction band and the valance band. It emits mainly in the form of heat or light, and emits in the form of light.

For example, nitride semiconductors have received great interest in the development of optical devices and high power electronic devices due to their high thermal stability and wide bandgap energy. Particularly, blue light emitting devices, green light emitting devices, ultraviolet (UV) light emitting devices, and the like using nitride semiconductors have been commercialized and widely used.

The Epi layer structure employed in the light emitting device according to the prior art includes an electron injection layer, a light emitting layer, and a hole injection layer, and the light emitting layer is important for device characteristics.

According to the prior art, the emission recombination of electrons and holes in the last quantum well, which is closest to the hole injection layer due to the low mobility of holes, In the quantum well adjacent to the electron injection layer, the light emitting recombination does not occur well, while it occurs most actively.

Meanwhile, in the conventional multi-quantum well structure, electron leakage occurs due to the rapid mobility of electrons, and as a result, the efficiency of internal light emission decreases as the current increases An efficiency droop occurs, and further, due to the low hole injection efficiency, the device characteristics are deteriorated due to the reduction of radiative recombination.

Further, according to the related art, an electron blocking layer is introduced between the active layer and the hole injection layer in order to prevent the occurrence of electron leakage. In such an electron blocking layer, lattice strain is induced by the difference between the active layer and the crystal lattice, And the emission efficiency is lowered.

Embodiments provide a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and an illumination system capable of increasing light emitting efficiency.

The light emitting device according to the embodiment includes a first conductive semiconductor layer 112; An active layer 114 on the first conductive semiconductor layer 112; And an Al _z Ga _{1 -z} N layer (where 0? _Z ? 1) (124) on the active layer 114.

In the embodiment, an In _x Al _y Ga _1-xy N superlattice layer (0? _{X? 1} , 0? _{Y? 1} ) is formed between the active layer 114 and the Al _z Ga _{1 -z} N layer 124, (Not shown).

Further, the illumination system according to the embodiment may include a light emitting unit having the light emitting element.

According to the light emitting device, the method of manufacturing the light emitting device, the light emitting device package, and the illumination system according to the embodiments, the injection efficiency of holes can be increased and the light emitting efficiency can be increased.

According to the embodiment, the strain between the active layer and the electron blocking layer can be relaxed to increase the luminous efficiency and increase the reliability of the device.

1 is a cross-sectional view of a light emitting device according to an embodiment.
2 is an exemplary view of a band diagram of a light emitting device according to the first embodiment;
3 is an exemplary view of a band diagram of a light emitting device according to a second embodiment;
4 is an exemplary view of a band diagram of a light emitting device according to a third embodiment;
5 is a graph showing the internal quantum efficiency data of the light emitting device and the comparative example according to the embodiment.
6 is a graph showing the operating voltage data of the light emitting device and the comparative example according to the embodiment.
Fig. 7 is a plot of integration data of the light emitting device and the comparative example according to the embodiment.
FIGS. 8 to 12 are views showing a manufacturing process of the light emitting device according to the embodiment. FIG.

In the description of the embodiments, each layer (film), region, pattern or structure is referred to as being "on" or "under" the substrate, each layer (film) Quot; on "and" under "are intended to include both" directly "or" indirectly " do. Also, the criteria for top, bottom, or bottom of each layer will be described with reference to the drawings.

(Example)

1 is a cross-sectional view of a light emitting device 100 according to an embodiment.

The light emitting device 100 according to the embodiment includes a first conductive semiconductor layer 112, an active layer 114 on the first conductive semiconductor layer 112, and an Al _z Ga _{1 -z} N layer (where 0? z? 1) (124).

The first conductive semiconductor layer 112 may be formed on the ohmic layer 130 and the second electrode 152 on the ohmic layer 130. The ohmic layer 130 may be formed on the second conductive semiconductor layer 116, And may include a first electrode 151 connected thereto.

The embodiment may be applied to a horizontal type light emitting device, and thus the substrate 102 may be provided on the bottom surface of the first conductivity type semiconductor layer 112, but the present invention is not limited thereto. have.

In order to provide a light emitting device capable of enhancing the luminous efficiency, the embodiment is characterized in that an In _x Al _y Ga _1-xy N superlattice layer (layered structure) is formed between the active layer 114 and the Al _z Ga _{1 -z} N layer 124 , 0? X? 1, 0? Y? 1) 122.

2 is an exemplary view of a band diagram of a light emitting device according to the first embodiment.

In the first embodiment, the In _x Al _y Ga _1-xy N superlattice layer 122 has a super lattice structure of an In _x Ga _1-x N layer 122a / Al _y Ga _{1 -y} N layer 122b . &Lt; / RTI &gt;

Layer structure of the In _x Ga _1-x N layer 122a / Al _y Ga ₁ -yN layer 122b is formed between the active layer 114 and the Al _z Ga _{1 -z} N layer 124 according to the embodiment, The strain due to the lattice difference between the active layer and the Al _z Ga _{1 -z} N layer 124 can be relaxed.

For example, the In _x Al _y Ga _1-xy N superlattice layer 122 may include an In _x Ga _1-x N layer 122a and an Al _z Ga _{1 -z} N layer (which are similar to the quantum well material of the active layer The Al _y Ga _{1 -y} N layer 122 b, which is similar to the material of the Al _z Ga _{1 -z} N layer 124, is arranged in a superlattice structure to relax strain due to the lattice difference between the active layer and the Al _z Ga _{1 -z} N layer 124 The efficiency of the radiant recombination can be increased.

According to the embodiment, the strain due to the lattice difference between the active layer 114 and the Al _z Ga _{1 -z} N layer 124 can be relaxed to increase the hole injection efficiency and increase the luminous efficiency, The reliability can be enhanced and the emission efficiency droop phenomenon can be improved.

The composition of indium (In) in the In _x Ga _1-x N layer 122a may be lower than the composition of indium (In) in the quantum well 114w of the active layer. For example, the concentration (x) of indium in the In _x Ga _1-x N layer 122a may be about 1.0% to 5.0%. When the concentration (x) of indium in the In _x Ga _1-x N layer 122a is less than 1.0%, the effect of strain relaxation may be small due to a small content of indium, which is a material of the quantum well of the active layer. The energy level is lower than or equal to that of the quantum well of the quantum well.

In the embodiment, the composition of aluminum (Al) in the Al _y Ga _{1 - y} N layer 122b may be lower than the composition of aluminum (Al) in the Al _z Ga _{1 -z} N layer 124. For example, the composition (y) of aluminum in the Al _y Ga _{1 - y} N layer 122b may be 10% to 20%. When the composition (y) of aluminum in the Al _y Ga _{1 - y} N layer 122b is less than 10%, the composition of the Al _z Ga _{1 -z} N layer 124 is different from that of aluminum, so that the effect of strain relaxation may be low have. On the other hand, when the composition (y) of aluminum in the Al _y Ga _{1 - y} N layer 122b exceeds 20%, the film quality may deteriorate.

In the embodiment, the In _x Al _y Ga _1-xy N superlattice layer 122 includes five pairs to ten pairs of In _x Ga _1-x N layers 122a / Al _y Ga _{1 -y} N layers (Not shown).

In the embodiment, when the pair of the In _x Ga _{1 -x} N layer 122a / Al _y Ga _{1 -y} N layer 122b is less than 5 pairs, the strain relaxation effect is low and the light intensity may not be improved. In _x Ga _{When the} pair of _1-x N layer 122a / Al _y Ga ₁ -yN layer 122b is more than 10 pairs, the operating voltage VF3 may increase and electrical characteristics may be degraded.

In the embodiment, the In _x Ga _1-x N layer 122a and the Al _y Ga ₁ -yN layer 122b are each repeatedly formed to a thickness of about 1 nm or less to form a superlattice structure.

Accordingly, when the In _x Al _y Ga _1-xy N superlattice layer 122 is formed of five to ten pairs of In _x Ga _1-x N layer 122a / Al _y Ga ₁ -yN layer (122b) super lattice, the In _x Al _y Ga _{1 -xy} N superlattice layer 122 may have a thickness of 10 nm to 20 nm.

The embodiment can prevent Mg back diffusion by providing an undoped GaN barrier 115 between the In _x Al _y Ga _1-xy N superlattice layer 122 and the active layer 114.

3 is an exemplary view of a band diagram of a light emitting device according to the second embodiment.

The second embodiment can employ the technical features of the first embodiment.

In the second embodiment, the In _x Al _y Ga _1-xy N superlattice layer 122 is a superlattice layer of the In _x Ga _1-x N layer 122a / In _x Al _y Ga _1-xy N layer 122c Structure.

The second embodiment is an active layer 114 and the Al _z Ga _1-z N layer _{(124) In x Ga 1-} x N layer (122a), which portion comprises a material composition of the quantum between / In _x Al _y Ga _1- By arranging the superlattice structure of the _xy N layer 122c, the lattice strain can be relaxed, the hole injection efficiency can be improved, the luminous intensity can be increased, and the operating voltage can be improved.

4 is an exemplary view of a band diagram of a light emitting device according to the third embodiment.

The third embodiment can adopt the technical features of the first embodiment or the second embodiment.

In the third embodiment, the In _x Al _y Ga _1-xy N superlattice layer 122 is formed of In _x Al _y Ga _1-xy N layer 122c / In _x Ga _1-x N layer 122a / Al _y And a superlattice structure of Ga _{1 - y} N layer 122b.

The third embodiment includes a superlattice structure of an In _x Al _y Ga _1-xy N layer 122c / In _x Ga _{1 -x} N layer 122a / Al _y Ga _{1 -y} N layer 122b , The strain caused by the lattice difference between the active layer 114 and the Al _z Ga _{1 -z} N layer 124 can be further relaxed to further increase the light emitting recombination efficiency.

In addition, according to the third embodiment, the In _x Al _y Ga _1-xy N layer 122c / In _x (x) is formed so that the band gap energy level gradually decreases from the Al _z Ga _{1 -z} N layer 124 toward the active layer 114 Ga _1-x N layer _{(122a) / Al y Ga 1} - by arranging the _y N layer (122b) super lattice structure by increasing the hole injection and transfer efficiency can be improved luminous efficiency.

The light intensity Po in the chip Operating voltage (VF3) The luminous intensity (Po) at the integrating sphere at 95 mA Comparative Example 138.4 2.931 140.5 Example 141.0 2.898 143.7

Table 1 shows the luminous intensity Po, the operating voltage VF3, and integral sphere comparison data in the light emitting device according to the comparative example and the example.

5 is internal quantum efficiency data of the light emitting device and the comparative example according to the embodiment.

According to the embodiment (E1), the strain due to the lattice difference between the active layer 114 and the Al _z Ga _{1 -z} N layer 124 is relaxed, and the efficiency of the radiative recombination is increased so that the maximum value of the internal quantum efficiency EQE peak) of the light emitting device chip was increased compared to the comparative example (R1), and the luminous intensity Po of the light emitting device chip was improved as shown in Table 1.

6 is an operating voltage data of the light emitting device and the comparative example according to the embodiment.

According to the embodiment (E2), the strain due to the lattice difference between the active layer 114 and the Al _z Ga _{1 -z} N layer 124 is relaxed to increase the hole injection efficiency, and the value of the operating voltage VF3 is shown in Table 1 And the electrical characteristics are improved.

7 is brightness data (Po) data on the integrating sphere of the light emitting device and the comparative example according to the embodiment.

According to the embodiment (E3), the strain due to the lattice difference between the active layer 114 and the Al _z Ga _{1 -z} N layer 124 is relaxed, and the luminous recombination efficiency is increased, so that the luminous intensity Po values on the integrating sphere are compared It can be seen from Table 1 and FIG. 7 that it is improved by about 1.5% compared to Example (R3).

According to the light emitting device according to the embodiment, the injection efficiency of holes can be increased, and the luminous efficiency can be increased. According to the embodiment, the strain between the active layer and the electron blocking layer can be relaxed to increase the luminous efficiency and increase the reliability of the device.

Hereinafter, a method of manufacturing a light emitting device according to an embodiment will be described with reference to FIGS. 8 to 12, and the technical features of the embodiment will be described in detail.

First, the substrate 102 is prepared as shown in Fig. The substrate 102 may be formed of a material having excellent thermal conductivity, and may be a conductive substrate or an insulating substrate.

For example, at least one of sapphire (Al ₂ O ₃ ), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga ₂ O ₃ may be used as the substrate 102. A concavo-convex structure may be formed on the substrate 102, but the present invention is not limited thereto.

At this time, a buffer layer (not shown) may be formed on the substrate 102. The buffer layer may mitigate the lattice mismatch between the material of the light emitting structure 110 to be formed and the substrate 102 and the material of the buffer layer may be a group III-V compound semiconductor such as GaN, InN, AlN, InGaN, AlGaN , InAlGaN, and AlInN.

Next, a light emitting structure 110 including a first conductive semiconductor layer 112, an active layer 114, and a second conductive semiconductor layer 116 may be formed on the first substrate 102.

First, the first conductive semiconductor layer 112 may be formed of a compound semiconductor such as a Group 3-Group-5, Group-6, or Group-6 semiconductor, and may be doped with a first conductive type dopant . When the first conductive semiconductor layer 112 is an n-type semiconductor layer, the first conductive dopant may include Si, Ge, Sn, Se, and Te as an n-type dopant.

The first conductive semiconductor layer 112 includes a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0? X? 1, 0? _Y? 1, 0? _X + y? 1) .

The first conductive semiconductor layer 112 may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP and InP.

Next, the active layer 114 is formed on the first conductivity type semiconductor layer 112.

The active layer 114 may be formed of at least one of a single quantum well structure, a multi quantum well (MQW) structure, a quantum-wire structure, or a quantum dot structure.

For example, the active layer 114 may be formed with a multiple quantum well structure by injecting trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) But is not limited thereto.

InGaN / InGaN, InGaN / AlGaN, InGaN / AlGaN, InAlGaN / GaN, GaAs (InGaAs) / AlGaAs, GaP (InGaP) / InGaN / InGaN / InGaN / InGaN / quantum well 114w / quantum wall 114b of the active layer 114, AlGaP, but the present invention is not limited thereto.

Next, an In _x Al _y Ga _1-xy N superlattice layer (0? _{X? 1} , 0? _Y? 1) 122 is formed on the active layer 114 as shown in FIG. Thereafter, an Al _z Ga _{1 -z} N layer (with 0? _Z ? 1) 124 is formed on the In _x Al _y Ga _1-xy N superlattice layer 122.

The In _x Al _y Ga _1-xy N series superlattice layer 122 and the Al _z Ga _{1 -z} N layer 124 will be described with reference to FIGS. 2 to 4.

In the embodiment, the Al _z Ga _{1 -z} N layer 124 functions as an electron blocking layer and cladding of the active layer (MQW cladding), thereby improving the light emitting efficiency.

2, the In _x Al _y Ga _1-xy N superlattice layer 122 in the first embodiment includes an In _x Ga _1-x N layer 122a / Al _y Ga ₁ -yN layer 122b ) Superlattice structure.

In the embodiment, the In _x Ga _1-x N layer 122a may be lower than the indium (In) composition of the quantum well 114w of the active layer.

For example, the concentration (x) of indium in the In _x Ga _1-x N layer 122a may be about 1.0% to 5.0%. When the concentration (x) of indium in the In _x Ga _1-x N layer 122a is less than 1.0%, the effect of strain relaxation may be small due to a small content of indium, which is a material of the quantum well of the active layer. The energy level is lower than or equal to that of the quantum well of the quantum well.

In the embodiment, the Al _y Ga _{1 - y} N layer 122b may be lower than the composition of aluminum (Al) in the Al _z Ga _{1 -z} N layer 124.

For example, the composition (y) of aluminum in the Al _y Ga _{1 - y} N layer 122b may be 10% to 20%. When the composition (y) of aluminum in the Al _y Ga _{1 - y} N layer 122b is less than 10%, the composition of the Al _z Ga _{1 -z} N layer 124 is different from that of aluminum, so that the effect of strain relaxation may be low have. On the other hand, when the composition (y) of aluminum in the Al _y Ga _{1 - y} N layer 122b exceeds 20%, the film quality may deteriorate.

In the embodiment, the In _x Al _y Ga _1-xy N superlattice layer 122 includes five pairs to ten pairs of In _x Ga _1-x N layers 122a / Al _y Ga _{1 -y} N layers (Not shown).

In the embodiment, when the pair of the In _x Ga _{1 -x} N layer 122a / Al _y Ga _{1 -y} N layer 122b is less than 5 pairs, the strain relaxation effect is low and the light intensity may not be improved. In _x Ga _{When the} pair of _1-x N layer 122a / Al _y Ga ₁ -yN layer 122b is more than 10 pairs, the operating voltage VF3 may increase and electrical characteristics may be degraded.

In the embodiment, the In _x Ga _1-x N layer 122a and the Al _y Ga ₁ -yN layer 122b are each repeatedly formed to a thickness of about 1 nm or less to form a superlattice structure.

Accordingly, when the In _x Al _y Ga _1-xy N superlattice layer 122 is formed of five to ten pairs of In _x Ga _1-x N layer 122a / Al _y Ga ₁ -yN layer (122b) super lattice, the In _x Al _y Ga _{1 -xy} N superlattice layer 122 may have a thickness of 10 nm to 20 nm.

The embodiment can prevent Mg back diffusion by providing an undoped GaN barrier 115 between the In _x Al _y Ga _1-xy N superlattice layer 122 and the active layer 114.

3, the In _x Al _y Ga _1-xy N superlattice layer 122 in the second embodiment includes an In _x Ga _1-x N layer 122a / In _x Al _y Ga _1-xy N layer 122c. &Lt; / RTI &gt;

The second embodiment is an active layer 114 and the Al _z Ga _1-z N layer _{(124) In x Ga 1-} x N layer (122a), which portion comprises a material composition of the quantum between / In _x Al _y Ga _1- By arranging the superlattice structure of the _xy N layer 122c, the lattice strain can be relaxed, the hole injection efficiency can be improved, the luminous intensity can be increased, and the operating voltage can be improved.

4, the In _x Al _y Ga _1-xy N superlattice layer 122 in the third embodiment includes an In _x Ga _1-x N layer 122a / In _x Al _y Ga _1-xy N layer 122c) / Al _y Ga _{1 -} including the superlattice structure of _y N layer (122b), with more ease the strain caused by the lattice difference between the active layer 114 and the Al _z Ga _1-z N layer 124 The efficiency of light-emitting recombination can be further increased.

According to the third embodiment, the In _x Ga _1-x N layer 122a / In _x Al _y (In) layer 122a is formed so that the band gap energy level gradually decreases from the Al _z Ga _{1 -z} N layer 124 toward the active layer 114 By arranging the super lattice structure of the Ga _1-xy N layer 122c / Al _y Ga _{1 -y} N layer 122b, the efficiency of injecting and transporting holes can be increased and the luminous efficiency can be increased.

Next, as shown in FIG. 10, a second conductive semiconductor layer 116 may be formed on the Al _z Ga _{1 -z} N layer 124.

The second conductive semiconductor layer 116 may include a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0? X? 1, 0? _Y? 1, 0? _X + y? .

When the second conductive semiconductor layer 116 is a p-type semiconductor layer, the second conductive dopant may include Mg, Zn, Ca, Sr, and Ba as p-type dopants.

In an embodiment, the first conductive semiconductor layer 112 may be an n-type semiconductor layer, and the second conductive semiconductor layer 116 may be a p-type semiconductor layer.

Also, on the second conductive semiconductor layer 116, a semiconductor (e.g., an n-type semiconductor) (not shown) having a polarity opposite to that of the second conductive type may be formed. Accordingly, the light emitting structure 110 may have any one of an n-p junction structure, a p-n junction structure, an n-p-n junction structure, and a p-n-p junction structure.

Next, the light-transmitting electrode 130 may be formed on the second conductive type semiconductor layer 116.

For example, the light-transmitting electrode 130 may include an ohmic layer, and may be formed by laminating a single metal, a metal alloy, a metal oxide, or the like so as to efficiently inject holes.

For example, the transmissive electrode 130 may be formed of a material selected from the group consisting of ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IAZO (indium aluminum zinc oxide), IGZO (ZnO), indium gallium tin oxide (AZO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZON nitride, AGZO Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Ni, IrOx / Au, and Ni / IrOx / , Au, and Hf, and is not limited to such a material.

Next, as shown in FIG. 11, the light-transmitting electrode 130, the second conductivity type semiconductor layer 116, the Al _z Ga _{1 -z} N layer 124, the In _x Al _y Ga _1-xy N superlattice layer 122 and a part of the active layer 114 can be removed.

Next, as shown in FIG. 12, a second electrode 152 is formed on the transparent electrode 130, and a first electrode 151 is formed on the exposed first conductive semiconductor layer 112, Device can be formed.

According to the light emitting device, the method of manufacturing the light emitting device, the light emitting device package, and the illumination system according to the embodiments, the injection efficiency of holes can be increased and the light emitting efficiency can be increased.

According to the embodiment, the strain between the active layer and the electron blocking layer can be relaxed to increase the luminous efficiency and increase the reliability of the device.

A plurality of light emitting devices according to the embodiments may be arrayed on a substrate in the form of a package, and a light guide plate, a prism sheet, a diffusion sheet, a fluorescent sheet, and the like may be disposed on a path of light emitted from the light emitting device package.

The light emitting device according to the embodiment may be applied to a backlight unit, a lighting unit, a display device, a pointing device, a lamp, a streetlight, a vehicle lighting device, a vehicle display device, a smart watch, but is not limited thereto.

The features, structures, effects and the like described in the embodiments are included in at least one embodiment and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong.

Accordingly, the contents of such combinations and modifications should be construed as being included in the scope of the embodiments.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. It can be seen that the modification and application of branches are possible.

For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

The first conductive semiconductor layer 112, the active layer 114,
In _x Al _y Ga _1-xy N series superlattice layers (where 0? _{X? 1} , 0? _Y? 1) 122,
The super lattice structure of the In _x Ga _{1 -x} N layer 122a / Al _y Ga _{1 - y} N layer 122b,
Al _z Ga _{1 -z} N layer (where 0? _Z ? 1) (124)

Claims (8)

A first conductive semiconductor layer;
An active layer on the first conductive semiconductor layer;
An In _x Al _y Ga _1-xy N superlattice layer (0? _{X? 1} , 0? _{Y? 1} ) on the active layer; And
And an Al _z Ga _{1 -z} N layer (0? _Z ? 1) on the In _x Al _y Ga _1-xy N series superlattice layer. The method according to claim 1,
The In _x Al _y Ga _1-xy N series super lattice layer
And a super lattice structure of In _x Ga ₁ -xN layer / Al _y Ga ₁ -yN layer. 3. The method of claim 2,
The composition of indium (In) in the In _x Ga _1-x N layer is
And the quantum well of said active layer is lower than the composition of indium. 3. The method of claim 2,
The composition of aluminum (Al) in the Al _y Ga _{1 - y} N layer is
Emitting layer is lower than the composition of aluminum of the Al _z Ga _{1 -z} N layer. The method according to claim 1,
The In _x Al _y Ga _1-xy N series super lattice layer
5 pairs to 10 pairs of In _x Ga _1-x N layers / Al _y Ga _{1 - y} N layers. The method according to claim 1,
The In _x Al _y Ga _1-xy N series super lattice layer
In _x Ga _1-x N layer / In _x Al _y Ga _1-xy N layer. The method according to claim 1,
The In _x Al _y Ga _1-xy N series super lattice layer
In _x Al _y Ga _1-xy N layer / In _x Ga _{1 -x} N layer / Al _y Ga _{1 - y} N layer. A lighting system comprising a light-emitting unit comprising the light-emitting element according to any one of claims 1 to 7.

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