KR20130067770A

KR20130067770A - Light-emitting diode

Info

Publication number: KR20130067770A
Application number: KR1020110134670A
Authority: KR
Inventors: 김동욱
Original assignee: 엘지이노텍 주식회사
Priority date: 2011-12-14
Filing date: 2011-12-14
Publication date: 2013-06-25

Abstract

The light emitting device includes at least one of a first conductivity type semiconductor layer, an active layer disposed on the first conductivity type semiconductor layer, a second conductivity type semiconductor layer disposed on the active layer, and a second conductivity type semiconductor layer. An electron blocking layer.

Description

Light-emitting diode

An embodiment relates to a light emitting device.

Light-emitting diodes (LEDs) are semiconductor light emitting devices that convert current into light.

BACKGROUND ART A semiconductor light emitting device can obtain light having high luminance and is widely used as a light source for a display, a light source for an automobile, and a light source for an illumination.

The light emitting device still has a relatively low internal quantum efficiency. There may be various reasons for the low internal quantum efficiency of the light emitting device. However, one of the reasons is that electrons supplied to the active layer do not contribute to recombination and move to the adjacent conductive semiconductor layer.

The embodiment provides a light emitting device capable of improving internal quantum efficiency by preventing electrons in the active layer from being moved to an adjacent conductive semiconductor layer.

The embodiment provides a light emitting device capable of stably supplying holes of a conductive semiconductor layer to an active layer to improve internal quantum efficiency.

According to an embodiment, the light emitting element includes a first conductivity type semiconductor layer; An active layer disposed on the first conductivity type semiconductor layer; A second conductive semiconductor layer disposed on the active layer; And at least one electron blocking layer disposed on the second conductive semiconductor layer, wherein the at least one electron blocking layer comprises: a first electron blocking layer disposed between the active layer and the second conductive semiconductor layer; And a second electron blocking layer disposed between the second conductive semiconductor layer.

The embodiment allows the first electron blocking layer far from the active layer to have a larger thickness than the second electron blocking layer close to the active layer, thereby blocking the movement of the electrons to the second conductive semiconductor layer while the second conductivity type semiconductor layer Holes in the channel may facilitate supply to the active layer, thereby improving internal quantum efficiency.

In the embodiment, the first electron blocking layer farther from the active layer is formed with a larger bandgap than the second electron blocking layer closer to the active layer, thereby blocking the movement of the electrons to the second conductive semiconductor layer while the second conductivity type semiconductor. Holes in the layer facilitate the supply to the active layer, thereby improving internal quantum efficiency.

The embodiment forms a second conductive semiconductor layer between the active layer and the first electron blocking layer, so that the holes of the conductive semiconductor layer are smoothly supplied to the active layer without being affected by the electron blocking layer, thereby improving internal quantum efficiency. Can be.

1 is a cross-sectional view showing a light emitting device according to the first embodiment.
FIG. 2 is an exemplary view of the electron blocking layer of FIG. 1.
3 is another exemplary diagram of the electron blocking layer of FIG. 2.
4 is a diagram illustrating Al content of the electron blocking layer of FIGS. 2 and 3.
FIG. 5 is a diagram illustrating an energy band diagram of the light emitting device of FIG. 1.
6 is a cross-sectional view illustrating a light emitting device according to a second embodiment.
FIG. 7 is a diagram illustrating Al content of the electron blocking layer of FIG. 6.
FIG. 8 is a diagram illustrating an energy band diagram of the light emitting device of FIG. 6.
9 is a sectional view showing a light emitting device according to the third embodiment.
FIG. 10 is an exemplary diagram of an energy band diagram of the light emitting device of FIG. 9.
FIG. 11 is another exemplary diagram of an energy band diagram of the light emitting device of FIG. 9.
12 is a sectional view showing a light emitting device according to the fourth embodiment.
13 is a cross-sectional view illustrating a horizontal light emitting device according to the embodiment.
14 is a cross-sectional view illustrating a flip type light emitting device according to the embodiment.
15 is a cross-sectional view illustrating a vertical light emitting device according to the embodiment.
16A and 16B are simulation diagrams showing energy band diagrams of light emitting devices according to Comparative Examples and Examples.
17A and 17B are enlarged views of the balance band of FIGS. 16A and 16B.
18A and 18B are simulation diagrams showing hole concentrations of light emitting devices according to Comparative Examples and Examples.
19A and 19B are simulation diagrams showing electric fields of light emitting devices according to Comparative Examples and Examples.
20 is an exploded perspective view of a display device according to an exemplary embodiment.
21 is a diagram illustrating a display device having a light emitting device according to an embodiment.
22 is a perspective view of a lighting apparatus according to an embodiment.

In the description of the embodiment according to the invention, in the case where it is described as being formed on the "top" or "bottom" of each component, the top (bottom) or the bottom (bottom) means that the two components It includes both direct contact or one or more other components disposed between and formed between the two components. Also, in the case of "upper (upper) or lower (lower)", it may include not only the upward direction but also the downward direction based on one component.

1 is a cross-sectional view showing a light emitting device according to the first embodiment.

Referring to FIG. 1, the light emitting device 10 according to the first exemplary embodiment may include a substrate 11, a first conductive semiconductor layer 13, an active layer 15, and a second conductive semiconductor layer 17 and a first conductive layer. And a second electron blocking layer.

The light emitting structure 19 may be formed by the first conductive semiconductor layer 13, the active layer 15, and the second conductive semiconductor layer 17.

The light emitting device 10 according to the first exemplary embodiment includes the substrate 11 to mitigate lattice mismatch due to a lattice constant difference between the substrate 11 and the first conductive semiconductor layer 13. ) And the first conductive semiconductor layer 13 may further include a buffer layer, but the embodiment is not limited thereto.

Defects such as cracks, voids, grains and bowing do not occur in the light emitting structure 19 formed on the substrate 11 by the buffer layer.

Although not shown, a non-conductive semiconductor layer containing no dopant may be further included between the buffer layer and the first conductive semiconductor layer 13, but embodiments are not limited thereto.

The buffer layer, the nonconductive semiconductor layer, the first conductive semiconductor layer 13, the active layer 15, and the second conductive semiconductor layer 17 may be formed of Group III and Group V compound semiconductor materials, but It does not limit about.

The compound semiconductor material may include, for example, Al, In, Ga, and N, but is not limited thereto.

The substrate 11 may be formed of a material having excellent thermal conductivity and / or transmittance, but is not limited thereto. For example, the substrate 11 may be formed of at least one selected from the group consisting of sapphire (Al ₂ O ₃ ), SiC, Si, GaAs, GaN, ZnO, Si, GaP, InP, and Ge, but is not limited thereto. .

The first conductivity type semiconductor layer 13 may be formed on the substrate 11 or the buffer layer.

The first conductivity-type semiconductor layer 13 may be, for example, an n-type semiconductor layer including an n-type dopant, but is not limited thereto. The first conductivity type semiconductor layer 13 may include, for example, AlGaN or GaN, but is not limited thereto. The n-type dopant may include Si, Ge, or Sn, but is not limited thereto.

The first conductivity type semiconductor layer 13 may serve as a conductive layer for supplying a first carrier, for example, electrons, to the active layer 15. That is, the dopant having a high concentration is doped into the first conductive semiconductor layer 13, and thus may serve as a conductive layer in which electrons can move freely.

The first conductivity type semiconductor layer 13 is formed of a compound semiconductor material having a band gap equal to or greater than that of the active layer 15, thereby preventing the active layer 15 supplied from the second conductivity type semiconductor layer 17. It may serve as, but is not limited to, a barrier layer that prevents second carriers, such as holes, from falling into the buffer layer.

The active layer 15 may be formed on the first conductive semiconductor layer 13.

For example, the active layer 15 may recombine electrons supplied from the first conductive semiconductor layer 13 and holes supplied from the second conductive semiconductor layer 17 to emit ultraviolet light.

The active layer 15 may include any one of a single quantum well structure (SQW), a multiple quantum well structure (MQW), a quantum dot structure, and a quantum line structure.

The active layer 15 may be formed by one or a periodic repetition thereof selected from GaN, InGaN, AlGaN, and AlInGaN.

When the active layer 15 is formed of a multi-quantum well structure (MQW), the active layer 15 may be repeatedly arranged in a cycle of the barrier layer and the well layer.

The barrier layer may have a larger bandgap than the well layer. Therefore, electrons and holes are mainly collected in the well layer.

For example, the period may be arranged in a period of GaN barrier / GaN wells, a period of AlGaN barrier / GaN wells, a period of GaN barrier / InGaN wells, or a period of InGaN barrier / InGaN wells, but is not limited thereto.

The active layer 15 may generate ultraviolet light, visible light, or infrared light, but is not limited thereto.

The second conductivity type semiconductor layer 17 may be formed on the active layer 15.

The second conductive semiconductor layer 17 may be, for example, a p-type semiconductor layer including a p-type dopant, but is not limited thereto. The second conductivity type semiconductor layer 17 may be, for example, AlGaN or GaN, but is not limited thereto. The p-type dopant may include Mg, Zn, Ca, Sr or Ba, but is not limited thereto.

The second conductive semiconductor layer 17 may serve as a conductive layer for supplying holes to the active layer 15.

A high concentration of dopant is doped into the second conductive semiconductor layer 17, and thus may serve as a conductive layer through which holes may freely move.

Typically, the electron mobility is much faster than the hole mobility. Therefore, the number of electrons supplied from the first conductive semiconductor layer 13 to the active layer 15 is much larger than the number of holes supplied from the second conductive semiconductor layer 17.

In the well layer of the active layer 15, one electron and one hole recombine to generate light. Since the number of electrons is much larger than the number of holes, many electrons cannot be recombined with the holes. These electrons may be attracted by the holes present in the second conductivity type semiconductor layer 17 and may be moved to the second conductivity type semiconductor layer 17. The electrons moved to the second conductivity type semiconductor layer 17 do not contribute to reconstruction to generate any more light, but disappear in the second conductivity type semiconductor layer 17, thereby reducing the internal quantum efficiency of the light emitting device 10. It is a major cause of deterioration.

According to the light emitting device 10 according to the first embodiment, at least one electron blocking layer 21, 23 is formed to prevent electrons of the active layer 15 from being transferred to the second conductive semiconductor layer 17. It may be formed on the second conductive semiconductor layer 17.

In other words, at least one barrier may be formed in the second conductive semiconductor layer 17 to prevent electrons of the active layer 15 from moving to the second conductive semiconductor layer 17. Such a barrier may correspond to the electron blocking layers 21 and 23.

The at least one electron blocking layers 21 and 23 may have a bandgap larger than at least the active layer 15, specifically, the barrier layer.

For example, a first electron blocking layer 21 is formed on the active layer 15, and an odd second conductive semiconductor layer 17a is formed on the first electron blocking layer 21. The second electron blocking layer 23 may be formed on the second conductive semiconductor layer 17a, and the even second second conductive semiconductor layer 17b may be formed on the second electron blocking layer 23. .

The first electron blocking layer 21 may be formed in surface contact with the active layer 15.

In other words, the first electron blocking layer 21 is formed between the active layer 15 and the odd second conductive semiconductor layer 17a, and the second electron blocking layer 23 is the odd number. It may be formed between the second conductive semiconductor layer 17a and the even second conductive semiconductor layer 17b.

The first and second electron blocking layers 21 and 23 may be AlGaN, but are not limited thereto.

The first and second electron blocking layers 21 and 23 may have a band gap larger than at least the barrier layer of the active layer 15 or the second conductive semiconductor layer 17, but is not limited thereto.

The second conductivity type semiconductor layer 17 may have a band gap equal to or greater than that of the barrier layer of the active layer 15, but is not limited thereto.

The first embodiment forms at least one or more electron blocking layers 21, 23 having a bandgap at least larger than the active layer 15, whereby electrons in the active layer 15 move to the second conductivity type semiconductor layer 17. The internal quantum efficiency can be improved by making it difficult to do so.

Meanwhile, since the electron blocking layers 21 and 23 have a band gap larger than at least the second conductivity type semiconductor layer 17, holes generated in the second conductivity type semiconductor layer 17 are not supplied to the active layer 15. It can also be a barrier.

The first embodiment proposes various techniques for smoothly supplying holes generated in the second conductivity type semiconductor layer 17 to the active layer 15, which will be described in detail below.

In the following description, the thickness of the first electron blocking layer 21 will be named t1, the thickness of the second electron blocking layer 23 will be named t2, and the thickness of the odd second conductivity-type semiconductor layer 17a will be described. Is referred to as T1, and the thickness of the even-numbered second conductive semiconductor layer 17b is referred to as T2.

In the first embodiment, the thickness of the first electron blocking layer 21 may be 2 nm to 10 nm, and the second electron blocking layer 23 may be 10 nm to 50 nm, but is not limited thereto.

The odd-numbered second conductive semiconductor layer 17a and the even-numbered second conductive semiconductor layer 17b may be 10 nm to 50 nm, respectively, but are not limited thereto.

The total thicknesses of the first and second electron blocking layers 21 and 23, the odd second conductive semiconductor layer 17a and the even second second conductive semiconductor layer 17b may be 100 nm to 200 nm. This is not limitative.

As shown in FIG. 2, the thickness of the second electron blocking layer 23 may be greater than the thickness of the first electron blocking layer 21. In other words, the thickness of the second electron blocking layer 23 far from the active layer 15 may be greater than that of the first electron blocking layer 21 close to the active layer 15.

The thickness of the odd-numbered second conductive semiconductor layer 17a may be the same as the thickness of the even-numbered second conductive semiconductor layer 17b.

As shown in FIG. 3, the thickness of the second electron blocking layer 23 may be greater than the thickness of the first electron blocking layer 21. In other words, the thickness of the second electron blocking layer 23 far from the active layer 15 may be greater than that of the first electron blocking layer 21 close to the active layer 15.

The thickness of the even-numbered second conductive semiconductor layer 17b may be greater than the thickness of the odd-numbered second conductive semiconductor layer 17a. In other words, the thickness of the even-numbered second conductivity-type semiconductor layer 17b farther from the active layer 15 is greater than the thickness of the odd-numbered second conductivity-type semiconductor layer 17a closer to the active layer 15. Can be.

In this case, the first and second electron blocking layers 21 and 23 may have the same Al content of 10% to 20%, as shown in FIG. 4, but is not limited thereto. This may mean that the first and second electron blocking layers 21 and 23 have the same band gap.

As shown in FIG. 5, in the energy band diagram of the first embodiment, the bandgaps of the first and second electron blocking layers 21 and 23 are the same, but the second electron blocking layer 23 is the first electron blocking. It can be seen that it has a larger width than layer 21.

The first electron blocking layer 21 may play a role of smoothly supplying holes rather than blocking electron movement, but is not limited thereto.

The second electron blocking layer 23 may serve to block electron movement rather than to facilitate supply of holes, but is not limited thereto.

2 and 3, the second electron blocking layer 23 farther from the active layer 15 is formed to have a larger thickness, so that the electrons of the active layer 15 are transferred to the first electron blocking layer 21 or the same. The second electron blocking layer 23 may prevent the second conductive semiconductor layer 17 from moving. Although the thickness of the second electron blocking layer 23 is large so that holes generated in the even-numbered second conductive semiconductor layer 17b are not easy to cross the second electron blocking layer 23, the radix The holes created in the second second conductive semiconductor layer 17a may be relatively easily supplied to the active layer 15 beyond the first electron blocking layer 21 having a relatively small thickness.

Hereinafter, the comparative examples and the examples are compared through various experiments.

In the horizontal axis of the graphs below, 235 nm and 280 nm may represent the vehicle blocking layer, and between 235 nm and 280 nm may represent the second conductivity-type semiconductor layer 17.

16A and 16B are simulation diagrams showing energy band diagrams of light emitting devices according to Comparative Examples and Examples, and FIGS. 17A and 17B are enlarged views of the balance bands of FIGS. 16A and 16B.

16A and 17A are energy band diagrams when one electron blocking layer is formed in the second conductive semiconductor layer as a comparative example, and FIGS. 16B and 17B are examples of the second conductive semiconductor layer 17 as an example. This is an energy band diagram when two electron blocking layers 21 and 23 are formed.

Although the barrier in the conduction band is lowered by the first and second electron blocking layers 21 and 23 in the embodiment, the barrier is prevented by the second electron blocking layer 23 than the first electron blocking layer 21. Is formed, and it becomes difficult for electrons to move to the second conductivity type semiconductor layer 17.

In contrast, the band offset of the first electron blocking layer 21 of the balance band in the embodiment is more than the band off set (region A) of the electron blocking layer of the balance band in the comparative example. As the region (B) is reduced, the holes of the second conductivity-type semiconductor layer 17 can be more easily supplied to the active layer.

18A and 18B are simulation diagrams showing hole concentrations of light emitting devices according to Comparative Examples and Examples.

As shown in FIG. 18A, the concentration of the holes in the electron blocking layer is about 1E + 14, whereas in FIG. 18B, the concentration of the holes in the first electron blocking layer 21 is 1E +. The concentration of the hole in the second electron blocking layer 23 is about 1E + 15. Thus, the example shows higher hole concentration than the comparative example by the first and second blocking layers, which shows that the holes can be supplied with the active layer more smoothly in the example.

19A and 19B are simulation diagrams showing electric fields of light emitting devices according to Comparative Examples and Examples.

As shown in FIG. 19A, in the comparative example, the internal electric field is largely formed in the vehicle blocking layer, whereas in FIG. 19B, in the embodiment, the internal electric field in the first electron blocking layer 21 is higher than that of the comparative example. It can be seen that greatly reduced. As such, since the internal electric field of the embodiment is small, the supply of the holes to the active layer can be made smoothly.

In the first embodiment, the second electron blocking layer 23 far from the active layer 15 has a thickness larger than that of the first electron blocking layer 21 close to the active layer 15. While blocking the movement to the conductive semiconductor layer 17, holes in the second conductive semiconductor layer 17 facilitate supply to the active layer 15, thereby improving internal quantum efficiency.

6 is a cross-sectional view illustrating a light emitting device according to a second embodiment, and FIG. 7 is a diagram showing Al content of the electron blocking layer of FIG. 6.

The second embodiment is the first embodiment except that the first and second electron blocking layers 21 and 23 have the same thickness and the first and second electron blocking layers 21 and 23 have different Al contents from each other. Almost the same as the example.

In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

Descriptions omitted in the description of the second embodiment can be easily understood from the first embodiment.

Referring to FIG. 6, the light emitting device 10A according to the second exemplary embodiment may include a substrate 11, a first conductive semiconductor layer 13, an active layer 15, and a second conductive semiconductor layer 17 and a first conductive layer. And second electron blocking layers 21 and 23.

The first and second electron blocking layers 21 and 23 may be formed on the second conductive semiconductor layer 17.

The thickness of the first electron blocking layer 21 and the thickness of the second electron blocking layer 23 are the same.

The odd-numbered second conductive semiconductor layer 17a and the even-numbered second conductive semiconductor layer 17b may have the same thickness or different thicknesses.

As shown in FIG. 7, the Al content of the second electron blocking layer 23 may be higher than the Al content of the first electron blocking layer 21.

For example, the Al content of the first electron blocking layer 21 may be 5% to 10%, and the Al content of the second electron blocking layer 23 may be 15% to 30%, but is not limited thereto.

Therefore, the second electron blocking layer 23 may have a larger bandgap than the first electron blocking layer 21.

As shown in FIG. 8, the band gap of the second electron blocking layer 23 may be larger than the band gap of the first electron blocking layer 21.

As shown in FIG. 7, the Al content of the second electron blocking layer 23 farther from the active layer 15 is increased to make the bandgap larger, so that the electrons of the active layer 15 are transferred to the first electron blocking layer. It may not be possible to move to the second conductivity-type semiconductor layer 17 by the 21 or the second electron blocking layer 23. Although the band gap of the second electron blocking layer 23 is formed high so that holes generated in the even-numbered second conductive semiconductor layer 17b are not easy to cross the second electron blocking layer 23, Holes generated in the odd second conductive semiconductor layer 17a may be relatively easily supplied to the active layer 15 beyond the first electron blocking layer 21 having a relatively low band gap.

In the second embodiment, the first electron blocking layer 21 far from the active layer 15 is formed to have a larger bandgap than the second electron blocking layer 23 close to the active layer 15, thereby reducing the electrons of the active layer 15. While the movement to the second conductive semiconductor layer 17 is blocked, the holes of the second conductive semiconductor layer 17 can be smoothly supplied to the active layer 15 to improve the internal quantum efficiency.

9 is a sectional view showing a light emitting device according to the third embodiment.

The third embodiment is almost the same as the first embodiment except that the second conductivity type semiconductor layer 17 is also formed between the first electron blocking layer 21 and the active layer 15.

In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

Descriptions omitted from the description of the third embodiment can be easily understood from the first embodiment.

Referring to FIG. 9, the light emitting device 10B according to the third embodiment may include a substrate 11, a first conductive semiconductor layer 13, an active layer 15, and a second conductive semiconductor layer 17 and a first conductive layer. And second electron blocking layers 21 and 23.

For example, an odd second conductive semiconductor layer 17a may be formed on the active layer 15, and a first electron blocking layer 21 may be formed on the odd second conductive semiconductor layer 17a. have.

The even second second conductive semiconductor layer 17b is formed on the first electron blocking layer 21, and the second electron blocking layer 23 is formed on the even second second conductive semiconductor layer 17b. Can be.

Radix second conductive semiconductor layers 17a and 17c may be formed on the second electron blocking layer 23.

In other words, the first electron blocking layer 21 is formed between the odd second conductive semiconductor layer 17a and the even second conductive semiconductor layer 17b, and the second electron blocking layer Reference numeral 23 may be formed between the even-numbered second conductivity-type semiconductor layer 17b and the odd-numbered second conductivity-type semiconductor layer 17c.

The first electron blocking layer 21 and the even second second conductivity type semiconductor layer 17b between the odd second second conductivity type semiconductor layer 17a and the even second second conductivity type semiconductor layer 17b and the odd number The second electron blocking layers 23 between the second second conductive semiconductor layers 17c may have the same thickness or different thicknesses.

For example, as illustrated in FIG. 10, the thickness of the second electron blocking layer 23 may be greater than the thickness of the first electron blocking layer 21.

An odd second conductive semiconductor layer 17a between the active layer 15 and the first electron blocking layer 21, and between the first electron blocking layer 21 and the second electron blocking layer 23. The even-numbered second conductive semiconductor layer 17b and the odd-numbered second conductive semiconductor layer 17c contacting the second electron blocking layer 23 may have the same thickness or different thicknesses.

For example, the thickness of the even-numbered second conductivity-type semiconductor layer 17b in contact with the first electron blocking layer 21 is greater than the thickness of the odd-numbered second conductivity-type semiconductor layer 17a in contact with the active layer 15, The odd-numbered second conductivity-type semiconductor layer 17c in contact with the second electron blocking layer 23 may be larger than the thickness of the even-numbered second conductivity-type semiconductor layer 17b.

The first and second electron blocking layers 21 and 23 may have the same Al content or different Al contents.

For example, the Al content of the second electron blocking layer 23 may be formed so that the first electron blocking layer 21 is higher than the Al content. In this case, as shown in FIG. 11, the band gap of the second electron blocking layer 23 may be greater than the band gap of the first electron blocking layer 21.

In the third embodiment, the odd second conductive semiconductor layer 17a is formed between the active layer 15 and the first electron blocking layer 21, so that the holes of the odd second conductive semiconductor layer 17a are formed. The internal quantum efficiency may be improved by being smoothly supplied to the active layer 15 without being affected by the first and second electron blocking layers 21 and 23.

12 is a sectional view showing a light emitting device according to the fourth embodiment.

The fourth embodiment is almost the same as the first embodiment except for the plurality of electron blocking layers 25_1 to 25_n.

In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

Descriptions omitted in the description of the fourth embodiment can be easily understood from the first embodiment.

12, the light emitting device 10C according to the fourth embodiment may include a substrate 11, a first conductive semiconductor layer 13, an active layer 15, a second conductive semiconductor layer 17, and a plurality of light emitting devices 10C. The electron blocking layers 25_1 to 25_n may be included.

The plurality of electron blocking layers 25_1 to 25_n may be formed on the second conductive semiconductor layer 17.

The second conductive semiconductor layer 17 includes a plurality of odd second conductive semiconductor layers 17_1,..., 17_ (n-1) and a plurality of even second second conductive semiconductor layers 17_2. .., 17_n).

Therefore, the plurality of electron blocking layers 25_1 to 25_n may include a plurality of odd second conductive semiconductor layers 17_1,..., 17_ (n-1) or even second second conductive semiconductor layers 17_2, ..., 17_n) may be formed alternately.

For example, a first electron blocking layer 25_1 is formed on the active layer 15, and an odd second conductive semiconductor layer 17_1,..., 17_ (n) is formed on the first electron blocking layer 25_1. -1)), and a second electron blocking layer 25_2 may be formed on the odd-numbered second conductivity-type semiconductor layers 17_1,..., 17_ (n-1).

Even-numbered second conductive semiconductor layers 17_2,..., 17_n are formed on the second electron blocking layer 25_2, and the even-numbered second conductive semiconductor layers 17_2,..., 17_n are formed. The third electron blocking layer 25_3 may be formed on the second electron blocking layer 25_3.

An odd second conductivity type semiconductor layer 17_1,..., 17_ (n-1) is formed on the third electron blocking layer 25_3, and the odd second conductivity type semiconductor layer 17_1. .., The fourth electron blocking layer 25_4 may be formed on 17_ (n-1).

In this manner, the even-numbered second conductive semiconductor layers 17_2,..., 17_n may be formed on the nth electron blocking layer 25_n.

Like the first to third embodiments, the plurality of electron blockings of the fourth embodiment may also have the same or different thicknesses and Al contents.

The above light emitting devices 10, 10A, 10B, and 10C may be manufactured as the horizontal light emitting device of FIG. 13, the flip light emitting device of FIG. 14, and the vertical light emitting device of FIG. 15.

The description omitted in the following description can be easily understood from the description of the first to fourth embodiments.

13 is a cross-sectional view illustrating a horizontal light emitting device according to the embodiment.

As shown in FIG. 13, in the horizontal light emitting device according to the embodiment, the first conductive semiconductor layer 13 may have a predetermined depth in the light emitting devices 10, 10A, 10B, and 10C of the first to fourth embodiments. Mesa can be etched until. Accordingly, the first conductivity type semiconductor layer 13 may be exposed.

A transparent electrode layer 27 is formed on the second conductive semiconductor layer 17 for current spreading, a first electrode 31 is formed on the first conductive semiconductor layer 13, and the transparent electrode layer is formed. The second electrode 33 may be formed on the 27.

If current spreading is not required, the transparent electrode layer 27 may not be formed. In this case, the second electrode 33 may be formed on the second conductivity type semiconductor layer 17.

The transparent electrode layer 27 may be formed of a material having excellent transparency in order to emit light to the outside. The transparent electrode layer 27 may include, for example, ITO, IZO (In-ZnO), GZO (Ga-ZnO), AZO (Al-ZnO), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), IrOx, At least one selected from the group consisting of RuOx, RuOx / ITO, Ni / IrOx / Au, and Ni / IrOx / Au / ITO may be included, but is not limited thereto.

The first and second electrodes 31 and 33 may be formed of a material having excellent electrical conductivity. The first and second electrodes 31 and 33 may include, for example, at least one or an alloy thereof selected from the group consisting of Au, Ti, Ni, Cu, Al, Cr, Ag, and Pt.

At least one electron blocking layer 21, 23, 25_1 to 25_n is formed in the second conductive semiconductor layer 17 to block electron movement and to smoothly supply holes, thereby improving internal quantum efficiency. have.

14 is a cross-sectional view illustrating a flip type light emitting device according to the embodiment.

As shown in FIG. 14, the horizontal light emitting device according to the embodiment is turned upside down by 180 degrees and the reflective electrode layer 29 is formed instead of the transparent electrode layer 27 of the horizontal light emitting device. The manufacture can be completed.

When the light generated by the active layer 15 proceeds downward, the reflective electrode layer 29 may reflect the light and proceed upward, thereby improving light extraction efficiency.

For example, the reflective electrode layer 29 may be formed of a metal material having excellent conductivity and reflectivity, and may be selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, and Hf. It may include one or an alloy thereof, but is not limited thereto.

15 is a cross-sectional view illustrating a vertical light emitting device according to the embodiment.

As shown in FIG. 15, in the horizontal light emitting device of FIG. 13, the channel layer 43, the reflective electrode layer 45, the bonding layer 47, and the conductive support member 49 are formed on the second conductive semiconductor layer 17. ), And then flipped 180 degrees, the substrate 11 can be removed. Subsequently, the side surface of the light emitting structure 19 may be inclined through mesa etching. Subsequently, a protective layer 51 is formed on a side surface of the light emitting structure 19, an upper surface of the channel layer 43, and a portion of the upper surface of the light emitting structure 19 to protect the light emitting structure 19. The electrode 53 may be formed on the semiconductor layer 13. In this way, a vertical light emitting device according to the embodiment may be manufactured.

The reflective electrode layer 45 may be formed of a material having reflective properties for reflecting light and conductive properties for supplying power to the light emitting structure 19.

The reflective electrode layer 45 may be formed of, for example, at least one selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, and Hf, or an alloy thereof. It does not limit about.

The conductive support member 49 is formed of a conductive material through which electricity can flow. For example, the conductive support member 49 may be formed of at least one selected from the group consisting of Cu, Au, Ni, Mo, and Cu-W, but is not limited thereto.

The protective layer 51 may be formed of the same material as the channel layer 43, but is not limited thereto.

The channel layer 43 and the protective layer 51 may be formed of one of an oxide, a nitride, and an insulating material. The channel layer 43 and the protective layer 51 may include, for example, ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, GZO, SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , At least one selected from the group consisting of Al ₂ O ₃ , and TiO ₂ .

The electrode 53 may be formed of a material having excellent electrical conductivity. The electrode 53 may include, for example, at least one or an alloy thereof selected from the group consisting of Au, Ti, Ni, Cu, Al, Cr, Ag, and Pt.

On the other hand, the current blocking layer 41 for preventing the concentration of the current in the vertical direction may be formed to overlap the electrode 53 in the vertical direction.

The current blocking layer 41 may be formed of the same material as the protective layer 51 and the channel layer 43, but is not limited thereto.

The light emitting device 10 according to the embodiment may be applied to a light unit. The light unit includes a structure in which a plurality of light emitting elements 10 are arranged, and includes a display device shown in FIGS. 20 and 21 and a lighting device shown in FIG. 22. Can be applied to units such as indicators.

20 is an exploded perspective view of a display device according to an exemplary embodiment.

Referring to FIG. 20, the display device 1000 includes a light guide plate 1041, a light emitting module 1031 that provides light to the light guide plate 1041, a reflective member 1022 under the light guide plate 1041, and the light guide plate 1041. A bottom cover 1011 that houses an optical sheet 1051 on the light guide plate 1041, a display panel 1061 on the optical sheet 1051, the light guide plate 1041, a light emitting module 1031, and a reflective member 1022. ), But is not limited thereto.

The bottom cover 1011, the reflective sheet 1022, the light guide plate 1041, and the optical sheet 1051 can be defined as a light unit 1050.

The light guide plate 1041 serves to diffuse the light provided from the light emitting module 1031 to make a surface light source. The light guide plate 1041 is made of a transparent material, for example, acrylic resin-based such as polymethyl metaacrylate (PMMA), polyethylene terephthlate (PET), polycarbonate (PC), cycloolefin copolymer (COC), and polyethylene naphthalate (PEN). It may include one of the resins.

The light emitting module 1031 is disposed on at least one side of the light guide plate 1041 to provide light to at least one side of the light guide plate 1041, and ultimately serves as a light source of the display device.

At least one light emitting module 1031 may be disposed in the bottom cover, and may provide light directly or indirectly at one side of the light guide plate 1041. The light emitting module 1031 may include a substrate 1033 and a light emitting device 10 according to the exemplary embodiment disclosed above, and the light emitting device 10 may be arranged on the substrate 1033 at predetermined intervals. The substrate may be a printed circuit board, but is not limited thereto. In addition, the substrate 1033 may include a metal core PCB (MCPCB, Metal Core PCB), flexible PCB (FPCB, Flexible PCB) and the like, but is not limited thereto. When the light emitting device 10 is mounted on the side surface of the bottom cover 1011 or the heat dissipation plate, the substrate 1033 may be removed. A part of the heat radiation plate may be in contact with the upper surface of the bottom cover 1011. Therefore, heat generated in the light emitting device 10 may be discharged to the bottom cover 1011 via the heat dissipation plate.

The plurality of light emitting devices 10 may be mounted on the substrate 1033 such that an emission surface from which light is emitted is spaced apart from the light guide plate 1041 by a predetermined distance, but is not limited thereto. The light emitting device 10 may directly or indirectly provide light to a light incident part, which is one side of the light guide plate 1041, but is not limited thereto.

The reflective member 1022 may be disposed under the light guide plate 1041. The reflective member 1022 reflects the light incident on the lower surface of the light guide plate 1041 and supplies the reflected light to the display panel 1061 to improve the brightness of the display panel 1061. The reflective member 1022 may be formed of, for example, PET, PC, or PVC resin, but is not limited thereto. The reflective member 1022 may be an upper surface of the bottom cover 1011, but is not limited thereto.

The bottom cover 1011 may house the light guide plate 1041, the light emitting module 1031, the reflective member 1022, and the like. To this end, the bottom cover 1011 may be provided with a housing portion 1012 having a box-like shape with an opened upper surface, but the present invention is not limited thereto. The bottom cover 1011 may be coupled to a top cover (not shown), but is not limited thereto.

The bottom cover 1011 may be formed of a metal material or a resin material, and may be manufactured using a process such as press molding or extrusion molding. In addition, the bottom cover 1011 may include a metal or a non-metal material having good thermal conductivity, but the present invention is not limited thereto.

The display panel 1061 is, for example, an LCD panel, and includes a first and second substrates of transparent materials facing each other, and a liquid crystal layer interposed between the first and second substrates. A polarizing plate may be attached to at least one surface of the display panel 1061, but the present invention is not limited thereto. The display panel 1061 displays information by transmitting or blocking light provided from the light emitting module 1031. The display device 1000 can be applied to video display devices such as portable terminals, monitors of notebook computers, monitors of laptop computers, and televisions.

The optical sheet 1051 is disposed between the display panel 1061 and the light guide plate 1041 and includes at least one light-transmitting sheet. The optical sheet 1051 may include at least one of a sheet such as a diffusion sheet, a horizontal / vertical prism sheet, a brightness enhanced sheet, and the like. The diffusion sheet diffuses incident light, and the horizontal and / or vertical prism sheet concentrates incident light on the display panel 1061. The brightness enhancing sheet reuses the lost light to improve the brightness I will. A protective sheet may be disposed on the display panel 1061, but the present invention is not limited thereto.

The light guide plate 1041 and the optical sheet 1051 may be included as an optical member on the optical path of the light emitting module 1031, but are not limited thereto.

21 is a diagram illustrating a display device having a light emitting device according to an embodiment.

Referring to FIG. 21, the display device 1100 includes a bottom cover 1152, a substrate 1120 on which the light emitting device 10 disclosed above is arranged, an optical member 1154, and a display panel 1155.

The substrate 1120 and the light emitting device 10 may be defined as a light emitting module 1160. The bottom cover 1152, the at least one light emitting module 1160, and the optical member 1154 may be defined as a light unit (not shown).

The bottom cover 1152 may include a receiving portion 1153, but the present invention is not limited thereto.

The optical member 1154 may include at least one of a lens, a light guide plate, a diffusion sheet, a horizontal and vertical prism sheet, and a brightness enhancement sheet. The light guide plate may be made of a PC material or a PMMA (poly methy methacrylate) material, and such a light guide plate may be removed. The diffusion sheet diffuses the incident light, the horizontal and vertical prism sheets focus the incident light onto the display panel 1155, and the brightness enhancement sheet reuses the lost light to improve the brightness. .

The optical member 1154 is disposed on the light emitting module 1060, and performs surface light source, diffusion, and light condensation of the light emitted from the light emitting module 1060.

22 is a perspective view of a lighting apparatus according to an embodiment.

Referring to FIG. 22, the lighting device 1500 includes a case 1510, a light emitting module 1530 installed in the case 1510, and a connection terminal installed in the case 1510 and receiving power from an external power source. 1520).

The case 1510 may be formed of a material having good heat dissipation, for example, may be formed of a metal material or a resin material.

The light emitting module 1530 may include a substrate 1532 and a light emitting device 10 according to an embodiment mounted on the substrate 1532. The plurality of light emitting devices 10 may be arranged in a matrix form or spaced apart at predetermined intervals.

The substrate 1532 may be a circuit pattern printed on an insulator. For example, a general printed circuit board (PCB), a metal core PCB, a flexible PCB, a ceramic PCB, FR-4 substrates and the like.

In addition, the substrate 1532 may be formed of a material that reflects light efficiently, or the surface may be a coating layer of a color, for example, white or silver, in which light is efficiently reflected.

At least one light emitting device 10 may be mounted on the substrate 1532. Each of the light emitting devices 10 may include at least one light emitting diode (LED) chip. The LED chip may include a light emitting diode in a visible light band such as red, green, blue, or white, or a UV light emitting diode emitting ultraviolet (UV) light.

The light emitting module 1530 may be arranged to have a combination of various light emitting devices 10 to obtain color and luminance. For example, a white light emitting diode, a red light emitting diode, and a green light emitting diode may be combined to secure high color rendering (CRI).

The connection terminal 1520 may be electrically connected to the light emitting module 1530 to supply power. The connection terminal 1520 is inserted into and coupled to an external power source in a socket manner, but is not limited thereto. For example, the connection terminal 1520 may be formed in a pin shape and inserted into an external power source, or may be connected to the external power source by a wire.

10, 10A, 10B, 10C: Light emitting element 11: Substrate
13: first conductive semiconductor layer 15: active layer
17: second conductivity type semiconductor layer
17a, 17_1, 17_ (n-1): odd second conductive semiconductor layer
17b, 17_2, 17_n: even second second conductive semiconductor layer
19: light emitting structure
21, 23, 25_1 to 25_n: electron blocking layer
27: transparent electrode layer
29, 45: reflective electrode layer 31: first electrode
33: second electrode 41: current blocking layer
43: channel layer 47: bonding layer
49: conductive support member 51: protective film
53: electrode

Claims

A first conductive semiconductor layer;
An active layer disposed on the first conductive semiconductor layer;
A second conductive semiconductor layer disposed on the active layer; And
At least one electron blocking layer disposed on the second conductivity type semiconductor layer,
The at least one electron blocking layer,
A first electron blocking layer disposed between the active layer and the second conductive semiconductor layer; And
A light emitting device comprising a second electron blocking layer disposed between the second conductive semiconductor layer.

The method of claim 1,
The first electron blocking layer is disposed in surface contact with the active layer.

The method of claim 1,
The at least one electron blocking layer,
A first electron blocking layer disposed between the second conductive semiconductor layer; And
A light emitting device comprising a second electron blocking layer disposed between the second conductive semiconductor layer.

The method of claim 3,
The second light emitting device is disposed between the first electron blocking layer and the active layer.

The method according to claim 1 or 3,
A light emitting device in which the second conductivity type semiconductor layer is disposed between the first and second electron blocking layers.

The method according to claim 1 or 3,
The first and second electron blocking layers have the same thickness.

The method according to claim 1 or 3,
The first and second electron blocking layers have different thicknesses from each other.

The method of claim 7, wherein
The first electron blocking layer has a thickness of 2nm to 10nm, the second electron blocking layer is 10nm to 50nm light emitting device.

The method according to claim 1 or 3,
The first and second electron blocking layers include AlGaN.

The method according to claim 1 or 3,
The first and second electron blocking layers have the same Al content.

The method of claim 10,
The Al content is 10% to 20% light emitting device.

The method according to claim 1 or 3,
The first and second electron blocking layers have a different Al content from each other.

The method of claim 12,
The first electron blocking layer is 5% to 10%, the second electron blocking layer is 15% to 30% light emitting device.

An illuminating device comprising the light emitting element according to claim 1.