KR102065381B1 - Light emitting device and light emitting device package - Google Patents

Abstract

The light emitting device includes a first conductivity type semiconductor layer disposed on a substrate, an active layer disposed on the first conductivity type semiconductor layer, an electron blocking layer disposed on the active layer, and a second conductivity type disposed on the electron blocking layer. It includes a semiconductor layer. The active layer includes a plurality of barrier layers, a plurality of well layers disposed between the plurality of barrier layers, and a dummy layer disposed to contact at least one barrier layer adjacent to the electron blocking layer. The electron blocking layer includes a plurality of odd-numbered layers and a plurality of even-numbered layers disposed between the plurality of odd-numbered layers. The energy bandgap of each of the plurality of radix layers may be different.

Description

Light emitting device and light emitting device package

An embodiment relates to a light emitting device.

Embodiments relate to a light emitting device package.

Research into light emitting device packages having light emitting devices is being actively conducted.

The light emitting device is, for example, a semiconductor light emitting device or a semiconductor light emitting diode which is formed of a semiconductor material and converts electrical energy into light.

Semiconductor light emitting devices have the advantages of low power consumption, semi-permanent life, fast response speed, safety and environmental friendliness compared to conventional light sources such as fluorescent and incandescent lamps. Accordingly, many researches are being conducted to replace the existing light source with a semiconductor light emitting device.

BACKGROUND OF THE INVENTION Semiconductor light emitting devices have been increasingly used as light sources for lighting devices such as various lamps, liquid crystal display devices, electronic signs, and street lamps that are used indoors and outdoors.

The embodiment provides a light emitting device capable of improving the color rendering index.

The embodiment provides a light emitting device capable of improving light output.

The embodiment provides a light emitting device capable of lowering a driving voltage.

An embodiment provides a light emitting device package including the light emitting device.

According to an embodiment, the light emitting device comprises: a substrate; A first conductivity type semiconductor layer disposed on the substrate; An active layer disposed on the first conductivity type semiconductor layer; An electron blocking layer disposed on the active layer; And a second conductivity type semiconductor layer disposed on the electron blocking layer, wherein the active layer comprises: a plurality of barrier layers; A plurality of well layers disposed between the plurality of barrier layers; And a dummy layer disposed to contact at least one barrier layer adjacent to the electron blocking layer, wherein the electron blocking layer comprises: a plurality of radix layers; And a plurality of even-numbered layers disposed between the plurality of odd-numbered layers, wherein the energy bandgap of each of the plurality of odd-numbered layers is different.

According to an embodiment, the light emitting device package, the body; First and second lead electrodes on the body; And a light emitting device disposed on the body or any one of the first and second lead electrodes.

In embodiments, by varying the thickness of the barrier layer, the color rendering index and the light output may be improved and the driving voltage may be lowered.

According to the embodiment, by varying the energy band gaps of the odd-numbered layers of the electron blocking layer, the color rendering index and the light output may be improved, and the driving voltage may be lowered.

1 is a cross-sectional view showing a light emitting device according to the embodiment.
2 is a graph showing the relationship between the color rendering index and light output.
3 is a graph showing the light output according to the thickness of the barrier layer.
4 is a cross-sectional view of the active layer of FIG. 1.
5 is an exemplary diagram illustrating an energy band diagram of the light emitting device of FIG. 1.
6 is another exemplary diagram illustrating an energy band diagram of the light emitting device of FIG. 1.
7 is a graph showing the light output according to the wavelength of the embodiment.
8 is a cross-sectional view illustrating a horizontal light emitting device according to the embodiment.
9 is a cross-sectional view illustrating a flip type light emitting device according to the embodiment.
10 is a cross-sectional view illustrating a vertical light emitting device according to the embodiment.
11 is a cross-sectional view showing a light emitting device package according to the 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) is the two components are mutually It includes both direct contact or one or more other components disposed between and formed between the two components. In addition, when expressed as "up (up) or down (down)" may include the meaning of the down direction as well as the up direction based on one component.

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

Referring to FIG. 1, the light emitting device 1 according to the embodiment includes a substrate 3, a light emitting structure 10 disposed on the substrate 3, and an electron blocking layer 15 formed on the light emitting structure 10. ) May be included.

The substrate 1 grows the light emitting structure 10 and supports the light emitting structure 10, and may be formed of a material suitable for growth of a semiconductor material, that is, a carrier wafer. The substrate 1 may be formed of a material having a similar lattice constant and thermal stability to the light emitting structure 10, and may be a conductive substrate or an insulating substrate.

The substrate 1 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.

The buffer layer 3 may be disposed between the substrate 1 and the light emitting structure 10, but is not limited thereto.

The buffer layer 3 may be formed to mitigate a large lattice constant difference between the substrate 1 and the light emitting structure 10. That is, the buffer layer 3 may be formed on the substrate 1, and the light emitting structure 10 may be formed on the buffer layer 3. In this case, since the light emitting structure 10 has a small lattice constant difference from the buffer layer 3, the light emitting structure 10 is stably grown on the buffer layer 3 without defects, thereby improving electrical and optical characteristics. Can be.

The light emitting structure 10 may include, but is not limited to, at least a first conductivity type semiconductor layer 5, an active layer 7, and a second conductivity type semiconductor layer 9.

For example, the active layer 7 may be disposed on the first conductive semiconductor layer 5, and the second conductive semiconductor layer 9 may be disposed on the active layer 7.

The buffer layer 3, the first conductivity type semiconductor layer 5, the active layer 7, and the second conductivity type semiconductor layer 9 may be formed of a II-VI or III-V compound semiconductor material. have. For example, the first conductive semiconductor layer 5, the active layer 7, and the second conductive semiconductor layer 9 are at least one selected from the group consisting of InAlGaN, GaN, AlGaN, InGaN, AlN, InN, and AlInN. It may include, but is not limited thereto.

For example, the first conductivity-type semiconductor layer 5 may be an n-type semiconductor layer including an n-type dopant, and the second conductivity-type semiconductor layer 9 may be a p-type semiconductor layer, but is not limited thereto. The n-type dopant includes Si, Ge, Sn, and the like, and the p-type dopant includes, but is not limited to, Mg, Zn, Ca, Sr, Ba, and the like.

The active layer 7 couples a first carrier, eg, electron, injected through the first conductivity type semiconductor layer 5, and a second carrier, eg, hole, injected through the second conductivity type semiconductor layer 9 to each other. As a result, light having a wavelength corresponding to an energy band gap according to a material forming the active layer 7 may be emitted.

The active layer 7 may include any one of a multi quantum well structure (MQW), a quantum dot structure, or a quantum line structure. The active layer 7 may have a well layer and a barrier layer repeatedly formed with a well layer and a barrier layer as a cycle. Since the repetition period of the well layer and the barrier layer can be modified according to the characteristics of the light emitting device, the present invention is not limited thereto.

The active layer 7 may be formed, for example, with a period of InGaN / GaN, a period of InGaN / AlGaN, a period of InGaN / InGaN, or the like. The band gap of the barrier layer may be larger than the band gap of the well layer.

Although not shown, a third conductive semiconductor layer may be disposed under the first conductive semiconductor layer 5 and / or on the second conductive semiconductor layer 9. For example, the third conductive semiconductor layer disposed under the first conductive semiconductor layer 5 may include the same conductive dopant as the second conductive semiconductor layer 9, but is not limited thereto. . For example, the third conductive semiconductor layer disposed on the second conductive semiconductor layer 9 may include the same conductive dopant as the first conductive semiconductor layer 5, but is not limited thereto.

As shown in FIG. 2, in general, color rendering index (CRI) and light output may have an inverse relationship.

That is, as the wavelength of the light emitting device increases, the color rendering index increases, while the light output may decrease. In particular, the light output may be increased at the peak wavelength of 450 nm or less. However, from the peak wavelength of 450 nm, the color rendering index increases but the light output may decrease.

Typically, the color rendering index required by the industry is 80 or higher and 82 or 83 may be required for general lighting products.

For example, the color rendering index at a peak wavelength of 452.5 nm or more can achieve at least 85 or more and a color rendering index of about 90 can be achieved at a peak wavelength of 457.5 nm or more.

Therefore, the development of a light emitting device that can increase or at least maintain the light output with an increase in the color rendering index at a peak wavelength of 450nm or more is urgent.

The light output is related to the main wavelength of the light emitting device because the efficiency of the phosphor technology currently in the commercialization stage is lowered below 450 nm.

In order to have a peak wavelength of 450 nm or more in the light emitting device, it is necessary to adjust the energy band gap of the active layer. For example, when the active layer is InGaN / GaN, the energy band gap may be controlled by adjusting the In content of the well layer. By increasing the content of In, however, since the film quality of the active layer is lowered, it is necessary to increase the thickness of the barrier layer to compensate for this. When there are a plurality of barrier layers, the thickness can be compensated by increasing the thicknesses of the barrier layers.

3 is experimental data obtained by measuring the light output (Po) of the light emitting device after changing the thickness of the plurality of barrier layers of the active layer from 6.5nm, 7nm, 8nm and 9nm. As shown in FIG. 3, as the thickness of the barrier layer increases, the light output Po decreases.

As the thickness of the barrier layer decreases to 9 nm, 8 nm, and 7 nm, the light output increases at the peak wavelength of 450 nm or more. That is, a larger light output can be obtained in a barrier layer having a thickness of 8 nm than a barrier layer having a thickness of 9 nm, and a larger light output can be obtained in a barrier layer having a thickness of 7 nm than a barrier layer having a thickness of 8 nm. . However, as the wavelength increases in both the barrier layer having a thickness of 9 nm, the barrier layer having a thickness of 8 nm, and the barrier layer having a thickness of 7 nm, the light output tends to decrease gradually. In particular, when the thickness of the barrier layer is 6.5nm, the light output tends to decrease rapidly.

Here, the thicknesses of all barrier layers included in the active layer are the same. For example, all barrier layers included in the active layer may have a thickness of 9 nm.

As shown in FIG. 3, the light output is improved as the thickness of the barrier layer decreases, but inversely, the driving voltage increases as the thickness of the barrier layer decreases. This is because the bulk resistance of the active layer increases as the thickness of the barrier layer increases, and the driving voltage increases due to the increase of the bulk resistance.

The embodiment can implement a light emitting device capable of lowering a driving voltage while improving color rendering index and light output.

4 is a cross-sectional view of the active layer of FIG. 1.

Referring to FIG. 4, the active layer 7 includes a plurality of barrier layers 11a, 11b, 11c and 11d, a plurality of well layers 13a, 13b and 13c, and first and second dummy layers 15a and 15b. It may include.

The well layers 13a, 13b, and 13c may be disposed between the barrier layers 11a, 11b, 11c, and 11d. For example, a first well layer 13a is disposed on the first barrier layer 11a, a second barrier layer 11b is disposed on the first well layer 13a, and the second barrier layer 11b is disposed. The second well layer 13b may be disposed on the C). A third barrier layer 11c is disposed on the second well layer 13b, a third well layer 13c is disposed on the third barrier layer 11c, and the third well layer 13c. The fourth barrier layer 11d may be disposed on the fourth barrier layer 11d.

The first to third well layers 13a, 13b, and 13c may be filled with electrons or holes provided from adjacent barrier layers 11a, 11b, 11c, and 11d. The electrons or holes may be recombined to generate light.

The thickness of the barrier layer 11d proximate to the electron blocking layer 15 may be greater than the thickness of the barrier layer 11a proximate to the first conductive semiconductor layer 5, but is not limited thereto.

The dummy layer 15b having a thickness equal to the difference between the thickness of the barrier layer 11d proximate to the electron blocking layer 15 and the thickness of the barrier layer 11a proximate to the first conductivity-type semiconductor layer 5 is formed. It may be formed in contact with the barrier layer 11d adjacent to the electron blocking layer 15.

The first dummy layer 15a and the second dummy layer 15b may be disposed adjacent to the third well layer 13c. That is, the second dummy layer 15b is disposed between the fourth barrier layer 11d and the third well layer 13c, and the first dummy layer 15a is the third well layer 13c. And the third barrier layer 11c, but the embodiment is not limited thereto.

Each of the first and second dummy layers 15a and 15b may increase the thickness of the third barrier layer 11c and the fourth barrier layer 11d to increase the thickness of the third well layer 13c and the fourth barrier layer 13. Energy band may be increased by alleviating band bending due to the lattice constant difference between 11d).

This may play a role of not affecting the film quality even if the composition of the third well layer 13c, which contributes to light emission so as to have a main peak region of 450 nm or more, is not affected.

In addition, by forming the first and second dummy layers 15a and 15b adjacent to the third barrier layer 11c and the fourth barrier layer 11d adjacent to the second conductive semiconductor layer 9, the entire bulk resistance is achieved. It is possible to increase the light output while minimizing the increase of.

The active layer 7 of the embodiment can generate light having a peak wavelength of 450 nm or more, but is not limited thereto.

In FIG. 4, the first and second dummy layers 15a and 15b are disposed on both sides of the third well layer 13c, but the second dummy layer 15b is the second conductive semiconductor layer. It may be arranged between the N well layers adjacent to (9) and the barrier layer adjacent to the N well layers. Here, N is a natural number of 0 or more.

Although not shown, the second dummy layer 15b may be disposed between the second well layer 13b and the third barrier layer 11c. That is, the second well layer 13b is disposed on the second barrier layer 11b, a second dummy layer 15b is disposed on the second well layer 13b, and the second dummy layer is disposed on the second well layer 13b. The third barrier layer 11c may be disposed on 15b. In this case, the second dummy layer 15b increases the thickness of the third barrier layer 11c, thereby causing an energy band due to a lattice constant difference between the second well layer 13b and the third barrier layer 11c. It may serve to increase the light output by alleviating the bending.

For example, each of the first to fourth barrier layers 11a, 11b, 11c, and 11d has a thickness S1, S2, S3, and S4 of 6 mm, and each of the first and second dummy layers 15a and 15b. May have thicknesses t1 and t2 of 10 kW, but is not limited thereto.

Each of the first and second dummy layers 15a and 15b may have thicknesses t1 and t2 in a range of 5 kPa to 30 kPa, but is not limited thereto.

Each of the first to third well layers 13a, 13b, and 13c may have a thickness of 20 μm to 50 μm. Each of the first to third well layers 13a, 13b, and 13c may be preferably 32 kV, but is not limited thereto.

5 is an exemplary diagram illustrating an energy band diagram of the light emitting device of FIG. 1.

For example, the energy band gap Egn1 of the first conductivity type semiconductor layer 5 may be the same as the energy band gap Egp1 of the second conductivity type semiconductor layer 9, but is not limited thereto. The first conductive semiconductor layer 5 and the second conductive semiconductor layer 9 may include AlGaN, but are not limited thereto.

The active layer 7 may include a plurality of barrier layers 11a, 11b, 11c and 11d and a plurality of well layers 13a, 13b and 13c.

The energy bandgap Ega1 of the barrier layers 11a, 11b, 11c, and 11d may be larger than the energy bandgap Ega2 of the well layers 13a, 13b, and 13c, but is not limited thereto. The barrier layers 11a, 11b, 11c, and 11d may include GaN, and the well layers 13a, 13b, and 13c may include InGaN, but the present invention is not limited thereto.

The electron blocking layer 15 may have a superlattice structure including a plurality of layers having different energy band gaps Ego1, Ego2, Ego3, Ego4, and Ege1. That is, the electron blocking layer 15 may include a plurality of odd-numbered layers 17a, 17b, 17c, and 17d and a plurality of even-numbered layers 19a, 19b, and 19c. The odd-numbered layers 17a, 17b, 17c, and 17d and the even-numbered layers 19a, 19b, and 19c may be alternately disposed.

For example, among the plurality of radix layers 17a, 17b, 17c, and 17d, the energy bandgap Ego2 of the second radix layer 17b is the largest, and the third radix from the third radix layer 17c is the last radix. The layer 17d may have, but is not limited to, energy bandgaps Ego3 and Ego4 becoming linear or nonlinear. In this case, a plurality of radix layers may be further disposed between the third radix layer 17c and the last radix layer 17d.

For example, a first radix layer 17a is formed in contact with the last barrier layer of the active layer 7, that is, the fourth barrier layer 11a, and the first even-numbered layer is in contact with the first radix layer 17a. 19a can be formed. A second odd layer 17b may be formed in contact with the first even-numbered layer 19a and a second even layer 19b may be formed in contact with the second odd-numbered layer 17b. The third odd-numbered layer 17c is formed in contact with the second even-numbered layer 19b, and the third even-numbered layer 19c is formed in contact with the third odd-numbered layer 17c. The fourth odd layer 19d may be formed in contact with the even-numbered layer 19c.

The first to fourth radix layers 17a, 17b, 17c, and 17d may be formed of a compound semiconductor material having a compositional formula of Al x Ga (1-x) N (0 <x <1). The third even layer 19a, 19b, 19c may include GaN, but is not limited thereto.

The energy bandgaps of the first to fourth radix layers 17a, 17b, 17c, and 17d may be different from each other, but are not limited thereto.

The energy bandgap of each of the first to third even-numbered layers 19a, 19b, and 19c may be the same, but is not limited thereto.

The energy bandgap of the first to third even-numbered layers 19a, 19b, and 19c may be the same as the energy bandgap of the well layers 13a, 13b, and 13c of the active layer 7, but is not limited thereto. Do not.

The thickness of each of the first to fourth radix layers 17a, 17b, 17c, and 17d and the first to third even layers 19a, 19b, and 19c may be the same, but is not limited thereto.

For example, each of the first to fourth radix layers 17a, 17b, 17c, and 17d and the first to third even-numbered layers 19a, 19b, and 19c may have a thickness of about 4 nm to about 10 nm. The thickness of each of the first to fourth radix layers 17a, 17b, 17c, and 17d and the first to third even-numbered layers 19a, 19b, and 19c may be preferably 6 nm, but is not limited thereto.

The energy bandgaps Eg1, Eg3, Eg5, and Eg7 of each of the first to fourth radix layers 17a, 17b, 17c, and 17d are respectively the first to third even-numbered layers 19a, 19b, and 19c. It may be at least larger than the energy bandgap (Eg2, Eg4, Eg6) of, but is not limited thereto.

For example, the Al content of each of the first to fourth radix layers 17a, 17b, 17c, and 17d may be 10% to 30%. For example, the Al content of the first radix layer 17a is preferably 15%, the Al content of the second radix layer 17b is preferably 25%, and that of the third radix layer 17c. The Al content is preferably 18%, and the Al content of the fourth radix layer 17d may be preferably 12%, but is not limited thereto.

The energy band gaps Ego1, Ego2, Ego3, and Ego4 of the radix-th layers 17a, 17b, 17c, and 17d increase and decrease from the active layer 7 to the second conductive semiconductor layer 9. Can have

For example, the energy bandgap Ego2 of the second radix layer 17b is the largest among the first to fourth radix layers 17a, 17b, 17c, and 17d, and the energy of the third radix layer 17c is the largest. Although the bandgap Ego3 is next larger, the energy bandgap Ego1 of the first radix layer 17a is the next largest, and the energy bandgap Ego4 of the fourth radix layer 17d may be the smallest. This is not limitative.

The energy bandgap Ego4 of the last radix layer 17d may be larger or smaller than the energy bandgap Ego1 of the first radix layer 17a, but is not limited thereto.

The electron blocking layer 15 of FIG. 5 has a shape in which the energy band gaps Ego1, Ego2, Ego3, and Ego4 of each of the radix layers 17a, 17b, 17c, and 17d become larger and smaller, thereby reducing the electron blocking layer ( The internal electric field in 15 is minimized to eliminate band bending, thereby facilitating injection into the active layer 15 of holes generated in the second conductive semiconductor layer 19, thereby improving color rendering index and driving. The voltage can be lowered and the light output can be improved or maintained.

6 is another exemplary diagram illustrating an energy band diagram of the light emitting device of FIG. 1.

FIG. 6 is similar to FIG. 5 except for the shape of the energy band of the electron blocking layer. Therefore, in the description of FIG. 6, a description overlapping with FIG. 5 will be omitted.

In FIG. 6, the energy band gaps Ego1, Ego2, Ego3, and Ego4 of the radix layers 17a, 17b, 17c, and 17d of the electron blocking layer 15 are the same as those of FIG. 5.

The energy bandgap Ege1 of each of the even-numbered layers 19a, 19b, and 19c of the electron blocking layer 15 is larger than the energy bandgap Ege1 of each of the even-numbered layers 19a, 19b, and 19c of FIG. 5.

In other words, the even-numbered layers 19a, 19b, and 19c may include AlGaN, but are not limited thereto.

The Al content of each of the even layers 19a, 19b, and 19c may be different from the Al content of each of the radix layers 17a, 17b, 17c, and 17d. That is, the first to fourth radix layers 17a, 17b, 17c, and 17d may be formed of a compound semiconductor material having a compositional formula of Al x Ga (1-x) N (0 <x <1). The first to third even layers 19a, 19b, and 19c may be formed of a compound semiconductor material having a composition formula of AlyGa (1-y) N, but are not limited thereto.

The energy band gaps Ego1, Ego2, Ego3, and Ego4 of each of the first to fourth radix layers 17a, 17b, 17c, and 17d are each of the first to third even-numbered layers 19a, 19b, and 19c. It may be at least larger than the energy bandgap (Ege1), but is not limited thereto.

For example, the Al content of each of the first to fourth radix layers 17a, 17b, 17c, and 17d is 10% to 30%, and each of the first to third even layers 19a, 19b, and 19c is respectively. Al content may be 2% to 15%, but is not limited thereto. For example, the Al content of each of the first to third even layers 19a, 19b, and 19c may be preferably 8%, but is not limited thereto.

The electron blocking layer 15 of FIG. 6 is at least Al in all layers, i.e., both the first through fourth radix layers 17a, 17b, 17c, 17d and the first through third even-numbered layers 19a, 19b, 19c. Electron blocking by reducing the difference in the energy band gap between the first to fourth odd layers 17a, 17b, 17c, and 17d and the first to third even layers 19a, 19b, and 19c. The internal electric field in the layer 15 is minimized to eliminate band bending, thereby facilitating injection into the active layer 15 of holes generated in the second conductive semiconductor layer 19, thereby improving color rendering index. And the driving voltage can be lowered and the light output can be improved or maintained.

As shown in FIG. 7, by changing the shape of the energy band gap of the plurality of layers 17a, 17b, 17c, 17d, 19a, 19b, and 19c of the vehicle blocking layer 15 as shown in FIGS. 5 and 6. Therefore, it can be seen that the light output is kept constant even when the wavelength is increased. In particular, it can be seen that the light output does not decrease even at a long wavelength of 455 nm.

The odd-numbered layers 17a, 17b, 17c, and 17d and / or the even-numbered layers 19a, 19b, and 19c may further include 0% to 3% of In. As such, by adding a small amount of In, the band bending caused by the electron blocking layer 15 may be further alleviated, thereby improving optical characteristics.

8 to 10 show products in which the light emitting device of FIG. 1 is actually employed.

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

Referring to FIG. 8, the horizontal light emitting device according to the embodiment may include a substrate 3, a buffer layer 5, a light emitting structure 20, a transparent conductive layer 32, and first and second electrodes 34 and 36. It may include.

Since the substrate 3, the buffer layer 5, and the light emitting structure 20 have already been described in detail above, further description thereof will be omitted.

The transparent conductive layer 32 may be disposed on the light emitting structure 20, specifically, the second conductive semiconductor layer 9. If the third conductive semiconductor layer including the same conductive dopant as the first conductive semiconductor layer 7 is disposed on the second conductive semiconductor layer 9, the transparent conductive layer 32 may be It may be disposed on the third conductive semiconductor layer.

The transparent conductive layer 32 may serve to spread current or to form an ohmic contact with the light emitting structure 20 to allow a current to flow easily in the light emitting structure 20, but It does not limit about.

The transparent conductive layer 32 may be formed of a transparent conductive material through which light is transmitted. Examples of the transparent conductive material include ITO, IZO (In-ZnO), GZO (Ga-ZnO), AZO (Al-ZnO), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), IrOx, RuOx, At least one selected from the group consisting of RuOx / ITO, Ni / IrOx / Au, and Ni / IrOx / Au / ITO may be included, but is not limited thereto.

The first electrode 34 may be electrically connected to the first conductive semiconductor layer 7, and the second electrode 36 may be electrically connected to the transparent conductive layer 32, but embodiments of the present disclosure are not limited thereto. Do not.

The first and second electrodes 34, 36 may comprise, for example, one or a stack of these selected from the group consisting of Al, Ti, Cr, Ni, Pt, Au, W, Cu and Mo, but is not limited thereto. I never do that.

Although not shown, a current blocking layer may be disposed below each of the first and second electrodes 34 and 36 to prevent current from being concentrated.

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

9 is almost similar to FIG. 8 except for the reflective layer.

Referring to FIG. 9, the flip type light emitting device according to the embodiment may include a substrate 3, a buffer layer 5, a light emitting structure 20, a reflective layer 42, and first and second electrodes 44.46.

The buffer layer 5 is disposed under the substrate 3, the light emitting structure 20 is disposed under the buffer layer 5, the reflective layer 42 is disposed under the light emitting structure 20, The first electrode 44 may be disposed under the first conductive semiconductor layer 7, and the second electrode 46 may be disposed under the second conductive semiconductor layer 9. It is not limited.

Since the substrate 3, the buffer layer 5, and the light emitting structure 20 have already been described in detail above, further description thereof will be omitted.

The reflective layer 42 may be disposed on the light emitting structure 20, specifically, the second conductive semiconductor layer 9. When the third conductive semiconductor layer including the same conductive dopant as the first conductive semiconductor layer 7 is disposed below the second conductive semiconductor layer 9, the reflective layer 42 is formed of the third conductive layer. It may be disposed below the type semiconductor layer.

The reflective layer 42 may serve to improve light emission efficiency by reflecting light generated in the active layer 7 and traveling in a downward direction to the upper direction, but is not limited thereto.

The reflective layer 42 includes a reflective material having excellent reflective properties, for example, one or a stack thereof selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, and Hf. It may include, but is not limited thereto.

When the reflective layer 42 has a poor ohmic contact characteristic with the second conductive semiconductor layer 9, a transparent conductive layer (not shown) may form the second conductive semiconductor layer 9 and the reflective layer 42. It may be arranged in between, but is not limited thereto. The transparent conductive layer may be formed of a transparent material having excellent ohmic contact characteristics with the second conductive semiconductor layer 9. For example, the transparent conductive layer may include ITO, IZO (In-ZnO), GZO (Ga-ZnO), AZO (Al-ZnO), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), IrOx, RuOx, At least one selected from the group consisting of RuOx / ITO, Ni / IrOx / Au, and Ni / IrOx / Au / ITO may be included, but is not limited thereto.

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

In the description of FIG. 10, detailed descriptions of components having the same functions illustrated in FIG. 8 will be omitted.

Referring to FIG. 10, the vertical light emitting device according to the embodiment may include a support substrate 61, a bonding layer 59, an electrode layer 57, an ohmic contact layer 55, a current blocking layer 53, and a channel layer 51. ), A protective layer 63, and an electrode 65.

The support substrate 61 may not only support a plurality of layers formed thereon but also have a function as an electrode.

The support substrate 61 is, for example, titanium (Ti), chromium (Cr), nickel (Ni), aluminum (Al), platinum (Pt), gold (Au), tungsten (W), copper (Cu) , Molybdenum (Mo) and copper-tungsten (Cu-W).

The bonding layer 59 is a bonding layer, and is formed between the electrode layer 57 and the support substrate 61. The bonding layer 59 may serve as a medium for enhancing adhesion between the electrode layer 57 and the support substrate 61.

The bonding layer 59 may include, for example, at least one selected from the group consisting of Ti, Au, Sn, Ni, Nb, Cr, Ga, In, Bi, Cu, Ag, and Ta.

The electrode layer 57 serves as an electrode for supplying power to the active layer 7 and may reflect the light generated from the active layer 7 and advanced downward. The electrode layer 57 may be referred to as a reflective layer.

If the electrode layer 57 is excellent in ohmic contact with the second conductivity-type semiconductor layer 9, the ohmic contact layer 55 may be omitted. In this case, the electrode layer 57 may have an electrode, a reflection function, and an ohmic contact function.

The electrode layer 57 may include, but is not limited to, one or a stack thereof, for example, selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, and Hf. Do not.

The channel layer 51 may be formed along the periphery of the peripheral area of the electrode layer 57 and the second conductivity-type semiconductor layer 9. The channel layer 51 may be disposed to be surrounded by the electrode layer 57 and the second conductivity-type semiconductor layer 9 when the ohmic contact layer 55 is omitted.

The channel layer 51 may prevent electrical short between the side of the electrode layer 57 and the side of the light emitting structure 20 due to external foreign matter.

The channel layer 51 may include at least one selected from the group consisting of an insulating material, for example, SiO 2, SiO x, SiO x N y, Si 3 N 4, and Al 2 O 3.

In order to prevent concentration of current, a current blocking layer 53 may be disposed between the second conductivity-type semiconductor layer 9 and the electrode layer 57.

The current blocking layer 53 may be disposed to overlap at least a portion of the electrode 65.

In the vertical light emitting device, the electrode layer 57 has a plate shape, whereas the electrode 65 has a pattern shape formed only in a portion of the light emitting structure 20, so that power is applied to the electrode 65 and the electrode layer 57. In this case, current flows intensively along the vertical direction of the electrode 65. Therefore, the current blocking layer 53 is disposed at a position perpendicular to the electrode 65 so that the current flowing vertically to the electrode 65 is distributed to the periphery of the current blocking layer 53.

The current blocking layer 53 has a smaller electrical conductivity than the electrode layer 57, has a larger electrical insulation than the electrode layer 57, or uses a material for forming a schottky contact with the light emitting structure 20. Can be formed. The current blocking layer 53 is, for example, a group consisting of ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, ZnO, SiO2, SiOx, SiOxNy, Si3N4, Al2O3, TiOx, Ti, Al and Cr. It may include at least one selected from. The SiO 2, SiO x, SiO x N y, Si 3 N 4, and Al 2 O 3 may be insulating materials.

A protective layer 63 may be disposed along the circumference of the side surface of the light emitting structure 20. The protective layer 63 may have one region in contact with the upper surface of the channel layer 51 and the other region may be disposed in an edge region of the upper surface of the first conductive semiconductor layer 7.

The protective layer 63 may serve to prevent electrical short between the light emitting structure 20 and the support substrate 61. The protective layer 63 may include, but is not limited to, an insulating material including one selected from the group consisting of SiO 2, SiO x, SiO x N y, Si 3 N 4, TiO 2, and Al 2 O 3, for example.

The protective layer 63 may include the same material as the channel layer 51, but is not limited thereto.

A light extraction structure for efficiently extracting light may be formed on the upper surface of the first conductive semiconductor layer 7. The light extraction structure may have an unevenness or roughness structure. The unevenness may be formed constantly or randomly.

An electrode 65 may be disposed on the light extraction structure.

The electrode 65 may include, but is not limited to, one or a stack of one selected from the group consisting of Al, Ti, Cr, Ni, Pt, Au, W, Cu, and Mo, for example.

11 is a cross-sectional view showing a light emitting device package according to the embodiment.

Referring to FIG. 11, the light emitting device package according to the embodiment includes a body 101, a first lead electrode 103 and a second lead electrode 105 installed on the body 101, and the first lead electrode ( And a light emitting element 107 and a molding member 113 surrounding the light emitting element 107.

The body 101 may include a silicon material, a synthetic resin material, or a metal material, and an inclined surface may be formed around the light emitting device 107.

The first lead electrode 103 and the second lead electrode 105 are electrically separated from each other, and provide power to the light emitting device 107.

In addition, the first and second lead electrodes 103 and 105 may increase light efficiency by reflecting the light generated from the light emitting device 107, and transmit heat generated from the light emitting device 107 to the outside. It can also play a role.

The light emitting device 107 may be installed on any one of the first lead electrode 103, the second lead electrode 105, and the body 101. It may be electrically connected to the second lead electrodes 103 and 105, but is not limited thereto. For example, one side of the light emitting device 107, for example, a rear surface of the light emitting device 107 may be in electrical contact with an upper surface of the first lead electrode 103, and the other side of the light emitting device 107 may connect a wire 109. It may be electrically connected to the second lead electrode 105 by using.

The light emitting device 107 of the embodiment may be any one of the above-described horizontal light emitting device, flip light emitting device, and vertical light emitting device, but is not limited thereto.

The molding member 113 may surround the light emitting device 107 to protect the light emitting device 107. In addition, the molding member 113 may include a phosphor to change the wavelength of light emitted from the light emitting device 107.

The light emitting device package according to the embodiment includes a chip on board (COB) type, the upper surface of the body 101 is flat, a plurality of light emitting devices 107 may be installed on the body 101.

1: substrate
3: buffer layer
5: first conductivity type semiconductor layer
7: active layer
9: second conductivity type semiconductor layer
10: light emitting structure
15: electron blocking layer
11a, 11b, 11c, and 11d: barrier layer
13a, 13b, 13c: well layer
15a, 15b: dummy layer
17a, 17b, 17c, 17d: radix layer
19a, 19b, 19c: even layer
32: transparent conductive layer
34, 36, 44, 46, 65: electrode
42: reflective layer
51: channel layer
53: current blocking layer
55: ohmic contact layer
57: electrode layer
59: bonding layer
61: support substrate
63: protective layer
t1, t2, S1, S2, S3, S4: thickness
Egn1: energy band gap of the first conductivity type semiconductor layer
Egp1: energy band gap of the second conductivity type semiconductor layer
Ega1: Bandgap of barrier layer
Ega2: Bandgap of the Well Layer
Ege1: Band gap of even layer
Ego1, Ego2, Ego3, Ego4: Bandgap of the Radix Layer

Claims (17)

Board;
A first conductivity type semiconductor layer disposed on the substrate;
An active layer disposed on the first conductivity type semiconductor layer and generating light having a peak wavelength of 450 nm or more;
An electron blocking layer disposed on the active layer; And
A second conductivity type semiconductor layer disposed on the electron blocking layer,
The active layer,
A plurality of barrier layers;
A plurality of well layers disposed between the plurality of barrier layers; And
A dummy layer disposed to contact at least one barrier layer adjacent to the electron blocking layer,
The electron blocking layer,
Multiple radix layers; And
A plurality of even-numbered layers disposed between the plurality of odd-numbered layers,
The energy bandgap of each of the plurality of radix layers is different,
The plurality of barrier layers may include a first barrier layer closest to the first conductive semiconductor layer, a fourth barrier layer closest to the second conductive semiconductor layer, and a third barrier layer below the fourth barrier layer. ,
The plurality of well layers includes a third well layer disposed between the third barrier layer and the fourth barrier layer.
The dummy layer includes a first dummy layer disposed between the third well layer and the third barrier layer, and a second dummy layer disposed between the fourth barrier layer and the third well layer,
An energy band gap of the first barrier layer is smaller than an energy band gap of the first conductive semiconductor layer.
The first dummy layer and the second dummy layer have the same band gap as the plurality of barrier layers. delete The method of claim 1,
The plurality of barrier layers may have a greater thickness of the barrier layer adjacent to the electron blocking layer than the thickness of the barrier layer adjacent to the first conductive semiconductor layer. The method of claim 3,
The light emitting device having a thickness of the first dummy layer and the second dummy layer is 5 kPa to 30 kPa. The method of claim 1,
The plurality of barrier layers includes a second barrier layer disposed between the first barrier layer and the third barrier layer,
The plurality of well layers includes a first well layer between the first barrier layer and the second barrier layer, and a second well layer between the second barrier layer and the third barrier layer. The method of claim 1,
The energy band gap of the plurality of odd-numbered layers has a shape that increases and decreases toward the second conductive semiconductor layer in the active layer. The method of claim 1,
The energy bandgap of one radix of the plurality of radix layers is larger than the energy bandgap of the other radix layers. The method of claim 1,
Wherein the odd-numbered layer is AlGaN, and the even-numbered layer is one of AlGaN and GaN. The method of claim 1,
The odd-numbered layer and the even-numbered layer comprise Al,
The Al content of the odd layer is greater than the Al content of the even layer. The method of claim 9,
And a first radix layer in contact with the active layer and a last radix layer in contact with the second conductive semiconductor layer. The method of claim 10,
And a second radix layer adjacent to the first radix layer among the radix layers has an energy band gap greater than that of the first radix layer. The method of claim 11,
A third radix layer adjacent to said second radix layer among said radix layers,
The energy band gap of each of the other odd layers between the third odd layer and the second conductive semiconductor layer decreases linearly toward the second conductive semiconductor layer in the active layer. The method of claim 11,
A third radix layer adjacent to said second radix layer among said radix layers,
And an energy band gap of each of the other odd layers between the third odd layer and the second conductive semiconductor layer becomes nonlinearly smaller toward the second conductive semiconductor layer in the active layer. The method of claim 1,
The Al content of the radix layer is 10% to 30%. The method of claim 1,
At least one of the odd-numbered layer and the even-numbered layer includes 0% to 3% of In. delete delete

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