KR20150028924A - Light emitting device - Google Patents

Abstract

A light emitting device according to an embodiment includes: a first semiconductor layer, a second semiconductor layer, an active layer which is arranged between the first semiconductor layer and the second semiconductor layer, and an intermediate layer which is arranged between the active layer and the second semiconductor layer. The active layer includes multiple well layers and multiple barrier layers which are located between the well layers and have higher band gap energy compared to the well layer. The intermediate layer includes a first intermediate layer which has higher bandgap energy compared to the active layer and touches the active layer, and a second intermediate layer which touches the second semiconductor layer and has lower bandgap energy compared to the first intermediate layer. The first intermediate layer may touch the well layer.

Description

[0001]

An embodiment relates to a light emitting element.

As a typical example of a light emitting device, a light emitting diode (LED) is a device for converting an electric signal into an infrared ray, a visible ray, or a light using the characteristics of a compound semiconductor, and is used for various devices such as household appliances, remote controllers, Automation equipment, and the like, and the use area of LEDs is gradually widening.

In general, miniaturized LEDs are made of a surface mounting device for mounting directly on a PCB (Printed Circuit Board) substrate, and an LED lamp used as a display device is also being developed as a surface mounting device type . Such a surface mount device can replace a conventional simple lighting lamp, which is used for a lighting indicator for various colors, a character indicator, an image indicator, and the like.

As the use area of the LED is widened as described above, it is important to increase the luminance of the LED as the brightness required for a lamp used in daily life and a lamp for a structural signal is increased.

The embodiment is to provide a light emitting device that increases efficiency of hole injection and increases efficiency.

The light emitting device according to the embodiment includes a first semiconductor layer, a second semiconductor layer, an active layer disposed between the first semiconductor layer and the second semiconductor layer, and an intermediate layer disposed between the active layer and the second semiconductor layer Wherein the active layer includes a plurality of well layers and a plurality of barrier layers located between the well layers and having a band gap energy greater than that of the well layers, the intermediate layer having a band gap energy greater than that of the active layer, A first intermediate layer disposed in contact with the active layer and a second intermediate layer disposed in contact with the second semiconductor layer and having a band gap energy lower than the band gap energy of the first intermediate layer, Can be disposed in contact with each other.

In the light emitting device according to the embodiment, since the intermediate layer is disposed between the second semiconductor layer and the active layer, the piezoelectric polarization phenomenon is improved and the recombination probability of electrons and holes is increased, and the luminous efficiency can be improved.

In addition, there is an advantage that the amount of the p-type dopant diffused into the active layer and the undoped silica of the first intermediate layer adjacent to the active layer is reduced, so that the luminous intensity of the light emitting device is not lowered.

In addition, the light emitting efficiency of the light emitting device can be improved by omitting the last barrier layer.

Further, in the embodiment, the luminous efficiency is improved and the operating voltage of the light emitting element is also decreased.

1 is a cross-sectional view illustrating a light emitting device according to an embodiment.
2 is an enlarged view of a portion of FIG.
3 is an energy band diagram of the light emitting device according to the embodiment of FIG.
4 is a cross-sectional view illustrating a light emitting device according to another embodiment.
5 is a cross-sectional view illustrating a light emitting device package including the light emitting device according to the embodiment.
6 is an exploded perspective view of a display device including a light emitting device according to an embodiment.
7 is a cross-sectional view of the display device of Fig.
8 is an exploded perspective view of a lighting device including a light emitting device according to an embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

The terms spatially relative, "below", "beneath", "lower", "above", "upper" May be used to readily describe a device or a relationship of components to other devices or components. Spatially relative terms should be understood to include, in addition to the orientation shown in the drawings, terms that include different orientations of the device during use or operation. For example, when inverting an element shown in the figures, an element described as "below" or "beneath" of another element may be placed "above" another element. Thus, the exemplary term "below" can include both downward and upward directions. The elements can also be oriented in different directions, so that spatially relative terms can be interpreted according to orientation.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. It is noted that the terms "comprises" and / or "comprising" used in the specification are intended to be inclusive in a manner similar to the components, steps, operations, and / Or additions.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size and area of each component do not entirely reflect actual size or area.

Further, the angle and direction mentioned in the description of the structure of the light emitting device in the embodiment are based on those shown in the drawings. In the description of the structure of the light emitting device in the specification, reference points and positional relationship with respect to angles are not explicitly referred to, refer to the related drawings.

FIG. 1 is a cross-sectional view showing a light emitting device according to an embodiment, FIG. 2 is a partially enlarged view of FIG. 1, and FIG. 3 is an energy band diagram of a light emitting device according to the embodiment of FIG.

1, the light emitting device 100 may include a substrate 110 and a light emitting structure disposed on the substrate 110. The light emitting structure may include a first semiconductor layer 120, an active layer 130, A first semiconductor layer 140 and a second semiconductor layer 150.

The substrate 110 may be formed of any material having optical transparency, for example, sapphire (Al ₂ O ₃ ), GaN, ZnO, or AlO, but is not limited thereto. In addition, the substrate 110 may be formed of a carrier wafer, a material suitable for semiconductor material growth. A SiC substrate having a higher thermal conductivity than a sapphire (Al ₂ O ₃ ) substrate or an SiC substrate including Si, GaAs, GaP, InP, Ga ₂ O ₃ can be used.

On the other hand, a concavo-convex structure may be provided on the upper surface of the substrate 110 to enhance light extraction efficiency. The substrate 110 referred to herein may or may not have a concave-convex structure.

A buffer layer (not shown) may be disposed on the substrate 110 to mitigate lattice mismatch between the substrate 110 and the first semiconductor layer 120 and to facilitate growth of the semiconductor layer. The buffer layer (not shown) can be formed in a low-temperature atmosphere and can be made of a material that can alleviate the difference in lattice constant between the semiconductor layer and the substrate 110. But are not limited to, materials such as, for example, GaN, InN, AlN, AlInN, InGaN, AlGaN, and InAlGaN. .

A buffer layer (not shown) may be grown on the substrate 110 as a single crystal, and a buffer layer (not shown) grown by a single crystal may improve the crystallinity of the first semiconductor layer 120 grown on the buffer layer have.

A light emitting structure 160 including a first semiconductor layer 120, an active layer 130, and a second semiconductor layer 150 may be formed on a buffer layer (not shown).

The first semiconductor layer 120 may be located on a buffer layer (not shown). The first semiconductor layer 120 may be formed of a semiconductor compound and may be doped with a first conductive dopant. For example, the first semiconductor layer 120 may be formed of an n-type semiconductor layer and may provide electrons to the active layer 130. The first semiconductor layer 120 may be a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0? X? 1, 0? _Y? 1, 0? _X + y? For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN and AlInN, and n-type dopants such as Si, Ge, Sn, Se and Te can be doped.

Further, the semiconductor layer 120 may further include an undoped semiconductor layer (not shown), but the present invention is not limited thereto. The un-doped semiconductor layer is a layer formed for improving the crystallinity of the first semiconductor layer 120 and has a lower electrical conductivity than the first semiconductor layer 120 without doping the n-type dopant. May be the same as the semiconductor layer 120.

The active layer 130 may be formed on the first semiconductor layer 120. The active layer 130 may be formed of a single or multiple quantum well structure, a quantum-wire structure, a quantum dot structure, or the like using a compound semiconductor material of Group 3-V group elements.

When the active layer 130 has a quantum well structure, for example, a well layer having a composition formula of In _x Al _y Ga _1-xy N (0? X? 1, 0? _Y? 1, 0? _X + y? 1) And a barrier layer having a composition formula of In _a Al _b Ga _1-ab N (0? A? 1, 0? B? 1, 0? A + b? 1). The well layer may be formed of a material having a band gap smaller than the band gap of the barrier layer.

In addition, when the active layer 130 has a multiple quantum well structure, each well layer (not shown) may have a different In content and different band gaps, which will be described later with reference to FIG.

A conductive clad layer (not shown) may be formed on and / or below the active layer 130. The conductive clad layer (not shown) may be formed of a semiconductor and may have a band gap larger than that of the active layer 130. For example, the conductive clad layer (not shown) may be formed including AlGaN,

The second semiconductor layer 150 may be formed of a semiconductor compound to inject holes into the active layer 130 and may be doped with a second conductive dopant. For example, the second semiconductor layer 150 may be implemented as a p-type semiconductor layer. The second semiconductor layer 150 may be a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0? X? 1, 0? _Y? 1, 0? _X + y? For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN and AlInN, and a p-type dopant such as Mg, Zn, Ca, Sr and Ba may be doped.

An intermediate layer 140 may be formed between the active layer 130 and the second semiconductor layer 150 and the intermediate layer 140 may be injected into the active layer 130 from the first semiconductor layer 120 It is possible to prevent a phenomenon that electrons flow to the second semiconductor layer 150 without being recombined in the active layer 130. The intermediate layer 140 has a relatively larger bandgap than the active layer 130 so that electrons injected from the first semiconductor layer 120 are injected into the second semiconductor layer 150 without being recombined in the active layer 130 Can be prevented. Accordingly, the probability of recombination of electrons and holes in the active layer 130 can be increased and the leakage current can be prevented.

The intermediate layer 140 may be disposed between the active layer 130 and the second semiconductor layer 150. The intermediate layer 140 may have a larger lattice constant than the second semiconductor layer 150.

The intermediate layer 140 will be described later in detail.

The first semiconductor layer 120, the active layer 130, the intermediate layer 140, and the second semiconductor layer 150 may be formed by, for example, metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD) (Chemical Vapor Deposition), plasma enhanced chemical vapor deposition (PECVD), molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE), sputtering, etc. But the present invention is not limited thereto.

In addition, the doping concentration of the conductive dopant in the first semiconductor layer 120 and the second semiconductor layer 150 can be uniformly or nonuniformly formed. That is, the plurality of semiconductor layers may be formed to have various doping concentration distributions, but the invention is not limited thereto.

The first semiconductor layer 120 may be a p-type semiconductor layer, the second semiconductor layer 150 may be an n-type semiconductor layer, and the second semiconductor layer 150 A third semiconductor layer (not shown) including an n-type or p-type semiconductor layer which is opposite to the polarity of the n-type or p-type semiconductor layer may be formed. Accordingly, the light emitting device 100 may have at least one of np, pn, npn, and pnp junction structures.

A light-transmitting electrode layer 170 may be formed on the second semiconductor layer 150. The transparent electrode layer 170 is ITO, IZO (In-ZnO) , GZO (Ga-ZnO), AZO (Al-ZnO), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), IrO x, RuO x , RuO _x / ITO, Ni / IrO _x / Au, and Ni / IrO _x / Au / ITO. Accordingly, the light generated in the active layer 130 can be diverted to the outside, and formed on the whole or a part of the outer side of the second semiconductor layer 150, thereby preventing current clustering.

A first electrode 172 electrically connected to the first semiconductor layer 120 may be disposed on the first semiconductor layer 120. For example, the active layer 130 and the second semiconductor layer 150 may be partially removed to expose a portion of the first semiconductor layer 120, and a first electrode (not shown) may be formed on the exposed first semiconductor layer 120, 172 may be formed. That is, the first semiconductor layer 120 includes a top surface facing the active layer 130 and a bottom surface facing the substrate 110, and an upper surface includes a region exposed at least one region, As shown in FIG. However, the present invention is not limited thereto.

Meanwhile, a method of exposing a part of the first semiconductor layer 120 may use a predetermined etching method, but is not limited thereto. The etching method may be a wet etching method or a dry etching method.

Also, a second electrode 174 may be formed on the second semiconductor layer 150.

The first and second electrodes 172 and 174 may be formed of a conductive material such as In, Co, Si, Ge, Au, Pd, Pt, Ru, Re, Mg, Zn, Hf, Ta, , A metal selected from Ti, Ag, Cr, Mo, Nb, Al, Ni, Cu, and WTi or an alloy thereof and may be formed as a single layer or a multilayer .

1 and 2, the active layer 130 of the light emitting device 100 may have a multiple quantum well structure. For example, the active layer 130 may include first through third well layers Q1, Q2, Q3, and first and second barrier layers B1, B2.

The first through third well layers Q1, Q2 and Q3 and the first and second barrier layers B1 and B2 may have a structure in which they are alternately stacked as shown in FIG.

In FIG. 2, first through third well layers Q1, Q2 and Q3 and first and second barrier layers B1 and B2 are formed and first through third well layers Q1, Q2 and Q3 But the present invention is not limited thereto and the well layers Q1, Q2 and Q3 and the barrier layers B1 and B2 may be formed in any number The barrier layers B1 and B2 may have band gap energies greater than those of the well layers Q1, Q2 and Q3. Preferably, the barrier layers B1 and B2 comprise GaN and the well layers Q1, Q2 and Q3 may comprise InGaN.

Referring again to FIGS. 1 to 3, the intermediate layer 140 may be disposed between the active layer 130 and the second semiconductor layer 150. The intermediate layer 140 may have a larger lattice constant than the second semiconductor layer 150.

For example, the intermediate layer 140 may include a first intermediate layer 141 disposed in contact with the active layer, and a second intermediate layer 142 disposed in contact with the second semiconductor layer.

The first intermediate layer 141 is disposed in contact with the active layer 130. Specifically, the first intermediate layer 141 may be disposed adjacent to the last well layer (for example, the third well layer Q3) of the active layer 130. [

The band gap energy of the first intermediate layer 141 may be lower than the band gap energy of the second intermediate layer 142.

The first intermediate layer 141 and the second intermediate layer 142 may include AlGaN and the Al content of the first intermediate layer 141 may be larger than the Al content of the second intermediate layer 142. [

The first intermediate layer 141 can reduce the diffusion of the dopant of the second semiconductor layer 150 or the second intermediate layer 142 to the final well layer Q3 of the active layer 130, Can be prevented from being escaped to the second semiconductor layer 150 without being recombined in the active layer 130.

Specifically, the Al content of the first intermediate layer 141 can be reduced from the active layer toward the second semiconductor layer. The abrupt change in the Al content causes severe lattice mismatching in the semiconductor layer and degrades the quality of the light emitting device.

More specifically, the aluminum content of the first intermediate layer 141 may be 15% to 20%. When the aluminum content of the first intermediate layer 141 is less than 15%, the difference in the energy band gap with the barrier layer in the active layer 130 hardly occurs, and the role of preventing the electron migration can be reduced. %, The quality of the light emitting device is deteriorated due to a rapid Al content change.

More specifically, the Al content of the second intermediate layer 142 may be between 12% and 14%. When the aluminum content of the second intermediate layer 142 is less than 12%, the difference in the energy band gap with the barrier layer in the active layer 130 hardly occurs, , There is a problem that the quality of the light emitting device is deteriorated due to the difference in Al content between the second semiconductor layer and the second semiconductor layer.

On the other hand, the first intermediate layer 141 may be an undoped layer and the second intermediate layer 142 may be doped with a dopant (for example, a p-type dopant) having the same polarity as the second semiconductor layer 150 .

Since the first intermediate layer 141 is an undoped layer, electrons can be effectively blocked even at a thin thickness due to low conductivity.

The second intermediate layer 142 may be doped with a p-type dopant, and the p-type dopant may include any one of Mg, Zn, Ca, Sr, and Ba. For example, the second intermediate layer 142 may be doped with Mg (magnesium).

Doping the second intermediate layer 142 with the p-type dopant improves the efficiency of injecting holes injected into the active layer 130 from the second semiconductor layer 150. However, when the p-type dopant is doped into the adjacent active layer 130 A phenomenon of diffusion is generated. The p-type dopant diffused into the active layer 130 lowers the luminous intensity of the light emitting device.

Therefore, if the first intermediate layer 141 adjacent to the active layer 130 is undoped, the amount of the p-type dopant diffused into the active layer 130 is reduced, And has an effect of improving injection efficiency of holes injected into the active layer 130.

The thickness of the first intermediate layer 141 may be thinner than the thickness of the second intermediate layer 142.

Specifically, the thickness of the first intermediate layer 141 may be 2 nm to 5 nm. When the first intermediate layer 141 is thicker than 5 nm, the efficiency of the light emitting device may be lowered due to the low conductivity of the first intermediate layer 141. When the first intermediate layer 141 is thinner than 2 nm, Electrons flowing to the second semiconductor layer 150 can not be blocked.

In addition, the thickness of the second intermediate layer 142 may be 25 nm to 50 nm. When the thickness of the second intermediate layer 142 is thinner than 25 nm, electrons flowing from the active layer 130 to the second semiconductor layer 150 can not be blocked. When the thickness of the second intermediate layer 142 is thicker than 50 nm, As shown in FIG.

An indentation (not shown) may be formed by temperature control during growth of the intermediate layer 140.

The above-described indentation may have a v-shape or a hexagonal conical shape and a downward concave shape.

For example, when the intermediate layer 140 is grown at a temperature of 550 to 940 ° C. and a pressure of 100 to 500 torr, a depressed portion may be formed on the upper surface of the intermediate layer 140.

In the initial growth of the intermediate layer 140, 1000? Or more, and at the final stage of growth, when the growth temperature is lowered to 550 to 940 ?, the indentation portion is formed. In the initial stage of growth of the intermediate layer 140, 1000? (TGMA or the like), N source (NH3 or the like), H2 or the like is supplied and the growth temperature is reduced to 550 to 940? At the final stage of growth and the Ga source and the N source are stopped The first indenting portion (not shown) is formed.

4 is a cross-sectional view illustrating a light emitting device according to another embodiment.

4, the light emitting device 200 according to the embodiment includes a support member 210, a first electrode layer 220 disposed on the support member 210, a first semiconductor layer 120, an active layer 130, A second semiconductor layer 150, and an intermediate layer 140, and a second electrode layer 282. The second electrode layer 282 may include a first electrode layer, a second electrode layer, and a second electrode layer.

Here, the structure of the light emitting structure is the same as that described in the embodiment of FIG. 1 except that the upper and lower portions are changed, and the description thereof will be omitted.

The support member 210 may be formed using a material having a high thermal conductivity, or may be formed of a conductive material. The support member 210 may be formed using a metal material or a conductive ceramic. The support member 210 may be formed as a single layer, and may be formed as a double structure or a multiple structure.

That is, the support member 210 may be formed of any one selected from a metal, for example, Au, Ni, W, Mo, Cu, Al, Ta, Ag, Pt, and Cr, or may be formed of two or more alloys. The above materials can be laminated. In addition, the support member 210 may be implemented with a carrier wafer such as Si, Ge, GaAs, ZnO, SiC, SiGe, GaN, Ga 2 O 3.

Such a support member 210 facilitates the release of heat generated in the light emitting device 200, thereby improving the thermal stability of the light emitting device 200.

A first electrode layer 220 may be formed on the support member 210. The first electrode layer 220 may include an ohmic layer (not shown), a reflective layer (not shown) and a bonding layer (not shown). For example, the first electrode layer 220 may be a structure of an ohmic layer / a reflection layer / a bonding layer, a laminate structure of an ohmic layer / a reflection layer, or a structure of a reflection layer (including an ohmic layer) / a bonding layer. For example, the first electrode layer 220 may be formed by sequentially stacking a reflective layer and an ohmic layer on an insulating layer.

The reflective layer (not shown) may be disposed between an ohmic layer (not shown) and an insulating layer (not shown), and may be formed of a material having excellent reflection characteristics, such as Ag, Ni, Al, Rh, Pd, , Zn, Pt, Au, Hf, and combinations thereof. Alternatively, the metal material and the transparent conductive material such as IZO, IZTO, IAZO, IGZO, IGTO, AZO, . Further, the reflective layer (not shown) can be laminated with IZO / Ni, AZO / Ag, IZO / Ag / Ni, AZO / Ag / Ni and the like. When a reflective layer (not shown) is formed of a material in ohmic contact with the light emitting structure 270 (for example, the first semiconductor layer 230), an ohmic layer (not shown) may not be formed separately, I do not.

The ohmic layer (not shown) is in ohmic contact with the lower surface of the light emitting structure 270, and may be formed as a layer or a plurality of patterns. The ohmic layer (not shown) may be formed of a transparent electrode layer and a metal. For example, ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide) ), IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IrO _x , RuO _x , RuO _x / Ni, Ag, Ni / IrO _x / Au, and Ni / IrO _x / Au / ITO. The ohmic layer (not shown) is provided for facilitating the injection of carriers into the first semiconductor layer 230, and is not necessarily formed.

The first electrode layer 220 may include a bonding layer (not shown), wherein the bonding layer (not shown) may include a barrier metal or a bonding metal such as Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, or Ta.

A second electrode layer 282 electrically connected to the first semiconductor layer 120 may be formed on the first semiconductor layer 120. The second electrode layer 282 may include at least one pad and / And an electrode having an electrode. The second electrode layer 282 may be disposed in the center region, the outer region, or the edge region of the upper surface of the first semiconductor layer 120, but the present invention is not limited thereto. The second electrode layer 282 may be disposed in a region other than the upper portion of the first semiconductor layer 120, but the present invention is not limited thereto.

The second electrode layer 282 may be formed of a conductive material such as In, Co, Si, Ge, Au, Pd, Pt, Ru, Re, Mg, Zn, Hf, Ta, Rh, Ir, W, , Mo, Nb, Al, Ni, Cu, and WTi.

A light extracting structure 284 may be formed on the first semiconductor layer 120.

The light extraction structure 270 may be formed on the top surface of the first semiconductor layer 120 or may be formed on the top of the transparent electrode layer (not shown) after forming a transparent electrode layer (not shown) on the top of the first semiconductor layer 120 But is not limited thereto.

The light extracting structure 284 may be formed on a light transmitting electrode layer (not shown), or on a part or all of the upper surface of the first semiconductor layer 120. The light extracting structure 284 may be formed by performing etching on at least one region of the light transmitting electrode layer (not shown) or the upper surface of the first semiconductor layer 120, but is not limited thereto. The etching process includes a wet etching process and / or a dry etching process. As the etching process is performed, the upper surface of the light transmitting electrode layer (not shown) or the upper surface of the first semiconductor layer 120 forms a light extracting structure 284 And may include roughness. The roughness may be irregularly formed in a random size, but is not limited thereto. The roughness may be at least one of a texture pattern, a concave-convex pattern, and an uneven pattern, which is an uneven surface.

The roughness may be formed to have various shapes such as a cylinder, a polygonal column, a cone, a polygonal pyramid, a truncated cone, a polygonal pyramid, and the like, preferably including a horn shape.

Meanwhile, the light extracting structure 284 may be formed by a photoelectrochemical (PEC) method or the like, but is not limited thereto. Light generated from the active layer 130 may be transmitted through the light-transmitting electrode layer (not shown) or the first semiconductor layer 120 (or the first semiconductor layer 120) as the light extracting structure 284 is formed on the upper surface of the light- Can be prevented from being totally reflected from the upper surface of the light emitting device 120 and reabsorbed or scattered, thereby contributing to improvement of light extraction efficiency of the light emitting device 200.

The passivation 290 may be formed on the side and upper regions of the light emitting structure, and the passivation 290 may be formed of an insulating material.

5 is a cross-sectional view illustrating a light emitting device package including the light emitting device according to the embodiment.

5, the light emitting device package 300 according to the embodiment includes a body 310 having a cavity, a light source 320 mounted on the cavity of the body 310, and an encapsulant 350 filled in the cavity 310 can do.

The body 310 may be made of a resin material such as polyphthalamide (PPA), silicon (Si), aluminum (Al), aluminum nitride (AlN), photo sensitive glass (PSG), polyamide 9T (SPS), a metal material, sapphire (Al2O3), beryllium oxide (BeO), a printed circuit board (PCB), and ceramics. The body 310 may be formed by injection molding, etching, or the like, but is not limited thereto.

The light source unit 320 may be disposed on the bottom surface of the body 310. For example, the light source unit 320 may be any one of the light emitting devices illustrated in FIGS. The light emitting device may be, for example, a colored light emitting device that emits light such as red, green, blue, or white, or a UV (Ultra Violet) light emitting device that emits ultraviolet light. In addition, one or more light emitting elements can be mounted.

The body 310 may include a first electrode 330 and a second electrode 340. The first electrode 330 and the second electrode 340 may be electrically connected to the light source 320 to supply power to the light source 320.

In addition, the first electrode 330 and the second electrode 340 are electrically separated from each other. The first electrode 330 and the second electrode 340 can reflect the light generated from the light source unit 320 to increase the light efficiency. Further, To the outside.

5 illustrates that both the first electrode 330 and the second electrode 340 are bonded to the light source 320 by the wire 360. However, the present invention is not limited thereto. Particularly, in the case of the vertical light emitting device, Any one of the electrode 330 and the second electrode 340 may be bonded to the light source 320 by the wire 360 and may be electrically connected to the light source 320 without the wire 360 by the flip- have.

The first electrode 330 and the second electrode 340 may be formed of a metal material such as titanium (Ti), copper (Cu), nickel (Ni), gold (Au), chromium (Cr), tantalum Ta, Pt, Sn, Ag, P, Al, Pd, Co, Si, Ge, Ge), hafnium (Hf), ruthenium (Ru), and iron (Fe). The first electrode 330 and the second electrode 340 may have a single-layer structure or a multi-layer structure, but the present invention is not limited thereto.

The encapsulant 350 may be filled in the cavity and may include a phosphor (not shown). The encapsulant 350 may be formed of a transparent silicone, epoxy, or other resin material, and may be formed in such a manner that the encapsulant 350 is filled in the cavity and then cured by UV or thermal curing.

The phosphor (not shown) may be selected according to the wavelength of the light emitted from the light source unit 320 so that the light emitting device package 300 may emit white light.

The fluorescent material (not shown) included in the encapsulant 350 may be a blue light emitting phosphor, a blue light emitting fluorescent material, a green light emitting fluorescent material, a yellow green light emitting fluorescent material, a yellow light emitting fluorescent material, , An orange light-emitting fluorescent substance, and a red light-emitting fluorescent substance may be applied.

That is, the phosphor (not shown) may be excited by the light having the first light emitted from the light source 320 to generate the second light. For example, when the light source 320 is a blue light emitting diode and the phosphor (not shown) is a yellow phosphor, the yellow phosphor may be excited by blue light to emit yellow light, and blue light emitted from the blue light emitting diode and blue The light emitting device package 300 can provide white light as yellow light generated by excitation by light is mixed.

The light emitting device according to the embodiment can be applied to an illumination system. The lighting system includes a structure in which a plurality of light emitting elements are arrayed and includes a display device shown in Figs. 6 and 7, a lighting device shown in Fig. 8, and may include a lighting lamp, a traffic light, a vehicle headlight, have.

6 is an exploded perspective view of a display device having a light emitting device according to an embodiment.

6, a display device 1000 according to an exemplary embodiment of the present invention includes a light guide plate 1041, a light source module 1031 for providing light to the light guide plate 1041, and a reflection member 1022 An optical sheet 1051 on the light guide plate 1041 and a display panel 1061 on the optical sheet 1051 and the light guide plate 1041 and the light source module 1031 and the reflection member 1022 But is not limited to, a bottom cover 1011.

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 light into a surface light source. The light guide plate 1041 may be made of a transparent material, for example, acrylic resin such as polymethylmethacrylate (PET), polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin copolymer (COC), and polyethylene naphtha late Resin. ≪ / RTI >

The light source module 1031 provides light to at least one side of the light guide plate 1041, and ultimately acts as a light source of the display device.

The light source module 1031 includes at least one light source module 1031 and may directly or indirectly provide light from one side of the light guide plate 1041. The light source module 1031 includes a substrate 1033 and a light emitting device 1035 according to the embodiment described above and the light emitting devices 1035 may be arrayed at a predetermined interval on the substrate 1033 .

The substrate 1033 may be a printed circuit board (PCB) including a circuit pattern (not shown). However, the substrate 1033 may include not only a general PCB, but also a metal core PCB (MCPCB), a flexible PCB (FPCB), and the like. When the light emitting element 1035 is mounted on the side surface of the bottom cover 1011 or on the heat radiation plate, the substrate 1033 can be removed. Here, a part of the heat radiating plate may be in contact with the upper surface of the bottom cover 1011.

The plurality of light emitting devices 1035 may be mounted on the substrate 1033 such that the light emitting surface is spaced apart from the light guiding plate 1041 by a predetermined distance. However, the present invention is not limited thereto. The light emitting device 1035 may directly or indirectly provide light to the light-incident portion, which is one surface of the light guide plate 1041, but the present invention is not limited thereto.

The reflective member 1022 may be disposed under the light guide plate 1041. The reflection member 1022 reflects the light incident on the lower surface of the light guide plate 1041 so as to face upward, thereby improving the brightness of the light unit 1050. 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 source 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 the top cover, 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, including first and second transparent substrates 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 light passing through the optical sheet 1051. Such a display device 1000 can be applied to various types of portable terminals, monitors of notebook computers, monitors of laptop computers, televisions, and the like.

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 and vertical prism sheet, and a brightness enhancement sheet. The diffusion sheet diffuses incident light, and the horizontal and / or vertical prism sheet condenses incident light into a display area. The brightness enhancing sheet improves the brightness by reusing the lost light. A protective sheet may be disposed on the display panel 1061, but the present invention is not limited thereto.

Here, the optical path of the light source module 1031 may include the light guide plate 1041 and the optical sheet 1051 as an optical member, but the invention is not limited thereto.

7 is a view showing a display device having a light emitting device according to an embodiment.

7, the display device 1100 includes a bottom cover 1152, a substrate 1120 on which the above-described light emitting device 1124 is arrayed, an optical member 1154, and a display panel 1155.

The substrate 1120 and the light emitting device 1124 may be defined as a light source module 1160. The bottom cover 1152, the at least one light source module 1160, and the optical member 1154 may be defined as a light unit 1150. The bottom cover 1152 may include a receiving portion 1153, but the present invention is not limited thereto. The light source module 1160 includes a substrate 1120 and a plurality of light emitting devices 1124 arranged on the substrate 1120.

Here, 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 polymethyl methacrylate (PMMA) material, and the light guide plate may be removed. The diffusion sheet diffuses incident light, and the horizontal and vertical prism sheets condense incident light into a display area. The brightness enhancing sheet enhances brightness by reusing the lost light.

The optical member 1154 is disposed on the light source module 1160 and performs surface light source, diffusion, and light condensation of light emitted from the light source module 1160.

8 is an exploded perspective view of a lighting apparatus having a light emitting element according to an embodiment.

8, the lighting apparatus according to the embodiment includes a cover 2100, a light source module 2200, a heat discharger 2400, a power supply unit 2600, an inner case 2700, and a socket 2800 . Further, the illumination device according to the embodiment may further include at least one of the member 2300 and the holder 2500. The light source module 2200 may include a light emitting device according to an embodiment of the present invention.

For example, the cover 2100 may have a shape of a bulb or a hemisphere, and may be provided in a shape in which the hollow is hollow and a part is opened. The cover 2100 may be optically coupled to the light source module 2200. For example, the cover 2100 may diffuse, scatter, or excite light provided from the light source module 2200. The cover 2100 may be a kind of optical member. The cover 2100 may be coupled to the heat discharging body 2400. The cover 2100 may have an engaging portion that engages with the heat discharging body 2400.

The inner surface of the cover 2100 may be coated with a milky white paint. Milky white paints may contain a diffusing agent to diffuse light. The surface roughness of the inner surface of the cover 2100 may be larger than the surface roughness of the outer surface of the cover 2100. This is for sufficiently diffusing and diffusing the light from the light source module 2200 and emitting it to the outside.

The cover 2100 may be made of glass, plastic, polypropylene (PP), polyethylene (PE), polycarbonate (PC), or the like. Here, polycarbonate is excellent in light resistance, heat resistance and strength. The cover 2100 may be transparent so that the light source module 2200 is visible from the outside, and may be opaque. The cover 2100 may be formed by blow molding.

The light source module 2200 may be disposed on one side of the heat discharging body 2400. Accordingly, heat from the light source module 2200 is conducted to the heat discharger 2400. The light source module 2200 may include a light emitting device 2210, a connection plate 2230, and a connector 2250.

The member 2300 is disposed on the upper surface of the heat discharging body 2400 and has guide grooves 2310 into which the plurality of light emitting elements 2210 and the connector 2250 are inserted. The guide groove 2310 corresponds to the substrate of the light emitting device 2210 and the connector 2250.

The surface of the member 2300 may be coated or coated with a light reflecting material. For example, the surface of the member 2300 may be coated or coated with a white paint. The member 2300 reflects the light reflected by the inner surface of the cover 2100 toward the cover 2100 in the direction toward the light source module 2200. Therefore, the light efficiency of the illumination device according to the embodiment can be improved.

The member 2300 may be made of an insulating material, for example. The connection plate 2230 of the light source module 2200 may include an electrically conductive material. Therefore, electrical contact can be made between the heat discharging body 2400 and the connecting plate 2230. The member 2300 may be formed of an insulating material to prevent an electrical short circuit between the connection plate 2230 and the heat discharging body 2400. The heat discharger 2400 receives heat from the light source module 2200 and heat from the power supply unit 2600 to dissipate heat.

The holder 2500 blocks the receiving groove 2719 of the insulating portion 2710 of the inner case 2700. Therefore, the power supply unit 2600 housed in the insulating portion 2710 of the inner case 2700 is sealed. The holder 2500 has a guide protrusion 2510. The guide protrusion 2510 may have a hole through which the protrusion 2610 of the power supply unit 2600 passes.

The power supply unit 2600 processes or converts an electrical signal provided from the outside and provides the electrical signal to the light source module 2200. The power supply unit 2600 is housed in the receiving groove 2719 of the inner case 2700 and is sealed inside the inner case 2700 by the holder 2500.

The power supply unit 2600 may include a protrusion 2610, a guide unit 2630, a base 2650, and a protrusion 2670.

The guide portion 2630 has a shape protruding outward from one side of the base 2650. The guide portion 2630 may be inserted into the holder 2500. A plurality of components may be disposed on one side of the base 2650. The plurality of components include, for example, a DC converter for converting AC power supplied from an external power source into DC power, a driving chip for controlling driving of the light source module 2200, an ESD (ElectroStatic discharge) protective device, and the like, but the present invention is not limited thereto.

The protrusion 2670 has a shape protruding outward from the other side of the base 2650. The protrusion 2670 is inserted into the connection portion 2750 of the inner case 2700 and receives an external electrical signal. For example, the protrusion 2670 may be equal to or smaller than the width of the connection portion 2750 of the inner case 2700. One end of each of the positive wire and the negative wire is electrically connected to the protrusion 2670 and the other end of the positive wire and the negative wire are electrically connected to the socket 2800.

The inner case 2700 may include a molding part together with the power supply part 2600. The molding part is a hardened portion of the molding liquid so that the power supply unit 2600 can be fixed inside the inner case 2700.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (8)

A first semiconductor layer;
A second semiconductor layer;
An active layer disposed between the first semiconductor layer and the second semiconductor layer; And
And an intermediate layer disposed between the active layer and the second semiconductor layer,
Wherein,
A plurality of well layers;
A plurality of barrier layers located between the well layers and having bandgap energies greater than the well layers,
Wherein the intermediate layer comprises:
And has a band gap energy larger than that of the active layer,
A first intermediate layer disposed in contact with the active layer and a second intermediate layer disposed in contact with the second semiconductor layer and having a band gap energy lower than the band gap energy of the first intermediate layer,
Wherein the first intermediate layer is disposed in contact with the well layer. The method according to claim 1,
Wherein the intermediate layer comprises AlGaN,
Wherein a content of Al in the first intermediate layer is larger than an Al content in the second intermediate layer. 3. The method of claim 2,
Wherein the Al content of the first intermediate layer is decreased from the active layer toward the second semiconductor layer. 3. The method of claim 2,
Wherein the first intermediate layer is an undoped layer and the second intermediate layer is doped with a dopant of the same polarity as the second semiconductor layer. 5. The method of claim 4,
And the second intermediate layer is doped with a p-type dopant. 6. The method of claim 5,
And the band gap energy of the intermediate layer is larger than that of the second semiconductor layer. 6. The method of claim 5,
Wherein a thickness of the first intermediate layer is thinner than a thickness of the second intermediate layer. A light emitting device package comprising the light emitting device according to any one of claims 1 to 7.

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