KR20140062944A

KR20140062944A - Light emitting device

Info

Publication number: KR20140062944A
Application number: KR1020120129275A
Authority: KR
Inventors: 심세환
Original assignee: 엘지이노텍 주식회사
Priority date: 2012-11-15
Filing date: 2012-11-15
Publication date: 2014-05-27

Abstract

The embodiment of the present invention relates to a light emitting device, a manufacturing method thereof, a light emitting device package, and a lighting system. The light emitting device according to the embodiment of the present invention includes: a first conductive semiconductor layer (112); a GaN-based superlattice layer (124) which is formed on the first conductive semiconductor layer (112); an active layer (114) which is formed on the GaN-based superlattice layer (124); and a second conductive semiconductor layer (116) which is formed on the active layer (114). The first conductive semiconductor layer (112) includes a plurality of layers with first conductive elements with different concentrations.

Description

[0001] LIGHT EMITTING DEVICE [0002]

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

Light Emitting Device is a pn junction diode whose electrical energy is converted into light energy. It can be produced from compound semiconductor such as group III and group V on the periodic table and by controlling the composition ratio of compound semiconductor, It is possible.

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

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

The epitaxial structure used in the light emitting device includes an electron injection layer, an active layer, and a hole injection layer, and the active layer is a multiple quantum well structure (MQWs), which is usually composed of a heterojunction of a III-V semiconductor that is not doped.

Conventional light-emitting diode epi (EPI) growth technology consists of an electron injection layer, a light-emitting layer and a hole-injection layer. Among them, the light-emitting layer is an important and sensitive part for determining device characteristics such as luminous efficiency and luminous efficiency.

Therefore, in order to reduce the strain and defects of the light emitting layer, layers having a structure similar to the light emitting layer are present at the bottom. The lower auxiliary layer is designed in such a direction as to minimize charge transfer and strain on the band structure by different growth temperatures from the light emitting layer.

However, according to the related art, doping of an n-type element such as Si or a p-type element such as Mg in a light emitting element is necessary to make a p-n junction structure.

On the other hand, the degree of doping of Si and Mg must be increased in order to form a carrier of high concentration in the intrinsic semiconductor. However, this deteriorates the quality of the semiconductor thin film and changes the strain, which adversely affects the device characteristics.

In particular, excessive Si doping for n-type GaN under multiple quantum wells (MQWs), which are light emitting layers, causes problems in low current characteristics and other electrical characteristics as it leads to quality degradation of MQWs.

Embodiments provide a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and an illumination system capable of improving brightness and improving electrical characteristics.

The light emitting device according to the embodiment includes a first conductive semiconductor layer 112; A gallium nitride-based superlattice layer 124 on the first conductive semiconductor layer 112; An active layer 114 on the gallium nitride superlattice layer 124; And a second conductive type semiconductor layer (116) on the active layer (114), wherein the first conductive type semiconductor layer (112) may include a plurality of layers having different concentrations of the first conductive type element have.

According to the light emitting device, the method of manufacturing the light emitting device, the light emitting device package, and the illumination system according to the embodiment, continuous doping of the n-type GaN is modulated in a specific layer, it is possible to improve the quality and strain of the upper multiple quantum wells (MQWs) without causing a driving voltage increase, that is, to increase the dopant amount. Thus, the light emitting device according to the embodiment can improve the light intensity and the improvement of the electrical characteristics.

1 is a cross-sectional view of a light emitting device according to an embodiment.
2 is a diagram illustrating a secondary-ion mass spectroscopy (SIMS) analysis of a light-emitting device according to an embodiment.
3 to 7 are cross-sectional views illustrating a method of manufacturing a light emitting device according to an embodiment.
8 is a sectional view of a light emitting device package according to an embodiment.
9 to 11 are views showing a lighting apparatus according to an embodiment.
12 and 13 are views showing another example of the lighting apparatus according to the embodiment.
14 is a perspective view of a backlight unit according to an embodiment.

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

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 of each component does not entirely reflect the actual size.

(Example)

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

The light emitting device 100 according to the embodiment includes a first conductive semiconductor layer 112, a gallium nitride superlattice layer 124 on the first conductive semiconductor layer 112, An active layer 114 on the layer 124 and a second conductive type semiconductor layer 116 on the active layer 114.

The first conductive semiconductor layer 112, the active layer 114, and the second conductive semiconductor layer 116 may form the light emitting structure 110 in the exemplary embodiment.

2 is an example of secondary-ion mass spectroscopy (SIMS) analysis of a light-emitting device according to an embodiment. And the X-axis is the depth (nm) from the second conductivity type semiconductor layer 116.

According to the prior art, doping of an n-type element such as Si or a p-type element such as Mg in a light emitting device is necessary for forming a pn junction structure. In order to form a carrier of high concentration in an intrinsic semiconductor, The degree of Mg doping must be increased. However, this deteriorates the quality of the semiconductor thin film and changes the strain, which adversely affects the device characteristics.

Accordingly, it is an object of the present invention to provide a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and an illumination system capable of improving brightness and improving electrical characteristics.

For this, the concentration of the first conductive type element of the first conductive type semiconductor layer 112 may be modulated. Accordingly, the first conductive type semiconductor layer 112 may include a plurality of layers having different concentrations of the first conductive type element.

In detail, the first conductive semiconductor layer 112 includes a first conductive semiconductor layer 112a closest to the gallium nitride-based superlattice layer 124, and a second conductive semiconductor layer The first conductivity type first semiconductor layer 112a may include a first conductive type second semiconductor layer 112b under the first conductive type first semiconductor layer 112a, 2 < / RTI > concentration.

For example, the second concentration of the first conductive type second semiconductor layer 112b may be 50% or more and less than 100% of the first concentration of the first conductive type first semiconductor layer 112a. The second concentration of said first conductivity type second semiconductor layer (112b) is not be a 1 × E18 to ^{4 × E18 (atoms / cm 3} ) , but is not limited thereto.

The first conductive semiconductor layer 112 may further include a first conductive type third semiconductor layer 112c under the first conductive type second semiconductor layer 112b, The second concentration of the second semiconductor layer 112b may be higher than the third concentration of the first conductive type third semiconductor layer 112c.

In addition, the first conductivity type semiconductor layer 112 may further include a first conductive type fourth semiconductor layer 112d below the first conductive type third semiconductor layer 112c.

The thickness of the first conductivity type semiconductor layer 112 modulated in the embodiment is controlled to be about 0.5 μm to about 1.5 μm so that the optical characteristic of the light emitting device can be improved while the operating voltage VF3 is maintained. For example, when the thickness of the first conductivity type semiconductor layer 112 is less than 0.5 μm, the modulation effect may be reduced by half. When the thickness of the first conductivity type semiconductor layer 112 is more than 1.5 μm, The operating voltage can be increased.

detail VF3 (20mA) WD (nm) IV (Chip) ESD yield Reference 2.88 452.1 112.7 54% Case 2.88 447.8 124.4 69%

Table 1 shows the characteristics of the light emitting device at predetermined wavelengths (WD: dominant wavelength) of Examples (Examples) and Comparative Examples (Reference).

According to the embodiment, the luminous intensity (IV) and ESD (electrostatic discharge) yield of the light emitting device can be improved without increasing the operating voltage VF3

According to the embodiment, the Si concentration of the first conductive type first semiconductor layer 112a before the active layer is maintained at a constant level, and the Si doping concentration of the first conductive type semiconductor layer before the active layer is maintained at a constant level, 112a) concentration to less than about 50% to less than 100%, thereby improving the quality and strain of the upper active layer without causing a rise in the driving voltage (VF3) It is possible to improve the luminous intensity (IV) and electrical characteristic (ESD yield) of the LED device remarkably.

The thickness of the first conductivity type semiconductor layer 112 modulated in the embodiment is controlled to be about 0.5 μm to about 1.5 μm so that the optical characteristic of the light emitting device can be improved while the operating voltage VF3 is maintained.

According to the light emitting device and the method of manufacturing the light emitting device according to the embodiments, the conventional doping of the n-type GaN is modulated in a specific layer, , It is possible to improve the quality and strain of the upper multiple quantum wells (MQWs) without causing a driving voltage rise. Thus, the light emitting device according to the embodiment can improve the light intensity and the improvement of the electrical characteristics.

In the embodiment, the gallium nitride-based superlattice layer 124 includes a first conductive-type gallium nitride-based superlattice layer 124a under the active layer 114 and a first gallium nitride- Wherein the first conductive type second gallium nitride based superlattice layer 124a includes a first conductive type second gallium nitride based superlattice layer 124b below the lattice layer 124a, May be higher than the concentration of the second gallium nitride-based superlattice layer 124b.

In order to form a pn junction structure in the light emitting device, the doping of the p-type element and the n-type element is required. In order to form a carrier with high concentration in the intrinsic semiconductor, the degree of doping must be increased. there is a problem that the characteristics of the light emitting device are adversely affected by causing a change in strain.

Accordingly, in order to improve the light intensity through charge balance matching of the LED device, the concentration of the first conductivity type element, for example Si, immediately before the growth of the multiple quantum well is important, The first GaN-based superlattice layer 124a is disposed closer to the active layer 114 than the second GaN-based superlattice layer 124b.

In the embodiment, the first gallium nitride superlattice layer 124a is formed so that the concentration of the first conductive type element is controlled to 1 × 10 ¹⁸ (atoms / cm ³ ) or more and the injection of carriers (for example, electrons) . For example, in the embodiment, the concentration of the first conductive type element in the first gallium nitride-based superlattice layer 124a is 1 × 10 ¹⁸ (atoms / cm ³ ) to 1 × 10 ¹⁹ (atoms / cm ³ ) But is not limited thereto.

Meanwhile, in the embodiment, the concentration of the first conductive type element in the second gallium nitride-based superlattice layer 124b may be about 5 × 10 ¹⁷ atoms / cm ³ or less. In the embodiment, the second gallium nitride superlattice layer 124b is not intentionally implanted with n-type ions, but the concentration of the undoped gallium nitride superlattice layer 124u is about 5 x 10 < ¹⁷ > atoms / cm < ³ >) or less, but is not limited thereto.

In this embodiment, attention is paid to the main role of the carrier injection layer, and in order to minimize the inverse effect due to doping, the carrier injection efficiency is increased by increasing the carrier concentration in the region adjacent to the active layer, and the doped first gallium nitride- The region of the layer 124a can be minimized to minimize the deterioration of the film quality due to the ion implantation, so that a high luminous intensity can be maintained even at a high current.

For example, the thickness of the doped first gallium nitride superlattice layer 124a may be thinner than the undoped second gallium nitride superlattice layer 124b. Specifically, the thickness of the doped first gallium nitride based superlattice layer 124a is controlled to 10% to 30% of the thickness of the undoped second gallium nitride based superlattice layer 124b, By increasing the carrier concentration, the carrier injection efficiency can be enhanced and the region of the doped first gallium nitride superlattice layer 124a can be minimized, so that the deterioration of the film quality due to ion implantation can be minimized, and high light intensity can be maintained even at high currents.

For example, when the thickness of the doped first gallium nitride based superlattice layer 124a exceeds 30% of the thickness of the undoped second gallium nitride based superlattice layer 124b, The quality of the chip may be deteriorated.

On the other hand, when the thickness of the doped first gallium nitride superlattice layer 124a is less than 10% of the thickness of the undoped second gallium nitride superlattice layer 124b, the operating voltage VF3) may increase.

For example, in an embodiment, the thickness of the doped first gallium nitride based superlattice layer 124a is controlled to be between about 50 nm and about 200 nm so that the region of the second undoped second gallium nitride based superlattice layer 124b The decrease of the film quality due to the ion implantation is minimized, so that the high light intensity can be maintained even at high currents.

The embodiment further includes an AlGaN-based superlattice layer 109 below the first conductive semiconductor layer 112, and a first conductive-type fifth semiconductor layer (not shown) is formed under the AlGaN-based superlattice layer 109 111).

Hereinafter, reference numerals not shown in Figs. 1 and 2 will be described in the following manufacturing method.

According to the light emitting device and the method of manufacturing the light emitting device according to the embodiment, the improvement of the lightness and the improvement of the electrical characteristics can be improved.

Hereinafter, a method of manufacturing a light emitting device according to an embodiment will be described with reference to FIGS.

3 to 7 illustrate a horizontal light emitting device in which a light emitting device 100 according to an embodiment is grown on a predetermined growth substrate 105. However, the present invention is not limited thereto, And the electrode is formed on the first conductive type semiconductor layer that is exposed afterwards.

First, an undoped semiconductor layer 107 is formed on a substrate 105 as shown in FIG.

The substrate 105 may be formed of a material having excellent thermal conductivity, or may be a conductive substrate or an insulating substrate. For example, the substrate 105 is a sapphire (Al ₂ O _3), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga ₂ 0 ₃ May be used.

In addition, the embodiment may include the undoped semiconductor layer 107 to relieve the lattice mismatch between the material of the light emitting structure 110 and the substrate 105.

For example, the undoped semiconductor layer 107 and the undoped semiconductor layer 107 may be formed of at least one of a compound semiconductor such as GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN.

Thereafter, the first conductive type 5 semiconductor layer 111 and the AlGaN-based superlattice layer 109 may be formed on the undoped semiconductor layer 107.

The first conductive type fifth semiconductor layer 111 may be formed of a compound semiconductor such as a semiconductor compound, for example, a Group III-V, a Group II-VI, or the like, and may be doped with a first conductive dopant . When the first conductive type fifth semiconductor layer 111 is an n-type semiconductor layer, the first conductive type dopant may include Si, Ge, Sn, Se, and Te as n-type dopants, but is not limited thereto .

For example, the first conductive type fifth semiconductor layer 111 may be formed of In _x Al _y Ga ₁ _-x- _y N (0? X? 1, 0? _Y? 1, 0? _X + Semiconductor material having a composition formula. For example, the first conductive type fifth semiconductor layer 111 may include at least one of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, But the present invention is not limited thereto.

In the embodiment, an AlGaN-based superlattice layer 109 such as In _y Al _x Ga _(1-xy) N (0? X? 1, 0? _Y Lt; 1) / GaN superlattice layer can be formed to effectively alleviate the stress that is caused by the lattice mismatch between the first semiconductor layer 111 of the first conductivity type and the active layer 114.

Next, as shown in FIG. 5, a first conductive semiconductor layer 112 is formed on the AlGaN-based superlattice layer 109 (see FIG. 2).

The first conductive type semiconductor layer 112 may adopt the technical features of the method of manufacturing the first conductive type fifth semiconductor layer 111 and will hereinafter be described mainly on the main features of the first conductive type semiconductor layer 112 do.

As shown in Table 1, according to the embodiment, the luminous intensity (IV) and ESD (electrostatic discharge) yield of the light emitting device are improved without increasing the operating voltage VF3

For example, in the case of the first conductive type element, for example Si, the concentration immediately prior to the growth of the multiple quantum well is important for improving the luminance through charge balance matching of the LED device, The gallium nitride superlattice layer 124a is disposed closer to the active layer 114 than the second gallium nitride superlattice layer 124b.

The thickness of the doped first gallium nitride superlattice layer 124a may be thinner than that of the undoped second gallium nitride superlattice layer 124b. Specifically, the thickness of the doped first gallium nitride based superlattice layer 124a is controlled to 10% to 30% of the thickness of the undoped second gallium nitride based superlattice layer 124b, By increasing the carrier concentration, the carrier injection efficiency can be enhanced and the region of the doped first gallium nitride superlattice layer 124a can be minimized, so that the deterioration of the film quality due to ion implantation can be minimized, and high light intensity can be maintained even at high currents.

Next, the active layer 114 is formed on the gallium nitride-based super lattice layer 124.

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

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

The well layer / barrier layer of the active layer 114 may be formed of any one or more pairs of InGaN / GaN, InGaN / InGaN, GaN / AlGaN, InAlGaN / GaN, GaAs (InGaAs) / AlGaAs, GaP But is not limited thereto. The well layer may be formed of a material having a band gap lower than the band gap of the barrier layer.

Next, in the embodiment, the second conductivity type gallium nitride based layer 126 is formed on the active layer 114 to serve as electron blocking and cladding of the active layer (MQW cladding) have. For example, the second conductivity type gallium nitride based layer 126 may be formed of a semiconductor of Al _x In _y Ga _(1-xy) N (0? _X _{? 1, 0?} _Y _{? 1} ) The active layer 114 may have an energy band gap higher than the energy band gap of the active layer 114 and may be formed to a thickness of about 100 Å to about 600 Å.

The second conductivity type gallium nitride based layer 126 may be formed of a superlattice of Al _z Ga _(1-z) N / GaN (0? _Z ? 1), but is not limited thereto.

The second conductivity type gallium nitride based layer 126 can effectively block the electrons that are ion-implanted into the p-type and overflow, and increase the hole injection efficiency. For example, the second conductivity type gallium nitride based layer 126 may effectively prevent electrons that are over-implanted by ion implantation in a concentration range of about 10 ¹⁸ to 10 ²⁰ / cm ³ of Mg, .

Thereafter, the second conductivity type semiconductor layer 116 is formed on the second conductivity type gallium nitride series layer 126. The second conductive semiconductor layer 116 may be formed of a semiconductor compound. 3-group-5, group-2-group-6, and the like, and the second conductivity type dopant may be doped.

For example, the second conductive semiconductor layer 116 may have a composition formula of In _x Al _y Ga ₁ _-x- _y N (0? X? 1, 0? _Y? 1, 0? _X + And the like. When the second conductive semiconductor layer 116 is a p-type semiconductor layer, the second conductive dopant may include Mg, Zn, Ca, Sr, and Ba as p-type dopants.

In an embodiment, the first conductive semiconductor layer 112 may be an n-type semiconductor layer, and the second conductive semiconductor layer 116 may be a p-type semiconductor layer. Also, on the second conductive semiconductor layer 116, a semiconductor (e.g., an n-type semiconductor) (not shown) having a polarity opposite to that of the second conductive type may be formed. Accordingly, the light emitting structure 110 may have any one of an n-p junction structure, a p-n junction structure, an n-p-n junction structure, and a p-n-p junction structure.

Next, in the embodiment, the light-transmitting electrode 130 is formed on the second conductive type semiconductor layer 116, and the light-transmitting electrode 130 may include a light-transmitting ohmic layer, A single metal, a metal alloy, a metal oxide, or the like may be laminated in multiple layers.

For example, the transmissive electrode 130 may be formed of a material selected from the group consisting of ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IAZO (indium aluminum zinc oxide), IGZO (ZnO), indium gallium tin oxide (AZO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZON nitride, AGZO ZnO, IrOx, RuOx, and NiO, and is not limited to such a material.

6, the light-transmitting electrode 130, the second conductivity type semiconductor layer 116, the second conductivity type gallium nitride series layer 126, the active layer 130, the first conductivity type semiconductor layer 112, (114) and a portion of the gallium nitride-based superlattice layer (124).

7, a second electrode 132 is formed on the transparent electrode 130, and a first electrode 131 is formed on the exposed first conductive semiconductor layer 112. [

According to the light emitting device and the manufacturing method thereof according to the embodiment, it is possible to improve the brightness and the electrical characteristics.

8 is a view illustrating a light emitting device package 200 having a light emitting device according to embodiments.

The light emitting device package 200 according to the embodiment includes a package body 205, a third electrode layer 213 and a fourth electrode layer 214 provided on the package body 205, a package body 205, And a molding member 230 surrounding the light emitting device 100. The light emitting device 100 is electrically connected to the third electrode layer 213 and the fourth electrode layer 214,

The package body 205 may be formed of a silicon material, a synthetic resin material, or a metal material, and the inclined surface may be formed around the light emitting device 100.

The third electrode layer 213 and the fourth electrode layer 214 are electrically isolated from each other and provide power to the light emitting device 100. The third electrode layer 213 and the fourth electrode layer 214 may function to increase light efficiency by reflecting the light generated from the light emitting device 100, And may serve to discharge heat to the outside.

The light emitting device 100 may be a horizontal type light emitting device as illustrated in FIG. 1, but is not limited thereto. Vertical light emitting devices and flip chip light emitting devices may also be used.

The light emitting device 100 may be mounted on the package body 205 or on the third electrode layer 213 or the fourth electrode layer 214.

The light emitting device 100 may be electrically connected to the third electrode layer 213 and / or the fourth electrode layer 214 by a wire, flip chip, or die bonding method. The light emitting device 100 is electrically connected to the third electrode layer 213 through the wire 230 and is electrically connected to the fourth electrode layer 214 directly.

The molding member 230 surrounds the light emitting device 100 to protect the light emitting device 100. In addition, the molding member 230 may include a phosphor 232 to change the wavelength of light emitted from the light emitting device 100.

A light guide plate, a prism sheet, a diffusion sheet, a fluorescent sheet, and the like, which are optical members, may be disposed on a path of light emitted from the light emitting device package. The light emitting device package, the substrate, and the optical member may function as a backlight unit or function as a lighting unit. For example, the lighting system may include a backlight unit, a lighting unit, a pointing device, a lamp, and a streetlight.

9 to 11 are views showing a lighting apparatus according to an embodiment.

FIG. 9 is a perspective view of the illumination device according to the embodiment viewed from above, FIG. 10 is a perspective view of the illumination device shown in FIG. 9, and FIG. 11 is an exploded perspective view of the illumination device shown in FIG.

9 to 11, the illumination device 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, a socket 2800, . &Lt; / RTI > 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 or a light emitting device package according to the embodiment.

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 a second conductivity type gallium nitride based layer 126 and may be opaque to view the light source module 2200 from the outside. 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 source unit 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 through which the plurality of light source portions 2210 and the connector 2250 are inserted. The guide groove 2310 corresponds to the substrate of the light source unit 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 has 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 2630, a base 2650, and an extension 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 extension portion 2670 has a shape protruding outward from the other side of the base 2650. The extension portion 2670 is inserted into the connection portion 2750 of the inner case 2700 and receives an external electrical signal. For example, the extension portion 2670 may be provided to 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 extension portion 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.

12 and 13 are views showing another example of the lighting apparatus according to the embodiment.

Fig. 12 is a perspective view of a lighting apparatus according to the embodiment, and Fig. 13 is an exploded perspective view of the lighting apparatus shown in Fig.

12 and 13, the lighting device according to the embodiment includes a cover 3100, a light source 3200, a heat sink 3300, a circuit portion 3400, an inner case 3500, and a socket 3600 . The light source unit 3200 may include a light emitting device or a light emitting device package according to the embodiment.

The cover 3100 has a bulb shape and is hollow. The cover 3100 has an opening 3110. The light source unit 3200 and the member 3350 can be inserted through the opening 3110. [

The cover 3100 may be coupled to the heat discharging body 3300 and surround the light source unit 3200 and the member 3350. The light source part 3200 and the member 3350 may be shielded from the outside by the combination of the cover 3100 and the heat discharging body 3300. The coupling between the cover 3100 and the heat discharging body 3300 may be combined through an adhesive, or may be combined by various methods such as a rotational coupling method and a hook coupling method. The rotation coupling method is a method in which the cover 3100 is coupled with the heat discharging body 3300 by the rotation of the cover 3100 in such a manner that the thread of the cover 3100 is engaged with the thread groove of the heat discharging body 3300 In the hook coupling method, the protrusion of the cover 3100 is inserted into the groove of the heat discharging body 3300, and the cover 3100 and the heat discharging body 3300 are coupled.

The cover 3100 is optically coupled to the light source unit 3200. Specifically, the cover 3100 may diffuse, scatter, or excite light from the light emitting device 3230 of the light source unit 3200. The cover 3100 may be a kind of optical member. Here, the cover 3100 may have a phosphor inside / outside or in the inside thereof to excite light from the light source part 3200.

The inner surface of the cover 3100 may be coated with a milky white paint. Here, the milky white paint may include a diffusing agent for diffusing light. The surface roughness of the inner surface of the cover 3100 may be larger than the surface roughness of the outer surface of the cover 3100. This is for sufficiently scattering and diffusing light from the light source part 3200.

The cover 3100 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 3100 may be a transparent material that can be seen from the outside of the light source unit 3200 and the member 3350, and may be an invisible and opaque material. The cover 3100 may be formed, for example, by blow molding.

The light source unit 3200 is disposed on the member 3350 of the heat sink 3300 and may be disposed in a plurality of units. Specifically, the light source portion 3200 may be disposed on at least one of the plurality of side surfaces of the member 3350. The light source unit 3200 may be disposed at the upper end of the member 3350.

13, the light source portion 3200 may be disposed on three of the six sides of the member 3350. [ However, the present invention is not limited thereto, and the light source portion 3200 may be disposed on all the sides of the member 3350. The light source unit 3200 may include a substrate 3210 and a light emitting device 3230. The light emitting device 3230 may be disposed on one side of the substrate 3210.

The substrate 3210 has a rectangular plate shape, but is not limited thereto and may have various shapes. For example, the substrate 3210 may have a circular or polygonal plate shape. The substrate 3210 may be a printed circuit pattern on an insulator. For example, the substrate 3210 may be a printed circuit board (PCB), a metal core PCB, a flexible PCB, a ceramic PCB . &Lt; / RTI > In addition, a COB (Chips On Board) type that can directly bond an unpackaged LED chip on a printed circuit board can be used.

In addition, the substrate 3210 may be formed of a material that efficiently reflects light, or may be formed of a color whose surface efficiently reflects light, for example, white, silver, or the like. The substrate 3210 may be electrically connected to the circuit unit 3400 housed in the heat discharging body 3300. The substrate 3210 and the circuit portion 3400 may be connected, for example, via a wire. The wire may pass through the heat discharging body 3300 to connect the substrate 3210 and the circuit unit 3400.

The light emitting device 3230 may be a light emitting diode chip that emits red, green, or blue light, or a light emitting diode chip that emits UV light. Here, the light emitting diode chip may be a lateral type or a vertical type, and the light emitting diode chip may emit blue, red, yellow, or green light. .

The light emitting device 3230 may have a phosphor. The phosphor may be at least one of a garnet system (YAG, TAG), a silicate system, a nitride system, and an oxynitride system. Alternatively, the fluorescent material may be at least one of a yellow fluorescent material, a green fluorescent material, and a red fluorescent material.

The heat discharging body 3300 may be coupled to the cover 3100 to dissipate heat from the light source unit 3200. The heat discharging body 3300 has a predetermined volume and includes an upper surface 3310 and a side surface 3330. A member 3350 may be disposed on the upper surface 3310 of the heat discharging body 3300. An upper surface 3310 of the heat discharging body 3300 can be engaged with the cover 3100. The upper surface 3310 of the heat discharging body 3300 may have a shape corresponding to the opening 3110 of the cover 3100.

A plurality of radiating fins 3370 may be disposed on the side surface 3330 of the heat discharging body 3300. The radiating fin 3370 may extend outward from the side surface 3330 of the heat discharging body 3300 or may be connected to the side surface 3330. The heat dissipation fin 3370 may increase the heat dissipation area of the heat dissipator 3300 to improve heat dissipation efficiency. Here, the side surface 3330 may not include the radiating fin 3370.

The member 3350 may be disposed on the upper surface 3310 of the heat discharging body 3300. The member 3350 may be integral with the top surface 3310 or may be coupled to the top surface 3310. The member 3350 may be a polygonal column.

Specifically, the member 3350 may be a hexagonal column. The hexagonal column member 3350 has an upper surface, a lower surface, and six sides. Here, the member 3350 may be a circular column or an elliptic column as well as a polygonal column. When the member 3350 is a circular column or an elliptic column, the substrate 3210 of the light source portion 3200 may be a flexible substrate.

The light source unit 3200 may be disposed on six sides of the member 3350. The light source unit 3200 may be disposed on all six sides and the light source unit 3200 may be disposed on some of the six sides. In Fig. 9, the light source unit 3200 is disposed on three sides of six sides.

The substrate 3210 is disposed on a side surface of the member 3350. The side surface of the member 3350 may be substantially perpendicular to the upper surface 3310 of the heat discharging body 3300. Accordingly, the upper surface 3310 of the substrate 3210 and the heat discharging body 3300 may be substantially perpendicular to each other.

The material of the member 3350 may be a material having thermal conductivity. This is to receive the heat generated from the light source 3200 quickly. The material of the member 3350 may be, for example, aluminum (Al), nickel (Ni), copper (Cu), magnesium (Mg), silver (Ag), tin (Sn) Or the member 3350 may be formed of a thermally conductive plastic having thermal conductivity. Thermally conductive plastics are advantageous in that they are lighter in weight than metals and have unidirectional thermal conductivity.

The circuit unit 3400 receives power from the outside and converts the supplied power to the light source unit 3200. The circuit unit 3400 supplies the converted power to the light source unit 3200. The circuit unit 3400 may be disposed on the heat discharging body 3300. Specifically, the circuit unit 3400 may be housed in the inner case 3500 and stored in the heat discharging body 3300 together with the inner case 3500. The circuit portion 3400 may include a circuit board 3410 and a plurality of components 3430 mounted on the circuit board 3410.

The circuit board 3410 has a circular plate shape, but is not limited thereto and may have various shapes. For example, the circuit board 3410 may be in the shape of an oval or polygonal plate. Such a circuit board 3410 may be one in which a circuit pattern is printed on an insulator. The circuit board 3410 is electrically connected to the substrate 3210 of the light source unit 3200. The electrical connection between the circuit board 3410 and the substrate 3210 may be connected by wire, for example. The wires may be disposed inside the heat discharging body 3300 to connect the circuit board 3410 and the substrate 3210.

The plurality of components 3430 include, for example, a DC converter for converting AC power supplied from an external power source to DC power, a driving chip for controlling the driving of the light source 3200, An electrostatic discharge (ESD) protection device, and the like.

The inner case 3500 houses the circuit portion 3400 therein. The inner case 3500 may have a receiving portion 3510 for receiving the circuit portion 3400. The receiving portion 3510 may have a cylindrical shape as an example. The shape of the accommodating portion 3510 may vary depending on the shape of the heat discharging body 3300. The inner case 3500 may be housed in the heat discharging body 3300. The receiving portion 3510 of the inner case 3500 may be received in a receiving portion formed on the lower surface of the heat discharging body 3300.

The inner case 3500 may be coupled to the socket 3600. The inner case 3500 may have a connection portion 3530 that engages with the socket 3600. The connection portion 3530 may have a threaded structure corresponding to the thread groove structure of the socket 3600. The inner case 3500 is nonconductive. Therefore, electrical short circuit between the circuit portion 3400 and the heat discharging body 3300 is prevented. For example, the inner case 3500 may be formed of plastic or resin.

The socket 3600 may be coupled to the inner case 3500. Specifically, the socket 3600 may be engaged with the connection portion 3530 of the inner case 3500. The socket 3600 may have the same structure as a conventional incandescent bulb. The circuit portion 3400 and the socket 3600 are electrically connected. The electrical connection between the circuit part 3400 and the socket 3600 may be connected via a wire. Accordingly, when external power is applied to the socket 3600, the external power may be transmitted to the circuit unit 3400. The socket 3600 may have a screw groove structure corresponding to the threaded structure of the connection portion 3550.

14 is an exploded perspective view 1200 of a backlight unit according to an embodiment. However, the backlight unit 1200 of Fig. 14 is an example of the illumination system, and the invention is not limited thereto.

The backlight unit 1200 according to the embodiment includes a light guide plate 1210, a light emitting module unit 1240 for providing light to the light guide plate 1210, a reflection member 1220 below the light guide plate 1210, But the present invention is not limited thereto, and may include a bottom cover 1230 for housing the light emitting module unit 1210, the light emitting module unit 1240, and the reflecting member 1220.

The light guide plate 1210 serves to diffuse light into a surface light source. The light guide plate 1210 may be made of a transparent material such as acrylic resin such as PMMA (polymethyl methacrylate), polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin copolymer (COC), and polyethylene naphthalate Resin. &Lt; / RTI >

The light emitting module part 1240 provides light to at least one side of the light guide plate 1210 and ultimately acts as a light source of a display device in which the backlight unit is installed.

The light emitting module 1240 may be in contact with the light guide plate 1210, but is not limited thereto. Specifically, the light emitting module 1240 includes a substrate 1242 and a plurality of light emitting device packages 200 mounted on the substrate 1242. The substrate 1242 is mounted on the light guide plate 1210, But is not limited to.

The substrate 1242 may be a printed circuit board (PCB) including a circuit pattern (not shown). However, the substrate 1242 may include not only a general PCB, but also a metal core PCB (MCPCB), a flexible PCB (FPCB), and the like.

The plurality of light emitting device packages 200 may be mounted on the substrate 1242 such that a light emitting surface on which the light is emitted is spaced apart from the light guiding plate 1210 by a predetermined distance.

The reflective member 1220 may be formed under the light guide plate 1210. The reflection member 1220 reflects the light incident on the lower surface of the light guide plate 1210 so as to face upward, thereby improving the brightness of the backlight unit. The reflective member 1220 may be formed of, for example, PET, PC, or PVC resin, but is not limited thereto.

The bottom cover 1230 may receive the light guide plate 1210, the light emitting module 1240, and the reflective member 1220. For this purpose, the bottom cover 1230 may be formed in a box shape having an opened upper surface, but the present invention is not limited thereto.

The bottom cover 1230 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.

The light emitting device, the light emitting device manufacturing method, the light emitting device package, and the illumination system according to the embodiments can improve the light intensity and the electrical characteristics.

The features, structures, effects and the like described in the embodiments are included in at least one embodiment and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Accordingly, the contents of such combinations and modifications should be construed as being included in the scope of the embodiments.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. It can be seen that the modification and application of branches are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

The first conductive semiconductor layer 112,
The first conductive type first semiconductor layer 112a,
The first conductive type second semiconductor layer 112b,
The first conductive type third semiconductor layer 112c,
The first conductive type fourth semiconductor layer 112d,
A gallium nitride superlattice layer 124,
The first conductive type first gallium nitride-based superlattice layer 124a,
A first conductive type second gallium nitride-based superlattice layer 124b,
The active layer 114, the second conductivity type semiconductor layer 116,

Claims

A first conductive semiconductor layer;
A gallium nitride superlattice layer on the first conductive type semiconductor layer;
An active layer on the gallium nitride superlattice layer; And
And a second conductive semiconductor layer on the active layer,
Wherein the first conductivity type semiconductor layer includes a plurality of layers having different concentrations of the first conductive type element.

The method according to claim 1,
The first conductivity type semiconductor layer may include a first conductivity type semiconductor layer,
A first conductive type first semiconductor layer closest to the gallium nitride based super lattice layer,
And a first conductive type second semiconductor layer below the first conductive type first semiconductor layer,
The first concentration of the first conductive type first semiconductor layer is
And the second concentration of the first conductive type second semiconductor layer is higher than the second concentration of the first conductive type second semiconductor layer.

3. The method of claim 2,
The second concentration of the first conductive type second semiconductor layer
Wherein the first concentration of the first conductivity type first semiconductor layer is 50% or more and less than 100% of the first concentration.

The method of claim 3,
The second concentration of the first conductive type second semiconductor layer
The light emitting device 1 × E18 to ^{4 × E18 (atoms / cm 3} ).

3. The method of claim 2,
The first conductivity type semiconductor layer may include a first conductivity type semiconductor layer,
And a first conductive type third semiconductor layer below the first conductive type second semiconductor layer,
The second concentration of the first conductive type second semiconductor layer
And the third concentration of the first conductive type third semiconductor layer is higher than the third concentration of the first conductive type third semiconductor layer.

The method according to claim 1,
And the thickness of the first conductivity type semiconductor layer is 0.5 占 퐉 to 1.5 占 퐉.

The method according to claim 1,
The gallium nitride-based superlattice layer
A first gallium nitride superlattice layer of a first conductivity type below the active layer,
And a second conductive type second gallium nitride based superlattice layer under the first conductive type first gallium nitride based superlattice layer,
The concentration of the first conductive type first gallium nitride based superlattice layer is
Type gallium nitride superlattice layer is higher than the concentration of the first conductive type second gallium nitride superlattice layer.

8. The method of claim 7,
And the thickness of the first gallium nitride superlattice layer is thinner than that of the second gallium nitride superlattice layer.

9. The method of claim 8,
Wherein the thickness of the first gallium nitride superlattice layer is 10% to 30% of the thickness of the second gallium nitride superlattice layer.

The method according to claim 1,
Further comprising an AlGaN-based superlattice layer under the first conductive type semiconductor layer,
And a fifth conductive type semiconductor layer below the AlGaN-based superlattice layer.

The method according to claim 1,
And the active layer further comprises a second conductivity type gallium nitride series layer between the second conductivity type semiconductor layers.