Semiconductor light-emitting device

A semiconductor light-emitting device includes: a package substrate having a mounting surface on which a first circuit pattern and a second circuit pattern are disposed; a semiconductor LED chip mounted on the mounting surface, having a first surface which faces the mounting surface and on which a first electrode and a second electrode are disposed, a second surface opposing the first surface, and side surfaces located between the first surface and the second surface, the first electrode and the second electrode being connected to the first circuit pattern and the second circuit pattern, respectively; a wavelength conversion film disposed on the second surface; and a side surface inclined portion disposed on the side surfaces of the semiconductor LED chip, providing inclined surfaces, and including a light-transmitting resin containing a wavelength conversion material.

CROSS-REFERENCE TO THE RELATED APPLICATION

This application claims priority from Korean Patent Application No. 10-2015-0022467 filed on Feb. 13, 2015, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

Apparatuses and methods consistent with example embodiments relate to a semiconductor light-emitting device.

A semiconductor light-emitting diode (LED) is an element containing semiconductor materials which, when electrical energy is applied thereto, emits light through electron-hole recombination due to the application of electrical energy. The LED is widely being used as a light source of general lighting devices and a backlight unit of large-scale liquid crystal display (LCD) devices, and accordingly, the development thereof is currently being accelerated.

In general, LEDs may be provided as light-emitting devices packaged in a variety of forms to be easily provided in application devices. In the process of packaging such LEDs, disadvantageous effects such as deteriorations of light emission efficiency or increase in color deviation may occur in a product due to light loss and total internal reflection caused by other components.

SUMMARY

Example embodiments of the inventive concept provide a semiconductor light-emitting device having improved light extraction efficiency through a significant reduction of light loss due to total internal reflection.

According to an example embodiment, there is provided a semiconductor light-emitting device which may include: a package substrate having a mounting surface on which a first circuit pattern and a second circuit pattern are disposed; a semiconductor LED chip mounted on the mounting surface, having a first surface which faces the mounting surface and on which a first electrode and a second electrode are disposed, a second surface opposing the first surface, and side surfaces located between the first surface and the second surface, the first electrode and the second electrode being connected to the first circuit pattern and the second circuit pattern, respectively; a wavelength conversion film disposed on the second surface; and a side surface inclined portion disposed on the side surfaces of the semiconductor LED chip, providing inclined surfaces, and including a light-transmitting resin containing a wavelength conversion material.

The semiconductor light-emitting device may further include a light-transmitting adhesive layer disposed between the wavelength conversion film and the semiconductor LED chip. In this case, the light-transmitting adhesive layer may include the same light-transmitting resin as the light-transmitting resin of the side surface inclined portion. The light-transmitting adhesive layer may include the same wavelength conversion material as the wavelength conversion material of the side surface inclined portion.

The wavelength conversion material of the side surface inclined portion may contain the same material as the material contained in the wavelength conversion film.

The wavelength conversion film may have an area greater than an area of the semiconductor LED chip.

The semiconductor light-emitting device may further include a side surface reflection portion which is disposed on the mounting surface of the package substrate to surround the side surface inclined portion and includes the inwardly inclined surfaces by contacting the side surface inclined portion. The inwardly inclined surfaces may be used to guide light emitted from the semiconductor LED chip toward the wavelength conversion film. In this case, the side surface reflection portion may include a light-transmitting resin in which a reflective powder is contained. The reflective powder may be a white ceramic powder or a metal powder.

The package substrate may include a cup-shaped reflective structure disposed on the mounting face to surround the side surface reflection portion, and the semiconductor light-emitting device may further include an optical lens disposed on the wavelength conversion film.

According to an example embodiment, there is provided a semiconductor light-emitting device which may include: a package substrate having a mounting surface on which a first circuit pattern and a second circuit pattern are disposed; a semiconductor LED chip mounted on the mounting surface of the package substrate, having a first surface which faces the mounting surface and on which a first electrode and a second electrode are disposed, a second surface opposing the first surface, and side surfaces located between the first surface and the second surface, the first electrode and the second electrode being connected to the first circuit pattern and the second circuit pattern, respectively; a wavelength conversion film disposed on the second surface of the semiconductor LED chip, a side surface inclined portion disposed on the side surfaces of the semiconductor LED chip, providing a surface inclined inwardly toward the mounting surface of the package substrate, and composed of a light-transmitting resin containing a light dispersing material; and a side surface reflection portion disposed on the mounting surface of the package substrate to surround the side surface inclined portion.

The light dispersing material may contain at least one selected from a group consisting of SiO2, Al2O3, and TiO2.

According to an example embodiment, there is provided semiconductor light-emitting device which may include: a substrate; a semiconductor LED chip mounted on the substrate, having a first surface which faces the substrate, a second surface opposing the first surface, and side surfaces connecting the first surface and the second surface; a wavelength conversion film disposed on the second surface of the semiconductor LED chip; and a side surface structure disposed on the side surfaces of the semiconductor LED chip configured to reflect light emitted from the semiconductor LED chip toward the wavelength conversion film, and comprising a light-transmitting resin containing a wavelength conversion material or a light dispersing material which is different from the wavelength conversion material.

In a case that the light-transmitting resin contains the light dispersing material, the light-transmitting resin and the light dispersing material may have different refractive indexes.

The wavelength conversion film may include a yellow phosphor, and the light-transmitting resin may include a red phosphor or a green phosphor.

The semiconductor light-emitting device may further include a light-transmitting adhesive layer disposed between the wavelength conversion film and the semiconductor LED chip. Here, the light-transmitting adhesive layer and the side surface structure may include a same material.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

Example embodiments of the present inventive concept will now be described in detail with reference to the accompanying drawings.

The inventive concept may, however, be exemplified in many different forms and should not be construed as being limited to the specific 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 inventive concept to those skilled in the art. In the drawings, the shapes and dimensions of elements may be exaggerated for clarity, and the same reference numerals will be used throughout to designate the same or like elements. In this disclosure, terms such as “above”, “upper portion”, “upper surface”, “below”, “lower portion”, “lower surface”, “lateral surface”, and the like, are determined based on the drawings, and in actuality, the terms may be changed according to a direction in which a device or an element is disposed.

It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. It will also be understood that when a layer is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present.

The expression “an example embodiment or one example” used in the present disclosure does not refer to identical examples and is provided to stress different unique features between each of the examples. However, an example or example embodiment provided in the following description is not excluded from being associated with one or more features of another example or another example embodiment also provided therein or not provided therein but consistent with the inventive concept. For example, even if matters described in a specific example are not described in a different example thereto, the matters may be understood as being related to the other example, unless otherwise mentioned in descriptions thereof.

FIG. 1is a cross-sectional view illustrating a semiconductor light-emitting device according to an example embodiment, andFIG. 2is a plan view illustrating the semiconductor light-emitting device ofFIG. 1.

Referring toFIG. 1, a semiconductor light-emitting device30according to an example embodiment of the present disclosure may include a package substrate10having a mounting surface, and a semiconductor light-emitting diode (LED) chip20mounted above the mounting surface of the package substrate10.

The package substrate10may include first and second circuit patterns12aand12bdisposed on the mounting surface. The first and second circuit patterns12aand12bmay be extended onto side surfaces or onto the lower surface of the package substrate. The package substrate10may include an insulating resin, a ceramic substrate, or the like. The first and second circuit patterns12aand12bmay include a metallic component such as Au, Cu, Ag, and Al. For example, the package substrate10may be a Printed Circuit Board (PCB), a Metal Core PCB (MCPCB), a Metal PCB (MPCB), a Flexible PCB (FPCB), or the like.

The semiconductor LED chip20may have a first surface on which first and second electrodes29aand29bare disposed, a second surface opposing the first surface, and side surfaces connecting the first surface and the second surface. The semiconductor LED chip20may be mounted in such a manner that the first surface faces the mounting surface, and the first and second electrodes29aand29bmay be connected to the first and second circuit patterns12aand12bby solder balls15aand15b, respectively.

As illustrated inFIG. 3, the semiconductor LED chip20employed in the example embodiment may include a substrate21, and a first conductivity-type semiconductor layer24, an active layer25, and a second conductivity-type semiconductor layer26sequentially disposed on the substrate21. A buffer layer22may be disposed between the substrate21and the first conductivity-type semiconductor layer24.

The substrate21may be an insulating substrate formed of a material such as sapphire, but is not limited thereto. Thus, the substrate21may also be a conductive substrate or a semiconductor substrate in addition to being an insulating substrate. For example, the substrate21may be a SiC substrate, a Si substrate, a MgAl2O4substrate, a MgO substrate, a LiAlO2substrate, a LiGaO2substrate, or a GaN substrate, in addition to being the sapphire substrate. A corrugation (P) may be formed in the upper surface of the substrate21. The corrugation (P) may improve the quality of grown single crystal while improving light extraction efficiency.

The buffer layer22may be an InxAlyGa1−x−yN layer (0≤x≤1, 0≤y≤1). For example, the buffer layer22may be one of a GaN layer, an AlN layer, an AlGaN layer, or an InGaN layer. The buffer layer22may be used by combining a plurality of layers or progressively modifying the composition as needed.

The first conductivity-type semiconductor layer24may be a nitride semiconductor satisfying n-type InxAlyGa1−x−yN (0≤x<1, 0≤y<1, 0≤x+y<1), and an n-type impurity may be Si. For example, the first conductivity-type semiconductor layer24may include an n-type GaN. The second conductivity-type semiconductor layer26may be a nitride semiconductor layer satisfying p-type InxAlyGa1−x−yN (0≤x<1, 0≤y<1, 0≤x+y<1), and p-type impurity may be Mg. For example, although the second conductivity-type semiconductor layer26may be implemented as a single-layer structure, as in the example embodiment, the second conductivity-type semiconductor layer26may have a multilayer structure in which layers have different compositions with respect to one another. The active layer25may have a multiple quantum well (MQW) structure formed by a quantum well layer and a quantum barrier layer stacked alternately with each other. For example, the quantum well layer and the quantum barrier layer may be InxAlyGa1−x−yN (0≤x≤1, 0≤y≤1, 0≤x+y≤1) layers having different compositions. In certain example embodiments, the quantum well layer may be provided as an InxGa1−xN (0<x≤1) layer, and the quantum barrier layer may be a GaN layer or an AlGaN layer. The thickness of the quantum well layer and the quantum barrier layer may each be within a range of 1 nm to 50 nm. The active layer25is not limited to a multiple quantum well structure, but may also have a single quantum well structure.

The first and second electrodes29aand29bmay be disposed on a mesa etched region of the first conductivity-type semiconductor layer24and the second conductivity-type semiconductor layer26, respectively, to be located on the same surface (the first surface). The first electrode29amay contain a material such as Ag, Ni, Al, Cr, Rh, Pd, Ir, Ru, Mg, Zn, Pt, and Au, but is not limited to such materials, and may have a single-layer structure or a structure of two or more layers. The second electrode29bmay be configured of a transparent electrode formed using a material such as a transparent conductive oxide or a transparent conductive nitride, and may include graphene as necessary. The second electrode29bmay include at least one of Al, Au, Cr, Ni, Ti and Sn.

A wavelength conversion film38may be disposed on the upper surface, for example, the second surface, of the semiconductor LED chip20mounted on the package substrate10. The wavelength conversion film38may include a wavelength conversion material converting a portion of light emitted from the semiconductor LED chip20to light having a different wavelength. The wavelength conversion film38may be provided as a resin layer in which the wavelength conversion material is dispersed, or a ceramic film including a sintered body of a ceramic phosphor. The semiconductor LED chip20may emit blue light, and the wavelength conversion film38may emit white light by converting a portion of the blue light to yellow and/or red and green light, such that the semiconductor light emitting device30according to the example embodiment may be provided. The wavelength conversion materials that may be used in the present example embodiment will be described later (see Table 1 below).

The wavelength conversion film38may have an area greater than that of the semiconductor LED chip20. As illustrated inFIG. 2, the wavelength conversion film38may be disposed to cover the second surface of the semiconductor LED chip20.

In the example embodiment, a side surface inclined portion34may be disposed on side surfaces of the semiconductor LED chip20. The side surface inclined portion34may improve light extraction efficiency by reducing total internal reflection on the side surface of the semiconductor LED chip20by providing an inclined surface to be suitable for light extraction. Such inclined surfaces may be formed to face the package substrate10. For example, as illustrated inFIG. 1, the width of the side surface inclined portion34may become greater toward the wavelength conversion film38. The side surface inclined portion34may have an inclination angle of around 45° or less with respect to the side surface of the semiconductor LED chip20. However, the inventive concept may not be limited to the above structure of the side surface inclined portion34. That is, as long as the light extraction efficiency is improved and light emitted from the semiconductor LED chip20(e.g., light emitted from the side surfaces of the semiconductor LED chip20) can be guided toward the wavelength conversion film38, the side surface inclined portion34does not need to have inclined side surfaces.

The side surface inclined portion34employed in the example embodiment may include a light-transmitting resin containing a wavelength conversion material. For example, the light-transmitting resin may be a silicone resin. A refractive index of the silicone resin may be selected from within a range of 1.38 to 1.8. The wavelength conversion material contained in the light-transmitting resin of the side surface inclined portion34may include a material identical to the wavelength conversion material contained in the wavelength conversion film38, but is not limited thereto. Thus, the wavelength conversion material may also be provided as a wavelength conversion material for obtaining light having a different wavelength. For example, the wavelength conversion film38may include a yellow phosphor, and the side surface inclined portion34may include at least one of a red phosphor or a green phosphor to enhance color rendering properties (Ra).

As illustrated inFIG. 1andFIG. 2, a side surface reflection portion36surrounding the side surface inclined portion34may be disposed below the wavelength conversion film38. An interface of the side surface inclined portion34and the side surface reflection portion36may serve as a reflective surface, and the inclined surface according to the example embodiment may provide a structure suitable for guiding light toward the wavelength conversion film38. The side surface reflection portion36may include a light-transmitting resin containing a reflective powder. The reflective powder may be a white ceramic powder or a metal powder. For example, the ceramic powder may be a powder of at least one selected from a group consisting of TiO2, Al2O3, Nb2O5, Al2O3, and ZnO. The metal powder may be formed of a material such as Al or Ag.

Unlike the present example embodiment, the semiconductor light-emitting device30may not be provided with the side surface reflection portion36, but may be configured to emit light through the side surfaces of the semiconductor LED chip20.

In the example embodiment, a light-transmitting adhesive layer32may be disposed between the wavelength conversion film38and the semiconductor LED chip20to allow the wavelength conversion film38to be bonded to the second surface of the semiconductor LED chip20. In this case, the light-transmitting adhesive layer32may include the same material as the side surface inclined portion34. For example, the light-transmitting adhesive layer32and the side surface inclined portion34may be formed of the same material, a silicone resin containing a yellow phosphor. The side surface inclined portion34may be formed of the same material as the light-transmitting adhesive layer32in the bonding process of the wavelength conversion film38and the semiconductor LED chip20using the light-transmitting adhesive layer32(seeFIG. 5C).

In addition to providing an inclined surface suitable for light extraction, the side surface inclined portion34employed in the example embodiment may contain a wavelength conversion material such as a phosphor to allow for wavelength conversion of light entering the side surface inclined portion34. Furthermore, light loss due to total internal reflection may also be reduced to improve light extraction efficiency.

FIG. 4is a cross-sectional view illustrating a semiconductor light-emitting device according to an example embodiment.

Referring toFIG. 4, the semiconductor light-emitting device40according to the example embodiment may include a package substrate10having a mounting surface, and a semiconductor LED chip20bonded to the mounting surface of the package substrate10in a flip chip manner, similar to the example embodiments above.

In the example embodiment, a wavelength conversion film38may be disposed to cover the second surface of the semiconductor LED chip20. The wavelength conversion film38may have an area greater than that of the semiconductor LED chip20. A side surface inclined portion44disposed on side surfaces of the semiconductor LED chip20may provide an inclined surface suitable for light extraction similar to the side surface inclined portion34of the previous example embodiment, but may include a light dispersing material44ainstead of the wavelength conversion material. In detail, the side surface inclined portion44may be formed of a light-transmitting resin44bcontaining a light dispersing material44a. The light dispersing material44amay be a particle having a different refractive index from the light-transmitting resin44b, for example, at least one of SiO2(n=1.45), TiO2(n=1.48), and Al2O3(n=2.73). The light-transmitting resin44bmay be formed of silicone, an epoxy, or a combination thereof, but is not limited thereto.

In the example embodiment, a light-transmitting adhesive layer42may bond the wavelength conversion film38to the second side of the semiconductor LED chip20. The light-transmitting adhesive layer42may be formed of a light-transmitting resin identical to the light-transmitting resin44bincluded in the side surface inclined portion44which contains the light dispersing material44a. For example, the light-transmitting adhesive layer42and the side surface inclined portion44may be formed of a silicone resin containing silica (SiO2) powder as the light dispersing material44a.

As illustrated inFIG. 4, a side surface reflection portion46surrounding the side surface of the side surface inclined portion44may be disposed below the wavelength conversion film38. The side surface reflection portion46may be formed of a light-transmitting resin46bcontaining reflective powder46a. The reflective powder46amay be a white ceramic powder or a metal powder. The semiconductor light-emitting device40may further include an optical lens49disposed over the wavelength conversion film38. The optical lens49may be formed of a resin material having light transmissive properties, for example, polycarbonate (PC), polymethyl methacrylate (PMMA), an acrylic resin, or the like, or may also be formed of a glass material.

In addition to providing an inclined surface suitable for light extraction, the side surface inclined portion44employed in the example embodiment may contain a light dispersing material to allow scattering of light entering the side surface inclined portion44. As a result, a reduced color deviation effect may be obtained along with improved luminous efficiency. Furthermore, an increase in luminous efficiency and a decrease in color deviation may differ somewhat, according to a difference in refractive indexes of the light dispersing material44aand the light-transmitting resin44b. For example, in the case of a great difference in the refractive index, color deviation may be further decreased, and in the case of a small difference in the refractive index, luminous efficiency may be further increased.

FIG. 5AtoFIG. 5Dare cross-sectional views illustrating a process of manufacturing the semiconductor light-emitting device.

As illustrated inFIG. 5A, the semiconductor LED chip20may be mounted above the package substrate10.

The semiconductor LED chip20may have a flip chip structure in which the first surface is mounted to face the mounting surface. The semiconductor LED chip20may have a first surface on which first and second electrodes29aand29bare disposed, a second surface opposing the first surface, and side surfaces connecting the first surface and the second surface, and the package substrate10may include first and second circuit patterns12aand12bdisposed on the mounting surface. The first and second electrodes29aand29bmay be connected to the first and second circuit patterns12aand12b, respectively, using solder balls15aand15b.

As illustrated inFIG. 5B, a bonding resin42′ may be disposed on the second surface of the semiconductor LED chip20.

The bonding resin42′ may be a curable liquid resin44b′ mixed with a light dispersing material44ain a powder form. At least one of SiO2, TiO2, and Al2O3may be used as the light dispersing material44a. The curable liquid resin44b′ may be a resin formed of silicone, epoxy, or a combination thereof, but is not limited thereto. In the bonding process, the bonding resin42′ may be dripped in an amount greater than that required for bonding. In detail, a portion of the bonding resin42′ may flow along the side surface of the semiconductor LED chip20in a subsequent bonding process to provide an amount of resin sufficient to be provided as a side surface inclined portion (44inFIG. 5C). In addition, by controlling the viscosity of the bonding resin42′, the flowing portion thereof may form an inclined surface which may be maintained on the side surface of the semiconductor LED chip20until curing for a certain period of time.

FIG. 5Cillustrates a state in which the wavelength conversion film38is bonded to the second surface of the semiconductor LED chip20by the light-transmitting adhesive layer42after curing. This state may be obtained by curing the bonding resin42′. In the process of disposing the wavelength conversion film38on the semiconductor LED chip20, a portion of the bonding resin42′ may flow along the side surface of the semiconductor LED chip20in an inclined form, and by curing the bonding resin42′ so that the inclined shape of the flow may be maintained, the side surface inclined portion44may be formed together with the light-transmitting adhesive layer42. As a result, the side surface inclined portion44employed in the example embodiment may be formed of the same material as the light-transmitting adhesive layer42. According to the present process, the side surface inclined portion44may improve light extraction efficiency by reducing total internal reflection on the side surface of the semiconductor LED chip20by providing an inclined surface suitable for light extraction.

As illustrated inFIG. 5D, a side surface reflection portion46may be formed on the package substrate10to surround the side surface inclined portion44.

The interface of the side surface reflection portion46and the side surface inclined portion44may be provided as a reflective surface for guiding light toward the wavelength conversion film38. The side surface reflection portion46may be formed of a light-transmitting resin containing a reflective powder. The reflective powder may be a white ceramic powder or a metal powder. For example, the ceramic powder may be at least one selected from a group consisting of TiO2, Al2O3, Nb2O5, Al2O3, and ZnO. The metal powder may be a metal powder such as an Al or Ag powder.

Further, an optical lens49may be additionally formed as necessary such that the semiconductor light-emitting device illustrated inFIG. 4may be obtained. The optical lens49may be formed by a method of injecting a liquid solvent into a mold and curing it. For example, the optical lens49may be formed by a method such as injection molding, transfer molding, or a compression molding.

In the example embodiment, the bonding resin42is illustrated as containing a light dispersing material44a, however, unlike such a configuration, the bonding resin may be configured to contain a wavelength conversion material such as a phosphor powder to form a side surface inclined portion containing a wavelength conversion material together with a light-transmitting adhesive layer.

FIG. 6is a cross-sectional view illustrating a semiconductor light-emitting device according to an example embodiment.

A semiconductor light-emitting device70illustrated inFIG. 6may include a package substrate50having a mounting surface, and a semiconductor LED chip60bonded to the mounting surface of the package substrate50in a flip chip manner, similar to the foregoing example embodiment.

The package substrate may be a structure in which lead frames of the first and second circuit patterns52aand52bare bonded by an insulating resin portion51. The package substrate50may be disposed on the mounting surface, and may further include a reflective structure56formed to surround the semiconductor LED chip60. The reflective structure56may be cup-shaped with an inclined inner surface.

In the example embodiment, a wavelength conversion film78may be disposed to cover the second surface of the semiconductor LED chip60. The wavelength conversion film78may have an area greater than that of the semiconductor LED chip60. A side surface inclined portion74disposed on a side of the semiconductor LED chip60may have an inclined surface suitable for light extraction. The side surface inclined portion74may be formed of a light-transmitting resin containing a wavelength conversion material, such as the example embodiment illustrated inFIG. 1. Alternatively, the side surface inclined portion74may be formed of a light-transmitting resin containing a light dispersing material.

The light-transmitting adhesive layer72may bond the wavelength conversion film78to the second surface of the semiconductor LED chip60. The light-transmitting adhesive layer72may include a light-transmitting resin containing a wavelength conversion material identical to that of the wavelength conversion film78.

In the example embodiment, the side surface reflection portion76may be formed to surround the side surface inclined portion74within the reflective structure56having a cup shape. The side surface reflection portion76located below the wavelength conversion film78may be formed of a light-transmitting resin76bcontaining a reflective powder76a. The reflective powder76amay be a white ceramic powder or a metal powder.

In addition to providing an inclined surface suitable for light extraction, the side surface inclined portion74employed in the example embodiment may contain a wavelength conversion material such as a phosphor to allow for the scattering of light entering the side surface inclined portion74. As a result, a color deviation reduction effect may be obtained along with improved light extraction efficiency.

A semiconductor LED chip that may be employed in the example embodiment is not limited to the structure illustrated inFIG. 3, and chips having a variety of structures capable of being flip-chip bonded may be employed.FIG. 7andFIG. 8are cross-sectional views illustrating various examples of the semiconductor LED chip which may be employed in the semiconductor light-emitting device according to an example embodiment.

The semiconductor LED chip200illustrated inFIG. 7may include a substrate201, and a first conductivity-type semiconductor layer204, an active layer205, and a second conductivity-type semiconductor layer206disposed sequentially on the substrate201. A buffer layer202may be disposed between the substrate201and the first conductivity-type semiconductor layer204.

The substrate201may be an insulating substrate formed of a material such as sapphire but is not limited thereto, and the substrate201may be also be a conductive substrate or a semiconductor substrate in addition to being an insulating substrate. The buffer layer202may be an InxAlyGa1−x−yN (0≤x≤1, 0≤y≤1) layer. For example, the buffer layer202may be a GaN layer, an AlN layer, an AlGaN layer, or an InGaN layer. A thickness of the buffer layer202may be within a range of 0.1 nm to 500 nm. Materials such as ZrB2, HfB2, ZrN, HfN, and TiN may be used as necessary. In a detailed example embodiment, the buffer layer202may be used by combining a plurality of layers, or by progressively modifying a composition thereof.

Although the first and second conductivity-type semiconductor layers204and206may be formed of a single layer structure, alternatively, the semiconductor layers may have a multilayer structure having different compositions or thicknesses, and the like, as required. For example, the first and second conductivity-type semiconductor layers204and206may be provided with a carrier injection layer improving injection efficiency of electrons and/or holes in at least one layer of the first and second conductivity-type semiconductor layers204and206. Further, a superlattice structure having various forms may also be provided therein.

The semiconductor LED chip200according to the example embodiment may further include a V-pit generation layer220formed on an upper portion of the first conductivity-type semiconductor layer204. The V-pit generation layer220may be adjacent to the first conductivity-type semiconductor layer204. The V-pit generation layer220may have a V-pit density of, for example, approximately 1×108cm−2to approximately 5×109cm−2. According to example embodiments, the V-pit generation layer220may have a thickness of approximately 200 nm to approximately 800 nm. In addition, a width (D) of an inlet of a V-pit221may be approximately 200 nm to approximately 800 nm.

A V-pit221generated in the V-pit generation layer220may have an apex angle (θ) of around 10° to 90°, for example, 20° to 80°. In other words, when it is assumed that the V-pit221is to be viewed as a cross section on a vertical plane passing through a vertex of the V-pit221, an angle formed by the two inclined surfaces of the V-pit221, meeting at the vertex, may be between 10° to 90°.

The V-pit221generated in the example embodiment may have a growth surface ((0001) plane) parallel to a substrate surface, and inclined growth surfaces ((1-101) plane) and ((11-22) plane), or other inclined crystal surfaces, inclined with respect to the substrate surface. Such a V-pit221may be formed around a penetrating potential penetrating a light-emitting structure to prevent a phenomenon of current being concentrated on the penetrating potential.

In an example embodiment, the V-pit generation layer220may be a GaN layer or an impurity-doped GaN layer.

A location in which the V-pit221is generated in the V-pit generation layer220may be controlled by a growth temperature. For example, in a case in which the growth temperature is relatively low, the generation of the V-pit221may be initiated from a lower position. In addition, in a case in which the growth temperature is relatively high, the generation of V-pit221may be initiated in a higher position. Given that the V-pit generation layer220is of the same height, in a case in which the generation of the V-pit221is initiated in a lower position, a width of the upper portion of the V-pit221may be further increased.

A film enhancement layer230may be provided in the upper portion of the V-pit generation layer220. The film enhancement layer230may have a composition of MxGa1−xN. Here, M may be Al or In, and may satisfy 0.01≤x≤0.3. In some example embodiments, the composition may satisfy a range of 0.02≤x≤0.08. In a case in which the value of x is relatively too low, the effect of film enhancement may be insufficient. In contrast, in a case in which the value of x is relatively too high, high luminescence properties may be decreased. The value of x within the film enhancement layer230may be constant. Optionally, the film enhancement layer230may have a multilayer structure in which the GaN layer and the MxGa1-xN layers (wherein M is Al or In, and x satisfies 0.01≤x≤0.3) are layered alternately. Moreover, the film enhancement layer230may be a superlattice layer of GaN and MxGa1-xN (wherein M is Al or In, and x satisfies 0.01≤x≤0.3). A thickness of the film enhancement layer230may be approximately 20 nm to approximately 100 nm.

The film enhancement layer230may be formed on the entire upper surface of the V-pit generation layer220. In addition, the film enhancement layer230may have a substantially constant thickness in a vertical direction with respect to the upper surface of the V-pit generation layer220.

The film enhancement layer230may fill the V-pit221at least partially by covering the inside of the V-pit221of the V-pit generation layer220to a predetermined thickness. A V-pit231of the film enhancement layer230may be recessed into the V-pit221of the V-pit generation layer220. The thickness of the film enhancement layer230in a vertical direction with respect to the surface of the upper portion of the V-pit generation layer220may be approximately 5% to approximately 20% of the thickness of the V-pit generation layer220.

The V-pit231formed in the film enhancement layer230may have a dimension identical or similar to that of the V-pit221of the V-pit generation layer220.

In addition, an upper surface233of the film enhancement layer230may have enhanced surface roughness compared to an upper surface223of the V-pit generation layer220. For example, the surface roughness of the upper surface233of the film enhancement layer230may be 60% or less of the surface roughness of the upper surface223of the V-pit generation layer220. Such surface roughness may be measured with an atomic force microscope (AFM). In addition, the surface roughness may be based on measurement of an upper surface excluding the V-pits221and231. In addition, the surface roughness may be determined by measuring the uniformity (flatness) of an interface. For example, the uniformity of the film enhancement layer230and an interface adjacent thereto may be superior to the uniformity of the V-pit generation layer220and an interface adjacent thereto.

Therefore, by enhancing the surface roughness of the upper surface233of the film enhancement layer230, the surface roughness of a barrier layer and a quantum well layer within the active layer205disposed thereabove may both be enhanced. As a result, luminescence may be significantly improved since non-light-emitting recombination of electrons and holes may be reduced.

The semiconductor LED chip200may further include a superlattice layer240adjacent to the active layer205above the first conductivity-type semiconductor layer204. The superlattice layer240may have a structure in which a plurality of InxAlyGa(1−xy)N layers (here, 0≤x<1, 0≤y<1, 0≤x+y<1) having different compositions or impurity contents with respect to each other are stacked repeatedly, or an insulating material layer is partially formed therein. The superlattice layer240may facilitate uniform luminescence across a large area by promoting current diffusion.

A V-pit241corresponding to the V-pit231formed in the film enhancement layer230may also be formed in the superlattice layer240.

The superlattice layer240may fill the V-pit231at least partially by covering the inside of the V-pit231of the film enhancement layer230to a predetermined thickness. The V-pit241of the superlattice layer240may be recessed into the V-pit231of the film enhancement layer230.

A V-pit251corresponding to the V-pit241formed in the superlattice layer240may also be formed in the active layer250.

Like the superlattice layer240, the active layer250may fill the V-pit241at least partially by covering the inside of the V-pit241of the superlattice layer240to a predetermined thickness. The V-pit251of the active layer250may be recessed into the V-pit241of the superlattice layer240.

The second conductivity-type semiconductor layer206may further include an electron blocking layer disposed to be adjacent to the active layer205. The electron blocking layer (EBL) may have a structure in which a plurality of InxAlyGa(1−xy)N layers having different compositions with respect to each other are layered, or one or more layers including AlyGa(1−y)N. The electron blocking layer having a band gap wider than that of the active layer205may prevent electrons from moving to the second conductivity-type(p-type) semiconductor layer206.

A valley of the V-shape of a V-pit formed in the V-pit generation layer220, the film enhancement layer230, the superlattice layer240, or the active layer250may become gentle gradually in the thickness direction of each layer, for example, the closer to the second conductivity-type semiconductor layer206, the more flattened the V-pit may become by the active layer250or the second conductivity-type semiconductor layer206.

The semiconductor LED chip200may include a first electrode219adisposed on the first conductivity-type semiconductor layer204, and an ohmic contact layer218and a second electrode219bdisposed sequentially on the second conductivity-type semiconductor layer206.

FIG. 8is a side cross-sectional view illustrating an example of a semiconductor LED chip which may be employed in the present inventive concept.

Referring toFIG. 8, a semiconductor LED chip400may include a semiconductor laminate S formed on a substrate401. The semiconductor laminate S may include a first conductivity-type semiconductor layer414, an active layer415, and a second conductivity-type semiconductor layer416.

The semiconductor LED chip400may include first and second electrodes422and424connected to the first and second conductivity-type semiconductor layers414and416, respectively. The first electrode422may include a connecting electrode portion422apenetrating through the second conductivity-type semiconductor layer416and the active layer415so as to be connected to the first conductivity-type semiconductor layer414, similar to the conductive via, and a first electrode pad422bconnected to the connecting electrode portion422a. The connecting electrode portion422amay be surrounded by an insulating portion421to be electrically isolated from the active layer415and the second conductivity-type semiconductor layer416. The connecting electrode portion422amay be disposed on a region in which the semiconductor laminate (S) is etched. The number, a shape, a pitch, a contact area with the first conductivity-type semiconductor layer414, and the like, of the connecting electrode portion422amay be appropriately designed to lower contact resistance. In addition, the connecting electrode portion422amay improve current flow by being arranged to form rows and columns on the semiconductor laminate410. The second electrode424may include an ohmic contact layer424aon the second conductivity-type semiconductor layer416and a second electrode pad424b.

The connecting electrode portion422aand the ohmic contact layer424amay have a conductive material having ohmic contact with first and second conductivity type semiconductor layers414and416, respectively, and may have a single layer or multilayer structure thereof. For example, the connecting electrode portion422aand the ohmic contact layer424amay be formed by depositing or sputtering one or more materials, such as Ag, Al, Ni, Cr, a transparent conductive oxide (TCO), and the like.

The first and second electrode pads422band424bmay be respectively connected to the connecting electrode portion422aand the ohmic contact layer424ato serve as external terminals of the semiconductor light-emitting diode400. For example, the first and second electrode pads422band424bmay be Au, Ag, Al, Ti, W, Cu, Sn, Ni, Pt, Cr, NiSn, TiW, AuSn, or a eutectic metal of such elements.

The first and second electrodes422and424may be arranged in the same direction as each other, and may be mounted in the form of a flip chip on a lead frame and the like.

The two electrodes422and424may be electrically isolated from each other by the insulating portion421. Although as a material of the insulating portion421, any material having electrically insulating properties may be used, and any object having electrically insulating properties may be employed, a material having relatively low light absorption may be used. For example, a silicon oxide and silicon nitride such as SiO2, SiOxNy, and SixNymay be used. A light reflecting structure may be formed as necessary by dispersing a light-reflective filler in a light-transmitting material. Unlike that, the insulating unit421may have a multilayer reflective structure in which a plurality of insulating films having different refractive indices with respect to each other are alternately stacked. For example, such a multilayer structure may be provided as a distributed Bragg reflector (DBR) in which a first insulating film having a first refractive index and a second insulating film having a second refractive index are alternately stacked.

The multilayer reflective structure may be a structure in which a plurality of insulating films having different refractive indices with respect to one another are stacked repeatedly two to one hundred times. For example, the insulating films may be stacked repeatedly three to seventy times, and in detail, four to fifty times. The plurality of insulating films of the multilayer reflective structure may, respectively, be an oxide or a nitride such as SiO2, SiN, SiOxNy, TiO2, Si3N4, Al2O3, TiN, AlN, ZrO2, TiAlN, TiSiN, and combinations thereof. For example, given that λ is a wavelength of light generated in the active layer and n is a refractive index of a corresponding layer, the first insulating film and the second insulating film may be formed to have a thickness of λ/4n, and may have a thickness of approximately 300 Å to 900 Å. In this case, the multilayer reflective structure may be designed so that a refractive index and a thickness of the first insulating film and the second insulating layer are respectively selected to have a relatively high degree of reflectivity (for example, 95% or more) with respect to the wavelength of light generated in the active layer415.

The refractive indices of the first insulating film and the second insulating film may be determined to be values within a range of approximately 1.4 to 2.5, and may be values smaller than the refractive index of the first conductivity-type semiconductor layer404and the refractive index of the substrate, but may be a value smaller than the refractive index of the first conductivity-type semiconductor layer404and greater than the refractive index of the substrate.

FIG. 9AandFIG. 9Bare schematic views illustrating various examples of a light source module using the semiconductor light-emitting device according to the example embodiment.

The light source modules illustrated inFIG. 9AandFIG. 9Bmay include a plurality of light-emitting devices mounted on a circuit board respectively, and the plurality of light-emitting devices may be the semiconductor light-emitting device according to the above-described example embodiment. The plurality of light-emitting devices mounted in a single light source module may be configured as a single package, generating light of the same wavelength, but as in the example embodiment, the devices may be configured as packages of different types generating light of different wavelengths.

Referring toFIG. 9A, a white light source module may be configured by combining white light-emitting devices30and40having respective color temperatures of 3000 K and 4000 K, and a red light-emitting device. The white light source module may be adjusted to have a color temperature within a range of 3000 K to 4000 K, and may provide white light within a range of 85 to 100 color rendering property (Ra).

In another example embodiment, the white light source module may only be configured of a white light-emitting device, but a portion of the package thereof may produce white light of different color temperatures. For example, as illustrated inFIG. 9B, by combining a white light-emitting device27having a color temperature of 2700 K and a white light-emitting device50having a color temperature of 5000 K, the color temperature may be adjusted within a range of 2700 K to 5000 K, and white light having a color rendering property (Ra) within a range of 85 to 99 may be provided. Here, the number of light-emitting devices of each color temperature may be changed, mainly depending on a value of basic color temperature settings. For example, in a case in which a default color temperature value of a lighting device is within a vicinity of 4000 K, the number of light-emitting devices corresponding to 4000 K may be greater than the number of light-emitting devices corresponding to 3000 K or red light-emitting devices.

In this manner, different kinds of light-emitting devices may be configured to include at least one of purple, blue, green, red, or infrared LEDs, and a light source emitting white light by combining yellow, green, red, or orange phosphors with blue LEDs, such that the color temperature and color rendering index (CRI) of white light may be adjusted.

The above-described white light source module may be used as a lighting device, for example, the lighting device ofFIG. 16toFIG. 18.

In the semiconductor light-emitting device according to the example embodiment, light having a required color may be determined depending on a wavelength of the LED chip, and the type and blending ratio of a phosphor, and in the case of white light, a color temperature and color rendering index may be controlled. Thereby, the wavelength conversion film used in this example embodiment may be produced.

For example, when the LED chip emits blue light, a light-emitting device including at least one of yellow, green, and red phosphors may be configured to emit white light having a variety of color temperatures depending on the blending ratio of phosphors. In a different manner therefrom, an LED element package in which a green or red phosphor is applied to a blue LED chip may be configured to emit green or red light. In this way, the color temperature and color rendering index of white light may be adjusted by combining an LED element package emitting white light and a package emitting green or red light. Further, at least one of light-emitting diodes emitting purple, blue, green, red, or infrared light may be configured to be included in the lighting device.

In this case, the lighting device may adjust the color rendering index to a daylight level from a level of sodium (Na) light, and may generate a variety of white light having a color temperature level of 20000 K increased from 1500 K, and may adjust the color of lighting as necessary according to the surrounding atmosphere or the mood by generating violet, blue, green, red, and orange visible light or infrared light. Furthermore, light of a specific wavelength promoting plant growth may also be generated.

White light created by combining yellow, green, and red phosphors and/or green and red light-emitting elements with blue light-emitting diodes may have two or more peak wavelengths, and, as illustrated inFIG. 10, the (x, y) coordinates of a CIE 1931 chromaticity diagram may be located within a line segment area connecting (0.4476, 0.4074), (0.3484, 0.3516), (0.3101, 0.3162), (0.3128, 0.3292), and (0.3333, 0.3333), or in an area surrounded by a line segment and a black body radiation spectrum. The color temperature of white light may be between 1500 K and 20000 K.

A variety of materials, such as a phosphor and/or a quantum dot may be used as a wavelength conversion material for converting a wavelength of light emitted from the semiconductor light-emitting diode.

Phosphors may have the following formula and colors.

Silicates: Yellow and Green (Ba, Sr)2SiO4:Eu, yellow and orange (Ba, Sr)3SiO5:Ce

However, Ln in formula (1) may be at least one type of element selected from a group consisting of group IIIa elements and rare earth elements, and M may be at least one type of element selected from a group consisting of Ca, Ba, Sr, and Mg.

The composition of phosphor may basically coincide with stoichiometry, and respective elements may be substituted with other elements within the respective groups of elements in the periodic table. For example, Sr may be substituted with Ba, Ca, Mg, or the like of an alkaline earth group II element, and Y may be substituted with Tb, Lu, Sc, Gd, or the like of lanthanides. In addition, an activator Eu and the like may be substituted with Ce, Tb, Pr, Er, Yb, and the like, depending on the required energy level, and co-activators and the like may be additionally applied solely to the activator or for a property change.

In detail, individual fluoride-based red phosphors may be coated with a fluoride which does not contain Mn, or may further include an organic coating on a surface of the phosphor or on a fluoride coated surface which does not contain Mn to improve dependability in high temperature/high humidity environments. Since the fluoride-based red phosphor such as the above may implement a narrow full width at half maximum of 40 nm or less, unlike other phosphors, the phosphor may be used in high-definition televisions such as UHD TVs.

The following Table 1 shows the types of phosphors according to fields of application of white light-emitting elements using blue LED chips (440 nm to 460 nm) or UV LED chips (380 nm to 440 nm).

Further, a wavelength conversion portion may be formed using a wavelength conversion material such as a quantum dot (QD) by substituting a phosphor therewith or by combining the QD with the phosphor.

FIG. 11is a schematic view illustrating a cross sectional structure of a quantum dot (QD) used as a wavelength conversion material according to an example embodiment. The quantum dot (QD) may have a core-shell structure using group III-V or group II-VI compound semiconductors. For example, the quantum dot may have a core formed of a material such as CdSe, InP, or the like and a shell formed of a material such as ZnS, or ZnSe. In addition, the quantum dots may include a ligand for the stabilization of the core and the shell. For example, a diameter of the core may be between 1 nm to 30 nm, or in detail, between 3 nm to 10 nm, and a thickness of the shell may be between 0.1 nm to 20 nm, or in detail, between 0.5 nm to 2 nm.

The quantum dot may implement various colors depending on the size; in detail, in a case in which the quantum dots are used as a substitute material for a phosphor, the quantum dots may be used as red or green phosphors. In a case in which the quantum dots are used, a narrow full width at half maximum of approximately 35 nm may be implemented.

The wavelength conversion material may be prepared in advance as the wavelength conversion film described in the previous example embodiment, and may be used by adhering to the surface of an optical structure such as an LED chip. In this case, the wavelength conversion material may be readily applicable in a structure of a uniform thickness on a required region.

FIG. 12andFIG. 13are cross-sectional views illustrating a backlight unit according to various example embodiments.

Referring toFIG. 12, a backlight unit2000may include a light guide plate2040and light source modules2010provided on both sides of the light guide plate2040. Further, the backlight unit2000may further include a reflective plate2020disposed on the lower portion of the light guide plate2040. The backlight unit2000in the example embodiment may be an edge type backlight unit.

According to an example embodiment, the light source module2010may only be provided on one side of the light guide plate2040, or may be additionally provided on the other side thereof. The light source module2010may include a printed circuit board2001and a plurality of light sources2005mounted on a top surface of the printed circuit board2001. The light source2005used in this case may be a semiconductor light-emitting device according to the previously described example embodiment.

Referring toFIG. 13, a backlight unit2100may include a light diffusing plate2140and a light source module2110arranged on the lower portion of the light diffusion plate2140. Further, the backlight unit2100may be arranged on the lower portion of the light diffusing plate2140, and may further include a bottom case2160for accommodating the light source module2110therein. The backlight unit2100in the example embodiment may be a direct type backlight unit.

The light source module2110may include a printed circuit board2101and a plurality of light sources2105mounted on a top surface of the printed circuit board2101. The light source2015used in this case may be a semiconductor light-emitting device according to the previously described example embodiment.

FIG. 14is a cross-sectional view illustrating a direct type backlight unit according to an example embodiment.

Referring toFIG. 14, a backlight unit2400may include a light source2405mounted on a circuit board2401, and one or more optical sheets2406disposed on the upper portion of the light source2405.

The light source2405may be provided as a white light-emitting device containing a red phosphor according to an example embodiment, and the light source2405used in this case may be provided as the semiconductor light-emitting device according to the previously described example embodiment.

The circuit board2401employed in the example embodiment may have a first flat surface portion2401acorresponding to a main area, an inclined portion2401bdisposed around the main area, in which at least a portion thereof may be inclined, and a second flat surface portion2401cdisposed on an edge of the circuit board2401which is an external side of the inclined portion2401b. On the first flat surface portion2401a, the light sources2405may be arranged to have a first interval D2therebetween, and on the inclined portion2401b, at least one or more light sources2405may also be arranged to have a second interval D1therebetween. The first interval d1may be identical to the second interval d2. A width (or a length thereof in cross-section) of the inclined portion2401bmay be shorter than a width of the first flat surface portion2401a, and may be formed to be longer than a width of the second flat surface portion2401c. In addition, at least one light source2405may be arranged as necessary on the second flat surface portion2401c.

A gradient of the inclined portion2401bmay be adequately adjustable within a range of being greater than 0° and less than 90°, based on the first flat surface portion2401a. By taking such a structure, the circuit board2401may maintain a uniform degree of brightness even in the vicinity of the edge of the optical sheet2406.

FIG. 15is an exploded perspective view illustrating a display device according to an example embodiment.

Referring toFIG. 15, a display device3000may include a backlight unit3100, an optical sheet3200, and an image display panel3300such as a liquid crystal panel.

The backlight unit3100may include a bottom case3110, a reflector3120, a light guide plate3140, and a light source module3130provided on at least one side of the light guide plate3140. The light source module3130may include a printed circuit board3131and a light source3132. The light source3132used in this case may be provided as the semiconductor light-emitting device according to the previously described example embodiment.

The optical sheet3200may be disposed between the light guide plate3140and the image display panel3300, and may include various types of sheets such as a diffusion sheet, a prism sheet, or a protective sheet.

The image display panel3300may display an image using light emitted from the optical sheet3200. The image display panel3300may include an array substrate3320, a liquid crystal layer3330, and a color filter substrate3340. The array substrate3320may include pixel electrodes arranged in a matrix form, thin-film transistors applying a driving voltage to the pixel electrodes, and signal lines for operating the thin-film transistors. The color filter substrate3340may include a transparent substrate, a color filter, and a common electrode. The color filter may include filters for selectively passing white light of a particular wavelength in white light emitted from the backlight unit3100. The liquid crystal layer3330may control light transmittance by being rearranged by an electrical field formed between the pixel electrodes and the common electrode. The light transmittance-adjusted light may be passed through the color filter of the color filter substrate3340to display an image. The image display panel3300may further include a driving circuit unit for processing video signals and the like.

According to the display device3000in the example embodiment, since the display device3000employs a light source3132that emits blue light, green light, and red light having a relatively small full width at half maximum therein, the emitted light may implement blue, green, and red colors having high levels of color purity after passing through the color filter substrate3340.

FIG. 16is a perspective view illustrating a lighting device according to an example embodiment.

Referring toFIG. 16, a planar lighting device4100may include a light source module4110, a power supply device4120, and a housing4030. According to the example embodiment, the light source module4110may include a light source array, and the light source2015used in this case may be a semiconductor light-emitting device according to the previously described example embodiment. The power supply device4120may include a light-emitting diode driving unit.

The light source module4110may include a light source array, and may be formed to have an overall planar shape. According to the example embodiment, the light source module4110may include a light-emitting diode and a controller storing driving information of the light-emitting diode.

The power supply device4120may be configured to supply power to the light source module4110. A receiving space to allow the light source module4110and the power supply device4120to be received therein may be formed in the housing4130, and the housing4130may be formed in a hexahedral shape with an open side, but is not limited thereto. The light source module4110may be disposed to emit light through the open one side of the housing4130.

FIG. 17is an exploded perspective view of a bulb-type lighting device according to an example embodiment.

A lighting device4200illustrated inFIG. 17may include a socket4210, a power unit4220, a heat-radiating unit4230, a light source module4240, and an optical unit4250. According to an illustrative example embodiment, the light source module4240may include a light-emitting diode array, and the power unit4220may include a light-emitting diode driving unit.

The socket4210may be configured to be replaced with an existing lighting device. Power supplied to the lighting device4200may be applied through the socket4210. As illustrated, the power unit4220may be divided into a first power unit4221and a second power unit4222and may be assembled. The heat-radiating unit4230may include an internal heat-radiating unit4231and an external heat-radiating unit4232. The internal heat-radiating unit4231may be connected directly to the light source module4240and/or the power unit4220, through which heat may be transferred to the external heat-radiating unit4232. The optical portion4250may include an internal optical unit (not illustrated) and an external optical unit (not illustrated), and may be configured to evenly distribute light emitted from the light source module4240.

The light source module4240may receive power from the power source unit4220and emit light to the optical unit4250. The light source module4240may include one or more light sources4241, a circuit board4242, and a controller4243, and the controller4243may store driving information of light-emitting diodes4241. The light source4241used in this case may be a semiconductor light-emitting device according to the previously described example embodiment.

The lighting device4300according to the example embodiment may include a reflecting plate4310above the light source module4240, and the reflecting plate4310may reduce glare by allowing light from the light source to be dispersed evenly to the side and rear.

A communications module4320may be mounted on the upper portion of the reflecting plate4310, through which home-network communications may be implemented. For example, the communications module4320may be a wireless communications module using ZigBee®, Wi-Fi, or Li-Fi and may control lights installed in and around the home, such as turning a lighting device on/off or adjusting brightness, via a smartphone or a wireless controller. In addition, with the use of a Li-Fi communications module with a visible light wavelength of lighting devices installed in and around the home, electronics and automotive systems in and around the home such as TVs, refrigerators, air conditioners, door locks, and automobiles may be controlled.

The reflecting plate4310and the communications module4320may be covered by a cover unit4330.

FIG. 18is an exploded perspective view of a tubular lighting device according to an example embodiment.

A lighting device4400illustrated inFIG. 18may include a heat-radiating member4410, a cover4441, a light source module4450, a first socket4460, and a second socket4470. A plurality of heat-radiating fins4420and4431on the inner and/or outer surfaces of the heat-radiating member4410in a corrugated form, and the heat-radiating fins4420and4431, may be designed to have various shapes and spacings. A support portion4432may be formed in a protruding form on an inner side of the heat-radiating member4410. The light source module4450may be fixed to the supporting portion4432. Locking projections4433may be formed on both sides of the radiating member4410.

Locking grooves4442may be formed in the cover4441, and the locking projections4433of the heat-radiating member4410may be coupled to the locking grooves4442in a hook coupling structure. Locations in which the locking grooves4442and the locking projections4433are formed may be interchangeable with each other.

The light source module4450may include a light source array. The light source module4450may include a printed circuit board4451, a light source4452, and a controller4453. The light source4452used in this case may be a semiconductor light-emitting device according to the previously described example embodiment. As described above, the controller4453may store driving information of the light source4452. Circuit wiring for operating the light source4452may be formed in the printed circuit board4451. In addition, the light source module4450may include configuration elements for operating the light source4452.

The first and second sockets4460and4470as a pair of sockets may have a structure of being coupled to both ends of a cylindrical cover unit configured of the heat-radiating member4410and the cover4441. For example, the first socket4460may include an electrode terminal4461and a power device4462, and a dummy terminal4471may be disposed on the second socket4470. In addition, an optical sensor and/or a communications module may be provided in either of the first socket4460or the second socket4470. For example, an optical sensor and/or a communications module may be provided in the second socket4470in which the dummy terminal4471is provided. As another example, an optical sensor and/or a communications module may be provided in the first socket4460in which the electrode terminal4461is disposed.

As set forth above, according to various example embodiments, re-incident light in the semiconductor LED chip may be reduced to decrease light loss due to total internal reflection by disposing a side surface inclined portion on the side of the semiconductor LED chip to form an inclined surface on the side surface of the semiconductor LED chip. Furthermore, light extraction efficiency may be additionally increased by including a wavelength conversion material or light dispersing material to the side surface inclined portion, and in detail, color deviation may be improved.