Source: http://www.patentsencyclopedia.com/app/20120193604
Timestamp: 2016-09-29 10:55:17
Document Index: 275147854

Matched Legal Cases: ['art 110', 'art 120', 'art\n110', 'art 130', 'art 130', 'art 130', 'art 110', 'art 150', 'art 150', 'art 120', 'art 120', 'art 120', 'art\n210', 'art 220', 'art 230', 'art 250', 'art 220', 'art 310', 'art 320', 'art 330', 'art 350', 'art 350', 'art 410', 'art 420', 'art 430', 'art\n450', 'art 450']

Jae Il Kim (Seoul, KR)
Bae Kyun Kim (Seongnam, KR)
Dong Hyun Cho (Gimhae, KR)
Kyoung Soon Park (Suwon, KR)
In Hyung Lee (Seoul, KR)
Patent application number: 20120193604
Provided is a wavelength conversion plate having excellent luminous
efficiency of a wavelength-converted light. The wavelength conversion
plate includes a dielectric layer with nano pattern, a metal layer formed
inside the nano pattern, and a wavelength conversion layer formed on the
metal layer and having quantum dot or phosphor which wavelength-converts
an excitation light to generate a wavelength-converted light.Claims:
16. A wavelength conversion plate comprising: a dielectric layer having a
planar upper surface and a nano pattern formed in a cylindrical shape
with a curved bottom, wherein the nano pattern comprises a plurality of
nano scale grooves; a metal layer formed on an inside wall of the nano
scale grooves of the nano pattern; and a wavelength conversion layer
formed on the metal layer and comprising quantum dots or phosphors which
wave length-convert excited light to generate wavelength-converted light.
17. The wavelength conversion plate of claim 16, wherein the dielectric
layer comprises a polymer resin or a metal oxide.
18. The wavelength conversion plate of claim 17, wherein the polymer
resin comprises poly methyl methacrylate (PMMA), poly lauryl methacrylate
(PLMA), or polystyrene.
19. The wavelength conversion plate of claim 17, wherein the metal oxide
comprises SiO2 or TiO.sub.2.
20. The wavelength conversion plate of claim 16, wherein the metal layer
comprises any one of Au, Ag, Al, Cu, Pt, Pd, and alloys thereof.
21. The wavelength conversion plate of claim 16, wherein the quantum dot
comprises any one of an Si nanocrystal, a group II-VI compound
semiconductor nanocrystal, a group III-V compound semiconductor
nanocrystal, a group IV-VI compound semiconductor nanocrystal, and
compounds thereof.
22. The wavelength conversion plate of claim 21, wherein the group II-VI
compound semiconductor nanocrystal comprises any one material selected
from the group consisting of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe,
HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe,
CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe,
CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS,
HgZnSeTe, and HgZnSTe.
23. The wavelength conversion plate of claim 21, wherein the group III-V
from the group consisting of GaN, GaP, GaAs, AlN, AlP, AlAs, InN, InP,
InAs, GaNP, GaNAa, GaPAs, AlNP, AlNAs, AlPAs, InNP, InNAs, InPAs, GaAlP,
GaAlNAs, GaAIPAs, GaInNP, GaInAs, GaInPAs, InAlNP, InAlNAs, and InAlPAs.
24. The wavelength conversion plate of claim 21, wherein the group IV-VI
compound semiconductor nanocrystal comprises SbTe.
25. The wavelength conversion plate of claim 16, wherein the dielectric
layer is formed by using an Anodic Aluminum Oxide template.
26. A method of manufacturing a wavelength conversion plate comprising:
forming a nano pattern in a dielectric layer, wherein the nano pattern
comprises a plurality of nano scale grooves and is formed in a
cylindrical shape with a curved bottom; forming a metal layer on an
inside wall of the nano scale grooves of the nano pattern; and forming a
wavelength conversion layer comprising quantum dots or phosphors which
wave length-convert excited to generate wave length-converted light, on
27. The method of claim 26, wherein the dielectric layer comprises a
polymer resin or a metal oxide.
28. The method of claim 27, wherein the polymer resin comprises poly
methyl methacrylate (PMMA), poly lauryl methacrylate (PLMA), or
29. The method of claim 27, wherein the metal oxide comprises SiO2
or TiO.sub.2.
30. The method of claim 26, wherein the metal layer comprises any one of
Au, Ag, Al, Cu, Pt, Pd, and alloys thereof.
31. The method of claim 26, wherein the quantum dot comprises any one of
an Si nanocrystal, a group II-VI compound semiconductor nanocrystal, a
group III-V compound semiconductor nanocrystal, a group IV-VI compound
semiconductor nanocrystal, and compounds thereof.
32. The method of claim 31, wherein the group II-VI compound
semiconductor nanocrystal comprises any one material selected from the
group consisting of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe,
CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS,
CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS,
CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and
HgZnSTe.
33. The method of claim 31, wherein the group III-V compound
group consisting of GaN, GaP, GaAs, AlN, AlP, AlAs, InN, InP, InAs, GaNP,
GaNAa, GaPAs, AlNP, AlNAs, AlPAs, InNP, InNAs, InPAs, GaAlP, GaAlNAs,
GaAIPAs, GaInNP, GaInAs, GaInPAs, InAlNP, InAlNAs, and InAlPAs.
34. The method of claim 31, wherein the group IV-VI compound
semiconductor nanocrystal comprises SbTe.
35. The method of claim 26, wherein the dielectric layer is formed by
using an Anodic Aluminum Oxide template.Description:
No. 2008-0086983 filed on Sep. 3, 2008, in the Korean Intellectual
[0003] The present invention relates to a light emitting device and a
method for manufacturing the same, and more particularly, to a wavelength
conversion plate having excellent luminous efficiency of a
wavelength-converted light, and a light emitting device using the same.
[0005] Light emitting diode (LED) is characterized in that it emits light
substantially identical to monochromatic light, while light from other
light emitting devices such as an incandescent lamp has a wide light
emission spectrum. Since LEDs have different energies according to their
electron-hole recombination, they emit a red light, a green light, a blue
light, a reddish yellow light, or a yellow light according to their
[0006] Recently, there have been developed LEDs which can emit a white
light or reproduce a plurality of colors. A white LED is manufactured by
combination of several color LED chips, or combination of LED chips
emitting specific color light and phosphors emitting specific color
fluorescence. The currently commercialized white LED generally employs
[0007] For example, a white LED package can be obtained by encapsulating a
blue LED chip with a molding resin where a yellow phosphor is dispersed.
If light having a wavelength of 460 nm is generated from the blue LED
chip, the yellow phosphor absorbs the light and generates light having a
wavelength of 545 nm. The two lights having the different wavelengths are
mixed to output a white light. Therefore, a desired color light can be
obtained by combining different kinds of phosphors.
[0008] Although the desired color can be obtained using the phosphors, the
increase of the luminous efficiency is still required in view of the
emission of the LED.
[0009] An aspect of the present invention provides a wavelength conversion
plate having excellent luminous efficiency of a wavelength-converted
light, and a light emitting device using the same.
a wavelength conversion plate including: a dielectric layer with nano
pattern; a metal layer formed inside the nano pattern; and a wavelength
conversion layer formed on the metal layer and comprising quantum dot or
phosphor which wavelength-converts an excitation light to generate a
wavelength-converted light.
[0011] The dielectric layer may include polymer resin or metal oxide. The
polymer resin may include poly methyl methacrylate (PMMA), poly lauryl
methacrylate (PLMA), or polystyrene. The metal oxide may include
SiO2 or TiO2. The metal layer may include any one of Au, Ag,
Al, Cu, Pt, Pd, and alloy thereof.
[0012] The quantum dot may include any one of Si nanocrystal, group II-VI
compound semiconductor nanocrystal, group III-V compound semiconductor
nanocrystal, group IV-VI compound semiconductor nanocrystal, and
compounds thereof. The group II-VI compound semiconductor nanocrystal may
include any one material selected from the group consisting of CdS, CdSe,
CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS,
ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS,
CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe,
CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The group
III-V compound semiconductor nanocrystal may include any one material
selected from the group consisting of GaN, GaP, GaAs, AlN, AlP, AlAs,
InN, InP, InAs, GaNP, GaNAa, GaPAs, AlNP, AlNAs, AlPAs, InNP, InNAs,
InPAs, GaAlP, GaAlNAs, GaAlPAs, GaInNP, GaInAs, GaInPAs, InAlNP, InAlNAs,
and InAlPAs. The group IV-VI compound semiconductor nanocrystal may
include SbTe.
provided a light emitting device including: a light emitting element; a
groove part having a bottom surface where the light emitting element is
mounted, and aside surface where a reflection part is formed; a support
part supporting the groove part and having an electrode part electrically
connected to the light emitting element; and a wavelength conversion
plate disposed in at least one of the bottom surface and the side surface
of the groove part, wherein the wavelength conversion plate includes: a
dielectric layer with nano pattern; a metal layer formed inside the nano
pattern; and a wavelength conversion layer formed on the metal layer and
comprising quantum dot or phosphor which wavelength-converts an
excitation light to generate a wavelength-converted light.
[0014] The light emitting device may further include a wavelength
conversion unit disposed on the light emitting element and having quantum
dot or phosphor which wavelength-converts light from the light emitting
element. The wavelength conversion unit may be implemented with a
plurality of layers. In this case, the wavelength conversion unit may be
formed inside the groove part where the light emitting element is
[0015] When the wavelength conversion unit is implemented with a plurality
of layers, at least two wavelength conversion units among the plurality
of wavelength conversion units may include quantum dots or phosphors
which convert the light emitted from the light emitting element into
light having different wavelengths. Therefore, the light emitting element
may emit an infrared light; the wavelength conversion plate may emit a
blue light; a first wavelength conversion unit among the plurality of
wavelength conversion units may emit a red light; and a second wavelength
conversion unit different from the first wavelength conversion unit among
the plurality of wavelength conversion units may emit a green light. In
this way, the light emitting device can emit a white light.
[0016] The above and other aspects, features and other advantages of the
[0017] FIG. 1 illustrates a wavelength conversion plate according to an
[0018] FIG. 2 illustrates a light emitting device including the wavelength
conversion plate according to an embodiment of the present invention;
[0019] FIG. 3 illustrates a light emitting device including the wavelength
conversion plate on the bottom surface of a groove part according to
[0020] FIG. 4 illustrates a light emitting device further including a
wavelength conversion unit according to another embodiment of the present
[0021] FIG. 5 illustrates a light emitting device further including a
plurality of wavelength conversion units according to another embodiment
[0022] Exemplary embodiments of the present invention will now be
thorough and complete and will fully convey the concept of the invention
to those skilled in the art. In the drawings, the thicknesses of layers
and regions are exaggerated for clarity.
[0023] FIG. 1 illustrates a wavelength conversion plate according to an
embodiment of the present invention. The wavelength conversion plate 10
according to the embodiment of the present invention includes a
dielectric layer 11 with nano pattern 12, a metal layer 13 formed inside
the nano pattern 12, and a wavelength conversion layer 14 formed on the
metal layer 13 and having quantum dot or phosphor wavelength-converting
an excitation light to generate a wavelength-converted light.
[0024] Since the wavelength conversion plate 10 according to the
embodiment of the present invention includes the dielectric layer 11 with
the nano pattern 12 and the film-type metal layer 13 inside the nano
pattern 12, that is, the patterned metal layer 13, incident light is
amplified by surface plasmon phenomenon generated at an interface of the
dielectric layer 11 and the metal layer 13.
[0025] The surface plasmon phenomenon is a collective charge density
oscillation generated at the surface of the metal film, and a surface
plasmon wave generated by the collective charge density oscillation is a
surface electromagnetic wave which propagates along the interface of the
metal and the dielectric. Such a phenomenon is generated in metals, such
as gold (Au), silver (Ag), copper (Cu) or aluminum (Al), which are easily
subject to emission of electrons by external stimulation and have a
negative dielectric constant. Among those metals, silver (Ag) exhibiting
the sharpest surface plasmon resonance (SPR) peak and gold (Au)
exhibiting excellent surface stability are usually used.
[0026] The excitation of the surface Plasmon refers to the phenomenon
that, when an electric field is applied from the outside to the interface
of two media (i.e., metal and dielectric) having a different dielectric
constant, surface charges are induced because of the discontinuity of
vertical components of the electric field at the interface of the two
media, and oscillation of those surface charges is exhibited as the
surface plasmon wave.
[0027] Recently, the emission increase phenomenon derived from the surface
plasmon phenomenon has been reported (Nano Letters, Vol. 5, No. 8,
1557-1561, 2005). According to this document, after patterning a polymer
resin with constant sizes and intervals, an Ag layer was formed and a
visible ray was irradiated thereon. In this case, the luminous efficiency
was rapidly increased more than 10 times.
[0028] In the wavelength conversion plate 10 according to the embodiment
of the present invention, if the quantum dot or phosphor included in the
wavelength conversion layer 14 wavelength-converts the excitation light,
the surface plasmon phenomenon is generated in the metal layer 13 and
thus the wavelength-converted light is amplified.
[0029] The dielectric layer 11 may include a material having a different
dielectric function from the metal layer 13 in order to generate the
surface plasmon phenomenon in the metal layer 13. For example, the
dielectric layer 11 may include polymer resin or metal oxide. The polymer
resin used herein may be, but is not limited to, poly methyl methacrylate
(PMMA), poly lauryl methacrylate (PLMA), or polystyrene. Also, the metal
oxide used herein may be, but is not limited to, SiO2 or TiO2.
[0030] The nano pattern 12 is formed in the dielectric layer 11. Referring
to FIG. 1, the nano pattern 12 may be formed in a cylindrical shape with
a curved bottom. However, there is no special limitation in the shape of
the nano pattern 12 only if the pattern itself is nano-sized.
[0031] As a method of forming the nano pattern 12 in the dielectric layer
11, an Anodic Aluminum Oxide template (AAO template) formed by oxidizing
aluminum may be used. In the method using the AAO template, aluminum is
used because of its unique characteristic in that aluminum forms a pore
arrangement in itself in an oxidation process for forming aluminum oxide.
In this case, the pore is several ten to several hundred nanometers in
diameter and is several micrometers in length according to voltage and
concentration of an acid solution in the aluminum oxidation process.
[0032] Therefore, if the dielectric layer is formed and its upper surface
is etched using the AAO template, the nano pattern 12 is formed in the
same shape as the pore formed in the AAO template.
[0033] The metal layer 13 patterned along the pattern inside the nano
pattern 12 is formed on the dielectric layer 11. As described above, the
metal layer 13 may be formed using a metal where the surface Plasmon
phenomenon is easily generated, that is, a metal which is easily subject
to emission of electrons by external stimulation and has a negative
dielectric constant. The metal may include, but is not limited to, Au,
Ag, Al, Cu, Pt, or Pd. There are many methods of forming the metal layer
13. As one method, the metal layer 13 may be formed by sputtering a metal
onto the dielectric layer 11 where the nano pattern 12 is formed.
[0034] The wavelength conversion layer 14 is formed on the metal layer 13.
The wavelength conversion layer 14 includes quantum dot or phosphor which
wavelength-converts the excitation light to generate the
wavelength-converted light. The wavelength conversion layer 14 is formed
while filling the inside of the pattern of the metal layer 13.
[0035] The quantum dot is a nano-sized light emitting body which has a
diameter of 10 nm or less and exhibits a quantum confinement effect. The
quantum dot generates stronger light than a typical phosphor in a narrow
wavelength. The emission of the quantum dot is generated when excited
electrons move from a conduction band to a valence band. Even the same
material exhibits different wavelengths according to the particle size.
As the size of the quantum dot is smaller, light having a shorter
wavelength is emitted. Thus, light having a desired wavelength range can
be obtained by adjusting the size of the quantum dot.
[0036] The quantum dot emits light even at an arbitrary excitation
wavelength. Thus, when several kinds of quantum dots exist, several color
light can be observed at a time even though the quantum dot is excited at
a single wavelength. Furthermore, since the quantum dot moves from the
ground oscillation state of the conduction band to the ground oscillation
state of the valence band, it is advantageous that the emission
wavelength is almost the monochromatic light.
[0037] The quantum dot may be a semiconductor nanocrystal. Examples of the
quantum dot may include Si nanocrystal, group II-VI compound
semiconductor nanocrystal, group III-V compound semiconductor
nanocrystal, or group IV-VI compound semiconductor nanocrystal. In the
current embodiment, the quantum dots may be used solely or in mixture
[0038] The group II-VI compound semiconductor nanocrystal may include, but
is not limited to, CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe,
CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, or
[0039] Furthermore, the group III-V compound semiconductor nanocrystal may
include, but is not limited to, GaN, GaP, GaAs, AlN, AlP, AlAs, InN, InP,
GaAlNAs, GaAlPAs, GaInNP, GaInAs, GaInPAs, InAlNP, InAlNAs, or InAlPAs.
[0040] Moreover, the group IV-VI compound semiconductor nanocrystal may
include, but is not limited to, SbTe.
[0041] As a method of synthesizing the nanocrystal as the quantum dot, the
quantum dot is formed by a vapor deposition method, such as a metal
organic chemical vapor deposition (MOCVD) or a molecular beam epitaxy
(MBE), or a chemical wet method of growing a crystal by putting a
precursor material into an organic solvent.
[0042] The phosphor may be selected from an oxide phosphor, a sulfide
phosphor, and a nitride phosphor according to the conversion wavelength.
For example, the phosphor may include a yellow emission phosphor based on
β-SiAlON:Eu,Re, a silicate-based green emission phosphor such as
(Ba,Sr,Ca,Mg)2SiO4:Eu,Re, or a sulfide-based green emission
phosphor such as (Ba,Sr,Ca,Mg) (Ga,Al,In)2(S,Se,Te)4:Eu,Re, a
nitride-based red emission phosphor such as
(Sr,Ca,Ba,Mg)AlSiNx:Eu,Re (1≦x≦5), or a sulfide-based
red emission phosphor such as (Sr,Ca,Ba,Mg) (S,Se,Te):Eu,Re. Herein, Re
may be any one of Nd, Pm, Sm, Tb, Dy, Ho, Er, Tm, Yb, F, Cl, Br, and I.
[0043] The wavelength conversion layer 14 may be used by dispersing the
quantum dot in a dispersive medium. The dispersive medium may be a resin
such as epoxy resin or silicon. The wavelength conversion layer 14 may be
formed by dispersing the quantum dot or phosphor in the dispersive medium
and coating the dispersive medium on the metal layer 13. The wavelength
conversion performance of the wavelength conversion layer 14 may be
selected by adjusting the concentration of the quantum dot or phosphor
dispersed in the dispersive medium.
[0044] In the wavelength conversion plate 10, the quantum dot or phosphor
included in the wavelength conversion layer 14 absorbs the incident light
and emits the wavelength-converted light. Thus, in addition to the
wavelength conversion function, the wavelength conversion plate 10 can
amplify the emission of the wavelength-converted light due to the surface
plasmon phenomenon generated in the metal layer 13 formed inside the nano
[0045] Therefore, the wavelength conversion plate 10 can be variously used
when it is necessary to receive an excitation light from a light source,
wavelength-convert the received excitation light and then amplify the
wavelength-converted light. For example, the wavelength conversion plate
10 may be used as a reflection plate of a light guide panel in an LED
package or backlight unit, but it is not limited thereto. Hereinafter, a
light emitting device using the wavelength conversion plate 10 will be
described in detail with reference to FIGS. 2 to 5.
[0046] FIG. 2 illustrates a light emitting device including a wavelength
conversion plate according to an embodiment of the present invention.
Herein, duplicate description about the dielectric layer, the nano
pattern, the metal layer, and the wavelength conversion layer in the
light emitting device 100 of FIG. 2 will be omitted, except when
[0047] The light emitting device 100 according to the embodiment of the
present invention includes a light emitting element 140, a groove part, a
support part 110, and a wavelength conversion plate 160. The groove part
has a bottom surface where the light emitting element 140 is mounted, and
a side surface where a reflection part 120 is formed. The support part
110 supports the groove part and includes an electrode part 130
electrically connected to the light emitting element 140. The wavelength
conversion plate 160 is disposed in at least one of the bottom surface
and the side surface of the groove part. The wavelength conversion plate
160 includes a dielectric layer with nano pattern, a metal layer formed
metal layer and including quantum dot or phosphor which
wavelength-converts an excitation light to generate a
wavelength-converted light. The electrode part 130 is formed with two
sections which are electrically separated.
[0048] The light emitting element 140 may be one of a light emitting diode
and a laser diode. A blue LED may be used as the light emitting element
140. The blue LED may be a GaN-based LED emitting a blue light of 420-480
nm. The electrode part 130 is formed on the support part 110 and is
electrically connected to the light emitting element 140 through a wire.
[0049] An encapsulation part 150 is formed of an encapsulation material on
the light emitting element 140 in order to encapsulate the light emitting
element 140. The encapsulation part 150 is formed by filling the groove
part with an encapsulation material, such as epoxy, silicon, acryl-based
polymer, glass, carbonate-based polymer, or a mixture thereof.
[0050] The reflection part 120 formed in the side surface of the groove
part reflects light generated from the light emitting element 140 toward
the outside of the groove part. In FIG. 2, the wavelength conversion
plate 160 is formed in the reflection part 120.
[0051] The wavelength conversion plate 160 includes the dielectric layer
with the nano pattern, the metal layer formed on the dielectric layer,
and the wavelength conversion layer formed on the metal layer and
including the quantum dot or phosphor which wavelength-converts the light
generated from the light emitting element 140 to generate the
wavelength-converted light. As described above with reference to FIG. 1,
the wavelength conversion layer may be used by dispersing the quantum dot
or phosphor in the dispersive medium. Since the dispersive medium may be
a resin such as epoxy resin or silicon, it may be an identical or similar
material to the encapsulation material.
[0052] Since the wavelength conversion plate 160 wavelength-converts and
amplifies the light from the light emitting element 140, the quantum dot
or phosphor inside the wavelength conversion plate 160 may be selected
considering color and intensity of light desired to be obtained from the
light emitting device 100. For example, when the light emitting element
140 emits a blue light, the light emitting device 100 can emit a white
color by selecting the quantum dot or phosphor inside the wavelength
conversion plate 160 such that it emits a yellow color.
[0053] Although the wavelength conversion plate 160 shown in FIG. 2 is
disposed at the reflection part 120 located on the side surface of the
groove part, it can also be disposed on the bottom surface of the groove
part. FIG. 3 illustrates a light emitting device according to another
embodiment of the present invention, in which a wavelength conversion
plate is disposed on a bottom surface of a groove part. Regarding a
dielectric layer, a nano pattern, a metal layer, and a wavelength
conversion layer in the light emitting device 200 of FIG. 3, the
description of the same parts as described with reference to FIGS. 1 and
2 will be omitted, except when necessary. Also, regarding a support part
210, a reflection part 220, an electrode part 230, a light emitting
element 240, an encapsulation part 250, and a wavelength conversion plate
260, the description of the same parts as described with reference to
FIG. 2 will be omitted.
[0054] Unlike in FIG. 2, the wavelength conversion plate 260 is disposed
on the bottom surface of the groove part where the light emitting element
240 is mounted. The wavelength conversion plate 260 is formed in a region
other than the region where the light emitting element 240 is formed. The
case where the wavelength conversion plate 260 is formed on the bottom
surface of the groove part is related to the shape of the light emitting
device 200. In order for the wavelength conversion plate 260 to
effectively wavelength-convert and amplify the light from the light
emitting element 240, the quantity of light reaching the wavelength
conversion plate 260 should be large. However, if the width of the light
emitting device 200 is wide, the case where the excitation light reaches
the bottom surface may be much more than the case where the excitation
light reaches the reflection part 220. Therefore, in such a case, the
wavelength conversion plate 260 is formed on the bottom surface of the
groove part.
[0055] According to another embodiment of the present invention, in
addition to the wavelength conversion plate formed in at least one of the
side surface and the bottom surface of the groove part, a light emitting
device further includes a wavelength conversion unit which
wavelength-converts light from the light emitting element. FIG. 4
illustrates the light emitting device which further includes the wave
conversion unit according to the embodiment of the present invention.
Regarding a dielectric layer, a nano pattern, a metal layer, and a
wavelength conversion layer in the light emitting device 300 of FIG. 4,
the description of the same parts as described with reference to FIGS. 1
to 3 will be omitted, except when necessary. Also, regarding a support
part 310, a reflection part 320, an electrode part 330, a light emitting
element 340, an encapsulation part 350, and a wavelength conversion plate
360, the description of the same parts as described with reference to
FIGS. 2 and 3 will be omitted.
[0056] In the current embodiment, the wavelength conversion unit 370
further included in the light emitting device 300 includes a wavelength
conversion body 371 and a dispersive medium 372. The wavelength
conversion body 371 may be a typical quantum dot or phosphor. The
dispersive medium 372 may be a medium which properly disperses polymer
resin and the wavelength conversion body 371. The dispersive medium 372
may be an identical or similar material to an encapsulation material of
the encapsulation part 350.
[0057] After mounting the light emitting element 340, the wavelength
conversion unit 370 may be formed on the light emitting element 340
before the groove part is filled with the encapsulation material 350. The
wavelength conversion unit 370 can include an appropriate quantum dot or
phosphor according to the wavelength of light desired to be obtained from
the light emitting device 300, the color of the light emitted from the
light emitting device 300 can be controlled together with the quantum dot
or phosphor included in the wavelength conversion plate 360. Although the
wavelength conversion unit 370 shown in FIG. 4 is formed in a layer type,
it can also be formed to cover the surface of the light emitting device
340. Also, the wavelength conversion unit 370 may be disposed in any
shape only if the light incident from the light emitting element 340 can
be wavelength-converted at the wavelength conversion unit 370.
[0058] At this point, the light emitting device 300 can emit a white
light, when the light emitting element 340 emits a blue light, the
quantum dot or phosphor of the wavelength conversion unit 370 emits a red
light, and the quantum dot or phosphor of the wavelength conversion plate
360 emits a green light. Furthermore, the light emitting element 340 can
be made to emit a blue light, and the quantum dot or phosphor of the
wavelength conversion unit 370 can be made to emit a yellow light. In
this case, the quantum dot of the wavelength conversion plate 360 can be
selected to emit a blue light or a yellow light. The color rendering of
the light emitted from the light emitting device 300 can be controlled by
making the quantum dot of the wavelength conversion plate 360 emit the
light having the lower intensity of the blue light and the yellow light.
[0059] According to another embodiment of the present invention, a light
emitting device may further include a plurality of wavelength conversion
units. FIG. 5 illustrates the light emitting device which further
includes the plurality of wave conversion units according to the
embodiment of the present invention. Regarding a dielectric layer, a nano
pattern, a metal layer, and a wavelength conversion layer in the light
emitting device 400 of FIG. 5, the description of the same parts as
described with reference to FIGS. 1 to 4 will be omitted, except when
necessary. Also, regarding a support part 410, a reflection part 420, an
electrode part 430, a light emitting element 440, an encapsulation part
450, and a wavelength conversion plate 460, the description of the same
parts as described with reference to FIGS. 2 and 4 will be omitted.
[0060] In the current embodiment, the wavelength conversion units further
included in the light emitting device 400 include a first wavelength
conversion unit 470 and a second wavelength conversion unit 480. In FIG.
5, a wavelength conversion unit nearer to the light emitting element 440
is referred to as the first wavelength conversion unit 470, and another
is referred to as the second wavelength conversion unit 480. The first
wavelength conversion unit 470 includes a first wavelength conversion
body 471 and a first dispersive medium 472, and the second wavelength
conversion unit 480 includes a second wavelength conversion body 481 and
a second dispersive medium 482. The first and second wavelength
conversion bodies 471 and 481 may be typical quantum dots or phosphors.
The first and second dispersive media 472 and 482 may be media which
properly disperse polymer resin and the first and second wavelength
conversion bodies 471 and 481. The first and second dispersive media 472
and 482 may be an identical or similar material to an encapsulation
material of the encapsulation part 450.
[0061] When the wavelength conversion unit is implemented with a plurality
of layers, at least two wavelength conversion units may include quantum
dots or phosphors which can convert the light emitted from the light
emitting element into light having different wavelengths. Therefore, the
light emitting element 440 emits a blue light, any one of the wavelength
conversion units emits a red light, and the second wavelength conversion
unit 480 different from the first wavelength conversion unit emits a
green light. In this way, the light emitting device can emit a white
light. Furthermore, the wavelength conversion plate 460 can select
quantum dots to emit light by appropriately selecting the wavelength of
the light required to be amplified among the blue light, the red light,
and the green light.
[0062] Alternatively, the light emitting device can emit a white light,
when the light emitting element 440 emits an infrared ray, and the
wavelength conversion plate 460, the first wavelength conversion unit 470
and the second wavelength conversion unit 480 emit a blue light, a green
light and a red light, respectively.
[0063] The light emitting devices are shown in a package type in FIGS. 2
to 5, but they are not limited thereto. For example, the light emitting
devices may be lamp-type light emitting devices.
[0064] The wavelength conversion plates according to the embodiments of
the present invention can use the surface plasmon phenomenon by forming
the metal layer on the dielectric layer with the nano pattern. Therefore,
the wavelength-converted light generated by the wavelength conversion of
the excitation light at the quantum dot, or the light emitted from the
light emitting source can be amplified by the surface plasmon phenomenon.
[0065] Furthermore, if the wavelength conversion plate capable of
amplifying the light by using the surface plasmon phenomenon is used on
the side surface of the light emitting package, the luminous efficiency
of the light emitting package can be increased. In addition, if the
wavelength conversion plate is used as the reflection plate or wavelength
conversion plate of the light emitting source, the light of the light
emitting source can be amplified. Thus, the light emitting device having
excellent efficiency can be manufactured.
[0066] While the present invention has been shown and described in
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