Light-emitting device and display device including the same

Abstract

Provided is a light-emitting device, comprising: a first metal reflective layer including a phase modulation surface configured to cause incident light to undergo magnetic resonance; a color conversion layer disposed on the phase modulation surface of the first metal reflective layer and including a photoluminescent material; a first electrode disposed on the color conversion layer opposite to the first metal reflective layer; a white organic light-emitting layer disposed on the first electrode opposite to the color conversion layer; and a second electrode disposed on the white organic light-emitting layer opposite to the first electrode.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority from Korean Patent Application No. 10-2019-0073149 filed on June 19, 2019, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. Technical Field

[0003] Example embodiments of the present disclosure relate to a light emitting device and a display apparatus including the same. Background Art

[0004] Organic light-emitting devices (OLEDs) are configured to emit light of a specific color when holes provided from an anode and electrons provided from a cathode combine with each other in an organic light-emitting layer. Display devices using such OLEDs can have characteristics such as a wide viewing angle, a high response speed, a small thickness, a low manufacturing cost, and a high contrast ratio. Recently, OLEDs and display devices configured to emit light of a desired color by using the microcavity effect have been developed. Summary of the Invention

[0005] One or more example embodiments provide a light emitting device and a display apparatus including the same.

[0006] According to one aspect of the present disclosure, a light-emitting device is provided, comprising: a first metal reflective layer including a phase modulation surface configured to cause incident light to undergo magnetic resonance; a color conversion layer disposed on the phase modulation surface of the first metal reflective layer and including a photoluminescent material; a first electrode disposed on the color conversion layer opposite to the first metal reflective layer; a white organic light-emitting layer disposed on the first electrode opposite to the color conversion layer; and a second electrode disposed on the white organic light-emitting layer opposite to the first electrode.

[0007] The first metal reflective layer and the second electrode may form a microcavity having a resonant wavelength.

[0008] The phase modulation surface may include a metastructure in which nanopatterns are periodically arranged.

[0009] The color conversion layer may further include a dielectric in which the photoluminescent material is dispersed.

[0010] The photoluminescent material may include a green photoluminescent material configured to convert blue light into green light or a red photoluminescent material configured to convert blue light and green light into red light, respectively.

[0011] The color conversion layer may cover the phase modulation surface of the first metal reflective layer.

[0012] The light emitting device may further include a transparent planarization layer disposed between the first metal reflective layer and the color conversion layer and covering the phase modulation surface of the first metal reflective layer.

[0013] The first electrode may include a transparent electrode, and the second electrode may include a semi-transparent electrode configured to transmit a portion of light incident on the second electrode and reflect the rest of the light incident on the second electrode.

[0014] The first electrode may include a transparent electrode and the second electrode may include a reflective electrode, and the first metal reflective layer may be a semitransparent layer configured to transmit a portion of light incident on the first metal reflective layer and reflect the rest of the light incident on the first metal reflective layer.

[0015] The light emitting device may further include: a second metal reflective layer disposed on the second electrode and including a phase modulation surface; and a planarization layer disposed between the second electrode and the second metal reflective layer and covering the phase modulation surface of the second metal reflective layer.

[0016] The first metal reflective layer and the second metal reflective layer may form a microcavity having a resonant wavelength.

[0017] The first electrode and the second electrode may respectively include transparent electrodes, and one of the first metal reflective layer and the second metal reflective layer may be configured to reflect light, and the other of the first metal reflective layer and the second metal reflective layer may be translucent and configured to transmit a portion of the light and reflect the rest of the light.

[0018] According to another aspect of an example embodiment, there is provided a display device including: a plurality of pixels configured to emit light having a plurality of colors, wherein at least one of the plurality of pixels includes: a first metal reflective layer including a phase modulation surface configured to cause light incident on the first metal reflective layer to magnetically resonate; a color conversion layer disposed on the phase modulation surface of the first metal reflective layer and including a photoluminescent material; a first electrode disposed on the color conversion layer opposite to the first metal reflective layer; a white organic light emitting layer disposed on the first electrode opposite to the color conversion layer; and a second electrode disposed on the white organic light emitting layer opposite to the first electrode.

[0019] The phase modulation surface may include a metastructure in which nanopatterns are periodically arranged.

[0020] The color conversion layer may also include a dielectric in which the photoluminescent material is dispersed.

[0021] The color conversion layer may cover the phase modulation surface of the first metal reflective layer.

[0022] The at least one pixel among the plurality of pixels may further include a transparent planarization layer disposed between the first metal reflective layer and the color conversion layer and covering a phase modulation surface of the first metal reflective layer.

[0023] The at least one pixel among the plurality of pixels may further include: a second metal reflective layer disposed on the second electrode and including a phase modulation surface; and a planarization layer disposed between the second electrode and the second metal reflective layer and covering the phase modulation surface of the second metal reflective layer.

[0024] The plurality of pixels may include blue pixels, green pixels, and red pixels.

[0025] The photoluminescent material included in the green pixel may include a green photoluminescent material configured to convert blue light into green light, and the photoluminescent material included in the red pixel may include a red photoluminescent material configured to convert blue light and green light into red light, respectively.

[0026] According to another aspect of the example embodiments, there is provided a light emitting device including: a first electrode; a second electrode; a light emitting layer disposed between the first electrode and the second electrode and configured to emit white light; a metal reflective layer disposed on the first electrode opposite to the light emitting layer, the metal reflective layer including a phase modulation surface configured to resonate a specific wavelength of the white light emitted from the light emitting layer; and a color conversion layer disposed between the first electrode and the metal reflective layer, the color conversion layer configured to convert a portion of the white light into light having a specific wavelength.

[0027] The metal reflective layer may include at least one of silver (Ag), aluminum (Al), and gold (Au).

[0028] The phase modulation surface may include a metastructure in which nanopatterns are periodically arranged.

[0029] Each nano-pattern may have a cylindrical shape or a polygonal column shape.

[0030] Each of the nano-patterns may have a width of 50 nm to 300 nm.

[0031] The nano-patterns may be arranged at a pitch of 100 nm to 400 nm, which is a distance between adjacent nano-patterns.

[0032] The color conversion layer may include a dielectric in which the photoluminescent material is dispersed.

[0033] The photoluminescent material may include at least one of quantum dots, organic fluorescent dyes, organic fluorescent semiconductors, and organic phosphorescent semiconductors.

[0034] The photoluminescent material may include a green photoluminescent material configured to convert blue light into green light or a red photoluminescent material configured to convert blue light and green light into red light, respectively.

[0035] The color conversion layer may cover the phase modulation surface of the metallic reflective layer.

[0036] The light emitting device may further include a transparent planarization layer disposed between the metal reflective layer and the color conversion layer and covering the phase modulation surface of the metal reflective layer.

[0037] The first electrode may include a transparent electrode, and the second electrode may include a semi-transparent electrode configured to transmit a portion of light incident on the second electrode and reflect the rest of the light incident on the second electrode.

[0038] The first electrode may be a transparent electrode and the second electrode may be a reflective electrode, and the first metal reflective layer may be a semitransparent layer configured to transmit a portion of light incident on the metal reflective layer and reflect the rest of the light incident on the metal reflective layer.

[0039] According to another aspect of the example embodiments, a light emitting device is provided, the light emitting device including: a metal reflective layer including a phase modulation surface configured to cause incident light to magnetically resonate, the phase modulation surface including a plurality of nanopatterns; a color conversion layer disposed on the phase modulation surface of the first metal reflective layer, the color conversion layer including a dielectric and a photoluminescent material; a first electrode disposed on the color conversion layer opposite to the first metal reflective layer; a white organic light emitting layer disposed on the first electrode opposite to the color conversion layer; and a second electrode disposed on the white organic light emitting layer opposite to the first electrode.

[0040] The color conversion layer may cover the phase modulation surface of the metallic reflective layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and other aspects, features and advantages of example embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0042] Figure 1 is a cross-sectional view showing a light emitting device according to an example embodiment;

[0043] Figure 2 It shows Figure 1 A perspective view of the metal reflective layer shown in FIG.

[0044] Figure 3 yes Figure 2 A cross-sectional view of the metal reflective layer shown in ;

[0045] Figure 4 It shows that it can be applied to Figure 1A view of a modified example of the metal reflective layer of the light emitting device shown in FIG;

[0046] Figure 5 It shows that it can be applied to Figure 1 A view of another modified example of the metal reflective layer of the light emitting device shown in FIG;

[0047] Figure 6 It shows that it can be applied to Figure 1 A view of another modified example of the metal reflective layer of the light emitting device shown in FIG;

[0048] Figure 7 It shows that it can be applied to Figure 1 A view of another modified example of the metal reflective layer of the light emitting device shown in FIG;

[0049] Figure 8A is a view showing an experimental model of a metal reflective layer;

[0050] Figure 8B It shows Figure 8A A graph showing the reflectivity of the metal reflective layer shown in FIG.

[0051] Figure 9A is a diagrammatic view showing another experimental model of a metal reflective layer;

[0052] Figure 9B Is shown covering Figure 9A A view of a color conversion layer on an upper surface of a metallic reflective layer as shown in FIG;

[0053] Figure 10 is a view showing a light emitting device according to another example embodiment;

[0054] Figure 11 is a view showing a light emitting device according to another example embodiment;

[0055] Figure 12 is a view showing a light emitting device according to another example embodiment;

[0056] Figure 13 is a view showing a light emitting device according to another example embodiment; and

[0057] Figure 14 is a view illustrating a display device according to an example embodiment. DETAILED DESCRIPTION

[0058] Reference will now be made in detail to the embodiments shown in the accompanying drawings, in which similar reference numerals represent similar elements throughout the accompanying drawings. In this regard, exemplary embodiments may have different forms and should not be construed as being limited to the description set forth herein. Therefore, exemplary embodiments will be described below only with reference to the accompanying drawings to explain various aspects. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Statements such as "at least one of..." modify the entire list of elements when preceding a list of elements, rather than modifying the individual elements in the list. For example, the statement "at least one of a, b, and c" should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0059] In the following description, when an element is referred to as being "above" or "on" another element, it can be directly on the other element while being in contact with the other element, or it can be above the other element without being in contact with the other element. Unless otherwise mentioned, terms in the singular may include plural forms. It will also be understood that the terms "include" and / or "comprising" used herein specify the presence of the described features or elements, but do not exclude the presence or addition of one or more other features or elements.

[0060] An element mentioned with a definite article or demonstrative pronoun may be interpreted as one or more elements, even if it is in the singular. Unless explicitly described or described to the contrary in terms of order, the operations of the method can be performed in the appropriate order. That is, the operations are not limited to the order in which they are described. Examples or exemplary terms are used herein only to describe the technical ideas and should not be regarded as limiting unless otherwise specified in the claims.

[0061] The light emitting device described in the following exemplary embodiments may be an organic light emitting device (OLED) that emits light having a given wavelength to the outside.

[0062] Figure 1 is a sectional view showing a light emitting device 100 according to example embodiments.

[0063] refer to Figure 1 The light-emitting device 100 includes: a metal reflective layer 110 including a phase modulation surface; a color conversion layer 120 disposed on the phase modulation surface of the metal reflective layer 110 and including a photoluminescent material 122; a first electrode 131 disposed on the color conversion layer 120; a white organic light-emitting layer 140 disposed above the first electrode 131; and a second electrode 132 disposed above the white organic light-emitting layer 140.

[0064] The first electrode 131 may function as an anode that provides holes to the white organic light emitting layer 140, and the second electrode 132 may function as a cathode that provides electrons to the white organic light emitting layer 140. To this end, the first electrode 131 may include a material having a relatively high work function, and the second electrode 132 may include a material having a relatively low work function.

[0065] The first electrode 131 may include a transparent electrode configured to transmit light. For example, the first electrode 131 may include a transparent conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), or aluminum zinc oxide (AZO).

[0066] The second electrode 132 may include a semi-transparent electrode configured to reflect a portion of the light and transmit the rest of the light. The second electrode 132 may include a metal layer having a relatively small thickness. For example, the second electrode 132 may include a mixed layer of silver (Ag) and magnesium (Mg) or a mixed layer of aluminum (Al) and lithium (Li), and the thickness of the second electrode 132 may be about 10 nm to about 20 nm. Since the thickness of the second electrode 132 is relatively small, light can partially pass through the second electrode 132.

[0067] The white organic light-emitting layer 140 has the following structure: a red organic light-emitting layer 141, a green organic light-emitting layer 142, and a blue organic light-emitting layer 143 are sequentially stacked between a first electrode 131 and a second electrode 132. Here, an exciton blocking layer 144 may be provided between the red organic light-emitting layer 141 and the green organic light-emitting layer 142, and an exciton blocking layer 145 may be provided between the green organic light-emitting layer 142 and the blue organic light-emitting layer 143.

[0068] The hole injection layer 151 may be disposed between the first electrode 131 and the white organic light-emitting layer 140. In addition, a hole transport layer may be further disposed between the hole injection layer 151 and the white organic light-emitting layer 140. The electron injection layer 152 may be disposed between the second electrode 132 and the white organic light-emitting layer 140. In addition, an electron transfer layer may be further disposed between the electron injection layer 152 and the white organic light-emitting layer 140.

[0069] The light emitting device 100 may further include various additional layers. For example, an electron blocking layer may be further disposed between the hole transport layer and the white organic light emitting layer 140 , and a hole blocking layer may be further disposed between the electron transport layer and the white organic light emitting layer 140 .

[0070] According to example embodiments, holes provided from the first electrode 131 through the hole injection layer 151 and electrons provided from the second electrode 132 through the electron injection layer 152 may be combined with each other in the red organic light-emitting layer 141, the green organic light-emitting layer 142, and the blue organic light-emitting layer 143, so that the red organic light-emitting layer 141, the green organic light-emitting layer 142, and the blue organic light-emitting layer 143 may generate red light R, green light G, and blue light B, respectively.

[0071] The metal reflective layer 110 may be configured to form a microcavity L together with the second electrode 132. That is, the microcavity L may be formed between the metal reflective layer 110 and the second electrode 132. For example, light generated in the white organic light emitting layer 140 may resonate while reciprocating between the metal reflective layer 110 and the second electrode 132, and then light corresponding to the resonant wavelength of the microcavity L may be emitted through the second electrode 132.

[0072] The resonant wavelength of the microcavity L can be determined by the optical length of the microcavity L. For example, when the resonant wavelength of the microcavity L is represented by λ, the optical length of the microcavity L can be nλ / 2 (where n is a natural number). The optical length of the microcavity L can be determined by the sum of the optical thicknesses of the layers forming the microcavity L between the metal reflective layer 110 and the second electrode 132, the phase delay caused by the second electrode 132, and the phase shift (e.g., phase delay) caused by the metal reflective layer 110. Here, the optical thickness of the layers forming the microcavity L is not a simple physical thickness, but rather a thickness that takes into account the refractive index of these layers.

[0073] According to example embodiments, the optical thickness of the layers forming the microcavity L and the phase delay caused by the second electrode 132 may be fixed, and the phase shift caused by the metal reflective layer 110 may be adjusted to adjust the optical length or resonant wavelength of the microcavity L.

[0074] A phase modulation surface is formed on the reflection surface of the metal reflection layer 110 to adjust the phase shift caused by the metal reflection layer 110. The phase modulation surface may have a metastructure in which nano-patterns 112 having a nano-size are periodically arranged.

[0075] Figure 2 It shows Figure 1 A perspective view of the metal reflective layer 110 shown in FIG. Figure 3 It shows Figure 2 sectional view of the metal reflective layer 110 shown in FIG.

[0076] refer to Figure 2 and Figure 3, the metal reflective layer 110 may include a base 111 and a phase modulation surface formed on the upper surface of the base 111. The phase modulation surface includes nanopatterns 112 periodically arranged on the upper surface of the base 111. Here, each of the nanopatterns 112 may have a columnar shape protruding from the upper surface of the base 111. For example, each of the nanopatterns 112 may have a cylindrical shape. The base 111 and the nanopatterns 112 may be formed as one body. For example, the base 111 and the nanopatterns 112 may include at least one metal material selected from silver (Ag), aluminum (Al), and gold (Au). However, the embodiment is not limited thereto.

[0077] The optical properties of the phase modulation surface (e.g., phase delay of reflected light) can be determined by the size (e.g., diameter (w) and height (h)) of each nanopattern in the nanopatterns 112 and the pitch (p) of the nanopatterns 112. Therefore, the resonant wavelength of the microcavity L can be determined by the diameter (w) and height (h) of each nanopattern in the nanopatterns 112 of the phase modulation surface and the pitch p of the nanopatterns 112. For example, when the resonant wavelength of the microcavity L is represented by λ, the diameter (w) and height (h) of each nanopattern in the nanopatterns 112 of the phase modulation surface and the pitch p of the nanopatterns 112 can be selected so that the optical length of the microcavity L can be nλ / 2 (where n is a natural number).

[0078] The microcavity L of the light-emitting device 100 may have a resonant wavelength in the range of about 300 nm to about 700 nm. In this case, the diameter (w) of each nanopattern in the nanopatterns 112 of the phase modulation surface may be in the range of about 50 nm to about 300 nm, and the height (h) of each nanopattern in the nanopatterns 112 may be in the range of about 0 nm to about 150 nm. In addition, the pitch (p) of the nanopatterns 112 may be in the range of about 100 nm to about 400 nm. However, the embodiment is not limited thereto. Figure 1 An example is shown in which the microcavity L is adjusted to have the wavelength of green light G as a resonance wavelength, so that the light emitting device 100 can emit green light G.

[0079] When the size of the nanopatterns 112 of the phase modulation surface is smaller than the resonant wavelength, incident light can resonate around the nanopatterns 112, forming multiple nano-optical resonant structures. The electric field component of the incident light may not penetrate into the spaces between the nanopatterns 112, and only the magnetic field component of the incident light can resonate around the nanopatterns 112. Therefore, the multiple nano-optical resonant structures formed in the spaces between the nanopatterns 112 can be configured as magnetic resonators to resonate the incident light.

[0080] although Figure 2 and Figure 3 An example is shown in which each of the nano-patterns 112 has a cylindrical shape, but each of the nano-patterns 112 may have any other shape. For example, the nano-pattern 112 may have an elliptical cylinder shape.

[0081] Figure 4 It shows that it can be applied to Figure 1 FIG. 1 is a view of a modified example of the metal reflective layer 110 of the light emitting device 100 shown in FIG. Figure 4 The metal reflective layer 110' includes a base 111' and a phase modulation surface formed on the upper surface of the base 111'. The phase modulation surface includes nanopatterns 112' periodically arranged on the upper surface of the base 111'. Here, each of the nanopatterns 112' may have a quadrangular prism shape protruding from the upper surface of the base 111'.

[0082] exist Figure 4 In the embodiment, the optical properties of the phase modulation surface (eg, phase delay of reflected light) can be determined by the size (eg, width and height) of each nano-pattern in the nano-pattern 112' and the pitch of the nano-pattern 112'. Figure 4 An example is shown in which each of the nano-patterns 112 ′ has a quadrangular prism shape, but each of the nano-patterns 112 ′ may have any other polygonal prism shape, such as a triangular prism shape or a pentagonal prism shape.

[0083] Figure 5 It shows that it can be applied to Figure 1 FIG. 1 is a view of another modified example of the metal reflective layer 110 of the light emitting device 100 shown in FIG. Figure 5 The metal reflective layer 110" includes a base 111" and a phase modulation surface formed on the upper surface of the base 111". The phase modulation surface includes nano patterns 112" periodically arranged on the upper surface of the base 111". Here, each of the nano patterns 112" may include a groove formed in a given shape to a given depth in the upper surface of the base 111". Although Figure 5 , each groove has a cylindrical shape, but each groove may have any other shape. Figure 5 In the embodiment, the optical characteristics of the phase modulation surface (eg, phase delay of reflected light) can be determined by the diameter and height of each nano-pattern in the nano-patterns 112 ″ and the pitch of the nano-patterns 112 ″.

[0084] Figure 6 It shows that it can be applied to Figure 1 FIG. 1 is a view of another modified example of the metal reflective layer 110 of the light emitting device 100 shown in FIG. Figure 6 The metal reflective layer 210 includes a base 211 and a phase modulation surface formed on the upper surface of the base 211. The phase modulation surface includes a nano pattern 212 protruding from the upper surface of the base 211. Here, the nano pattern 212 may be provided separately from the base 211. The base 211 may include various materials, and the nano pattern 212 may include at least one metal material selected from silver (Ag), aluminum (Al), and gold (Au).

[0085] Figure 7 It shows that it can be applied to Figure 1 FIG. 1 is a view of another modified example of the metal reflective layer 110 of the light emitting device 100 shown in FIG. Figure 7 , the metal reflective layer 310 includes a base 311 and a phase modulation surface formed on the upper surface of the base 311. The phase modulation surface includes a nano pattern provided on the upper surface of the base 311. Here, the nano pattern may include a nano structure 312 protruding from the upper surface of the base 311, and a metal coating 313 formed to cover the surface of the nano structure 312 and the upper surface of the base 311. The nano structure 312 may be formed integrally with the base 311 or formed separately from the base 311. The base 311 and the nano structure 312 may include various materials. For example, the metal coating 313 may include at least one metal material selected from silver (Ag), aluminum (Al), and gold (Au).

[0086] Figure 8A is a diagram showing an experimental model of a metal reflective layer. Figure 8A The Ag metal reflective layer 410 is shown, in which a nano pattern 412 having a cylindrical shape is arranged on the upper surface of the base 411. Here, the upper surface of the base 411 has a 300x300 μm 2 Each of the nano-patterns 412 has a diameter of 100 nm and a height of 100 nm, and the nano-patterns 412 are periodically arranged at a pitch of 225 nm.

[0087] For example, the nano-transfer printing process can be used to form Figure 8A However, the embodiment is not limited thereto, and the Ag metal reflective layer 410 may be formed by any other method.

[0088] To form the Ag metal reflective layer 410, first, an electron beam (e-beam) resist is applied to a 300×300 μm 2The nanopore patterns were formed on the upper surface of a silicon wafer with an area of ​​100 nm and an electron beam resist by electron beam lithography. Here, each nanopore pattern has a diameter of 100 nm and is periodically formed at a pitch of 225 nm.

[0089] Next, the silicon wafer is etched to a depth of 100 nm using the nanopore pattern formed in the patterned electron beam resist. Here, the silicon wafer can be etched for about 10 to about 20 seconds using a reactive ion etching (RIE) process, for example, under an SF6 gas environment. Afterwards, the electron beam resist is removed from the upper surface of the silicon wafer to completely manufacture a silicon master having the nanopore pattern.

[0090] Afterwards, a fluorine-based ultraviolet (UV) curable resin is applied to the silicon master, which is then covered with a polyethylene terephthalate (PET) film. Next, an exposure process using a UV lamp is performed to complete the polymerization reaction. When the PET film is removed, a reverse pattern of the nanopore pattern formed on the silicon master is transferred to the thin fluorine-based polymer film.

[0091] Next, a fluorine-based UV curable resin is applied to the thin fluorine-based polymer film on which the reverse pattern is formed, the thin fluorine-based polymer film is covered with a PET film, and a UV exposure process is performed to form a polymer mold on which nanopore patterns are formed. These nanopore patterns are the same as the nanopore patterns formed in the silicon master. Then, the polymer mold on which the nanopore pattern is formed is placed in a vacuum deposition device, and a thin silver (Ag) film is deposited on the polymer mold by a thermal deposition method. Thereafter, the thin silver (Ag) film is separated from the polymer mold, and then as shown in FIG. Figure 8A As shown in FIG, the Ag metal reflective layer 410 including the nano pattern 412 having a cylindrical shape and protruding from the upper surface of the base 411 can be completely manufactured.

[0092] Figure 8B It shows Figure 8A FIG. 4 is a graph showing the reflectivity of the Ag metal reflective layer 410 . Figure 8B The Ag metal reflective layer 410 is shown to have the characteristics of a meta-mirror, which has a large resonance effect at a wavelength of approximately 500 nm, corresponding to the wavelength of green light, and has high reflectivity at a wavelength of approximately 600 nm, corresponding to the wavelength of red light, and at a wavelength of approximately 450 nm, corresponding to the wavelength of blue light. Here, the degree or wavelength of optical resonance can be controlled by adjusting the shape, size, height, and spacing of the nanopatterns 412.

[0093] Reference again Figure 1The color conversion layer 120 is disposed between the phase modulation surface of the metal reflective layer 110 and the first electrode 131. Here, the color conversion layer 120 may include a dielectric 121 and a photoluminescent material 122 dispersed in the dielectric 121.

[0094] For uniform current density, the dielectric 121 may be configured to flatten the upper portion of the phase modulation surface having the metastructure. The dielectric 121 may cover the phase modulation surface of the metal reflective layer 110 so that the upper surface of the metal reflective layer 110 may be flat. The dielectric 121 may include an insulating material that is transparent to visible light. For example, the dielectric 121 may include, but is not limited to, materials such as silicon dioxide (SiO2), silicon nitride (SiN x ), aluminum oxide (Al2O3) or hafnium (IV) oxide (HfO2) materials.

[0095] The photoluminescent material 122 can be configured to convert incident light into light having a given wavelength. For example, the photoluminescent material 122 can convert light having a relatively high energy level into light having a relatively low energy level. For example, the photoluminescent material 122 can convert blue light B into green light G, or can convert blue light B and green light G into red light R. Figure 1 An example is shown in which a green photoluminescent material that converts blue light B into green light G is used as an example of the photoluminescent material 122 .

[0096] The photoluminescent material 122 may include, for example, at least one selected from quantum dots, organic fluorescent dyes, organic fluorescent semiconductors, and organic phosphorescent semiconductors. Here, the quantum dots may include, for example, II-VI semiconductor materials or III-V semiconductor materials.

[0097] The color conversion layer 120 may be formed using an organic binder including the photoluminescent material 122. In this case, for example, the organic binder including the photoluminescent material 122 may be prepared by dissolving a polymer material together with the photoluminescent material 122 in an organic solvent or mixing a heat-crosslinkable resin or a UV-crosslinkable resin with the photoluminescent material 122. However, the embodiment is not limited thereto.

[0098] In the case of a structure having only a planarization layer including a dielectric layer formed on a phase modulation surface having a metastructure, the microcavity can output light having only specific wavelengths among the red, green, and blue lights generated in the white organic light-emitting layer. As a result, since there is no loss of light output to the outside, the efficiency of the light-emitting device may be low.

[0099] However, in the light emitting device 100 of the exemplary embodiment, as Figure 1As shown in FIG, the microcavity L has a wavelength of green light G as a resonant wavelength, and a green photoluminescent material is used as the photoluminescent material 122, so that the green light G generated in the green organic light-emitting layer 142 can resonate while reciprocating between the metal reflective layer 110 and the second electrode 132, and can then be output to the outside through the second electrode 132. In addition, the blue light B generated in the blue organic light-emitting layer 143 can be converted into green light G by the photoluminescent material 122, and after the green light G resonates while reciprocating between the metal reflective layer 110 and the second electrode 132, the green light G can be output to the outside through the second electrode 132, thereby improving the efficiency of green light emission. In this case, the red light R generated in the red organic light-emitting layer 141 can remain inside the microcavity L without being converted into green light G.

[0100] When blue light B generated in blue organic light-emitting layer 143 is converted into surface plasmons within the metastructures of the phase modulation surface, the surface plasmons can improve the efficiency of conversion to green light G. This conversion occurs within photoluminescent material 122, which serves as the green photoluminescent material of color conversion layer 120. Because surface plasmons concentrate light energy in a small volume on the metal surface with the metastructures, significantly increasing light intensity, they can improve light conversion efficiency. Furthermore, when the intensity of the electric field surrounding the metastructures increases and photoluminescent material 122 is located within this electric field, light conversion efficiency can be further enhanced through the Seer effect.

[0101] As described above, in the light emitting device 100 of the example embodiment, the color conversion layer 120 including the photoluminescent material 122 is provided on the phase modulation surface having the metastructure, and thus the light emitting efficiency may be significantly improved.

[0102] Figure 9A is a view showing another experimental model of a metal reflective layer. Figure 9A The Ag metal reflective layer 510 is shown to have a nano pattern 512 on the upper surface of the base 511. Here, the Ag metal reflective layer 510 includes a central portion on which the nano pattern 512 having a cylindrical shape is arranged, and a flat outer portion surrounding the nano pattern 512. The central portion on which the nano pattern 512 is provided may have a size of 300×300 μm. 2 The nano-patterns 512 may each have a diameter of 100 nm and a height of 100 nm, and the nano-patterns 512 may be periodically arranged at a pitch of 225 nm.

[0103] Figure 9B Is shown covering Figure 9A FIG. 5 is a view of the color conversion layer 520 on the upper surface of the Ag metal reflective layer 510 shown in FIG. Figure 9BThe color conversion layer 520 shown in FIG can be formed by spin coating the upper surface of the Ag metal reflective layer 510 with a solution in which polymethyl methacrylate (PMMA) 521 as a dielectric and rhodamine 6G 522 as an organic fluorescent dye are dissolved in chlorobenzene as an organic solvent.

[0104] Use dark field imaging to measure Figure 9B , and the measurement results show that light emission in the metastructure region A where the nanopattern 512 is formed is relatively strong, while light emission in the flat region B where the nanopattern 512 is not formed is relatively weak. Therefore, when the photoluminescent material is provided on the metal surface having the metastructure, the light emission characteristics can be further improved compared to when the photoluminescent material is provided on the flat metal surface.

[0105] Figure 10 1 is a view showing a light emitting device 600 according to another exemplary embodiment. In addition to the light emitting device 600 outputting red light R, Figure 10 The light emitting device 600 shown in FIG. Figure 1 The light emitting devices 100 shown in FIG. 1 are the same.

[0106] refer to Figure 10 , the metal reflective layer 610 may form a microcavity L together with the second electrode 132, and a phase modulation surface for phase shift adjustment is formed on the reflective surface of the metal reflective layer 610. The phase modulation surface may have a metastructure in which nanopatterns 612 are periodically arranged on the upper surface of the base 611. In example embodiments, the microcavity L may be adjusted to have a wavelength of red light R as a resonant wavelength. In addition, Figure 10 The metal reflective layer 610 shown in FIG. 4 may include a Figures 2 to 7 The metal reflective layer 110 , the metal reflective layer 110 ′, the metal reflective layer 110 ″, the metal reflective layer 210 and the metal reflective layer 310 are described.

[0107] The color conversion layer 620 is provided on the phase modulation surface of the metal reflective layer 610. The color conversion layer 620 may include a dielectric 621 and a photoluminescent material 622 dispersed in the dielectric 621. In example embodiments, a red photoluminescent material configured to convert blue light B and green light G into red light R may be used as the photoluminescent material 622.

[0108] exist Figure 10In the light-emitting device 600 shown in FIG, red light R generated in the red organic light-emitting layer 141 can resonate while reciprocating between the metal reflective layer 610 and the second electrode 132, and can then be output to the outside through the second electrode 132. In addition, blue light B generated in the blue organic light-emitting layer 143 can be converted into red light R by the photoluminescent material 622, and after the red light R resonates while reciprocating between the metal reflective layer 610 and the second electrode 132, the red light R can be output to the outside through the second electrode 132. In addition, green light G generated in the green organic light-emitting layer 142 can be converted into red light R by the photoluminescent material 622, and after the red light R resonates while reciprocating between the metal reflective layer 610 and the second electrode 132, the red light R can be output to the outside through the second electrode 132, thereby improving the efficiency of red light emission.

[0109] As mentioned above, in Figure 10 In the light-emitting device 600 shown in FIG, the photoluminescent material 622 is disposed above the phase modulation surface of the metal reflective layer 610. Therefore, incident light can be converted into light having a desired wavelength and then output, thereby improving luminous efficiency. Furthermore, because the phase modulation surface of the metal reflective layer 610 has a metastructure and the photoluminescent material 622 is disposed above the metastructure, luminous efficiency can be further improved.

[0110] Figure 11 7 is a view showing a light emitting device 700 according to another exemplary embodiment. In addition to the transparent planarization layer 760 being provided between the metal reflective layer 110 and the color conversion layer 720, Figure 11 The light emitting device 700 shown in FIG. Figure 1 The light emitting devices 100 shown in FIG. 1 are the same.

[0111] refer to Figure 11 , a transparent planarization layer 760 is provided on the phase modulation surface of the metal reflective layer 110, and the color conversion layer 720 is provided on the planarization layer 760. Here, the planarization layer 760 can be configured to planarize the upper portion of the phase modulation surface having the metastructure to obtain a uniform current density. To this end, the planarization layer 760 can cover the phase modulation surface of the metal reflective layer 110 so that the upper surface of the metal reflective layer 110 can be flat. The planarization layer 760 may include an insulating material that is transparent to visible light. For example, the planarization layer 760 may include, but is not limited to, materials such as SiO2, SiN x , Al2O3 or HfO2 materials.

[0112] Color conversion layer 720 is disposed on the upper surface of planarization layer 760. Color conversion layer 720 may include dielectric 721 and photoluminescent material 722 dispersed in dielectric 721. Dielectric 721 may include an insulating material transparent to visible light. Dielectric 721 may include the same material as planarization layer 760, but is not limited thereto.

[0113] Photoluminescent material 722 can be configured to convert incident light into light having a given wavelength. For example, photoluminescent material 722 can convert light having a relatively high energy level into light having a relatively low energy level. Photoluminescent material 722 can include, for example, at least one selected from quantum dots, organic fluorescent dyes, organic fluorescent semiconductors, and organic phosphorescent semiconductors. Color conversion layer 720 can be formed using an organic binder including photoluminescent material 722.

[0114] Figure 12 8 is a view showing a light emitting device 800 according to another exemplary embodiment. Except that the metal reflective layer 810 is semi-transparent and the second electrode 832 is a reflective electrode, Figure 12 The light emitting device 800 shown in FIG. Figure 1 The light emitting devices 100 shown in FIG. 1 are the same.

[0115] refer to Figure 12 , the first electrode 131 disposed under the white organic light emitting layer 140 may include a transparent electrode, and the second electrode 832 disposed above the white organic light emitting layer 140 may include a reflective electrode that reflects incident light. In addition, the metal reflective layer 810 disposed under the first electrode 131 may include a semi-transparent layer configured to transmit a portion of the incident light and reflect the rest of the incident light.

[0116] The metal reflective layer 810 may form a microcavity L together with the second electrode 832, and a phase modulation surface for phase shift adjustment may be formed on the reflective surface of the metal reflective layer 810. Here, the phase modulation surface of the metal reflective layer 810 may have a metastructure in which nanopatterns 812 are periodically arranged on the upper surface of the base 811. Figure 12 An example is shown in which the microcavity L is adjusted to have the wavelength of green light G as the resonance wavelength.

[0117] The color conversion layer 120 is provided between the phase modulation surface of the metal reflective layer 810 and the first electrode 131. Here, the color conversion layer 120 may include a dielectric 121 and a photoluminescent material 122 dispersed in the dielectric 121. Figure 12 An example is shown in which a green photoluminescent material configured to convert blue light B into green light G is used as the photoluminescent material 122 .

[0118] exist Figure 12In the light-emitting device 800 shown in FIG, green light G generated in the green organic light-emitting layer 142 can resonate while reciprocating between the metal reflective layer 810 and the second electrode 832, and can then be output to the outside through the translucent metal reflective layer 810. In addition, blue light B generated in the blue organic light-emitting layer 143 can be converted into green light G by the photoluminescent material 122, and after the green light G resonates while reciprocating between the metal reflective layer 810 and the second electrode 832, the green light G can be output to the outside through the metal reflective layer 810.

[0119] Figure 13 is a view showing a light emitting device 900 according to another example embodiment.

[0120] refer to Figure 13 The light-emitting device 900 includes a first metal reflective layer 910 having a first phase modulation surface, a color conversion layer 120, a first electrode 131, a white organic light-emitting layer 140, a second electrode 932, a planarization layer 980, and a second metal reflective layer 970 having a second phase modulation surface. The first metal reflective layer 910 and the second metal reflective layer 970 may form a microcavity L.

[0121] The first phase modulation surface of the first metal reflective layer 910 may have a metastructure in which first nanopatterns 912 are periodically arranged on the upper surface of the first base 911, and the second phase modulation surface of the second metal reflective layer 970 may have a metastructure in which second nanopatterns 972 are periodically arranged on the lower surface of the second base 971. Here, the shapes, sizes, and spacings of the first nanopatterns 912 and the second nanopatterns 972 may be adjusted so that the microcavity L formed by the first metal reflective layer 910 and the second metal reflective layer 970 can have a given resonant wavelength.

[0122] One of the first and second metal reflective layers 910 and 970 may be reflective, and the other of the first and second metal reflective layers 910 and 970 may be translucent and configured to transmit a portion of light and reflect the rest of the light. Figure 13 An example is shown in which the first metal reflective layer 910 is a reflective layer and the second metal reflective layer 970 is a semi-transparent layer. In addition, the first electrode 131 and the second electrode 932 may include transparent electrodes.

[0123] Color conversion layer 120 is disposed between first metal reflective layer 910 and first electrode 131. Here, color conversion layer 120 may include dielectric 121 and photoluminescent material 122 dispersed in dielectric 121. A transparent planarization layer 980 is disposed between second metal reflective layer 970 and second electrode 932. Here, planarization layer 980 may be configured to flatten the lower portion of the second phase modulation surface having the metastructure to achieve uniform current density. To this end, planarization layer 980 may cover the second phase modulation surface of second metal reflective layer 970, ensuring a flat lower surface. Planarization layer 980 may include an insulating material transparent to visible light. Furthermore, photoluminescent material 122 included in color conversion layer 120 may be further disposed within planarization layer 980.

[0124] exist Figure 13 In the light-emitting device 900 shown in FIG, light generated in the white organic light-emitting layer 140 can be converted into light having a given wavelength by the photoluminescent material 122 in the color conversion layer 120, and after the light resonates while reciprocating between the first metal reflective layer 910 and the second metal reflective layer 970, it can be output to the outside through the translucent second metal reflective layer 970.

[0125] As described above, according to one or more of the above exemplary embodiments, the photoluminescent material is disposed above the phase modulation surface of the metal reflective layer. Therefore, incident light can be converted into light having a desired wavelength and then output, thereby improving luminous efficiency. Furthermore, a metastructure is formed on the phase modulation surface of the metal reflective layer, and the photoluminescent material is disposed above the metastructure, further improving luminous efficiency.

[0126] Figure 14 is a view illustrating a display apparatus 1000 according to an example embodiment.

[0127] refer to Figure 14 , the display device 1000 includes a plurality of pixels that emit light having different colors. Here, the plurality of pixels may include a red pixel 1300, a green pixel 1200, and a blue pixel 1100 that are adjacent to each other and arranged on the same surface of a substrate. Figure 14 , a unit pixel including a red pixel 1300, a green pixel 1200, and a blue pixel 1100 is shown. Figure 14 In the display device 1000 shown in FIG, the red pixel 1300 and the green pixel 1200 may have the same Figure 1 The light emitting device 100 shown in FIG.

[0128] The red pixel 1300 includes: a first metal reflective layer 1310, including a first phase modulation surface; a first color conversion layer 1320, disposed on the first phase modulation surface and including a first photoluminescent material 1322; a first electrode 1131, disposed on the first color conversion layer 1320; a white organic light-emitting layer 1140, disposed above the first electrode 1131; and a second electrode 1132, disposed above the white organic light-emitting layer 1140.

[0129] The first electrode 1131 may include a transparent electrode that transmits light, and the second electrode 1132 may include a semi-transparent electrode that reflects a portion of light and transmits the rest of the light. The white organic light-emitting layer 1140 has a structure in which a red organic light-emitting layer 1141, a green organic light-emitting layer 1142, and a blue organic light-emitting layer 1143 are sequentially stacked between the first electrode 1131 and the second electrode 1132.

[0130] The hole injection layer 1151 may be disposed between the first electrode 1131 and the white organic light-emitting layer 1140, and the electron injection layer 1152 may be disposed between the second electrode 1132 and the white organic light-emitting layer 1140. A hole transport layer may be further disposed between the hole injection layer 1151 and the white organic light-emitting layer 1140, and an electron transport layer may be further disposed between the electron injection layer 1152 and the white organic light-emitting layer 1140.

[0131] The first metal reflective layer 1310 may form a first microcavity together with the second electrode 1132. The first metal reflective layer 1310 may include, for example, at least one metal material selected from Ag, Al, and Au, but is not limited thereto.

[0132] The phase shift caused by the first metal reflective layer 1310 can be adjusted so that the first microcavity can have the wavelength of red light R as a resonance wavelength. To this end, a first phase modulation surface is formed on the reflective surface of the first metal reflective layer 1310. The first metal reflective layer 1310 can have Figure 2 and Figure 3 For example, the first phase modulation surface may have a metastructure in which cylindrical nanopatterns 1312 protruding from the upper surface of the base 1311 are periodically arranged. However, the embodiment is not limited thereto, and the first metal reflective layer 1310 may have Figures 4 to 7 Any structure shown in .

[0133] First color conversion layer 1320 covers the first phase modulation surface of first metal reflective layer 1310. First color conversion layer 1320 may include a dielectric 1321 and a first photoluminescent material 1322 dispersed within dielectric 1321. Dielectric 1321 may include an insulating material transparent to visible light. Alternatively, first photoluminescent material 1322 may include a red photoluminescent material that converts blue light B and green light G into red light R. First photoluminescent material 1322 may include, for example, at least one selected from quantum dots, organic fluorescent dyes, organic fluorescent semiconductors, and organic phosphorescent semiconductors.

[0134] Green pixel 1200 includes: a second metal reflective layer 1210 including a second phase modulation surface; a second color conversion layer 1220 disposed on the second phase modulation surface and including a second photoluminescent material 1222; a first electrode 1131 disposed on second color conversion layer 1220; a white organic light-emitting layer 1140 disposed above first electrode 1131; and a second electrode 1132 disposed above white organic light-emitting layer 1140. Since first electrode 1131, second electrode 1132, and white organic light-emitting layer 1140 have been described above, their description is omitted.

[0135] The second metal reflective layer 1210 may form a second microcavity together with the second electrode 1132. Similar to the first metal reflective layer 1310, the second metal reflective layer 1210 may include at least one metal material selected from, for example, Ag, Al, and Au, but is not limited thereto.

[0136] The phase shift caused by the second metal reflective layer 1210 can be adjusted so that the second microcavity can have the wavelength of green light G as the resonant wavelength. To this end, a second phase modulation surface is formed on the reflective surface of the second metal reflective layer 1210. The second metal reflective layer 1210 can have Figure 2 and Figure 3 For example, the second phase modulation surface may have a metastructure in which cylindrical nanopatterns 1212 protruding from the upper surface of the base 1211 are periodically arranged. However, this is only an example, and the second metal reflective layer 1210 may have Figures 4 to 7 Any structure shown in .

[0137] Second color conversion layer 1220 covers the second phase modulation surface of second metal reflective layer 1210. Second color conversion layer 1220 may include a dielectric 1221 and a second photoluminescent material 1222 dispersed in dielectric 1221. Here, second photoluminescent material 1222 may include a green photoluminescent material that converts blue light B into green light G. Similar to first photoluminescent material 1322, second photoluminescent material 1222 may include, for example, at least one of quantum dots, organic fluorescent dyes, organic fluorescent semiconductors, and organic phosphorescent semiconductors.

[0138] Blue pixel 1100 includes a third metal reflective layer 1110; a dielectric layer 1120 disposed on third metal reflective layer 1110; a first electrode 1131 disposed on dielectric layer 1120; a white organic light-emitting layer 1140 disposed above first electrode 1131; and a second electrode 1132 disposed above white organic light-emitting layer 1140. Since first electrode 1131, second electrode 1132, and white organic light-emitting layer 1140 have been described above, their description is omitted.

[0139] The third metal reflective layer 1110 can form a third microcavity together with the second electrode 1132. Similar to the first metal reflective layer 1310 and the second metal reflective layer 1210, the third metal reflective layer 1110 can include, for example, at least one metal material selected from Ag, Al, and Au, but is not limited thereto. The structure and optical properties of the layers forming the third microcavity can be adjusted so that the third microcavity can have a wavelength of blue light B as a resonant wavelength.

[0140] Dielectric layer 1120 covers the upper surface of third metal reflective layer 1110. Dielectric layer 1120 may include an insulating material transparent to visible light. Dielectric layer 1120 may include the same material as dielectric 1321 of first color conversion layer 1320 and dielectric 1221 of second color conversion layer 1220. However, the embodiment is not limited thereto.

[0141] In the display device 1000 having the above structure, the red pixel 1300 can output red light R generated in the red organic light-emitting layer 1141 and resonating between the first metal reflective layer 1310 and the second electrode 1132 through the second electrode 1132. In addition, blue light B generated in the blue organic light-emitting layer 1143 can be converted into red light R by the first photoluminescent material 1322. After the red light R resonates between the first metal reflective layer 1310 and the second electrode 1132, the red light R can be output from the red pixel 1300 to the outside through the second electrode 1132. In addition, green light G generated in the green organic light-emitting layer 1142 can be converted into red light R by the first photoluminescent material 1322. After the red light R resonates between the first metal reflective layer 1310 and the second electrode 1132, the red light R can be output from the red pixel 1300 to the outside through the second electrode 1132.

[0142] The green pixel 1200 can output green light G through the second electrode 1132. The green light G is generated in the green organic light-emitting layer 1142 and resonates while reciprocating between the second metal reflective layer 1210 and the second electrode 1132. In addition, the blue light B generated in the blue organic light-emitting layer 1143 can be converted into green light G by the second photoluminescent material 1222. After the green light G resonates while reciprocating between the second metal reflective layer 1210 and the second electrode 1132, the green light G can be output from the green pixel 1200 to the outside through the second electrode 1132.

[0143] The blue pixel 1100 may output blue light B through the second electrode 1132 , the blue light B being generated in the blue organic light emitting layer 1143 and resonating while reciprocating between the third metal reflective layer 1110 and the second electrode 1132 .

[0144] Described Figure 14 The red pixel 1300 and the green pixel 1200 of the display device 1000 shown in FIG. Figure 1 However, the embodiment is not limited thereto. For example, the red pixel 1300 and the green pixel 1200 may have the same structure as the light emitting device 100 shown in FIG. Figures 11 to 13 The light emitting device 700, the light emitting device 800 and the light emitting device 900 shown in FIG have the same structure. Figure 14The red pixel 1300 and the green pixel 1200 of the display device 1000 shown in FIG have a phase modulation surface, while the blue pixel 1100 of the display device 1000 does not have a phase modulation surface. However, the embodiment is not limited thereto. For example, any two pixels among the red pixel 1300, the green pixel 1200, and the blue pixel 1100 may have a phase modulation surface, and the remaining pixels may not have a phase modulation surface. In another example, the red pixel 1300, the green pixel 1200, and the blue pixel 1100 may all have a phase modulation surface.

[0145] As described above, according to one or more of the above exemplary embodiments, the photoluminescent material is disposed above the phase modulation surface of the metal reflective layer. Therefore, incident light can be converted into light having a desired wavelength and then output, thereby improving luminous efficiency. Furthermore, a metastructure is formed on the phase modulation surface of the metal reflective layer, and the photoluminescent material is disposed above the metastructure, further improving luminous efficiency.

[0146] It should be understood that the exemplary embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects in each exemplary embodiment should typically be considered as applicable to other similar features or aspects in other exemplary embodiments.

[0147] Although example embodiments have been described with reference to the accompanying drawings, workers skilled in the art will recognize that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the claims.

Claims

1. A light-emitting device, comprising: a first metal reflective layer comprising a phase modulation surface configured to cause light incident on the first metal reflective layer to magnetically resonate; a color conversion layer disposed on the phase modulation surface of the first metal reflective layer and comprising a photoluminescent material; a first electrode, disposed on the color conversion layer opposite to the first metal reflective layer; a white organic light-emitting layer, disposed on the first electrode opposite to the color conversion layer; as well as a second electrode, disposed on the white organic light-emitting layer opposite to the first electrode; The first metal reflective layer and the second electrode form a microcavity having a resonant wavelength, and the resonant wavelength of the microcavity is adjusted by adjusting the phase shift caused by the first metal reflective layer. 2 . The light emitting device according to claim 1 , wherein the phase modulation surface comprises a metastructure in which nano-patterns are periodically arranged. 3 . The light emitting device according to claim 1 , wherein the color conversion layer further comprises a dielectric, and the photoluminescent material is dispersed in the dielectric.

4. The light emitting device according to claim 1, wherein the photoluminescent material comprises: a green photoluminescent material configured to convert blue light into green light; or a red photoluminescent material configured to convert blue light and green light into red light, respectively. The light emitting device according to claim 1 , wherein the color conversion layer covers the phase modulation surface of the first metal reflective layer.

6. The light emitting device according to claim 1, further comprising: A transparent planarization layer is disposed between the first metal reflective layer and the color conversion layer and covers the phase modulation surface of the first metal reflective layer.

7. The light emitting device according to claim 1, wherein the first electrode comprises a transparent electrode, and the second electrode comprises a semi-transparent electrode, the semi-transparent electrode being configured to transmit a portion of light incident on the second electrode and reflect the rest of the light incident on the second electrode.

8. The light emitting device according to claim 1, wherein the first electrode comprises a transparent electrode and the second electrode comprises a reflective electrode, and The first metal reflective layer is a semi-transparent layer configured to transmit a portion of the light incident on the first metal reflective layer and reflect the remaining portion of the light incident on the first metal reflective layer.

9. A light-emitting device comprising: a first metal reflective layer comprising a phase modulation surface configured to cause light incident on the first metal reflective layer to magnetically resonate; a color conversion layer disposed on the phase modulation surface of the first metal reflective layer and comprising a photoluminescent material; a first electrode, disposed on the color conversion layer opposite to the first metal reflective layer; a white organic light-emitting layer, disposed on the first electrode opposite to the color conversion layer; a second electrode, disposed on the white organic light-emitting layer opposite to the first electrode; a second metal reflective layer, disposed on the second electrode and comprising a phase modulation surface; as well as a planarization layer, disposed between the second electrode and the second metal reflective layer and covering the phase modulation surface of the second metal reflective layer, The first metal reflective layer and the second metal reflective layer form a microcavity having a resonant wavelength, and the resonant wavelength of the microcavity is adjusted by adjusting the phase shift caused by the first metal reflective layer and / or the second metal reflective layer.

10. The light emitting device according to claim 9, wherein the first electrode and the second electrode respectively comprise transparent electrodes, and One of the first metal reflective layer and the second metal reflective layer is configured to reflect light, and the other of the first metal reflective layer and the second metal reflective layer is translucent and configured to transmit a portion of the light and reflect the rest of the light.

11. A display device comprising: a plurality of pixels configured to emit light having a plurality of colors, wherein at least one pixel of the plurality of pixels comprises: a first metal reflective layer comprising a phase modulation surface configured to cause light incident on the first metal reflective layer to magnetically resonate; a color conversion layer disposed on the phase modulation surface of the first metal reflective layer and comprising a photoluminescent material; a first electrode, disposed on the color conversion layer opposite to the first metal reflective layer; a white organic light-emitting layer, disposed on the first electrode opposite to the color conversion layer; and a second electrode, disposed on the white organic light-emitting layer opposite to the first electrode; The first metal reflective layer and the second electrode form a microcavity having a resonant wavelength, and the resonant wavelength of the microcavity is adjusted by adjusting the phase shift caused by the first metal reflective layer. 12 . The display device according to claim 11 , wherein the phase modulation surface comprises a metastructure in which nano-patterns are periodically arranged. 13 . The display device according to claim 11 , wherein the color conversion layer further comprises a dielectric, and the photoluminescent material is dispersed in the dielectric. The display device according to claim 11 , wherein the color conversion layer covers the phase modulation surface of the first metal reflective layer. 15 . The display device according to claim 11 , wherein the at least one pixel among the plurality of pixels further comprises a transparent planarization layer, the transparent planarization layer being disposed between the first metal reflective layer and the color conversion layer and covering the phase modulation surface of the first metal reflective layer.

16. The display device according to claim 11, wherein the at least one pixel among the plurality of pixels further comprises: a second metal reflective layer, disposed on the second electrode and comprising a phase modulation surface; as well as A planarization layer is disposed between the second electrode and the second metal reflective layer and covers the phase modulation surface of the second metal reflective layer. 17 . The display device according to claim 11 , wherein the plurality of pixels include blue pixels, green pixels, and red pixels.

18. The display device according to claim 17, wherein the photoluminescent material included in the green pixel comprises a green photoluminescent material configured to convert blue light into green light, and the photoluminescent material included in the red pixel comprises a red photoluminescent material configured to convert blue light and green light into red light, respectively.

19. A light emitting device comprising: a first electrode; a second electrode; as well as a light-emitting layer disposed between the first electrode and the second electrode and configured to emit white light; a metal reflective layer disposed on the first electrode opposite to the light emitting layer, the metal reflective layer comprising a phase modulation surface configured to resonate a specific wavelength of the white light emitted from the light emitting layer; as well as a color conversion layer disposed between the first electrode and the metal reflective layer and configured to convert a portion of the white light into light having the specific wavelength, The metal reflective layer and the second electrode form a microcavity having a resonant wavelength, and the resonant wavelength of the microcavity is adjusted by adjusting the phase shift caused by the metal reflective layer. 20 . The light emitting device according to claim 19 , wherein the metal reflective layer comprises at least one of silver (Ag), aluminum (Al), and gold (Au). The light emitting device according to claim 19 , wherein the phase modulation surface comprises a metastructure in which nano-patterns are periodically arranged. The light emitting device according to claim 21 , wherein each of the nano-patterns has a cylindrical shape or a polygonal prism shape. The light emitting device according to claim 21 , wherein each of the nano-patterns has a width of 50 nm to 300 nm. The light emitting device according to claim 21 , wherein the nano-patterns are arranged at a pitch of 100 nm to 400 nm, the pitch being a distance between adjacent nano-patterns.

25. The light emitting device of claim 19, wherein the color conversion layer comprises a dielectric in which a photoluminescent material is dispersed.

26. The light emitting device according to claim 25, wherein the photoluminescent material comprises at least one of quantum dots, organic fluorescent dyes, organic fluorescent semiconductors, and organic phosphorescent semiconductors.

27. The light emitting device according to claim 25, wherein the photoluminescent material comprises: a green photoluminescent material configured to convert blue light into green light; or a red photoluminescent material configured to convert blue light and green light into red light, respectively. The light emitting device according to claim 19 , wherein the color conversion layer covers the phase modulation surface of the metal reflective layer.

29. The light emitting device according to claim 19, further comprising: A transparent planarization layer is disposed between the metal reflective layer and the color conversion layer and covers the phase modulation surface of the metal reflective layer.

30. The light emitting device of claim 19, wherein the first electrode is a transparent electrode, and the second electrode is a semi-transparent electrode configured to transmit a portion of light incident on the second electrode and reflect the rest of the light incident on the second electrode.

31. The light emitting device according to claim 19, wherein the first electrode is a transparent electrode and the second electrode is a reflective electrode, and The metal reflective layer is a semi-transparent layer configured to transmit a portion of light incident on the metal reflective layer and reflect the remaining portion of the light incident on the metal reflective layer.

32. A light emitting device comprising: a metal reflective layer comprising a phase modulation surface configured to cause incident light to undergo magnetic resonance, the phase modulation surface comprising a plurality of nano-patterns; A color conversion layer is provided on the phase modulation surface of the metal reflective layer, wherein the color conversion layer comprises a dielectric and a photoluminescent material; a first electrode, disposed on the color conversion layer opposite to the metal reflective layer; a white organic light-emitting layer, disposed on the first electrode opposite to the color conversion layer; as well as a second electrode, disposed on the white organic light-emitting layer opposite to the first electrode; The metal reflective layer and the second electrode form a microcavity having a resonant wavelength, and the resonant wavelength of the microcavity is adjusted by adjusting the phase shift caused by the metal reflective layer. The light emitting device according to claim 32 , wherein the color conversion layer covers the phase modulation surface of the metal reflective layer.

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