Light emitting device and display device including the same

Abstract

Disclosed are a light emitting device and a display device including the same. The light emitting device may include a first electrode, a second electrode opposite to the first electrode, and an emission layer arranged between the first electrode and the second electrode. The emission layer may include a manganese complex and quantum dots. The service life and luminous efficiency characteristics of the light emitting device can be improved.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0043085, filed on April 12, 2019, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a light emitting device and a display device including the same, and in particular, to a light emitting device whose emission layer includes quantum dots and a display device including the same. Background Art

[0004] Various display devices are being developed for use in multimedia devices such as televisions, mobile phones, tablet computers, navigation systems, and / or game consoles, etc. In a self-luminous display device, a light-emitting material including an organic compound is used to generate light for displaying an image.

[0005] In addition, in order to improve the color reproduction characteristics of display devices, quantum dots are being developed as light-emitting materials for light-emitting devices. There is an industrial demand for improved reliability and lifetime of light-emitting devices using quantum dots. Summary of the invention

[0006] One or more aspects of embodiments of the inventive concept are directed to a light emitting device including an emission layer including quantum dots and a host material and having an increased lifetime and improved light emitting efficiency.

[0007] One or more embodiments of the inventive concept provide a display apparatus including a light emitting device including quantum dots and a host material and having good color reproduction characteristics, improved light emitting efficiency, and increased lifetime.

[0008] According to one or more embodiments of the present inventive concept, a light emitting device may include a first electrode, a second electrode opposite to the first electrode, and a plurality of functional layers arranged between the first electrode and the second electrode. The plurality of functional layers may include an emission layer. The emission layer may include a manganese complex and a quantum dot.

[0009] In one or more embodiments, the manganese complex may be a material represented by the following Chemical Formula 1:

[0010] Chemical formula 1

[0011] XpMnYq.

[0012] In Chemical Formula 1, X is a monovalent or divalent cationic organic compound group, Y is a halogen atom, p is 1 or 2, and q is 4 or 6.

[0013] In one or more embodiments, X may be BrMTPP ((bromomethyl)triphenylphosphine), BrPTPP ((3-bromopropyl)triphenylphosphine), TPP (tetraphenylphosphine), TMA (tetramethylammonium), and / or TEA (tetraethylammonium).

[0014] In one or more embodiments, the emission layer may include a host and a dopant, the host may include a manganese complex, and the dopant may include a quantum dot.

[0015] In one or more embodiments, the weight ratio between the manganese complex and the quantum dots may be in the range of 1:1 to 1:2.

[0016] In one or more embodiments, the emission layer may emit green light or red light.

[0017] In one or more embodiments, the plurality of functional layers may include a hole transport region disposed (located) between the first electrode and the emission layer, and an electron transport region disposed (located) between the emission layer and the second electrode.

[0018] In one or more embodiments, the hole transport region may include a plurality of sub-functional layers, and a difference in LUMO energy level between one of the sub-functional layers adjacent to the emission layer and the quantum dot may be greater than or equal to 1.5 eV.

[0019] In one or more embodiments, the emission layer may include a plurality of quantum dots, and the manganese complex may fill spaces between the plurality of quantum dots.

[0020] According to one or more embodiments of the inventive concept, a display device may include a plurality of light emitting devices. Each of the light emitting devices may include a first electrode, a second electrode opposite to the first electrode, and an emission layer arranged between the first electrode and the second electrode. The emission layer may include a manganese complex and a quantum dot.

[0021] In one or more embodiments, the manganese complex may be a material represented by the following Chemical Formula 1:

[0022] Chemical formula 1

[0023] X p Yj Y q .

[0024] In Chemical Formula 1, X is a monovalent or divalent cationic organic compound group, Y is a halogen atom, p is 1 or 2, and q is 4 or 6.

[0025] In one or more embodiments, the plurality of light emitting devices may include a first light emitting device, a second light emitting device, and a third light emitting device, wherein the first light emitting device includes a first quantum dot that emits a first color light, the second light emitting device includes a second quantum dot that emits a second color light, wherein the wavelength of the second color light is longer than the wavelength of the first color light, and the third light emitting device includes a third quantum dot that emits a third color light, wherein the wavelength of the third color light is longer than the wavelengths of the first color light and the second color light.

[0026] In one or more embodiments, the first to third quantum dots may be configured to satisfy an average diameter condition given by the following formula 1:

[0027] Formula 1

[0028] The average diameter of the first quantum dots is less than the average diameter of the second quantum dots and less than the average diameter of the third quantum dots.

[0029] In one or more embodiments, the first emission layer of the first light emitting device, the second emission layer of the second light emitting device, and the third emission layer of the third light emitting device may be arranged to satisfy a thickness condition given by the following formula 2:

[0030] Formula 2

[0031] T1≤T2≤T3.

[0032] In Formula 2, T1 is the thickness of the first emission layer, T2 is the thickness of the second emission layer, and T3 is the thickness of the third emission layer.

[0033] In one or more embodiments, the display device may further include a light control layer disposed on the light emitting device.

[0034] In one or more embodiments, the light management layer may be a polarizing layer.

[0035] In one or more embodiments, the light control layer may include a color filter layer. The color filter layer may include a first color filter transmitting a first color light, a second color filter transmitting a second color light, and a third color filter transmitting a third color light.

[0036] According to an embodiment of the present inventive concept, a display device may include a display panel and a light control layer. The display panel includes a plurality of light emitting devices, and the light control layer is arranged on the display panel. The light emitting device may include a first light emitting device, a second light emitting device, and a third light emitting device, wherein the first light emitting device includes a first emission layer including a first quantum dot and a first host, the second light emitting device includes a second emission layer including a second quantum dot and a second host, and the third light emitting device includes a third emission layer including a third quantum dot and a third host. At least one of the first host, the second host, and the third host may be a manganese complex represented by the following Chemical Formula 1:

[0037] Chemical formula 1

[0038] XpMnYq.

[0039] In Chemical Formula 1, X is a monovalent or divalent cationic organic compound group, Y is a halogen atom, p is 1 or 2, and q is 4 or 6.

[0040] In one or more embodiments, X may be BrMTPP ((bromomethyl)triphenylphosphine), BrPTPP ((3-bromopropyl)triphenylphosphine), TPP (tetraphenylphosphine), TMA (tetramethylammonium), and / or TEA (tetraethylammonium).

[0041] In one or more embodiments, the first emission layer may emit blue light, the second emission layer may emit green light, and the third emission layer may emit red light. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Exemplary embodiments will be more clearly understood from the following brief description taken in conjunction with the accompanying drawings.The accompanying drawings illustrate non-limiting exemplary embodiments as described herein.

[0043] Figure 1 is a perspective view of an electronic device according to an embodiment of the inventive concept.

[0044] Figure 2 is an embodiment according to the concept of the present invention Figure 1 A cross-sectional view of the display device taken along line II'.

[0045] Figure 3 is a cross-sectional view of a light emitting device according to an embodiment of the inventive concept.

[0046] Figure 4 2 is an energy band diagram illustrating an energy band structure of a light emitting device according to an embodiment of the inventive concept.

[0047] Figure 5 : is a graph showing the concentration distribution of holes and electrons in the exemplary embodiment and the comparative embodiment.

[0048] Figure 6 is a plan view of a display device according to an embodiment of the inventive concept.

[0049] Figure 7 is an embodiment according to the concept of the present invention Figure 6 A cross-sectional view of the display device taken along line II-II'.

[0050] Figure 8 is a cross-sectional view of a display device according to an embodiment of the inventive concept.

[0051] Fig. 9 is a cross-sectional view of a display device according to an embodiment of the inventive concept.

[0052] It should be noted that these figures are intended to illustrate the general characteristics of the methods, structures and / or materials used in certain exemplary embodiments, and are intended to supplement the written description provided below. However, these drawings are not drawn to scale and may not accurately reflect the precise structure or performance characteristics of any given embodiment, and should not be interpreted as limiting or restricting the range of values ​​or properties contained in the exemplary embodiments. For example, for clarity, the relative thickness and position of molecules, layers, regions and / or structural elements may be reduced or enlarged. The use of similar or identical reference numerals in various drawings is intended to indicate the presence of similar or identical elements or features. DETAILED DESCRIPTION

[0053] Exemplary embodiments of the inventive concept will now be described more fully with reference to the accompanying drawings showing exemplary embodiments. However, exemplary embodiments of the inventive concept can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and the concepts of the exemplary embodiments will be fully conveyed to those of ordinary skill in the art. In the accompanying drawings, the sizes of layers and regions are exaggerated for clarity. The same reference numerals in the drawings represent the same elements, and therefore their repeated description will not be provided.

[0054] It should be understood that when an element is referred to as being "connected to" or "coupled to" another element, the element may be directly connected to or coupled to the other element, or there may be an intermediate element. Conversely, when an element is referred to as being "directly connected to" or "directly coupled to" another element, there are no intermediate elements. Other expressions used to describe the relationship between elements or layers should be interpreted in the same manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," "on" versus "directly on"). Throughout the specification, similar reference numerals indicate similar elements. As used herein, the expression "and / or" includes any and all combinations of one or more of the relevant listed items.

[0055] It should be understood that although the terms "first", "second", etc. may be used herein to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, the first element, component, region, layer or part discussed below may be referred to as a second element, component, region, layer or part without departing from the teachings of the exemplary embodiments.

[0056] Spatially relative terms such as "beneath", "below", "lower", "above", "upper", etc. may be used herein for convenience of description to describe the relationship of one element or feature to another element or feature as shown in the figures. It should be understood that in addition to the orientation shown in the drawings, spatially relative terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is turned over, the elements described as being "below" or "beneath" other elements or features will subsequently be oriented to be above the other elements or features. Therefore, the exemplary term "below" may include both the orientations of above and below. The device can be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein are interpreted accordingly.

[0057] The terms used herein are for the purpose of describing specific embodiments only and are not intended to be limiting of the exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" as used herein are also intended to include the plural forms. It will also be understood that if the words "comprise", "comprising", "include", and / or "including" are used herein, the presence of stated features, integers, steps, operations, elements, and / or components is indicated, but the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or clusters thereof is not excluded.

[0058] Exemplary embodiments of the inventive concept are described herein with reference to cross-sectional views of schematic diagrams of idealized embodiments (and intermediate structures) of exemplary embodiments. Thus, variations in the shapes of the illustrations resulting from, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, exemplary embodiments of the inventive concept should not be construed as limited to the particular shapes of the regions shown herein, but rather include deviations in shape resulting from, for example, manufacturing.

[0059] Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the exemplary embodiments of the inventive concept belong. It should also be understood that, unless explicitly defined as such herein, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense.

[0060] Expressions such as "at least one of," "one of," and "selected from" following a list of elements modify the entire list of elements and do not modify the individual elements of the list. In addition, when describing embodiments of the inventive concept, the use of "may" refers to "one or more embodiments of the invention."

[0061] Figure 1 is a perspective view showing an example of the electronic device ED. Figure 2 is a cross-sectional view illustrating a display device DD according to an embodiment of the inventive concept. Figure 2 is along Figure 1 A cross-sectional view taken along line II'. Figure 3 is a cross-sectional view illustrating a light emitting device OEL according to an embodiment of the inventive concept.

[0062] In one or more embodiments, the electronic device ED may be one of large electronic devices (e.g., a television, a monitor, and / or an outdoor billboard). In one or more embodiments, the electronic device ED may be one of small and medium-sized electronic devices (e.g., a personal computer, a notebook computer, a personal digital assistant, a car navigation system, a game console, a portable electronic device, and / or a camera). However, it should be understood that these are some examples of the inventive concept, and other electronic devices may be used to implement the inventive concept as long as they do not deviate from the inventive concept.

[0063] The electronic device ED may include a display device DD and a housing HAU. The display device DD may display an image IM through a display surface IS. Figure 1 , the display surface IS is shown to be parallel to (eg, located at) a plane defined by the first direction axis DR1 and the second direction axis DR2 intersecting each other. However, the inventive concept is not limited to this example, and in one or more embodiments, the display surface IS of the display device DD may have a curved shape.

[0064] A direction perpendicular to the display surface IS (ie, the thickness direction of the display device DD or the third directional axis DR3) will be used to indicate the direction in which the image IM is displayed. The front or top surface and the rear or bottom surface of each member can be distinguished based on the third directional axis DR3.

[0065] The fourth direction axis DR4 may be a direction that is not parallel to both the first direction axis DR1 and the second direction axis DR2 (for example, the fourth direction axis DR4 may be a diagonal direction between the first direction axis DR1 and the second direction axis DR2). The fourth direction axis DR4 may be located on a plane defined by the first direction axis DR1 and the second direction axis DR2 or parallel to the plane. The directions indicated by the first direction axis DR1, the second direction axis DR2, the third direction axis DR3, and the fourth direction axis DR4 are relative, and in some embodiments, they may be used to indicate other directions.

[0066] The housing HAU may be an element that includes the display device DD. The housing HAU may be arranged to cover the display device DD while exposing the display surface IS or the top surface of the display device DD. The housing HAU may cover the side surface and the bottom surface of the display device DD, and may expose the entire top surface. However, the inventive concept is not limited to this example, and in one or more embodiments, the housing HAU may cover not only the side surface and the bottom surface of the display device DD, but also a portion of the top surface.

[0067] The display device DD may include a display panel DP and a light control layer PP located on the display panel DP. The display panel DP may include a light emitting device OEL. The display device DD may include a plurality of light emitting devices OEL. The light control layer PP may be arranged on the display panel DP to control reflected light from the display panel DP caused by external light. The light control layer PP may include, for example, a polarizing layer and / or a color filter layer.

[0068] Figure 3 is a diagram showing a light emitting device OEL according to an embodiment of the present inventive concept, and refers to Figure 3 The light emitting device OEL may include a first electrode EL1, a second electrode EL2 opposite to the first electrode EL1, and a plurality of functional layers disposed between the first electrode EL1 and the second electrode EL2 and including an emission layer EML.

[0069] The emission layer EML may include a manganese complex HS and quantum dots QD. The emission layer EML may include a plurality of quantum dots QD. The quantum dots QD included in the emission layer EML may be stacked to form a layer. Figure 3 An example in which quantum dots QD having a circular cross-section are arranged in two layers is shown, but the inventive concept is not limited to this example. For example, based on the thickness of the emission layer EML, the shape of the quantum dots QD included in the emission layer EML, and / or the average diameter of the quantum dots QD, the arrangement of the quantum dots QD may be changed. In one or more embodiments, the quantum dots QD in the emission layer EML may be aligned adjacent to each other (e.g., adjacent) to form a single layer, or may be aligned to form multiple layers (e.g., two layers or three layers).

[0070] The manganese complex HS may be included in the emission layer EML together with the quantum dot QD. The manganese complex HS may be arranged to fill the space between the quantum dots QD adjacent to each other or surround the quantum dot QD. That is, in the light-emitting device OEL according to one or more embodiments of the inventive concept, the emission layer EML may be filled with or composed of the quantum dot QD and the manganese complex HS.

[0071] In one or more embodiments, the manganese complex HS and the quantum dot QD may be included in the emission layer EML with a weight ratio of 1:1 to 1:2. In the case where the weight ratio between the manganese complex HS and the quantum dot QD is in the range of 1:1 to 1:2, the filling factor of the light-emitting material in the emission layer EML may be increased, and in this case, the loss of electrons or holes can be reduced, and the characteristics of the luminous efficiency and service life of the light-emitting device OEL are improved. For example, if the weight ratio between the manganese complex HS and the quantum dot QD is greater than 1:2, the manganese complex HS in the emission layer EML may have a relatively low content, and in this case, the filling factor in the emission layer EML may be reduced, resulting in a reduction in the service life of the light-emitting device OEL. If the weight ratio between the manganese complex HS and the quantum dot QD is less than 1:1, the quantum dot QD in the emission layer EML may have a relatively low content, and in this case, the amount of light emitted from the emission layer EML may be reduced, resulting in a reduction in the optical efficiency of the emission layer EML.

[0072] In one or more embodiments, the light emitting device OEL may include a plurality of functional layers disposed between the first electrode EL1 and the second electrode EL2. The functional layers may include a hole transport region HTR disposed between the first electrode EL1 and the emission layer EML and an electron transport region ETR disposed between the emission layer EML and the second electrode EL2.

[0073] Each of the hole transport region HTR and the electron transport region ETR may include a plurality of sub-functional layers. For example, the hole transport region HTR may include a hole injection layer HIL and a hole transport layer HTL as its sub-functional layers, and the electron transport region ETR may include an electron injection layer EIL and an electron transport layer ETL as its sub-functional layers. However, the inventive concept is not limited to this example, and in one or more embodiments, the hole transport region HTR may further include an electron blocking layer and / or a similar layer as its sub-functional layer, and the electron transport region ETR may further include a hole blocking layer and / or a similar layer as its sub-functional layer.

[0074] In one or more embodiments, the first electrode EL1 of the light emitting device OEL may be conductive. The first electrode EL1 may be formed of or include at least one of a metal alloy and a conductive compound. The first electrode EL1 may be an anode. The first electrode EL1 may be a pixel electrode.

[0075] In the light-emitting device OEL according to the embodiment of the present inventive concept, the first electrode EL1 may be a reflective electrode. However, the present inventive concept is not limited to this example. For example, the first electrode EL1 may be a transparent electrode and / or a transflective electrode, etc. In the case where the first electrode EL1 is a transflective electrode or a reflective electrode, the first electrode EL1 may be formed of at least one of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, a compound thereof, and a mixture thereof (e.g., a mixture of Ag and Mg), or include them. In one or more embodiments, the first electrode EL1 may be a multilayer structure including a reflective layer or a transflective layer (e.g., any one of the above materials) and a transparent conductive layer (e.g., indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO) and / or indium tin zinc oxide (ITZO)). For example, the first electrode EL1 may be a multilayer metal layer and may have a structure of a metal layer of stacked ITO / Ag / ITO.

[0076] The hole transport region HTR may be disposed on the first electrode EL1. The hole transport region HTR may include a hole injection layer HIL and / or a hole transport layer HTL, etc. In addition to the hole injection layer HIL and the hole transport layer HTL, the hole transport region HTR may further include at least one of a hole buffer layer and an electron blocking layer. The hole buffer layer may compensate for the resonance distance depending on the wavelength of light emitted from the emission layer EML, and therefore, the hole buffer layer may help improve the luminous efficiency. Any suitable material that can be used as the hole transport region HTR may be included in the hole buffer layer. The electron blocking layer may prevent or reduce the injection of electrons from the electron transport region ETR into the hole transport region HTR.

[0077] The hole transport region HTR may have a single-layer structure formed of a single material or a plurality of different materials, or a multilayer structure including a plurality of layers formed of a plurality of different materials. In one or more embodiments, the hole transport region HTR may have a single-layer structure made of a plurality of different materials. In one or more embodiments, the hole transport region HTR may have a multilayer structure of a hole injection layer HIL / hole transport layer HTL, a hole injection layer HIL / hole transport layer HTL / hole buffer layer, a hole injection layer HIL / hole buffer layer, a hole transport layer HTL / hole buffer layer, and a hole injection layer HIL / hole transport layer HTL / electron blocking layer sequentially stacked on the first electrode EL1, but the inventive concept is not limited to these examples.

[0078] The hole transport region HTR may be formed by at least one of various suitable methods such as a vacuum deposition method, a spin coating method, a casting method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method, and / or a laser induced thermal imaging (LITI) method.

[0079] The hole injection layer HIL may include a phthalocyanine compound (e.g., copper phthalocyanine), DNTPD (N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolylamino)-phenyl]-biphenyl-4,4'-diamine), m-MTDATA (4,4',4"-tris(3-methylphenylphenylamino)triphenylamine), TDATA (4,4'4"-tris(N,N-diphenylamino)triphenylamine), 2-TNATA (4,4',4"-tris{N,-(2-naphthyl)-N-phenylamino}-triphenylamine), PEDOT / PSS (poly(3,4-ethylenedioxythiophene) / poly( 4-styrene sulfonate)), PANI / DBSA (polyaniline / dodecylbenzenesulfonic acid), PANI / CSA (polyaniline / camphorsulfonic acid), PANI / PSS ((polyaniline) / poly(4-styrene sulfonate)), NPB (N,N'-di(naphthalene-1-yl)-N,N'-diphenylbenzidine), triphenylamine-containing polyetherketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate, and / or HAT-CN (bispyrazine[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexanenitrile).

[0080] The hole transport layer HTL may include, for example, carbazole derivatives (such as N-phenylcarbazole and / or polyvinylcarbazole), fluorine derivatives, triphenylamine derivatives (such as TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine) and / or TCTA (4,4',4"-tri(N-carbazolyl)triphenylamine)), NPB (N,N'-di(naphthalene-1-yl)-N,N'-diphenylbenzidine), TAPC (4,4'-cyclohexylenebis[N,N-bis(4-methylphenyl)benzylamine]), HMTPD (4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl) and / or mCP (1,3-bis(N-carbazolyl)benzene).

[0081] The emission layer EML may be disposed on the hole transport region HTR. The emission layer EML may have a thickness in a range of, for example, about 5 nm to about 20 nm or about 10 nm to about 20 nm. As described above, the emission layer EML may include a manganese complex HS and quantum dots QD.

[0082] The manganese complex HS may be represented by the following Chemical Formula 1.

[0083] Chemical formula 1

[0084] XpMnYq.

[0085] In Chemical Formula 1, X may be a monovalent or divalent cationic organic compound group, and Y may be a halogen atom. In Chemical Formula 1, p may be 1 or 2, and q may be 4 or 6.

[0086] X may be a monovalent or divalent cationic group and may be, for example, NEDA (N-(1-naphthyl)ethane ammonium), CETMA (2-(chloroethyl)trimethylammonium), CPTMA ((3-carboxypropyl)trimethylammonium), BzTBA (benzyltributylammonium), PTEA (phenyltriethylammonium), PPN (bis(triphenylphosphinidenyl)ammonium), Melam (melamine), TMPhA (trimethylphenylammonium), BuPyr (1-butylpyridine), Piper (piperidine), DodecA (dodecammonium), Dipyr ([4,4'-bipyridine]-1,1'-sodium), PEA (2-phenylethylammonium), PPA (3-phenylpropylammonium), Phenan (phenanthroline), EBzD (ethyl benzamide), tOHPyr (2-hydroxypyridinium), TEBzA (benzyltriethylammonium), MNA (1-methylnicotinamide), DPEDA (N,N'-diphenylethyldiamine), DopA (dopamine), DAPyr (2,6-diaminopyridine), DIPA (diisopropylamine), DBA (dibutylamine), tPicol (2-methylpyridine), DMBzA (N,N-dimethyl-1-phenylmethylammonium), VTPP (triphenylvinylphosphine), BrMTPP ((bromomethyl)triphenylphosphine), BrPTPP ((3-bromopropyl)triphenylphosphine), OHETPP ((2-hydroxyethyl)triphenylphosphine), TPP (tetraphenylphosphine), MPPP (methyltriphenylphosphine), ETPP (ethyltriphenylphosphine), BzTPP (benzyltriphenylphosphine), ATPP (allyltriphenylphosphine), PrTPP (propyltriphenylphosphine), BuTPP (butyltriphenylphosphine), TBP (tetrabutylphosphine), TMA (tetramethylammonium), TEA (tetraethylammonium), TPA (tetrapropylammonium), TBA (tetrabutylammonium), BMPIP (butylmethylpiperidinium), G (guanidinium), Acetam (acetamide), and / or TU (thiourea). For example, X may be a cationic form of the above compounds, and may correspond to a monovalent or divalent cationic group.

[0087] In one or more embodiments, X in the manganese complex HS included in the light emitting device OEL may be BrMTPP, BrPTPP, TPP, TMA, and / or TEA.

[0088] In Chemical Formula 1, p may be an integer of 1 or 2. If X is a monovalent cationic group, p may be 2, and if X is a divalent cationic group, p may be 1.

[0089] MnYq may be a divalent anion group. In other words, it may be represented as MnYq2-. Here, q may be 4 or 6. For example, MnYq2- may be MnY42- or MnY62-.

[0090] Y may be a halogen atom, and may be Cl, Br and / or I.

[0091] In one or more embodiments, the manganese complex HS may be [Ph4P]2MnBr4. Here, [Ph4P] may correspond to TPP (tetraphenylphosphine).

[0092] In one or more embodiments, the emission layer EML of the light emitting device OEL may include quantum dots QD. The core of the quantum dot QD may be selected from a cluster consisting of II-VI compounds, I-III-VI compounds, III-V compounds, IV-VI compounds, IV elements, IV compounds, and combinations thereof.

[0093] The II-VI compounds may be selected from binary compounds (e.g., comprising CdSe, CdTe, CdS, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe and / or MgS), mixtures of binary compounds, ternary compounds (e.g., comprising AgInS, CuInS, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe and / or MgZnS), mixtures of ternary compounds, quaternary compounds (for example, including HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and / or HgZnSTe) and mixtures of quaternary compounds.

[0094] The Group I-III-VI compound may be selected from a cluster consisting of a ternary compound (e.g., comprising AgInS2, CuInS2, AgGaS2 and / or CuGaS2), a mixture of ternary compounds, a quaternary compound (e.g., comprising AgInGaS2 and / or CuInGaS2) and a mixture of quaternary compounds.

[0095] The III-V compounds may be selected from a cluster consisting of binary compounds (e.g., comprising GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs and / or InSb), a mixture of binary compounds, a ternary compound (e.g., comprising GaNPs, GaNAs, GaNSb, GaPAs, GaPSb, AlNPs, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InAlP, InNP, InNAs, InNSb, InPAs and / or InPSb), a mixture of ternary compounds, a quaternary compound (e.g., comprising GaAlNPs, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNPs, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNPs, InAlNAs, InAlNSb, InAlPAs and / or InAlPSb) and a mixture of quaternary compounds.

[0096] The IV-VI compounds may be selected from a cluster consisting of binary compounds (e.g., including SnS, SnSe, SnTe, PbS, PbSe and / or PbTe), a mixture of binary compounds, a ternary compound (e.g., including SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe and / or SnPbTe), a mixture of ternary compounds, a quaternary compound (e.g., including SnPbSSe, SnPbSeTe and / or SnPbSTe), and a mixture of quaternary compounds. The IV group elements may be selected from a cluster consisting of Si, Ge, and mixtures thereof. The IV group compounds may include binary compounds selected from a cluster consisting of SiC, SiGe, and mixtures thereof.

[0097] Here, the binary compound, ternary compound and / or quaternary compound may have a uniform concentration throughout the particle, or may have a spatially varying concentration distribution in each particle. In one or more embodiments, each of the quantum dots may have a core / shell structure in which one quantum dot is surrounded by another quantum dot. At the interface between the core and the shell, the element contained in the shell may have a concentration gradient that decreases in the center direction (e.g., in the direction toward the center of the core).

[0098] In some embodiments, the quantum dot QD may have a core-shell structure including a core containing the above-mentioned nanocrystals and a shell surrounding the core. The shell of the quantum dot QD with a core-shell structure can be used as a protective layer that can prevent or protect the chemical properties of the core from being changed and can retain the semiconductor properties of the core, and / or can be used as a charged layer that allows the quantum dot QD to have electrophoretic properties. The shell may be a single layer or multiple layers. At the interface between the core and the shell, the elements contained in the shell may have a concentration gradient that decreases in the center direction. For example, the shell of the quantum dot QD with a core-shell structure may be formed by oxides of metals and / or non-metallic elements, semiconductor compounds, or any combination thereof, or include them.

[0099] The oxides of metal and / or non-metal elements may be, for example, binary compounds (e.g., SiO2, Al2O3, TiO2, ZnO, MnO, Mn2O3, Mn3O4, CuO, FeO, Fe2O3, Fe3O4, CoO, Co3O4 and / or NiO) and / or ternary compounds (e.g., MgAl2O4, CoFe2O4, NiFe2O4 and / or CoMn2O4), however, the inventive concept is not limited to these examples.

[0100] The semiconductor compounds may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP and / or AlSb, etc., but the inventive concepts are not limited to these examples.

[0101] Each of the quantum dots QD may have a light emission wavelength spectrum whose full width at half maximum (FWHM) is less than about 45 nm (e.g., less than about 40 nm or less than about 30 nm), and in this case, color purity or color reproduction characteristics can be improved. In addition, the quantum dot QD may allow light to be emitted radially in all directions, and therefore, viewing angle properties can be improved.

[0102] In one or more embodiments, the quantum dot QD may be a spherical, pyramidal, multi-armed and / or cubic nanoparticle. In one or more embodiments, the quantum dot QD may be a nanotube, nanowire, nanofiber, nanoplate-like particle, but the inventive concept is not limited to these examples.

[0103] The wavelength or color of light emitted from a quantum dot QD may be determined by the particle size of the quantum dot QD, and by providing quantum dots of various sizes, various colors (e.g., blue, red, and / or green) can be achieved. The smaller the particle size of the quantum dot QD, the shorter the wavelength of light emitted from the quantum dot QD. For example, even in a quantum dot QD having the same core, the particle size of a quantum dot emitting green light may be smaller than the particle size of a quantum dot emitting red light. In addition, even in a quantum dot QD having the same core, the particle size of a quantum dot emitting blue light may be smaller than the particle size of a quantum dot emitting green light. However, the inventive concept is not limited to these examples, and in one or more embodiments, even in a quantum dot QD having the same core, the particle size may be changed according to the material of the shell, the thickness of the shell, and the like.

[0104] In the case where the quantum dot QD has various luminescent colors such as blue, red and / or green, the quantum dot QDs having different luminescent colors may be different from each other in their core materials. In the light-emitting device OEL according to an embodiment of the inventive concept, the emission layer EML may include a host and a dopant. In one or more embodiments, the emission layer EML may include a manganese complex HS and a quantum dot QD used as a host and a dopant material, respectively.

[0105] In the light emitting device OEL according to an embodiment of the inventive concept, the emission layer EML may have a fluorescent light emitting property. For example, the quantum dot QD may be formed of a fluorescent dopant material or include a fluorescent dopant material.

[0106] In the light emitting device OEL according to an embodiment of the inventive concept, energy may be transferred from the manganese complex HS to the quantum dot QD. For example, energy may be transferred from the manganese complex HS to the quantum dot QD through a Forster resonance energy transfer (FRET) mechanism.

[0107] The wavelength of light emitted from the emission layer EML may vary according to the kind (or type) of quantum dots QD. The emission layer EML may include a manganese complex HS and quantum dots QD, and the light emitting device OEL may emit blue light, green light, or red light according to the combination of the manganese complex HS and the quantum dots QD.

[0108] If the manganese complex HS is XpMnY4, the manganese complex HS can be used as a host material of an emission layer EML that emits green light. If the manganese complex HS is XpMnY6, the manganese complex HS can be used as a host material of an emission layer EML that emits red light. For example, in the light-emitting device OEL according to an embodiment of the inventive concept, if the manganese complex HS is XpMnY4, the emission layer EML can emit green light, and if the manganese complex HS is XpMnY6, the emission layer EML can emit red light.

[0109] The hole transport region HTR can be formed by synchronously (or simultaneously) applying at least one of various suitable methods such as a vacuum deposition method, a spin coating method, a casting method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method and / or a laser induced thermal imaging (LITI) method to the manganese complex HS and the quantum dots QD.

[0110] In the light emitting device OEL according to an embodiment of the inventive concept, the emission layer EML may further include at least one of suitable anthracene-based light emitting materials.

[0111] In one or more embodiments, the emission layer EML may further include at least one of the suitable host materials. For example, the emission layer EML may further include Alq3 (tris (8-hydroxyquinolyl) aluminum), CBP (4,4'-bis (N-carbazolyl) -1,1'-biphenyl), PVK (poly (n-vinyl carbazole)), ADN (9,10-di (naphthalene-2-yl) anthracene), TCTA (4,4',4"-tri (carbazol-9-yl) -triphenylamine), TPBi (1,3,5-tri (N-phenylbenzimidazol-2-yl) benzene), TBADN (3-tert-butyl-9,10-di (naphthalene-2-yl) anthracene), DSA (distyrene), CDBP (4,4'-bis (9-carbazolyl) -2,2 ”-dimethyl-biphenyl), MADN (2-methyl-9,10-bis(naphthalene-2-yl)anthracene), DPEPO (bis[2-(diphenylphosphino)phenyl]ether oxide), CP1 (hexaphenylcyclotriphosphazene), UGH2 (1,4-bis(triphenylsilyl)benzene), DPSiO3 (hexaphenylcyclotrisiloxane), DPSiO4 (octaphenylcyclotetrasiloxane), PPF (2,8-bis(diphenylphosphino)dibenzofuran), mCBP (3,3'-bis(N-carbazolyl)-1,1'-biphenyl) and / or mCP (1,3-bis(N-carbazolyl)benzene), etc. as their main materials. However, the concept of the present invention is not limited to this example, and in one or more embodiments, in addition to the main materials listed above, at least one of other suitable main materials may be included in the emission layer EML.

[0112] In one or more embodiments, the emission layer EML of the light emitting device OEL may further include at least one of suitable dopant materials. For example, the emission layer EML may also include styryl derivatives (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styryl]diphenylethylene (DPAVB) and / or N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalene-2-yl)vinyl)phenyl)-N-phenylbenzylamine (N-BDAVBi)), perylene and its derivatives (e.g., 2,5,8,11-tetra-tert-butylperylene (TBP)), pyrene and its derivatives (e.g., 1,1-dipyrene, 1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene and / or 2,5,8,11-tetra-tert-butylperylene (TBP)) as dopant materials.

[0113] In the light emitting device OEL according to one or more embodiments of the inventive concept, the electron transport region ETR may be disposed on the emission layer EML. The electron transport region ETR may include at least one of a hole blocking layer, an electron transport layer ETL, and an electron injection layer EIL, but the inventive concept is not limited to this example.

[0114] The electron transport region ETR may have a single-layer structure formed of a single material or a plurality of different materials, or a multi-layer structure including a plurality of layers formed of a plurality of different materials.

[0115] For example, the electron transport region ETR may have a single-layer structure of an electron injection layer EIL or an electron transport layer ETL, or may have a single-layer structure formed of an electron injection material and an electron transport material. In one or more embodiments, the electron transport region ETR may have a single-layer structure made of a plurality of different materials, or may have a structure of an electron transport layer ETL / electron injection layer EIL or a structure of a hole blocking layer / electron transport layer ETL / electron injection layer EIL sequentially stacked from the emission layer EML, but the inventive concept is not limited to these examples. The thickness of the electron transport region ETR may be, for example, about 1000 Å. to about within the range.

[0116] The electron transport region ETR may be formed by at least one of various suitable methods such as a vacuum deposition method, a spin coating method, a casting method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method, and / or a laser induced thermal imaging (LITI) method.

[0117] In the case where the electron transport region ETR includes an electron transport layer ETL, the electron transport region ETR may include at least one of the anthracene-based compounds. However, the inventive concept is not limited to this example, and in one or more embodiments, the electron transport region ETR may include, for example, Alq3 (tris (8-hydroxyquinolyl) aluminum), 1,3,5-tris [(3-pyridyl) -phenyl-3-yl] benzene, 2,4,6-tris (3'- (pyridin-3-yl) biphenyl-3-yl) -1,3,5-triazine, 2- (4- (N-phenylbenzimidazolyl-1-yl) phenyl) -9,10-dinaphthyl anthracene, TPBi (1,3,5-tris (1-phenyl-1H-benzo [d] imidazole-2-yl) phenyl), BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen ( At least one of 4,7-diphenyl-1,10-phenanthroline), TAZ (3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), NTAZ (4-(naphthalene-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), tBu-PBD (2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), BAlq (bis(2-methyl-8-quinolyl-N1,O8)-(1,1'-biphenyl-4-ato)aluminum), Bebq2 (bis(benzoquinolin-10-ato)beryllium), ADN (9,10-di(naphthalene-2-yl)anthracene), and mixtures thereof. The thickness of the electron transport layer ETL may be about 1000 nm. to about within the range (particularly, within about to about In the case where the thickness of the electron transport layer ETL is within this range, satisfactory electron transport properties can be obtained without significantly increasing the driving voltage.

[0118] In the case where the electron transport region ETR includes an electron injection layer EIL, the electron transport region ETR may include a metal halide, a metal lanthanide and / or a co-deposited material of a metal halide and a metal lanthanide and / or the like. In one or more embodiments, the metal halide may be an alkali metal halide. For example, the electron transport region ETR may include LiF, Liq (lithium quinolinate), Li2O, BaO, NaCl, CsF, Yb, RbCl, RbI, KI and / or KI:Yb, but the inventive concept is not limited to these examples. In one or more embodiments, the electron injection layer EIL may be formed of a material mixed with an electron transport material and an insulating organic metal salt. For example, the organic metal salt may include an acetate metal salt, a benzoate metal salt, an acetoacetate metal salt, an acetylacetone metal salt and / or a stearate metal salt. The thickness of the electron injection layer EIL may be about 1000 nm. to about within the range of or about to about When the thickness of the electron injection layer EIL is within this range, a satisfactory electron injection property can be obtained without significantly increasing the driving voltage.

[0119] As described above, the electron transport region ETR may include a hole blocking layer. The hole blocking layer may include, for example, at least one of BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) and Bphen (4,7-diphenyl-1,10-phenanthroline), but the inventive concept is not limited to these examples.

[0120] The second electrode EL2 may be disposed on the electron transport region ETR. The second electrode EL2 may be a common electrode or a cathode. The second electrode EL2 may be a transparent electrode, a transflective electrode, or a reflective electrode. If the second electrode EL2 is a transparent electrode, the second electrode EL2 may be formed of a transparent metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and / or indium tin zinc oxide (ITZO).

[0121] If the second electrode EL2 is a transflective electrode or a reflective electrode, the second electrode EL2 may be formed of at least one of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, a compound thereof, and a mixture thereof (e.g., a mixture of Ag and Mg), or include them. In one or more embodiments, the second electrode EL2 may be a multilayer structure including a reflective layer or a transflective layer (e.g., of the above materials) and a transparent conductive layer (e.g., of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and / or indium tin zinc oxide (ITZO)).

[0122] The second electrode EL2 may be connected to the auxiliary electrode. If the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 may be reduced.

[0123] Figure 4 is an energy band diagram illustrating an energy band structure of a light emitting device OEL according to an embodiment of the inventive concept. Figure 4 The relative energy levels of the electrodes EL1 and EL2 and the functional layers HTR, EML and ETR are shown, rather than the absolute values ​​of the energy levels. In the energy band diagram, the sub-functional layers HIL, HTL, ETL and EIL, the manganese complex HS and the quantum dots QD are represented by rectangular boxes, the top of the rectangular box represents the lowest unoccupied molecular orbital (LUMO) energy level, and the bottom of the rectangular box represents the highest occupied molecular orbital (HOMO) energy level.

[0124] exist Figure 4, the LUMO energy level of the hole transport layer HTL is represented by E-HTL, and the LUMO energy level of the quantum dot QD is represented by E-QD. In one or more embodiments, the difference between the LUMO energy level E-HTL of the hole transport layer HTL and the LUMO energy level E-QD of the quantum dot QD may be greater than or equal to 1.5 eV. Since the difference between the LUMO energy level E-HTL of the hole transport layer HTL and the LUMO energy level E-QD of the quantum dot QD is greater than or equal to 1.5 eV, the loss of electrons lost from the emission layer EML to the hole transport region HTR can be reduced. In addition, the hole transport region HTR can be suppressed or prevented from being damaged by the movement of electrons. However, the inventive concept is not limited to this example, and in one or more embodiments, the difference between the LUMO energy level E-HTL of the hole transport layer HTL and the LUMO energy level E-QD of the quantum dot QD may be less than 1.5 eV, as long as the loss of electrons from the emission layer EML to the hole transport region HTR can be reduced or minimized.

[0125] Since the emission layer EML includes the manganese complex HS having a higher LUMO level than the LUMO level E-QD of the quantum dot QD, the manganese complex HS may serve as an energy barrier and thus, can reduce the amount of electrons transferred to the hole transport layer HTL and lost.

[0126] In the light emitting device OEL according to an embodiment of the inventive concept, the emission layer EML may include a manganese complex HS having a LUMO energy level higher than the LUMO energy level E-QD of the quantum dot QD, and the hole transport layer HTL and the quantum dot QD may be provided so that the difference between their LUMO energy levels E-HTL and E-QD is greater than or equal to 1.5 eV. Therefore, the amount of electrons transmitted to the hole transport layer HTL can be reduced, and thus the luminous efficiency of the quantum dot QD can be improved. As a result, the efficiency of the light emitting device OEL can be improved.

[0127] exist Figure 4 , the hole transport layer HTL as one of the sub-functional layers of the hole transport region HTR is shown as a sub-functional layer of the hole transport region HTR that is closest to the emission layer EML, but the inventive concept is not limited to this example. For example, the hole transport region HTR may also include an electron blocking layer that serves as a sub-functional layer adjacent to the emission layer EML, and in this case, the difference between the LUMO energy level of the electron blocking layer and the LUMO energy level E-QD of the quantum dot QD may be greater than or equal to 1.5 eV.

[0128] That is, in the light-emitting device OEL according to one or more embodiments of the present inventive concept, the difference between the LUMO energy level of the sub-functional layer which is one of the multiple sub-functional layers included in the hole transport region HTR and is closest to the emission layer EML and the LUMO energy level E-QD of the quantum dot QD may be greater than or equal to 1.5 eV.

[0129] Figure 5 The concentration distributions of holes and electrons in the exemplary embodiment and the comparative embodiment of the present disclosure are shown in a comparative manner. Figure 5 In the embodiment, the light emitting device according to the exemplary embodiment has Figure 3 The light emitting device OEL according to the exemplary embodiment has the same structure as the light emitting device OEL, while the light emitting device according to the comparative embodiment has a structure in which the manganese complex HS of the emission layer EML is removed, unlike the exemplary embodiment. In the light emitting devices according to the exemplary example and the comparative embodiment, the functional layers HTL and ETL may have substantially the same structure, although there is a difference in structure between the emission layers EML and EML'.

[0130] Figure 5 The hole concentration C-HL and the electron concentration C-EL in the hole transport layer HTL, the emission layer EML, and the electron transport layer ETL are shown.

[0131] exist Figure 5 EL-C0 represents the electron concentration at the interface between the hole transport layer HTL and the emission layer EML in the exemplary embodiment, and EL-C0′ represents the electron concentration at the interface between the hole transport layer HTL and the emission layer EML′ in the comparative embodiment. G-EL represents the difference between EL-C0 and EL-C0′. Figure 5 , the electron concentration at the interface between the hole transport layer HTL and the emission layer EML in the exemplary embodiment is lower than that in the comparative embodiment. Without being bound by any particular theory, it is believed that this may be because for the exemplary embodiment, due to the presence of the manganese complex further disposed in the emission layer EML, the amount of electrons transferred from the emission layer EML to the hole transport layer HTL is reduced.

[0132] exist Figure 5 HL-C0 represents the hole concentration at the interface between the electron transport layer ETL and the emission layer EML in the exemplary embodiment, and HL-C0′ represents the hole concentration at the interface between the electron transport layer ETL and the emission layer EML′ in the comparative embodiment. G-HL represents the difference between HL-C0 and HL-C0′. Figure 5 , the hole concentration at the interface between the electron transport layer ETL and the emission layer EML in the exemplary embodiment is lower than that in the comparative embodiment. Without being bound by any particular theory, it is believed that this may be because for the exemplary embodiment, due to the manganese complex further provided in the emission layer EML, the amount of holes transferred from the emission layer EML to the electron transport layer ETL is reduced.

[0133] In addition to quantum dots, the light-emitting device according to one or more embodiments of the present inventive concept may further include a manganese complex in the emission layer, and the manganese complex may enable the light-emitting device to have high luminous efficiency. In the light-emitting device according to one or more embodiments of the present inventive concept, the manganese complex included in the emission layer may maintain charges in the emission layer (such as holes or electrons provided from a hole transport region or an electron transport region adjacent to the emission layer), and may transfer energy to the quantum dots to improve the efficiency of light generated by the quantum dots. In addition, in the light-emitting device according to one or more embodiments of the present inventive concept, because the emission layer includes not only quantum dots but also manganese complexes, the filling factor of the emission layer is increased, and compared with the case where the emission layer includes only quantum dots, the problem of resistance increase that may be caused by the movement of charges can be suppressed or reduced, and thus high luminous efficiency is achieved.

[0134] Figure 6 is a plan view illustrating a display device DD according to an embodiment of the inventive concept. Figure 7 is a cross-sectional view showing a display device DD according to an embodiment of the present inventive concept. In detail, Figure 7 is along Figure 6 A cross-sectional view taken along line II-II'.

[0135] In one or more embodiments, the display device DD may include a plurality of light-emitting devices OEL-1, OEL-2, and OEL-3, and the light-emitting devices OEL-1, OEL-2, and OEL-3 may respectively include emission layers EML-B, EML-G, and EML-R respectively including quantum dots QD1, QD2, and QD3 and a manganese complex HS.

[0136] In addition, the display device DD may include a display panel DP including a plurality of light emitting devices OEL-1, OEL-2, and OEL-3, and a light control layer PP disposed on the display panel DP. In one or more embodiments, the light control layer PP may be omitted from the display device DD.

[0137] The display panel DP may include a base substrate BS, and a circuit layer DP-CL and a display device layer DP-OEL arranged on the base substrate BS. The display device layer DP-OEL may include a pixel defining layer PDL, light emitting devices OEL-1, OEL-2, and OEL-3 arranged between portions of the pixel defining layer PDL, and an encapsulation layer TFE arranged on the light emitting devices OEL-1, OEL-2, and OEL-3.

[0138] The base substrate BS may provide a base surface on which the display device layer DP-OEL is arranged. The base substrate BS may be a glass substrate, a metal substrate, and / or a plastic substrate, etc. However, the inventive concept is not limited to this example, and in one or more embodiments, the base substrate BS may be an inorganic layer, an organic layer, or a composite layer.

[0139] In one or more embodiments, the circuit layer DP-CL may be arranged on the base substrate BS and may include a plurality of transistors. Each of the transistors may include a control electrode, an input electrode, and an output electrode. In one or more embodiments, the circuit layer DP-CL may include a switching transistor and a driving transistor for driving the light emitting devices OEL-1, OEL-2, and OEL-3 of the display device layer DP-OEL.

[0140] Each of the light-emitting devices OEL-1, OEL-2, and OEL-3 may include a first electrode EL1, a hole transport region HTR, an emission layer EML-B, EML-G, or EML-R, an electron transport region ETR, and a second electrode EL2. The light-emitting devices OEL-1, OEL-2, and OEL-3 may be configured to have substantially the same features as the light-emitting device OEL described above. In other words, the emission layer EML-B, EML-G, or EML-R of the light-emitting device OEL-1, OEL-2, or OEL-3 may include a manganese complex HS and quantum dots QD1, QD2, or QD3.

[0141] The emission layer EML-B, EML-G, or EML-R may include a manganese complex represented by the following Chemical Formula 1 as a host thereof, and may include quantum dots QD1, QD2, or QD3 as a dopant thereof.

[0142] Chemical formula 1

[0143] XpMnYq.

[0144] In Chemical Formula 1, X may be a monovalent or divalent cationic organic compound group, and Y may be a halogen atom. In Chemical Formula 1, p may be 1 or 2, and q may be 4 or 6.

[0145] The encapsulation layer TFE may cover the light emitting devices OEL-1, OEL-2, and OEL-3. The encapsulation layer TFE may be a single layer or may include a plurality of stacked layers. The encapsulation layer TFE may be a thin encapsulation layer. The encapsulation layer TFE may protect the light emitting devices OEL-1, OEL-2, and OEL-3. The encapsulation layer TFE may cover the top surface of the second electrode EL2 disposed in the opening OH and may fill the opening OH.

[0146] In one or more embodiments, a cover layer may be further disposed on the second electrode EL2. In other words, the cover layer may be disposed between the second electrode EL2 and the encapsulation layer TFE. Figure 6 and Figure 7 , the display device DD may include a non-light emitting area NPXA and light emitting areas PXA-B, PXA-G, and PXA-R. Each of the light emitting areas PXA-B, PXA-G, and PXA-R may be an area through which light generated in the light emitting devices OEL-1, OEL-2, and OEL-3 is emitted. When viewed in a plan view, the light emitting areas PXA-B, PXA-G, and PXA-R may be spaced apart from each other (e.g., see Figure 6 ).

[0147] The light emitting regions PXA-B, PXA-G, and PXA-R may be divided into a plurality of groups according to the colors of the lights generated in the light emitting devices OEL-1, OEL-2, and OEL-3. Figure 6 and Figure 7 In the display device DD according to the embodiment shown in , three light emitting areas PXA-B, PXA-G and PXA-R that emit blue light, green light and red light, respectively, are exemplarily shown. For example, the display device DD may include a blue light emitting area PXA-B, a green light emitting area PXA-G and a red light emitting area PXA-R that are distinguished (separated / patterned) from each other.

[0148] The plurality of light emitting devices OEL-1, OEL-2, and OEL-3 may emit light of different wavelengths. For example, in one or more embodiments, the display device DD may include a first light emitting device OEL-1 that emits blue light, a second light emitting device OEL-2 that emits green light, and a third light emitting device OEL-3 that emits red light. However, the inventive concept is not limited to this example, and in one or more embodiments, the first light emitting device OEL-1, the second light emitting device OEL-2, and the third light emitting device OEL-3 may emit light of the same wavelength or may emit light of at least two different wavelengths.

[0149] For example, the blue light emitting area PXA-B, the green light emitting area PXA-G, and the red light emitting area PXA-R of the display device DD may correspond to the first light emitting device OEL-1, the second light emitting device OEL-2, and the third light emitting device OEL-3, respectively.

[0150] The first emission layer EML-B of the first light emitting device OEL-1 may include a first quantum dot QD1. The first quantum dot QD1 may emit blue light, and the blue light will be referred to as a first color light. The first light emitting device OEL-1 may include a first body.

[0151] The second emission layer EML-G of the second light emitting device OEL-2 and the third emission layer EML-R of the third light emitting device OEL-3 may include a second quantum dot QD2 and a third quantum dot QD3, respectively. The second quantum dot QD2 and the third quantum dot QD3 may emit green light and red light, respectively, and the green light and the red light will be referred to as the second color light and the third color light, respectively. The second light emitting device OEL-2 and the third light emitting device OEL-3 may include a second body and a third body, respectively.

[0152] At least one of the first host, the second host, and the third host may be a manganese complex HS represented by Chemical Formula 1. If at least one of the first to third hosts includes a host material other than the manganese complex HS, it may be formed of or include at least one of suitable host materials. If all of the first host, the second host, and the third host are a manganese complex HS represented by Chemical Formula 1, at least one or all of the first host, the second host, and the third host may be different from each other.

[0153] exist Figure 7 In one or more embodiments shown in , the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 may have sizes different from each other. For example, the first quantum dot QD1 of the first light-emitting device OEL-1 for emitting light of a relatively short wavelength may have an average diameter smaller than the average diameters of the second quantum dot QD2 and the third quantum dot QD3 of the second light-emitting device OEL-2 and the third light-emitting device OEL-3 emitting light of a relatively long wavelength.

[0154] For example, the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 may be arranged to satisfy the average diameter condition given by the following formula 1:

[0155] Formula 1

[0156] The average diameter of the first quantum dots is less than the average diameter of the second quantum dots and less than the average diameter of the third quantum dots.

[0157] In the present specification, the average diameter may correspond to the arithmetic mean of the diameters of a plurality of quantum dot particles. Meanwhile, in a cross-sectional view, the diameter of a quantum dot particle may be the average of the widths (or breadths) of the quantum dot particles.

[0158] The relationship between the average diameters of the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 is not limited to the relationship given by Formula 1. For example, although in accordance with Figure 7In the display device DD of the embodiment, the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 are shown to have different sizes, but the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 included in the light emitting devices OEL-1, OEL-2, and OEL-3 may have sizes similar to each other. In one or more embodiments, the average diameters of two quantum dots selected from the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 may be similar to each other, but may be different from each other.

[0159] In one or more embodiments, the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 included in the light emitting devices OEL-1, OEL-2, and OEL-3 may be formed of core materials different from each other. In one or more embodiments, the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 may be formed of the same core material. In one or more embodiments, two quantum dots selected from the first quantum dot QD1, the second quantum dot QD2, and the third quantum dot QD3 may be formed of the same core material, but may be formed of a core material different from the core material of the other (remaining) quantum dots.

[0160] In accordance with Figure 6 and Figure 7 In the display device DD of the embodiment of the present invention, the light emitting regions PXA-B, PXA-G, and PXA-R may have different areas from each other. Here, the area may be an area measured on a plane defined by the first direction axis DR1 and the second direction axis DR2 or on a plane parallel thereto.

[0161] The light emitting regions PXA-B, PXA-G, and PXA-R may have different areas based on the colors of light emitted from the emission layers EML-B, EML-G, and EML-R of the light emitting devices OEL-1, OEL-2, and OEL-3. Figure 6 and Figure 7 , in the display device DD according to an embodiment of the inventive concept, the blue light emitting region PXA-B corresponding to the first light emitting device OEL-1 emitting blue light may have the largest area, and the green light emitting region PXA-G corresponding to the second light emitting device OEL-2 emitting green light may have the smallest area. However, the inventive concept is not limited to this example. For example, in one or more embodiments, the light emitting regions PXA-B, PXA-G, and PXA-R may be configured to emit other light different from blue light, green light, and red light. In some embodiments, the light emitting regions PXA-B, PXA-G, and PXA-R may have the same area or may have different areas. Figure 6 Different area ratios shown in .

[0162] The light-emitting areas PXA-R, PXA-G, and PXA-B may be different areas defined by the pixel defining layer PDL. The non-light-emitting area NPXA may be an area located between adjacent light-emitting areas in the light-emitting areas PXA-B, PXA-G, and PXA-R and corresponding to a portion of the pixel defining layer PDL. Meanwhile, in the present specification, each of the light-emitting areas PXA-B, PXA-G, and PXA-R may correspond to a pixel. The pixel defining layer PDL may be used to define or define the boundaries of the light-emitting devices OEL-1, OEL-2, and OEL-3. The emission layers EML-B, EML-G, and EML-R of the light-emitting devices OEL-1, OEL-2, and OEL-3 may be arranged in the opening OH defined by the pixel defining layer PDL (e.g., present therein), and thus may be separated from each other.

[0163] The pixel defining layer PDL may be formed of a polymer resin. For example, the pixel defining layer PDL may be formed to include a polyacrylate resin and / or a polyimide resin. In one or more embodiments, in addition to the polymer resin, the pixel defining layer PDL may be formed to also include an inorganic material. In one or more embodiments, the pixel defining layer PDL may be formed to include at least one of a light absorbing material, a black pigment, and a black dye. In the case where the pixel defining layer PDL includes a black pigment and / or a black dye, the pixel defining layer PDL may realize a black pixel defining layer. Carbon black and / or the like may be used as a black pigment and / or a black dye for the pixel defining layer PDL, but the inventive concept is not limited to this example.

[0164] In one or more embodiments, the pixel defining layer PDL may be formed of an inorganic material. For example, the pixel defining layer PDL may be formed to include silicon nitride (SiNx), silicon oxide (SiOx) and / or silicon oxynitride (SiOxNy), etc. The pixel defining layer PDL may define or delimit the light-emitting areas PXA-B, PXA-G, and PXA-R. The light-emitting areas PXA-B, PXA-G, and PXA-R may be separated from the non-light-emitting areas NPXA by the pixel defining layer PDL.

[0165] exist Figure 7 , the hole transport region HTR and the electron transport region ETR are shown as a common layer covering the pixel defining layer PDL, but the inventive concept is not limited to this example. In one or more embodiments, the hole transport region HTR and the electron transport region ETR may be disposed in the opening OH defined in the pixel defining layer PDL.

[0166] For example, in the case where the hole transport region HTR and / or the electron transport region ETR are provided by an inkjet printing method, they may be provided to correspond to the opening OH defined between the portions of the pixel defining layer PDL. However, the inventive concept is not limited to this example, and in one or more embodiments, the hole transport region HTR and the electron transport region ETR may be provided in the form of an unpatterned common layer covering the pixel defining layer PDL, regardless of the formation Figure 7 A method for each of the functional layers shown in FIG.

[0167] Reference Figure 6 The blue light emitting areas PXA-B and the red light emitting areas PXA-R may be alternately arranged along the first direction axis DR1 to constitute a first group PXG1, and the green light emitting areas PXA-G may be arranged along the first direction axis DR1 to constitute a second group PXG2.

[0168] The first group PXG1 and the second group PXG2 may be spaced apart from each other along the second direction axis DR2. In one or more embodiments, a plurality of first groups PXG1 and a plurality of second groups PXG2 may be provided. The first group PXG1 and the second group PXG2 may be alternately arranged along the second direction axis DR2.

[0169] One green light emitting area PXA-G may be spaced apart from one blue light emitting area PXA-B or one red light emitting area PXA-R along the fourth direction axis DR4. The direction of the fourth direction axis DR4 may be a direction not parallel to both the first direction axis DR1 and the second direction axis DR2.

[0170] Figure 6 The arrangement structure of the light emitting areas PXA-B, PXA-G, and PXA-R shown in FIG. 1 may be referred to as a pentile structure. However, in the display device DD according to an embodiment of the inventive concept, the arrangement structure of the light emitting areas PXA-B, PXA-G, and PXA-R is not limited to Figure 6 For example, in one or more embodiments, the light emitting regions PXA-B, PXA-G, and PXA-R may have a stripe structure in which the blue light emitting regions PXA-B, the green light emitting regions PXA-G, and the red light emitting regions PXA-R are sequentially and alternately arranged along the first direction axis DR1.

[0171] Reference Figure 2 and Figure 7 , the display device DD may further include a light control layer PP. The light control layer PP may block or reduce external light propagating from the outside of the display device DD toward the display panel DP. The light control layer PP may block or reduce a portion of the external light. The light control layer PP may serve as an anti-reflection layer that minimizes reflection of external light.

[0172] exist Figure 7In one or more embodiments shown in , the light control layer PP may include a color filter layer CFL. In the display device DD according to an embodiment of the inventive concept, the light control layer PP may include a base layer BL and a color filter layer CFL.

[0173] The base layer BL may be a member that provides a base surface on which the color filter layer CFL and / or the like are arranged. The base layer BL may be a glass substrate, a metal substrate, and / or a plastic substrate, etc. However, the inventive concept is not limited to this example, and in one or more embodiments, the base layer BL may be an inorganic layer, an organic layer, or a composite layer.

[0174] The color filter layer CFL may include a light blocking portion BM and a color filter portion CF. The color filter portion CF may include a plurality of color filters CF-B, CF-G, and CF-R. In other words, the color filter layer CFL may include a first color filter CF-B for providing (e.g., filtering / transmitting) a first color light, a second color filter CF-G for providing a second color light, and a third color filter CF-R for providing a third color light. For example, the first color filter CF-B may be a blue color filter, the second color filter CF-G may be a green color filter, and the third color filter CF-R may be a red color filter.

[0175] Each of the color filters CF-B, CF-G, and CF-R may include a polymer photosensitive resin and a pigment and / or dye. The first color filter CF-B may include a blue pigment and / or dye, the second color filter CF-G may include a green pigment and / or dye, and the third color filter CF-R may include a red pigment and / or dye.

[0176] However, the inventive concept is not limited to this example, and in one or more embodiments, the first color filter CF-B may not include a pigment or a dye. For example, the first color filter CF-B may include a polymer photosensitive resin, but may not include a pigment or a dye. The first color filter CF-B may be transparent. The first color filter CF-B may be formed of a transparent photosensitive resin.

[0177] The light blocking part BM may be a black matrix. The light blocking part BM may be formed to include an organic light blocking material and / or an inorganic light blocking material including a black pigment and / or a black dye. The light blocking part BM may prevent or reduce a light leakage phenomenon, and may define the color filters CF-B, CF-G, and CF-R adjacent to each other.

[0178] The color filter layer CFL may further include a buffer layer BFL. For example, the buffer layer BFL may be a protective layer for protecting the color filters CF-B, CF-G, and CF-R. The buffer layer BFL may be an inorganic layer including at least one inorganic material such as silicon nitride, silicon oxide, and / or silicon oxynitride. The buffer layer BFL may be composed of a single layer or multiple layers.

[0179] exist Figure 7 In one or more embodiments shown in , the first color filter CF-B of the color filter layer CFL is shown as overlapping with the second color filter CF-G and the third color filter CF-R, but the inventive concept is not limited to this example. For example, the first color filter CF-B, the second color filter CF-G, and the third color filter CF-R may be defined by the light blocking portion BM and may not overlap with each other. In one or more embodiments, the first color filter CF-B, the second color filter CF-G, and the third color filter CF-R may be arranged at areas corresponding to the blue light emitting area PXA-B, the green light emitting area PXA-G, and the red light emitting area PXA-R, respectively.

[0180] Figure 8 and Fig. 9 are cross-sectional views of display devices DD-1 and DD-2 according to some embodiments of the inventive concept. Figure 8 and Fig. 9 In the following description of the display device DD-1 or DD-2 shown in FIG, for the sake of brevity, the previous reference Figures 1 to 7 The described elements may be identified by the same reference numerals without repeating their repeated description.

[0181] Reference Figure 8 , a display device DD-1 according to an embodiment of the inventive concept may include a display panel DP-1 and a light-controlling layer PP. The display panel DP-1 may include a plurality of light-emitting devices OEL-1, OEL-2, and OEL-3.

[0182] Each of the light emitting devices OEL-1, OEL-2 and OEL-3 may include a first electrode EL1, a second electrode EL2 facing the first electrode EL1, and an emission layer EML-B, EML-G or EML-R disposed between the first electrode EL1 and the second electrode EL2 and including a manganese complex HS and quantum dots QD.

[0183] In accordance with Figure 8 In the display device DD-1 of the embodiment shown in , the emission layers EML-B, EML-G, and EML-R of the first light-emitting device OEL-1, the second light-emitting device OEL-2, and the third light-emitting device OEL-3 may have different thicknesses from each other. The first emission layer EML-B of the first light-emitting device OEL-1, the second emission layer EML-G of the second light-emitting device OEL-2, and the third emission layer EML-R of the third light-emitting device OEL-3 may be set to satisfy the thickness condition given by the following formula 2:

[0184] Formula 2

[0185] T1≤T2≤T3.

[0186] In Formula 2, T1 is the thickness of the first emission layer EML-B, T2 is the thickness of the second emission layer EML-G, and T3 is the thickness of the third emission layer EML-R.

[0187] Reference Figure 8 , among the emission layers EML-B, EML-G, and EML-R of the first light-emitting device OEL-1, the second light-emitting device OEL-2, and the third light-emitting device OEL-3 in the display device DD-1 according to an embodiment of the inventive concept, the first emission layer EML-B of the first light-emitting device OEL-1 corresponding to the blue light-emitting area PXA-B may have the smallest thickness, and the third emission layer EML-R of the third light-emitting device OEL-3 corresponding to the red light-emitting area PXA-R may have the largest thickness.

[0188] In one or more embodiments, the light control layer PP included in the display device DD-1 may include a color filter layer CFL.

[0189] exist Fig. 9 In the embodiment shown in , the display device DD-2 may include a display panel DP, and the display panel DP includes a plurality of light emitting devices OEL-1, OEL-2 and OEL-3 and a light control layer PP-1. Fig. 9 The display panel DP and the light emitting devices OEL-1, OEL-2 and OEL-3 in the display device DD-2 of the present invention may be configured to have the same Figure 7 The features described are essentially the same features.

[0190] according to Fig. 9 The display device DD-2 of the embodiment shown in FIG. 1 can be connected to the light control layer PP-1. Figure 7 The display device DD is different. Fig. 9 The light control layer PP-1 in the display device DD-2 of the embodiment shown in FIG. 2 may include a polarization layer POL.

[0191] That is, in one or more embodiments, the light-control layer PP-1 may include a polarizing layer POL and a base layer BL supporting the polarizing layer POL.

[0192] The base layer BL may be a member that provides a base surface on which the polarization layer POL and / or the like are arranged. The base layer BL may be a glass substrate, a metal substrate, and / or a plastic substrate, etc. However, the inventive concept is not limited to this example, and in one or more embodiments, the base layer BL may be an inorganic layer, an organic layer, or a composite layer.

[0193] The polarizing layer POL may block or reduce external light provided to the display panel DP from the outside. The polarizing layer POL may block or reduce a portion of the external light.

[0194] In addition, the polarization layer POL may reduce reflected light generated from the display panel DP by external light. For example, the polarization layer POL may be configured to block or suppress reflected light that is incident into the display panel DP from the outside of the display device DD and then emitted from the display panel DP. The polarization layer POL may be a circular polarizer having an anti-reflection function, or the polarization layer POL may include a linear polarizer and a λ / 4 phase retarder.

[0195] exist Fig. 9 , the polarization layer POL is shown as an element disposed on the base layer BL and exposed to the outside, but the inventive concept is not limited to this example. For example, the polarization layer POL may be disposed under the base layer BL.

[0196] A display device according to one or more embodiments of the inventive concept may include a light emitting device in which quantum dots and a manganese complex are used as materials of an emission layer, and in this case, color reproduction, lifetime, and light emitting efficiency characteristics of the display device can be improved.

[0197] According to one or more embodiments of the inventive concepts, a light emitting device may include an emission layer including quantum dots and a manganese complex and thus may exhibit increased lifetime and improved efficiency.

[0198] According to one or more embodiments of the inventive concept, a display device may include a light emitting device including an emission layer including quantum dots and a manganese complex, and thus may exhibit good color reproduction characteristics, high reliability, and high light emitting efficiency.

[0199] As used herein, the terms "use," "using," and "used" may be considered synonymous with the terms "utilize," "utilizing," and "utilized," respectively.

[0200] Additionally, the words "substantially," "about," and similar words are used as words of approximation rather than degree, and are intended to take into account the inherent variations in measurements or calculations that those skilled in the art would recognize.

[0201] In addition, any numerical range listed herein is intended to include all sub-ranges of the same numerical precision included in the listed range. For example, the range of "1.0 to 10.0" is intended to include all sub-ranges between the listed minimum value of 1.0 and the listed maximum value of 10.0 (and including the listed minimum value of 1.0 and the listed maximum value of 10.0), that is, all sub-ranges with a minimum value greater than or equal to 1.0 and a maximum value less than or equal to 10.0, for example, 2.4 to 7.6. Any maximum numerical limit listed herein is intended to include all lower numerical limits included therein, and any minimum numerical limit listed in this specification is intended to include all greater numerical limits included therein. Therefore, the applicant reserves the right to modify this specification (including claims) to explicitly list any sub-ranges included in the range explicitly listed herein.

[0202] While exemplary embodiments of the inventive concepts have been particularly shown and described, it will be understood by those skilled in the art that changes in form and details may be made without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.

Claims

1. A light emitting device, comprising: a first electrode; a second electrode, the second electrode being opposite to the first electrode; as well as a plurality of functional layers, the plurality of functional layers being located between the first electrode and the second electrode, the plurality of functional layers including an emission layer, The emission layer includes a manganese complex and quantum dots, and a weight ratio between the manganese complex and the quantum dots is 1:1 to 1:

2.

2. The light emitting device according to claim 1, wherein: The manganese complex is represented by the following chemical formula 1: Chemical formula 1 X p MnY q , In Chemical Formula 1, X is a monovalent or divalent cationic organic compound group, Y is a halogen atom, p is 1 or 2, and q is 4 or 6.

3. The light emitting device according to claim 2, wherein: X is BrMTPP ((bromomethyl)triphenylphosphine), BrPTPP ((3-bromopropyl)triphenylphosphine), TPP (tetraphenylphosphine), TMA (tetramethylammonium) or TEA (tetraethylammonium).

4. The light emitting device according to claim 1, wherein: The emission layer includes a host and a dopant, The host includes the manganese complex, and The dopant includes the quantum dots.

5. The light emitting device according to claim 1, wherein: The emission layer emits green light or red light.

6. The light emitting device according to claim 1, wherein: The multiple functional layers include: a hole transport region, the hole transport region being located between the first electrode and the emission layer; and An electron transport region is located between the emission layer and the second electrode.

7. The light emitting device according to claim 6, wherein: The hole transport region includes a plurality of sub-functional layers, and A difference in LUMO energy level between one of the plurality of sub-functional layers adjacent to the emission layer and the quantum dot is greater than or equal to 1.5 eV.

8. The light emitting device according to claim 1, wherein: The emission layer includes a plurality of the quantum dots, and The manganese complex fills the spaces between the plurality of quantum dots.

9. A display device, comprising: A plurality of light emitting devices, each of the plurality of light emitting devices being a light emitting device according to any one of claims 1 to 8.

10. The display device according to claim 9, wherein: The plurality of light emitting devices include: a first light emitting device, the first light emitting device comprising a first quantum dot emitting a first color of light; a second light emitting device including second quantum dots that emit a second color of light that is longer in wavelength than the first color of light; and A third light emitting device includes a third quantum dot that emits a third color light, the third color light being longer in wavelength than each of the first color light and the second color light.

11. The display device according to claim 10, wherein: The first quantum dot, the second quantum dot and the third quantum dot satisfy the following formula 1: Formula 1 The average diameter of the first quantum dots is less than the average diameter of the second quantum dots and less than the average diameter of the third quantum dots.

12. The display device according to claim 10, wherein: The first emission layer of the first light emitting device, the second emission layer of the second light emitting device, and the third emission layer of the third light emitting device satisfy the following formula 2: Formula 2 T1≤T2≤T3, Wherein, in Formula 2, T1 is the thickness of the first emission layer, T2 is the thickness of the second emission layer, and T3 is the thickness of the third emission layer.

13. The display device according to claim 10, further comprising: A light control layer is disposed on the plurality of light emitting devices.

14. The display device according to claim 13, wherein: The light control layer is a polarizing layer.

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