DISPLAY DEVICE
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`CROSS-REFERENCE TO RELATED APPLICATION(S)
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`[0001] The present application claims priority to and benefits of Korean
`
`patent application 10-2021-0163496 under 35 U.S.C. § 119(a), filed on
`
`November 24, 2021, in the Korean Intellectual Property Office (KIPO), the
`
`entire contents of which are incorporated herein by reference.
`
`BACKGROUND
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`1.
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`Technical Field
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`[0002] The disclosure generally relates to a display device.
`
`2.
`
`Description of Related Art
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`[0003] Recently, as interest in information displays is increased, research
`
`and development of display devices have been continuously conducted.
`
`SUMMARY
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`[0004] Embodiments provide a display device capable of improving light
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`efficiency and luminance.
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`[0005] In accordance with an aspect of the disclosure, there is provided a
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`display device including light emitting elements disposed in pixels; a color
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`conversion layer disposed on the light emitting elements; a color filter
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`layer disposed on the color conversion layer; and a
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`resonant
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`filter
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`disposed between the color conversion layer and the color filter layer,
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`wherein the resonant filter
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`includes a first semi-transmissive layer, a
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`SD-220230-SKD
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`1
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`
`
`CROSS-REFERENCE TO RELATED APPLICATION(S)
`
`[0001] The present application claims priority to and benefits of Korean
`
`patent application 10-2021-0163496 under 35 U.S.C. § 119(a), filed on
`
`November 24, 2021, in the Korean Intellectual Property Office (KIPO), the
`
`entire contents of which are incorporated herein by reference.
`
`BACKGROUND
`
`1.
`
`Technical Field
`
`[0002] The disclosure generally relates to a display device.
`
`2.
`
`Description of Related Art
`
`[0003] Recently, as interest in information displays is increased, research
`
`and development of display devices have been continuously conducted.
`
`SUMMARY
`
`[0004] Embodiments provide a display device capable of improving light
`
`efficiency and luminance.
`
`[0005] In accordance with an aspect of the disclosure, there is provided a
`
`display device including light emitting elements disposed in pixels; a color
`
`conversion layer disposed on the light emitting elements; a color filter
`
`layer disposed on the color conversion layer; and a
`
`resonant
`
`filter
`
`disposed between the color conversion layer and the color filter layer,
`
`wherein the resonant filter
`
`includes a first semi-transmissive layer, a
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`SD-220230-SKD
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`second semi-transmissive layer, and a medium disposed between the first
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`semi-transmissive layer and the second semi-transmissive layer.
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`[0006] The pixels mayinclude a first pixel, a second pixel, and a third pixel.
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`The resonant filter may include a first resonant filter disposed in the first
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`pixel; and a second resonant filter disposed in the second pixel.
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`[0007] The first resonant filter and/or the second resonant filter may not
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`overlap the third pixel in a plan view.
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`[0008] The resonant
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`filter may further
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`include a third resonant
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`filter
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`overlapping the third pixel in a plan view.
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`[0009] A thickness of a medium of the first resonant filter may be different
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`from a thickness of a medium of the second resonant filter.
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`[0010] A thickness of a medium of the first resonant filter may be equal to
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`a thickness of a medium of the second resonant filter.
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`[0011] The pixels may include a first pixel emitting light of a first color; a
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`second pixel emitting light of a second color; and a third pixel emitting
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`light of a third color. The resonantfilter may allow the lights of the first
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`to third colors
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`to be selectively reflected therefrom or
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`transmitted
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`therethrough.
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`[0012] The resonantfilter may allow about 70%or more of the light of the
`
`
`
`first color and/or to be_transmittedthe light of the second color
`
`
`
`
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`therethrough, and allow about 20%or less of the light of the third color to
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`be transmitted therethrough.
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`[0013] The resonant filter may allow about 10%or less of the light of the
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`first color and/or the light of the second color to be reflected therefrom,
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`and allow about 60%or more of the light of the third color to be reflected
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`therefrom.
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`[0014] The medium of the resonant filter may have a refractive index of
`
`about 2.5 or less.
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`[0015] The
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`first
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`semi-transmissive
`
`layer
`
`and/or
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`the
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`second
`
`semi-
`
`transmissive layer may be a metal thin film.
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`[0016] In accordance with another aspect of
`
`the disclosure,
`
`there is
`
`provided a display device including first
`
`to third pixels
`
`respectively
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`emitting light of first to third colors;
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`light emitting elements disposed in
`
`the first
`
`to third pixels; a color conversion layer disposed on the light
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`emitting elements; a color filter layer disposed on the color conversion
`
`layer; a first resonant filter disposed in the first pixel between the color
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`conversion layer and the color filter layer; and a second resonant filter
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`disposed in the second pixel between the color conversion layer and the
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`color filter layer.
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`[0017] The first resonant filter and/or the second resonant filter may allow
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`the lights of the first to third colors to be selectively reflected therefrom or
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`transmitted therethrough.
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`[0018] The first resonant filter and/or the second resonant filter may not
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`overlap the third pixel.
`
`[0019] The display device may further
`
`include a third resonant
`
`filter
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`disposed in the third pixel between the color conversion layer and the
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`color filter layer.
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`[0020] A thickness of the first resonant filter may be different from a
`
`thickness of the second resonant filter.
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`[0021] A thickness of the first resonant filter may be equal to a thickness
`
`of the second resonant filter.
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`[0022] The color conversion layer mayinclude a first color conversion layer
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`disposed in the first pixel; a second color conversion layer disposed in the
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`second pixel; and a light scattering layer disposed in the third pixel.
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`[0023] The light emitting elements may emit the light of the third color.
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`[0024] Each a_firstof the light emitting elements may include
`
`
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`
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`SD-220230-SKD
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`semiconductor layer, a second semiconductor layer, and an active layer
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`disposed
`
`between the
`
`first
`
`semiconductor
`
`layer
`
`and
`
`the
`
`second
`
`semiconductor layer.
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`BRIEF DESCRIPTION OF THE DRAWINGS
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`[0025] Example embodiments will now be described more fully hereinafter
`
`with reference to the accompanying drawings; however,
`
`they may be
`
`embodied in different forms and should not be construed as limited to the
`
`embodiments set forth herein. Rather, these embodiments are provided
`
`so that this disclosure will be more thorough and complete, and will
`
`convey the scope of the example embodiments to those skilled in the art.
`
`[0026] In the drawing figures, dimensions may be exaggerated for clarity
`
`of illustration.
`
`It will be understood that when an element is referred to
`
`as being "between" two elements, it can be the only element between the
`
`two elements, or one or more intervening elements may also be present.
`
`Like reference numerals refer to like elements throughout.
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`[0027] FIG. 1 is a schematic perspective view illustrating a light emitting
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`element in accordance with an embodiment of the disclosure.
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`[0028] FIG. 2 is a schematic cross-sectional view illustrating the light
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`emitting element in accordance with the embodiment of the disclosure.
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`[0029] FIG. 3 is a schematic plan view illustrating a display device in
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`accordance with an embodiment of the disclosure.
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`[0030] FIG. 4 is a schematic diagram of an equivalent circuit illustrating a
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`pixel in accordance with an embodiment of the disclosure.
`
`[0031] FIG. 5 is a schematic plan view illustrating a pixel
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`in accordance
`
`with an embodiment of the disclosure.
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`[0032] FIG. 6 is a schematic cross-sectional view taken along line A-A’
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`SD-220230-SKD
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`shown in FIG. 5.
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`[0033] FIG. 7 is a schematic cross-sectional view taken along line B-B’
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`shown in FIG. 5.
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`[0034] FIG. 8 is a schematic cross-sectional view illustrating first to third
`
`pixels in accordance with an embodimentof the disclosure.
`
`[0035] FIGS. 9 to 11 are schematic cross-sectional views illustrating a
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`resonant filter.
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`[0036] FIG. 12 is a schematic cross-sectional view illustrating first to third
`
`pixels in accordance with an embodimentof the disclosure.
`
`[0037] FIGS. 13 to 15 are sectional viewsillustrating a resonant filter.
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`DETAILED DESCRIPTION OF THE EMBODIMENTS
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`[0038] The effects and characteristics of the disclosure and a method of
`
`achieving the effects and characteristics will be clear by referring to the
`
`embodiments described below in detail together with the accompanying
`
`drawings. However,
`
`the disclosure is not
`
`limited to the embodiments
`
`disclosed herein but may be
`
`implemented in various
`
`forms.
`
`The
`
`embodiments are provided by way of example only so that a person of
`
`ordinary skilled in the art can understand the features in the disclosure
`
`and the scope thereof. Therefore, the disclosure can be defined by the
`
`scope of the appended claims.
`
`[0039] The terminology used herein is
`
`for
`
`the purpose of describing
`
`particular embodiments only and is not construed as
`
`limiting the
`
`disclosure. As used herein, the singular forms are intended to include the
`
`plural forms (or meanings) as well, unless the context clearly indicates
`
`otherwise.
`
`The
`
`terms
`
`“comprises/includes”
`
`and/or
`
`“comprising/including,” when used in
`
`this
`
`specification,
`
`specify the
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`SD-220230-SKD
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`
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`presence of mentioned component, step, operation and/or element, but do
`
`not exclude the presence or addition of one or more other components,
`
`steps, operations and/or elements.
`
`[0040] When described as that any element is “connected”, “coupled” or
`
`“accessed” to another element, it should be understood that it is possible
`
`that
`
`still another element may “connected”, “coupled” or “accessed”
`
`between the two elements as well as that the two elements are directly
`
`“connected”, “coupled” or “accessed” to each other.
`
`It will be understood
`
`that the terms “contact,” “connected to,” and “coupled to” may include a
`
`physical and/or electrical contact, connection, or coupling.
`
`[0041] The term “on” that is used to designate that an element or layer is
`
`on another element or layer includes both a case where an element or
`
`layer is located directly on another element or layer, and a case where an
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`element or layer is located on another element or layer via still another
`
`element layer.
`
`Like reference numerals generally denote like elements
`
`throughout the specification.
`
`[0042] It will be understood that, although the terms “first,” “second,” and
`
`the like may be used herein to describe various elements, these elements
`
`should not be limited by these terms. These terms are only used to
`
`distinguish one element from another element. Thus, a “first” element
`
`discussed below could also be termed a “second” element without
`
`departing from the teachings of the disclosure.
`
`[0043] The terms “about” or “approximately” as used herein is inclusive of
`
`the stated value and means within an acceptable range of deviation for
`
`the particular value as determined by one of ordinary skill
`
`in the art,
`
`considering the measurement in question and the error associated with
`
`measurement of
`
`the particular quantity (i.e.,
`
`the limitations of
`
`the
`
`measurement system).
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`For example, “about” may mean within one or
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`more standard deviations, or within + 30%, 20%, 10%, 5% of the stated
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`value.
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`[0044] In the specification and the claims, the term “and/or”is intended to
`
`include any combination of the terms “and” and “or” for the purpose ofits
`
`
`
`meaning and_interpretation. For example, "A and/or B" may be
`
`
`
`understood to mean "A, B, or A and B." The terms “and” and “or” may be
`
`used in the conjunctive or disjunctive sense and may be understood to be
`
`equivalent to “and/or.” The phrase “at least one of” is intended to include
`
`the meaning of “at least one selected from the group of” for the purpose
`
`of its meaning and interpretation.
`
`For example, “at least one of A and B”
`
`may be understood to mean “A, B, or A and B.”
`
`[0045] Unless otherwise defined or implied herein, all
`
`terms (including
`
`technical and scientific terms) used herein have the same meaning as
`
`commonly understood by thoseskilled in the art to which this disclosure
`
`pertains.
`
`It will be further understood that terms, such as those defined
`
`in commonly used dictionaries, should be interpreted as having a meaning
`
`that is consistent with their meaning in the context of the relevant art and
`
`the disclosure, and should not be interpreted in an ideal or excessively
`
`formal sense unless clearly so defined herein.
`
`[0046] Hereinafter, embodiments of the disclosure will be described in
`
`more detail with reference to the accompanying drawings.
`
`[0047] FIG. 1 is a schematic perspective view illustrating a light emitting
`
`element in accordance with an embodiment of the disclosure.
`
`FIG. 2 is a
`
`schematic sectional view illustrating the light emitting element
`
`in
`
`accordance with the embodiment of the disclosure. Although FIGS. 1 and
`
`2 illustrate a pillar-shaped light emitting element LD,
`
`the kind and/or
`
`shape of the light emitting element LD is not limited thereto.
`
`[0048] Referring to FIGS.
`
`1 and 2,
`
`the light emitting element LD may
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`SD-220230-SKD
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`include a first semiconductor layer 11, an active layer 12, a second
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`semiconductor layer 13, and/or an electrode layer 14.
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`[0049] The light emitting element LD may be provided in a pillar shape
`
`extending in a direction. The light emitting element LD may havea first
`
`end portion EP1 and a second end portion EP2. One of the first and
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`second semiconductor layers 11 and 13 may be disposed at the first end
`
`portion EP1 of the light emitting element LD. The other of the first and
`
`second semiconductor layers 11 and 13 may be disposed at the second
`
`end portion EP2 of the light emitting element LD.
`
`For example, the first
`
`semiconductor layer 11 may be disposed at the first end portion EP1 of
`
`the light emitting element LD, and the second semiconductor layer 13 may
`
`be disposed at the second end portion EP2 of the light emitting element
`
`LD.
`
`[0050] In some embodiments, the light emitting element LD may be a light
`
`emitting element manufactured in a pillar shape through an etching
`
`process, etc.
`
`In this specification, the term “pillar shape” may include a
`
`rod- or bar-like shape of which an aspect ratio is greater than 1, such as a
`
`cylinder or a polyprism, and the shape of its section is not particularly
`
`limited.
`
`[0051] The light emitting element LD may havea size small to a degree of
`
`the nanometer scale to the micrometer scale.
`
`In an example, the light
`
`emitting element LD may have a diameter D (or width) in a range of the
`
`nanometer scale to the micrometer scale and/or a length L in a range of
`
`the nanometer scale to the micrometer scale. However, the size of the
`
`light emitting element LD is not limited thereto, and the size of the light
`
`emitting element LD may be variously changed according to design
`
`conditions of various types of devices, e.g., a display device, and the like,
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`which use, as a light source, a light emitting device using the light
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`SD-220230-SKD
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`
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`emitting element LD.
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`[0052] The first semiconductor layer 11 may be a first conductivity type
`
`semiconductor layer.
`
`For example, the first semiconductor layer 11 may
`
`include
`
`a p-type semiconductor
`
`layer.
`
`In
`
`an example,
`
`the first
`
`semiconductor layer 11 may include at least one semiconductor material
`
`among InAlGaN, GaN, AlGaN, InGaN, AIN, and InN, and include a p-type
`
`semiconductor layer doped with a first conductivity type dopant such as
`
`Mg.
`
`However,
`
`the material
`
`forming
`
`(or
`
`constituting)
`
`the
`
`first
`
`semiconductor layer 11 is not
`
`limited thereto.
`
`In addition,
`
`the first
`
`semiconductor layer 11 may be configured with various materials.
`
`[0053] The
`
`active
`
`layer
`
`12 may
`
`be
`
`disposed
`
`between
`
`the
`
`first
`
`semiconductor layer 11 and the second semiconductor layer 13.
`
`The
`
`active layer 12 may include a structure among a single well structure, a
`
`multi-well structure, a single quantum well structure, a multi-quantum
`
`well
`
`(MQW) structure, a quantum dot structure, and a quantum wire
`
`structure, but the disclosure is not limited thereto. The active layer 12
`
`may include GaN, InGaN, InAlGaN, AlGaN, AIN, or the like.
`
`In addition,
`
`the active layer 12 may be configured with various materials.
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`[0054] In case that a voltage which is a threshold voltage or more is
`
`applied to ends (e.g., both ends) of the light emitting element LD, the
`
`light emitting element LD emits light as electron-hole pairs are combined
`
`in the active layer 12. The light emission of the light emitting element LD
`
`is controlled by using such a principle, so that the light emitting element
`
`LD can be used as a light source for various light emitting devices,
`
`including a pixel of a display device.
`
`[0055] The second semiconductor layer 13 is formed on the active layer 12,
`
`and may include a semiconductor layer having a type different from that
`
`of
`
`the
`
`first
`
`semiconductor
`
`layer
`
`11.
`
`For
`
`example,
`
`the
`
`second
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`SD-220230-SKD
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`9
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`
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`semiconductor layer 13 may include an n-type semiconductor layer.
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`In an
`
`
`
`
`
`
`
`example, 13 may_includethe second semiconductor layer any
`
`
`
`
`
`
`
`semiconductor material among InAlGaN, GaN, AlGaN, InGaN, AIN, and InN,
`
`
`
`and layer doped with a_secondinclude an n-type semiconductor
`
`
`
`
`
`conductivity type dopant such as Si, Ge, or Sn. However, the material
`
`constituting the second semiconductor layer 13 is not limited thereto.
`
`In
`
`addition,
`
`the second semiconductor layer 13 may be configured with
`
`various materials.
`
`[0056] The electrode layer 14 may be disposed on the first end portion EP1
`
`and/or the second end portion EP2 of the light emitting element LD.
`
`Although FIG. 2 illustrates, as an example, a case where the electrode
`
`layer 14 is formed on the first semiconductor layer 11, the disclosure is
`
`not
`
`limited thereto.
`
`For example, a separate electrode layer may be
`
`further disposed on the second semiconductor layer 13.
`
`[0057] The electrode layer 14 may include a transparent metal or a
`
`transparent metal oxide.
`
`In an example,
`
`the electrode layer 14 may
`
`include at least one of indium tin oxide (ITO),
`
`indium zinc oxide (IZO),
`
`zinc oxide (ZnO), and zinc tin oxide (ZTO), but
`
`the disclosure is not
`
`limited thereto.
`
`In case that the electrode layer 14 may be made of a
`
`transparent metal or a transparent metal oxide,
`
`light generated in the
`
`active layer 12 of the light emitting element LD may pass through the
`
`electrode layer 14 and be emitted to the outside of the light emitting
`
`element LD.
`
`[0058] An insulative film INF may be provided on a surface of the light
`
`emitting element LD. The insulative film INF may be disposed directly on
`
`surfaces of the first semiconductor layer 11,
`
`the active layer 12,
`
`the
`
`second semiconductor
`
`layer 13, and/or the electrode layer 14.
`
`The
`
`insulative film INF may expose the first and second end portions EP1 and
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`SD-220230-SKD
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`EP2 of the light emitting element LD, which have different polarities.
`
`In
`
`some embodiments, the insulative film INF may expose a side portion of
`
`the electrode layer 14 and/or the second semiconductor layer 13, adjacent
`
`to the first and second end portions EP1 and EP2 of the light emitting
`
`element LD.
`
`[0059] The insulative film INF may prevent an electrical short circuit which
`
`may occur in case that the active layer 12 contacts (or is in contact with)
`
`a conductive material except the first and second semiconductor layers 11
`
`and 13. Also, the insulative film INF may minimize a surface defect of
`
`light emitting elements LD,
`
`thereby the lifespan and light emission
`
`efficiency of the light emitting elements LD.
`
`[0060] The insulative film INF may include at least one of silicon oxide
`
`(SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride
`
`(AINx), aluminum oxide (AlOx), zirconium oxide (ZrOx), hafnium oxide
`
`(HfOx), and titanium oxide (TiOx).
`
`For example, the insulative film INF
`
`may be configured as a double layer, and layers constituting the double
`
`layer may include different materials.
`
`In an example, the insulative film
`
`INF may be configured as a double layer including aluminum oxide (AlOx)
`
`and silicon oxide (SiOx), but the disclosure is not limited thereto.
`
`In some
`
`embodiments, the insulative film INF may be omitted.
`
`[0061] A light emitting device including the above-described light emitting
`
`element LD may be used in various kinds of devices which require a light
`
`source,
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`including a display device.
`
`For example,
`
`light emitting elements
`
`LD may be disposed in each pixel of a display panel, and be used as a
`
`light source of each pixel. However,
`
`the application field of the light
`
`emitting element LD is not limited to the above-described example.
`
`For
`
`example, the light emitting element LD may be used in other types of
`
`devices that require a light source, such as a lighting device.
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`[0062] FIG. 3 is a schematic plan view illustrating a display device in
`
`accordance with an embodiment of the disclosure.
`
`[0063] FIG. 3 illustrates a display device, particularly, a display panel PNL
`
`provided in the display device as an example of an electronic device which
`
`can use, as a light source, the light emitting element LD described in the
`
`embodiment shown in FIGS. 1 and 2.
`
`[0064] For convenience of description, FIG. 3 briefly illustrates a structure
`
`of the display panel PNL, focusing on a display area DA. However,
`
`in
`
`some embodiments, at least one driving circuit (e.g., at least one of a
`
`scan driver and a data driver), lines, and/or pads, which are not shown in
`
`the drawing, may be further disposed in the display panel PNL.
`
`[0065] Referring to FIG. 3, the display panel PNL and a base layer BSL for
`
`forming the same mayinclude the display area DA for displaying an image
`
`and a non-display area NDA except the display area DA. The display area
`
`may form a screen on which the image is displayed, and the non-display
`
`area NDA may be the other area except the display area DA.
`
`[0066] A pixel part (or pixel unit) PXU maybe disposed in the display area
`
`DA. The pixel part PXU mayinclude a first pixel PXL1, a second pixel
`
`PXL2, and/or a third pixel PXL3. Hereinafter,
`
`in case that at least one
`
`pixel among the first pixel PXL1, the second pixel PXL2, and the third pixel
`
`PXL3 is arbitrarily designated or in case that two or more kinds of pixels
`
`among the first pixel PXL1, the second pixel PXL2, and the third pixel PXL3
`
`are inclusively designated, the corresponding pixel or the corresponding
`
`pixels will be referred to as a “pixel PXL” or “pixels PXL.”
`
`[0067] The pixels PXL may be regularly arranged according to a stripe
`
`structure, a PENTILE™ structure, or the like. However, the arrangement
`
`structure of the pixels PXL is not limited thereto, and the pixels PXL may
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`be arranged in the display area DA by using various structures and/or
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`methods.
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`[0068] In some embodiments,
`
`two or more kinds of pixels PXL emitting
`
`lights of different colors may be disposed in the display area DA.
`
`In an
`
`example, first pixels PXL1 emitting light of a first color, second pixels PXL2
`
`emitting light of a second color, and third pixels PXL3 emitting light of a
`
`third color may be arranged in the display area DA. At least one first
`
`pixel PXL1, at least one second pixel PXL2, and at least one third pixel
`
`PXL3, which are disposed adjacent to each other, may constitute a pixel
`
`part PXU capable of emitting lights of various colors.
`
`For example, each
`
`of the first to third pixels PXL1, PXL2, and PXL3 may be a pixel emitting
`
`light of a color
`
`(e.g., a predetermined or selected color).
`
`In some
`
`embodiments, the first pixel PXL1 may be a red pixel emitting light of red,
`
`the second pixel PXL2 may be a green pixel emitting light of green, and
`
`the third pixel PXL3 may be a blue pixel emitting light of blue. However,
`
`the disclosure is not limited thereto.
`
`[0069] In an embodiment, the first pixel PXL1, the second pixel PXL2, and
`
`the third pixel PXL3 have light emitting elements emitting light of a same
`
`color, and may include color conversion layers and/or color filters of
`
`different colors, which are disposed on the respective light emitting
`
`elements,
`
`to respectively emit lights of the first color, the second color,
`
`and the third color.
`
`In an embodiment, the first pixel PXL1, the second
`
`pixel PXL2, and the third pixel PXL3 respectively have, as light sources, a
`
`light emitting element of the first color, a light emitting element of the
`
`second color, and a light emitting element of the third color, so that the
`
`light emitting elements can respectively emit lights of the first color, the
`
`second color, and the third color. However, the color, kind, and/or number
`
`of pixels PXL constituting each pixel part PXU are not particularly limited.
`
`In an example,
`
`the color of
`
`light emitted by each pixel PXL may be
`
`SD-220230-SKD
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`13
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`
`
`variously changed.
`
`[0070] The pixel PXL may include at least one light source driven by a
`
`control signal (e.g., a scan signal and a data signal) and/or a power
`
`source (e.g., a first power source and a second power source).
`
`In an
`
`embodiment,
`
`the light source may include at
`
`least one light emitting
`
`element LD in accordance with the embodiment shown in FIGS. 1 and 2,
`
`e.g., a subminiature pillar-shaped light emitting element LD having a size
`
`small
`
`to a degree of
`
`the nanometer scale to the micrometer scale.
`
`However, the disclosure is not limited thereto.
`
`In addition, various types
`
`of light emitting elements LD may be used as the light source of the pixel
`
`PXL.
`
`[0071] In an embodiment, each pixel PXL may be configured as an active
`
`pixel. However, the kind, structure, and/or driving method of pixels PXL
`
`which can be applied to the display device are not particularly limited.
`
`For example, each pixel PXL may be configured as a pixel of a passive or
`
`active light emitting display device using various structures and/or driving
`
`methods.
`
`[0072] FIG. 4 is a schematic diagram of an equivalent circuit illustrating a
`
`pixel in accordance with an embodiment of the disclosure.
`
`[0073] In some embodiments, the pixel PXL shown in FIG. 4 may be one
`
`of the first pixel PXL1, the second pixel PXL2, and the third pixel PXL3,
`
`which are provided in the display panel PNL shown in FIG. 3.
`
`The first
`
`pixel PXL1, the second pixel PXL2, and the third pixel PXL3 may have
`
`structures substantially identical or similar to one another.
`
`[0074] Referring to FIG. 4, the pixel PXL may include a light emitting part
`
`(or
`
`light emitting unit) EMU for generating light with a
`
`luminance
`
`corresponding to a data signal and a pixel circuit PXC for driving the light
`
`emitting part EMU.
`
`SD-220230-SKD
`
`14
`
`
`
`[0075] The pixel circuit PXC may be connected between a first power
`
`source VDD and the light emitting part EMU. Also, the pixel circuit PXC
`
`may be connected to a
`
`scan line SL and a data line DL of
`
`the
`
`corresponding pixel PXL to control an operation of the light emitting part
`
`EMU, corresponding to a scan signal and a data signal, which are supplied
`
`from the scan line SL and the data line DL. Also, the pixel circuit PXC
`
`may be selectively further connected to a sensing signal
`
`line SSL and a
`
`sensing line SENL.
`
`[0076] The pixel circuit PXC may include at
`
`least one transistor and a
`
`capacitor.
`
`For example, the pixel circuit PXC may include a first transistor
`
`Mi, a second transistor M2, a third transistor M3, and a storage capacitor
`
`Cst.
`
`[0077] The first transistor M1 may be connected between the first power
`
`source VDD andafirst connection electrode ELT1. A gate electrode of the
`
`first transistor M1 is connected to a first node Ni.
`
`The first transistor M1
`
`may control a driving current supplied to the light emitting part EMU,
`
`corresponding to a voltage of the first node N1.
`
`For example, the first
`
`transistor M1 may be a driving transistor for controlling the driving current
`
`of the pixel PXL.
`
`[0078] In an embodiment, the first transistor M1 may selectively include a
`
`lower conductive layer BML (also referred to as a “lower electrode,” a
`
`“back gate electrode,” or a “lower
`
`light blocking layer”).
`
`The gate
`
`electrode and the lower conductive layer BML of the first transistor M1
`
`may overlap each other with an insulating layer interposed therebetween.
`
`In an embodiment, the lower conductive layer BML may be connected to
`
`one (or first) electrode, e.g., a source or drain electrode of the first
`
`transistor M1.
`
`[0079] In case that the first transistor M1 includes the lower conductive
`
`SD-220230-SKD
`
`15
`
`
`
`layer BML,
`
`there may be applied a back-biasing technique (or sync
`
`technique) for moving a threshold voltage of the first transistor M1 in a
`
`negative or positive direction by applying a back-biasing voltage to the
`
`lower conductive layer BML of the first transistor M1 in driving the pixel
`
`PXL.
`
`In an example, a source-sync technique is applied by connecting
`
`the lower conductive layer BML to a source electrode of the first transistor
`
`Mi, so that the threshold voltage of the first transistor M1 can be moved
`
`in the negative or positive direction.
`
`In addition,
`
`in case that the lower
`
`conductive layer BML is disposed on the bottom of a semiconductor
`
`pattern forming a channel of the first transistor M1, the lower conductive
`
`layer BML severs
`
`as
`
`a
`
`light blocking pattern,
`
`thereby stabilizing
`
`operational characteristics of
`
`the first
`
`transistor M1.
`
`However,
`
`the
`
`function and/or application method of the lower conductive layer BML is
`
`not limited thereto.
`
`[0080] The second transistor M2 may be connected between the data line
`
`DL and the first node Ni.
`
`In addition, a gate electrode of the second
`
`transistor M2 is connected to the scan line SL. The second transistor M2
`
`is turned on in case that a scan signal having a gate-on voltage (e.g., a
`
`high-level voltage) is supplied from the scan line SL, to connect the data
`
`line DL and the first node N1 to each other.
`
`[0081] A data signal of a corresponding frame may be supplied to the data
`
`line DL for each frame period. The data signal may be transferred to the
`
`first node N1 through the turned-on second transistor M2 during a period
`
`in which the scan signal having the gate-on voltage is supplied.
`
`For
`
`example,
`
`the second transistor M2 may be a switching transistor for
`
`transferring each data signal to the inside of the pixel PXL.
`
`[0082] A first electrode of the storage capacitor Cst may be connected to
`
`the first node N1, and a second electrode of the storage capacitor Cst may
`
`SD-220230-SKD
`
`16
`
`
`
`be connected to a second electrode of the first transistor M1. The storage
`
`capacitor Cst is charged with a voltage corresponding to the data signal
`
`supplied to the first node N1 during each frame period.
`
`[0083] The third transistor M3 may be connected between the first
`
`connection electrode ELT1 (or the second electrode of the first transistor
`
`M1) and the sensing line SENL.
`
`In addition, a gate electrode of the third
`
`transistor M3 may be connected to the sensing signal line SSL. The third
`
`transistor M3 may transfer a voltage value, applied to the first connection
`
`electrode ELT1,
`
`to the sensing line SENL according to a sensing signal
`
`supplied to the sensing signal
`
`line SSL. The voltage value transferred
`
`through the sensing line SENL may be provided to an external circuit (e.g.,
`
`a timing controller), and the external circuit may extract characteristic
`
`information (e.g., the threshold voltage of the first transistor M1, etc.),
`
`based on the provided voltage value.
`
`The extracted characteristic
`
`information may be used to convert image data such that a characteristic
`
`deviation between the pixels PXL is compensated.
`
`[0084] Although FIG.4illustrates that the transistors included in the pixel
`
`circuit PXC are an n-type transistor, the disclosure is not limited thereto.
`
`For example, at least one of the first, second, and third transistors M1, M2,
`
`and M3 may be changedto a p-type transistor.
`
`[0085] In addition, the structure and driving method of the pixel PXL may
`
`be variously changed in some embodiments.
`
`For example,
`
`the pixel
`
`circuit PXC may be configured as a pixel circuit having various structures
`
`and/or various driving methods,
`
`in addition to the embodiment shown in
`
`FIG. 4.
`
`[0086] In an example,
`
`the pixel circuit PXC may not
`
`include the third
`
`transistor M3. Also, the pixel circuit PXC may further include other circuit
`
`elements such as a compensation transistor for compensating for the
`
`SD-220230-SKD
`
`17
`
`
`
`threshold voltage of the first transistor M1, etc., an initialization transistor
`
`for initializing a voltage of the first node N1 and/or the first connection
`
`electrode ELT1, an emission control transistor for controlling a period in
`
`which a driving current is supplied to the light emitting part EMU, and/or a
`
`boosting capacitor for boosting the voltage of the first node N1.
`
`[0087] The light emitting part EMU mayinclude at least one light emitting
`
`element LD, e.g.,
`
`light emitting elements LD connected to each other
`
`between the first power source VDD and a second power source VSS.
`
`[0088] For example,
`
`the light emitting part EMU may include the first
`
`connection electrode ELT1 connected to the first power source VDD
`
`through the pixel circuit PXC and a first power line PL1, a fifth connection
`
`electrode ELT5 connected to the second power source VSS through a
`
`second power line PL2, and light emitting elements LD connected to each
`
`other between the first and fifth connection electrodes ELT1 and ELT5.
`
`[0089] The first power source VDD and the second power source VSS may
`
`have different potentials such that the light emitting elements LD can emit
`
`light.
`
`In an example, the first power source VDD may be set as a high-
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