Display device

Abstract

A display device is provided, wherein a first light-emitting device is generated in a first microcavity and a second microcavity between a first electrode and a second electrode, and a second light-emitting device is generated in a third microcavity between the first electrode and the second electrode.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Korean Patent Application No. 10-2024-0189738, filed on December 18, 2024, each of which is incorporated herein by reference in its entirety. Technical Field

[0003] This disclosure relates to display devices. Background Technology

[0004] With the development of the information society, the demand for display devices for displaying images is increasing in various forms. As a result, a wide variety of display devices such as liquid crystal displays (LCDs), plasma display panels (PDPs), and organic light emitting displays (OLEDs) have recently been used.

[0005] In display devices, organic light-emitting diode (OLED) displays are self-emissive, offering better viewing angles and contrast than liquid crystal displays (LCDs). They are also lightweight and thin due to the elimination of the need for a separate backlight, and their power consumption is advantageous. Furthermore, OLED displays are driven by low DC voltages, have fast response times, and are particularly low in manufacturing costs.

[0006] Recently, research has been conducted to improve the optical characteristics of organic light-emitting display devices, such as brightness based on viewing angle, color based on viewing angle, and frontal efficiency. Summary of the Invention

[0007] This disclosure is made in view of the above problems, and one aspect of this disclosure is to provide an organic light-emitting device with improved optical properties and a display device including the thereof.

[0008] According to one aspect of this disclosure, the above and other technical effects can be achieved by providing a display device comprising: a plurality of sub-pixels, the plurality of sub-pixels including a light-emitting region and a non-light-emitting region surrounding the light-emitting region, and each of the plurality of sub-pixels including a first electrode disposed on a substrate in the light-emitting region, a first stack disposed on the first electrode, a doping prevention layer disposed on the first stack, and an n-type charge generation layer disposed on the doping prevention layer, wherein the n-type charge generation layer includes a doped region containing an n-type dopant material and an undoped region not containing an n-type dopant material, and wherein the doping prevention layer overlaps with the undoped region but not with the doped region.

[0009] It should be understood that both the foregoing general description and the following detailed description are exemplary and illustrative, and are intended to provide further explanation of the inventive concept as claimed. Attached Figure Description

[0010] The accompanying drawings, included to provide a further understanding of this disclosure and incorporated in and forming part of this application, illustrate embodiments of the disclosure and, together with the description, explain the principles of the disclosure. In the drawings:

[0011] Figure 1 This is a plan view of a display device according to one embodiment of the present disclosure.

[0012] Figure 2 A plan view of a pixel according to one embodiment of this disclosure.

[0013] Figure 3 This is a cross-sectional view of a sub-pixel according to one embodiment of the present disclosure.

[0014] Figure 4 This is a cross-sectional view of a light-emitting device according to a first embodiment of the present disclosure.

[0015] Figure 5 To show Figure 4 The graph shows the light intensity of the light-emitting device.

[0016] Figure 6 This is a cross-sectional view of a conventional light-emitting device.

[0017] Figure 7 This is a cross-sectional view of a light-emitting device according to a second embodiment of the present disclosure.

[0018] Figure 8 This is a cross-sectional view of a light-emitting device according to a third embodiment of the present disclosure.

[0019] Figure 9 To show Figure 7 The graph shows the transmittance of the semi-transmissive and semi-reflective electrodes of the light-emitting device.

[0020] Figure 10 To show Figure 7 The graph shows the light intensity of the light-emitting device.

[0021] Figure 11 This is a cross-sectional view of a light-emitting device according to the fourth embodiment of this disclosure.

[0022] Throughout the accompanying drawings and detailed embodiments, unless otherwise described, the same reference numerals should be understood to refer to the same elements, features, and structures. For clarity, illustration, and convenience, the relative dimensions and depictions of these elements may be exaggerated. Detailed Implementation

[0023] Reference will now be made in detail to embodiments of this disclosure, examples of which are illustrated in the accompanying drawings. The described processing steps and / or operations are examples; however, the order of steps and / or operations is not limited to the order set forth herein, except that they must occur in a specific order, and can be varied as is known in the art. The names of the various elements used in the following description may be chosen solely for convenience of writing the specification, and therefore may differ from the names used in the actual product.

[0024] The advantages and features of this disclosure and its implementation methods will be illustrated by the following examples described with reference to the accompanying drawings. However, this disclosure may be implemented in different forms and should not be construed as limited to the examples set forth herein. Rather, these examples are provided so that the specification of this disclosure will be exhaustive and complete, and will fully convey the scope of this disclosure to those skilled in the art. Furthermore, the scope of this disclosure is defined only by the appended claims.

[0025] The shapes, dimensions, ratios, angles, and quantities disclosed in the accompanying drawings used to describe examples of this disclosure are merely exemplary and therefore this disclosure is not limited to the details shown. Unless otherwise stated, the same reference numerals refer to the same elements throughout the specification. In the following description, detailed descriptions that determine relevant known functions or configurations will be omitted where such descriptions would unnecessarily obscure the essential points of this disclosure. Where the terms “comprising,” “having,” and “including” are used in this disclosure, additional parts may be added unless “only…” is used. Unless otherwise stated, singular terms may include plural forms.

[0026] When interpreting a component, it is interpreted as including the error range even if there is no separate explicit description of the error range.

[0027] When describing positional relationships, for example, when the positional relationship is described as "on," "above," "below," and "adjacent to," one or more parts may be placed between two other parts unless "exactly" or "directly" is used. Terms such as "below," "lower," "above," "upper," etc., may be used herein to describe the relationships between elements as shown in the figures. It will be understood that the terms are spatially relative and based on the orientation depicted in the figures.

[0028] The description of time relationships may include cases where time priority is described as "after", "following", or "before", and is not sequential unless "immediately" or "right away" is used.

[0029] Although terms like "first," "second," etc., are used to describe a wide variety of components, these components are not limited to these terms. These terms are only used to distinguish one component from another. Therefore, the "first component" mentioned below can be a "second component" within the technical concept of this disclosure.

[0030] It will be understood that although the terms “first,” “second,” “A,” “B,” “(a),” and “(b)” are used herein to describe a wide variety of elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0031] The features of each of the various instances disclosed herein can be partially or completely combined or integrated with each other, and various interoperability and driving mechanisms are technically possible, and each of the instances can be implemented independently of each other or can be implemented together in a related relationship.

[0032] In the following, one embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0033] Figure 1 This is a plan view of a display device according to one embodiment of the present disclosure.

[0034] Reference Figure 1 According to one embodiment of the present disclosure, the display device 10 may include a display area DA and a non-display area NDA surrounding the display area DA. The display area DA is the area in which an image can be displayed, and the non-display area NDA is the area in which an image is not displayed.

[0035] The display area DA may include a plurality of pixels P. The plurality of pixels P may be arranged in a matrix consisting of a plurality of rows and columns. In addition, the non-display area NDA may include a plurality of wiring, pads, driving circuits, etc. for driving the plurality of pixels P.

[0036] Figure 2 A plan view of a pixel according to one embodiment of this disclosure.

[0037] Reference Figure 2 A pixel P may include a first sub-pixel SP1, a second sub-pixel SP2, and a third sub-pixel SP3. The first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 may emit different lights from each other. For example, the first sub-pixel SP1 may emit red light, the second sub-pixel SP2 may emit green light, and the third sub-pixel SP3 may emit blue light, but this disclosure is not limited thereto. Furthermore, Figure 2The diagram illustrates a pixel P comprising three subpixels SP1 to SP3, but is not limited to this. For example, a pixel P may include more than three subpixels.

[0038] First sub-pixel SP1, second sub-pixel SP2, and third sub-pixel SP3 can be disposed on substrate 100. Each of the first sub-pixel SP1, second sub-pixel SP2, and third sub-pixel SP3 may include a light-emitting region EA and a non-light-emitting region NEA surrounding the light-emitting region EA. The light-emitting region EA is a region capable of emitting light, and the non-light-emitting region NEA is a region that does not emit light.

[0039] Figure 3 This is a cross-sectional view of a sub-pixel SP according to a first embodiment of the present disclosure. Figure 3 for Figure 2 The cross-sectional view of any one of the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 is shown in the figure.

[0040] Reference Figure 3 According to one embodiment of the present disclosure, a sub-pixel SP may include a substrate 100, a thin film transistor 120, a passivation layer 130, a planarization layer 140, a dam 150, and a light-emitting device OLED.

[0041] The substrate 100 can be made of glass or plastic, but is not limited to these. A display device according to one embodiment of this disclosure can be configured as a top-emitting type, in which upward light is emitted. Therefore, not only transparent materials but also opaque materials can be used as the material for the substrate 100.

[0042] The thin-film transistor 120 may be disposed on the substrate 100. The thin-film transistor 120 may include a gate electrode 121, a semiconductor layer 122, a gate insulating layer 123, a source electrode 124, and a drain electrode 125.

[0043] The gate electrode 121 of the thin-film transistor 120 can be disposed on the substrate 100. Furthermore, a semiconductor layer 122 can be disposed on the gate electrode 121. The semiconductor layer 122 can comprise a polysilicon semiconductor or an oxide semiconductor. Furthermore, when the semiconductor layer 122 comprises an oxide semiconductor, it can comprise at least one oxide selected from indium gallium zinc oxide (IGZO), indium gallium tin oxide (IGTO), and indium gallium oxide (IGO).

[0044] A gate insulating layer 123, used to insulate the gate electrode 121 from the semiconductor layer 122, can be disposed between the gate electrode 121 and the semiconductor layer 122. The gate insulating layer 123 can be formed of a single layer or multiple layers of silicon nitride (SiNx) or silicon oxide (SiOx). Furthermore, Figure 3A bottom gate structure in which the semiconductor layer 122 is disposed on the gate electrode 121 is shown, but is not limited thereto. For example, a top gate structure in which the gate electrode 121 is disposed on the semiconductor layer 122 may be disclosed.

[0045] Source electrode 124 and drain electrode 125 can be disposed on semiconductor layer 122, facing each other. Furthermore, passivation layer 130 can be disposed on source electrode 124 and drain electrode 125. Contact holes can be provided in passivation layer 130 to expose a portion of drain electrode 125. Furthermore, passivation layer 130 can be formed of an inorganic insulating material such as silicon oxide (SiOx), silicon nitride (SiNx), or silicon nitride oxide (SiOxNy).

[0046] A planarization layer 140 may be disposed on the thin-film transistor 120. The planarization layer 140 can compensate for the step difference caused by the thin-film transistor 120 to form a flat upper region of the thin-film transistor 120. In addition, the planarization layer 140 may be formed of an organic insulating material such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin.

[0047] The embankment 150 can be disposed on the planarization layer 140 and in the non-light-emitting region NEA. The embankment 150 can expose a portion of the planarization layer 140.

[0048] The light-emitting device OLED can be disposed on the planarization layer 140. The light-emitting device OLED may include a first electrode 200, a light-emitting layer 300, a second electrode 400, and a capping layer 500.

[0049] The first electrode 200 is disposed on the planarization layer 140 and can serve as the anode of the display device. The first electrode 200 can be electrically connected to the drain electrode 125 of the thin-film transistor 120 through contact holes disposed in the passivation layer 130 and the planarization layer 140.

[0050] The first electrode 200 can be disposed on the planarization layer 140 exposed through the embankment 150. The end of the first electrode 200 can be covered by the embankment 150. The first electrode 200 can be disposed in the light-emitting region EA.

[0051] The light-emitting layer 300 can be disposed on the first electrode 200. The light-emitting layer 300 can cover the entire upper surface of the first electrode 200 that is not covered by the embankment 150. Furthermore, the light-emitting layer 300 can be disposed on the embankment 150. That is, the light-emitting layer 300 can be disposed in the light-emitting region EA and the non-light-emitting region NEA.

[0052] The second electrode 400 can be disposed on the light-emitting layer 300. The second electrode 400 can serve as the cathode of the display device. Similar to the light-emitting layer 300, the second electrode 400 can also be disposed on the embankment 150. That is, the second electrode 400 can be disposed in the light-emitting area EA and the non-light-emitting area NEA.

[0053] A capping layer 500 can be disposed on the second electrode 400. The capping layer 500 can cover the entire surface of the second electrode 400 and protect the light-emitting device OLED. That is, the capping layer 500 can be disposed in the light-emitting region EA and the non-light-emitting region NEA.

[0054] Figure 4 This is a cross-sectional view of a light-emitting device according to a first embodiment of the present disclosure. Figure 4 An OLED is shown, which is a light-emitting device for any of the first sub-pixels SP1 to the third sub-pixels SP3.

[0055] As described above, an OLED light-emitting device may include a first electrode 200, a light-emitting layer 300, a second electrode 400, and a cover layer 500.

[0056] The first electrode 200 acts as an anode and can provide holes to the light-emitting layer 300. The first electrode 200 may include a reflective electrode 201, a first transparent electrode 202, a semi-transmissive and semi-reflective electrode 203, and a second transparent electrode 204.

[0057] The reflective electrode 201 may contain a metallic material, such as aluminum (Al), silver (Ag), copper (Cu), molybdenum (Mo), titanium (Ti), tungsten (W), or chromium (Cr), or alloys thereof. In this case, the reflective electrode 201 may have sufficient thickness to reflect incident light.

[0058] The first transparent electrode 202 can be disposed on the reflective electrode 201. The first transparent electrode 202 can contain a transparent conductive material, such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0059] A transmissive and reflective electrode 203 can be disposed on the first transparent electrode 202. The transmissive and reflective electrode 203 can comprise a metallic material, such as aluminum (Al), silver (Ag), copper (Cu), molybdenum (Mo), titanium (Ti), tungsten (W), or chromium (Cr), or alloys thereof. The transmissive and reflective electrode 203 can comprise the same material as the reflective electrode 201, but is not limited thereto. In this case, the transmissive and reflective electrode 203 can have a thickness that allows a portion of the incident light to be transmitted while a portion of the incident light is reflected. That is, the thickness of the transmissive and reflective electrode 203 can be less than the thickness of the reflective electrode 201.

[0060] The second transparent electrode 204 can be disposed on the semi-transparent and semi-reflective electrode 203. The second transparent electrode 204 can contain a transparent conductive material, such as indium tin oxide (ITO) or indium zinc oxide (IZO). The second transparent electrode 204 can contain the same material as the first transparent electrode 202, but is not limited thereto.

[0061] The light-emitting layer 300 may be disposed on the first electrode 200. The light-emitting layer 300 may include a hole transport layer, an emission layer, and an electron transport layer. In this case, when a voltage is applied to the first electrode 200 and the second electrode 400, holes and electrons move to the emission layer through the hole transport layer and the electron transport layer, respectively, and can combine with each other in the emission layer to emit light.

[0062] The second electrode 400 can be disposed on the light-emitting layer 300. The second electrode 400 can provide electrons to the light-emitting layer 300.

[0063] The second electrode 400 can be a semi-transmissive, semi-reflective electrode. The second electrode 400 can contain a metallic material, such as aluminum (Al), silver (Ag), copper (Cu), molybdenum (Mo), titanium (Ti), tungsten (W), or chromium (Cr), or alloys thereof. The second electrode 400 can contain the same material as the semi-transmissive, semi-reflective electrode 203, but is not limited thereto. In this case, the second electrode 400 can have a thickness that allows a portion of the incident light to be transmitted and a portion of the incident light to be reflected. Therefore, the second electrode 400 can emit light generated in the light-emitting layer 300 to the outside.

[0064] A capping layer 500 may be disposed on the second electrode 400. The capping layer 500 may be formed of an inorganic insulating material such as silicon oxide (SiOx), silicon nitride (SiNx), or silicon nitride oxide (SiOxNy). Furthermore, the capping layer 500 may transmit light generated by the light-emitting layer 300.

[0065] Simultaneously, microcavity characteristics can be generated by the first electrode 200 and the second electrode 400. Specifically, when the distance between the first electrode 200 and the second electrode 400 becomes an integer multiple of half the wavelength of the light generated in the light-emitting layer 300, constructive interference may occur, and the light may be amplified. That is, the reflection and re-reflection of light are repeated between the first electrode 200 and the second electrode 400, and the degree of light amplification can be continuously increased. Therefore, the efficiency of light emitted from the light-emitting layer 300 to the outside can be improved.

[0066] Reference Figure 4Since the reflective electrode 201 can reflect light, a microcavity characteristic can be generated between the reflective electrode 201 and the second electrode 400. In this case, the distance between the reflective electrode 201 and the second electrode 400 is the first optical distance D1, and the microcavity characteristic generated by the reflective electrode 201 and the second electrode 400 can be called the first microcavity MC1.

[0067] Furthermore, since the semi-transmissive and semi-reflective electrode 203 can reflect a portion of the incident light, a microcavity characteristic can be generated between the semi-transmissive and semi-reflective electrode 203 and the second electrode 400. In this case, the distance between the semi-transmissive and semi-reflective electrode 203 and the second electrode 400 is a second optical distance D2, and the microcavity characteristic generated by the semi-transmissive and semi-reflective electrode 203 and the second electrode 400 can be referred to as a second microcavity MC2. Moreover, the second optical distance D2 can be smaller than the first optical distance D1.

[0068] That is, since the first microcavity MC1 and the second microcavity MC2 are generated at different optical distances, the wavelength bands of the light amplified by the first microcavity MC1 and the second microcavity MC2 can be different. Therefore, according to this disclosure, by disclosing the first electrode 200 including the reflective electrode 201 and the semi-transmissive and semi-reflective electrode 203, microcavity characteristics according to different optical distances can be generated simultaneously.

[0069] Figure 5 To show Figure 4 A graph showing the intensity of light from the light-emitting device. Specifically, Figure 5 The relative intensity of light according to wavelength is shown. That is, Figure 5 The light intensity shown is not an absolute value, but rather a value used for relative comparison. Furthermore, Figure 5 The illustration shows a case where the light-emitting layer 300 of the OLED device emits green light, but it is not limited to this. The light-emitting layer 300 of the OLED device can also be a layer that emits red light or blue light.

[0070] That is, some regions of the first curve G1 and the second curve G2 may overlap, while some regions of the first curve G1 and the second curve G2 may not overlap. Furthermore, the maximum value of the first curve G1 and the maximum value of the second curve G2 may be different from each other. Additionally, the second curve G2 may be shifted to a shorter wavelength region than the first curve G1.

[0071] The third curve G3 represents the final result from... Figure 4The intensity of the light emitted by the OLED light-emitting device shown is illustrated. The light ultimately emitted from the OLED can be obtained by summing the enhanced interference caused by the first microcavity MC1 and the enhanced interference caused by the second microcavity MC2 to the light generated by the light-emitting layer 300. That is, the light generated by the light-emitting layer of the OLED includes the wavelength band of light amplified by the first microcavity MC1 and the second microcavity MC2, and the intensity of the light ultimately emitted from the OLED can be amplified by the first microcavity MC1 and the second microcavity MC2.

[0072] The fourth curve, G4, represents the intensity of the light ultimately emitted from a conventional OLED light-emitting device. (Refer to...) Figure 6 The first electrode 200 of a conventional light-emitting OLED device may include a reflective electrode 201 and a first transparent electrode 202 disposed on the reflective electrode 201. That is, with Figure 4 Unlike the OLED disclosed in the paper, a conventional OLED does not include a transmissive / reflective electrode 203 and a second transparent electrode 204. Therefore, a conventional OLED may only generate the first microcavity MC1. That is, the light ultimately emitted from a conventional OLED can be obtained by summing the enhanced interference caused by the first microcavity MC1 to the light generated by the light-emitting layer 300.

[0073] Reference Figure 5 The maximum value of the third curve G3 can be similar to the maximum value of the fourth curve G4. In contrast, the full width at half maximum (FWHM) W1 of the third curve G3 can be greater than the full width at half maximum (FWHM) W2 of the fourth curve G4. Specifically, the full width at half maximum (FWHM) can be the full width of the curve at half the maximum value (HM). The third curve G3 can have a half-value HM of the maximum value at the first wavelength λ1, and the fourth curve G4 can have a half-value HM of the maximum value at the second wavelength λ2. In this case, the first wavelength λ1 can be shorter than the second wavelength λ2. That is, compared to the fourth curve G4, the third curve G3 can have similar light intensity and a wider spectrum.

[0074] Therefore, this disclosure discloses a first microcavity MC1 and a second microcavity MC2 for different optical distances, thereby broadening the width of the light spectrum while maintaining the light intensity. Thus, brightness reduction based on viewing angle can be improved.

[0075] Figure 7 This is a cross-sectional view of a light-emitting device according to a second embodiment of the present disclosure. Specifically, Figure 7 A cross-sectional view of the light-emitting device of each of the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 is shown.

[0076] The first sub-pixel SP1 may include a red light-emitting device OLED_R. The red light-emitting device OLED_R may include a first electrode 210, a light-emitting layer 310, a second electrode 410, and a capping layer 510. The first electrode 210 of the red light-emitting device OLED_R may include a reflective electrode 211 and a first transparent electrode 212. That is, the first electrode 210 of the red light-emitting device OLED_R may have… Figure 6 The structure of the first electrode 200 is shown. Therefore, only the first microcavity MC1 can be generated. In addition, the light-emitting layer 310 can generate red light.

[0077] The second sub-pixel SP2 may include a green light-emitting device OLED_G. The green light-emitting device OLED_G may include a first electrode 220, a light-emitting layer 320, a second electrode 420, and a capping layer 520. The first electrode 220 of the green light-emitting device OLED_G may include a reflective electrode 221, a first transparent electrode 222, a transflective electrode 223, and a second transparent electrode 224. That is, the first electrode 220 of the green light-emitting device OLED_G may have… Figure 4 The structure of the first electrode 200 shown is illustrated. Therefore, a first microcavity MC1 and a second microcavity MC2 can be created. Furthermore, the light-emitting layer 320 can generate green light.

[0078] The third sub-pixel SP3 may include a blue light emitting device OLED_B. The blue light emitting device OLED_B may include a first electrode 230, a light-emitting layer 330, a second electrode 430, and a capping layer 530. The first electrode 230 of the blue light emitting device OLED_B may include a reflective electrode 231 and a first transparent electrode 232. That is, the first electrode 230 of the blue light emitting device OLED_B may have… Figure 6 The structure of the first electrode 200 shown is illustrated. Therefore, only the first microcavity MC1 can be generated. Furthermore, the light-emitting layer 330 can generate blue light.

[0079] The first electrodes 210, 220, and 230 of the red-emitting device OLED_R, the green-emitting device OLED_G, and the blue-emitting device OLED_B can be disposed in each of the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3.

[0080] The reflective electrodes 211, 221, and 231 of the red-light-emitting OLED_R, the green-light-emitting OLED_G, and the blue-light-emitting OLED_B can be formed together. Furthermore, the second electrodes 410, 420, and 430 of the red-light-emitting OLED_R, the green-light-emitting OLED_G, and the blue-light-emitting OLED_B can be formed together. Additionally, the capping layers 510, 520, and 530 of the red-light-emitting OLED_R, the green-light-emitting OLED_G, and the blue-light-emitting OLED_B can be formed together.

[0081] The first electrodes 210 and 230 of the red-light-emitting OLED_R and the blue-light-emitting OLED_B can have the same structure. Furthermore, the first electrode 220 of the green-light-emitting OLED_G can have a different structure than the first electrodes 210 and 230 of the red-light-emitting OLED_R and the blue-light-emitting OLED_B. That is, the structure of the first electrode can be selectively configured for each light-emitting OLED of each sub-pixel SP.

[0082] Figure 7 The first electrode 220 of the second light-emitting device OLED2 is disclosed to include a reflective electrode 221, a first transparent electrode 222, a transflective electrode 223, and a second transparent electrode 224, but is not limited thereto. For example, the same structure as the first electrode 220 of the second light-emitting device OLED2 can be applied to the first light-emitting device OLED1 or the third light-emitting device OLED3.

[0083] Figure 8 This is a cross-sectional view of a light-emitting device according to a third embodiment of this disclosure. Specifically, in Figure 4 The thickness of the transmissive and reflective electrode 203 of the first electrode 200 is shown in the disclosed light-emitting device OLED.

[0084] Reference Figure 8 The first light-emitting device OLED1 may include a first electrode 200a, a light-emitting layer 300, a second electrode 400, and a cover layer 500. The first electrode 200a of the first light-emitting device OLED1 may include a reflective electrode 201a, a first transparent electrode 202a, a semi-transmissive and semi-reflective electrode 203a, and a second transparent electrode 204a.

[0085] Similarly, the second light-emitting device OLED2 may include a first electrode 200b, a light-emitting layer 300, a second electrode 400, and a capping layer 500. The first electrode 200b of the second light-emitting device OLED2 may include a reflective electrode 201b, a first transparent electrode 202b, a transflective electrode 203b, and a second transparent electrode 204b.

[0086] That is, the first light-emitting device OLED1 and the second light-emitting device OLED2 can have the same stacked structure.

[0087] The transflective electrode 203a of the first light-emitting device OLED1 may have a first thickness T1, and the transflective electrode 203b of the second light-emitting device OLED2 may have a second thickness T2. The first thickness T1 may be less than the second thickness T2. Furthermore, the first transparent electrode 202a of the first light-emitting device OLED1 may have a third thickness T3, and the first transparent electrode 202b of the second light-emitting device OLED2 may have a fourth thickness T4. The third thickness T3 may be greater than the fourth thickness T4. Moreover, the sum of the first thickness T1 and the third thickness T3 may be the same as the sum of the second thickness T2 and the fourth thickness T4.

[0088] Therefore, the thicknesses of the transmissive and reflective electrodes 203a and 203b can be adjusted while maintaining the same second optical distance D2 between the first light-emitting device OLED1 and the second light-emitting device OLED2. Thus, the first light-emitting device OLED1 and the second light-emitting device OLED2 can generate the same second microcavity MC2.

[0089] Figure 9 To show Figure 7 The graph shows the transmittance of the semi-transmissive and semi-reflective electrodes of the light-emitting device.

[0090] Reference Figure 9 The first graph G1 shows the transmittance of the transflective electrode 203a of the first light-emitting device OLED1, and the second graph G2 shows the transmittance of the transflective electrode 203b of the second light-emitting device OLED2. As described above, the first thickness T1 of the transflective electrode 203a of the first light-emitting device OLED1 can be smaller than the second thickness T2 of the transflective electrode 203b of the second light-emitting device OLED2. Therefore, in all wavelength bands, the transmittance of the transflective electrode 203a of the first light-emitting device OLED1 can be higher than the transmittance of the transflective electrode 203b of the second light-emitting device OLED2. Conversely, in all wavelength bands, the reflectance of the transflective electrode 203a of the first light-emitting device OLED1 can be lower than the reflectance of the transflective electrode 203b of the second light-emitting device OLED2. That is, by adjusting the thickness of the transflective electrodes 203a and 203b, the transmittance and reflectance of the transflective electrodes 203a and 203b can be set.

[0091] Figure 10 To show Figure 7 A graph showing the intensity of light from the light-emitting device. Specifically, Figure 10The relative intensity of light according to wavelength is shown. That is, Figure 10 The light intensity shown is not an absolute value, but rather a value used for relative comparison. Furthermore, Figure 10 The illustration shows an OLED light-emitting layer 300 that emits green light, but it is not limited to this. The OLED light-emitting layer 300 can also be a red light-emitting layer or a blue light-emitting layer.

[0092] The first curve G1 represents the intensity of the light ultimately emitted from a conventional OLED light-emitting device. For example... Figure 5 and Figure 6 As described above, the light ultimately emitted from a conventional light-emitting device OLED can be obtained by adding the enhanced interference caused by the first microcavity MC1 to the light generated by the light-emitting layer 300.

[0093] The second curve G2 is from... Figure 8 The intensity of the light ultimately emitted by the first light-emitting device OLED1 shown in the diagram. The third curve G3 represents the intensity of the light emitted from... Figure 8 The intensity of the light ultimately emitted by the second light-emitting device OLED2 shown. The light ultimately emitted from each of the first light-emitting device OLED1 and the second light-emitting device OLED2 can be obtained by summing the enhanced interference caused by the first microcavity MC1 and the enhanced interference caused by the second microcavity MC2 to the light generated by the light-emitting layer 300.

[0094] Reference Figure 10 The maximum values ​​of the first curve G1, the second curve G2, and the third curve G3 can be similar to each other. On the other hand, the full width at half maximum (FWHM) W2 of the second curve G2 can be greater than the FWHM W1 of the first curve G1, and the FWHM W3 of the third curve G3 can be greater than the FWHM W2 of the second curve G2. Specifically, the FWHM can be the full width of the curve at half (HM) of its maximum value. The first wavelength λ1 can be the short wavelength value of FWHM W1 in the first curve G1, the second wavelength λ2 can be the short wavelength value of FWHM W2 in the second curve G2, and the third wavelength λ3 can be the short wavelength value of FWHM W3 in the third curve G3. In this case, the first wavelength λ1 can be longer than the second wavelength λ2, and the second wavelength λ2 can be longer than the third wavelength λ3.

[0095] That is, compared with the first curve G1, each of the second curve G2 and the third curve G3 can have similar light intensity and can have a wider spectral width. Furthermore, compared with the second curve G2, the third curve G3 can have similar light intensity and can have a wider spectral width.

[0096] like Figure 8 As described, the second thickness T2 of the transflective electrode 203b of the second light-emitting device OLED2 can be greater than the first thickness T1 of the transflective electrode 203a of the first light-emitting device OLED1. Furthermore, as... Figure 9 As described, as the thickness of the semi-transmissive and semi-reflective electrode increases, the transmittance decreases, and therefore the reflectance may increase. Therefore, the enhanced interference generated by the second microcavity MC2 in the second light-emitting device OLED2 can increase compared to the enhanced interference generated by the second microcavity MC2 in the first light-emitting device OLED1. Therefore, by adjusting the thickness of the semi-transmissive and semi-reflective electrode, the width of the light spectrum can be adjusted. In particular, the FWHM of the light spectrum can be adjusted.

[0097] Figure 11 This is a cross-sectional view of a light-emitting device according to a fourth embodiment of this disclosure. Specifically, Figure 11 A cross-sectional view of the light-emitting device of each of the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 is shown.

[0098] The first sub-pixel SP2 may include a red-light-emitting OLED_R device. The red-light-emitting OLED_R device may include a first electrode 210, a light-emitting layer 310, a second electrode 410, and a capping layer 510. The first electrode 210 of the red-light-emitting OLED_R device may include a reflective electrode 211, a first transparent electrode 212, a transflective electrode 213, and a second transparent electrode 214. Furthermore, the transflective electrode 213 of the red-light-emitting OLED_R device may have a first thickness T1. That is, the first electrode 210 of the red-light-emitting OLED_R device may have... Figure 8 The structure of the first electrode 200a of the first light-emitting device shown is illustrated. Therefore, a first microcavity MC1 and a second microcavity MC2 can be generated. Furthermore, the light-emitting layer 310 can generate red light.

[0099] The second sub-pixel SP2 may include a green light-emitting device OLED_G. The green light-emitting device OLED_G may include a first electrode 220, a light-emitting layer 320, a second electrode 420, and a capping layer 520. The first electrode 220 of the green light-emitting device OLED_G may include a reflective electrode 221, a first transparent electrode 222, a transflective electrode 223, and a second transparent electrode 224. Furthermore, the transflective electrode 223 of the green light-emitting device OLED_G may have a second thickness T2. That is, the first electrode 220 of the green light-emitting device OLED_G may have a second thickness T2. Figure 8The structure of the first electrode 200b of the second light-emitting device OLED2 shown is illustrated. Therefore, a first microcavity MC1 and a second microcavity MC2 can be generated. Furthermore, the light-emitting layer 320 can generate green light.

[0100] The third sub-pixel SP3 may include a blue light emitting device OLED_B. The blue light emitting device OLED_B may include a first electrode 230, a light-emitting layer 330, a second electrode 430, and a capping layer 530. The first electrode 230 of the blue light emitting device OLED_B may include a reflective electrode 231 and a first transparent electrode 232. That is, the first electrode 230 of the blue light emitting device OLED_B may have… Figure 6 The structure of the first electrode 200 shown is illustrated. Furthermore, the light-emitting layer 330 can produce blue light.

[0101] The first electrodes 210, 220, and 230 of the red light emitting device OLED_R, the green light emitting device OLED_G, and the blue light emitting device OLED_B can be disposed in each of the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3.

[0102] The reflective electrodes 211, 221, and 231 of the red-light-emitting OLED_R, the green-light-emitting OLED_G, and the blue-light-emitting OLED_B can be formed together. Furthermore, the second electrodes 410, 420, and 430 of the red-light-emitting OLED_R, the green-light-emitting OLED_G, and the blue-light-emitting OLED_B can be formed together. Additionally, the capping layers 510, 520, and 530 of the red-light-emitting OLED_R, the green-light-emitting OLED_G, and the blue-light-emitting OLED_B can be formed together.

[0103] The first electrodes 210, 220, and 230 of the red-emitting OLED_R, the green-emitting OLED_G, and the blue-emitting OLED_B can have different structures. That is, the structure of the first electrode can be selectively configured for each light-emitting OLED of each sub-pixel SP.

[0104] Typically, the light efficiency of the front surface of a display device can be severely affected by blue light. Therefore, this disclosure discloses that the first electrode 230 of a blue light-emitting device OLED_B is formed to include only a reflective electrode 231 and a first transparent electrode 232, thereby generating only a first microcavity MC1. Therefore, since the blue light-emitting device OLED_B includes a relatively narrow spectrum, the light efficiency of the front surface can be improved.

[0105] Furthermore, the brightness of a display device can typically be severely affected by green light depending on its viewing angle. Therefore, this disclosure discloses a method of forming a first microcavity MC1 and a second microcavity MC2 by forming the first electrode 220 of the green-light-emitting device OLED_G as including a transflective electrode 223. Furthermore, by forming the transflective electrode 223 relatively thickly, the spectral width of the green-light-emitting device OLED_G can be further broadened. Therefore, since the green-light-emitting device OLED_G includes a relatively broad spectrum, the brightness depending on the viewing angle can be improved.

[0106] Furthermore, this disclosure discloses a method of forming a first microcavity MC1 and a second microcavity MC2 by forming the first electrode 210 of the red-light-emitting OLED_R as including a transflective electrode 213. In this case, the spectral width of the red-light-emitting OLED_R can be adjusted by forming the transflective electrode 213 to be relatively thin. Therefore, the color from the viewing angle can be improved by maintaining a color balance between blue light with improved light efficiency of the front surface of the display device and green light with improved brightness from the viewing angle.

[0107] A display device according to one embodiment of the present disclosure includes a substrate, the substrate including a plurality of sub-pixels and a plurality of light-emitting devices in the plurality of sub-pixels. Each of the plurality of light-emitting devices includes a first electrode on the substrate, a light-emitting layer on the first electrode, and a second electrode on the light-emitting layer, wherein the plurality of sub-pixels includes a first sub-pixel having a first light-emitting device and a second sub-pixel having a second light-emitting device. The first light-emitting device generates a first microcavity for light in a first wavelength band and a second microcavity for light in a second wavelength band between the first electrode and the second electrode. The second light-emitting device generates a third microcavity for light in a third wavelength band between the first electrode and the second electrode.

[0108] In a display device according to one embodiment of the present disclosure, the light generated by the light-emitting layer of the first light-emitting device includes light of a first wavelength band and light of a second wavelength band, and the light generated by the light-emitting layer of the second light-emitting device includes light of a third wavelength band.

[0109] In a display device according to one embodiment of the present disclosure, the first electrode of the first light-emitting device includes a first reflective electrode on a substrate, a first transparent electrode on the first reflective electrode, a first transflective electrode on the first transparent electrode, and a second transparent electrode on the first transflective electrode. A first microcavity is generated by the distance between the first reflective electrode and the second electrode. Furthermore, a second microcavity is generated by the distance between the first transparent electrode and the second electrode.

[0110] In a display device according to one embodiment of the present disclosure, the spectrum of light caused by the second microcavity is shifted to a shorter wavelength region than the spectrum of light caused by the first microcavity.

[0111] In a display device according to one embodiment of the present disclosure, the first reflective electrode and the first semi-transmissive / semi-reflective electrode comprise metallic materials, such as aluminum (Al), silver (Ag), copper (Cu), molybdenum (Mo), titanium (Ti), tungsten (W), or chromium (Cr), or alloys thereof.

[0112] In a display device according to one embodiment of the present disclosure, the first transparent electrode and the second transparent electrode may comprise a transparent conductive material, such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0113] In a display device according to one embodiment of the present disclosure, the first electrode of the second light-emitting device includes a second reflective electrode on a substrate and a third transparent electrode on the second reflective electrode. Furthermore, a third microcavity is generated by the distance between the second reflective electrode and the second electrode.

[0114] In a display device according to one embodiment of the present disclosure, the first electrode of the second light-emitting device further includes a second semi-transmissive and semi-reflective electrode on the third transparent electrode and a fourth transparent electrode on the second semi-transmissive and semi-reflective electrode. Furthermore, a fourth microcavity is further created by the distance between the second semi-transmissive and semi-reflective electrode and the second electrode.

[0115] In a display device according to one embodiment of the present disclosure, the transmittance of the second semi-transmissive and semi-reflective electrode is greater than the transmittance of the first semi-transmissive and semi-reflective electrode.

[0116] In a display device according to one embodiment of the present disclosure, the light-emitting layer of the first light-emitting device generates green light, and the light-emitting layer of the second light-emitting device generates red light or blue light.

[0117] In a display device according to one embodiment of the present disclosure, the plurality of sub-pixels further includes a third sub-pixel having a third light-emitting device, wherein the first electrode of the third light-emitting device includes a third reflective electrode on a substrate and a fifth transparent electrode on the third reflective electrode. Furthermore, a fifth microcavity is created by the distance between the third reflective electrode and the second electrode.

[0118] In a display device according to one embodiment of the present disclosure, the light-emitting layer of the first light-emitting device generates green light, the light-emitting layer of the second light-emitting device generates red light, and the light-emitting layer of the third light-emitting device generates blue light.

[0119] In a display device according to one embodiment of the present disclosure, the full width at half maximum (FWHM) of the light emitted by the third light-emitting device is smaller than that of the light emitted by the second light-emitting device. Furthermore, the FWHM of the light emitted by the second light-emitting device is smaller than that of the light emitted by the first light-emitting device.

[0120] In a display device according to one embodiment of the present disclosure, the second electrode is a semi-transmissive and semi-reflective electrode.

[0121] It will be apparent to those skilled in the art that the present disclosure described above is not limited to the above embodiments and drawings, and that various substitutions, modifications, and variations may be made in this disclosure without departing from the spirit or scope thereof. Therefore, the scope of this disclosure is defined by the appended claims, and all variations or modifications derived from the meaning, scope, and equivalent concepts of the claims are intended to fall within the scope of this disclosure.

Claims

1. A display device, comprising: A substrate comprising multiple sub-pixels; as well as The plurality of light-emitting devices in the plurality of sub-pixels, Each of the plurality of light-emitting devices includes a first electrode on the substrate, a light-emitting layer on the first electrode, and a second electrode on the light-emitting layer. The plurality of sub-pixels includes a first sub-pixel equipped with a first light-emitting device and a second sub-pixel equipped with a second light-emitting device. The first light-emitting device generates a first microcavity for light in a first wavelength band and a second microcavity for light in a second wavelength band between the first electrode and the second electrode, and The second light-emitting device generates a third microcavity for light in a third wavelength band between the first electrode and the second electrode.

2. The display device according to claim 1, wherein the light generated by the light-emitting layer of the first light-emitting device includes light of the first wavelength band and light of the second wavelength band, and The light generated by the light-emitting layer of the second light-emitting device includes light of the third wavelength band.

3. The display device according to claim 1, wherein the first electrode of the first light-emitting device comprises a first reflective electrode on the substrate, a first transparent electrode on the first reflective electrode, a first semi-transparent and semi-reflective electrode on the first transparent electrode, and a second transparent electrode on the first semi-transparent and semi-reflective electrode. The first microcavity is generated by the distance between the first reflective electrode and the second electrode, and The second microcavity is generated by the distance between the first semi-transmissive and semi-reflective electrode and the second electrode.

4. The display device of claim 3, wherein the spectrum of the light caused by the second microcavity is shifted to a shorter wavelength region than the spectrum of the light caused by the first microcavity.

5. The display device according to claim 3, wherein the first reflective electrode and the first semi-transmissive semi-reflective electrode comprise metallic materials, such as aluminum (Al), silver (Ag), copper (Cu), molybdenum (Mo), titanium (Ti), tungsten (W), or chromium (Cr), or alloys thereof.

6. The display device according to claim 3, wherein the first transparent electrode and the second transparent electrode may comprise a transparent conductive material, such as indium tin oxide (ITO) or indium zinc oxide (IZO).

7. The display device according to claim 3, wherein the first electrode of the second light-emitting device comprises a second reflective electrode on the substrate and a third transparent electrode on the second reflective electrode, and The third microcavity is generated by the distance between the second reflective electrode and the second electrode.

8. The display device according to claim 7, wherein the first electrode of the second light-emitting device further comprises a second semi-transparent and semi-reflective electrode on the third transparent electrode and a fourth transparent electrode on the second semi-transparent and semi-reflective electrode, and The fourth microcavity is further generated by the distance between the second semi-transmissive and semi-reflective electrode and the second electrode.

9. The display device according to claim 8, wherein the transmittance of the second semi-transmissive semi-reflective electrode is greater than the transmittance of the first semi-transmissive semi-reflective electrode.

10. The display device according to claim 8, wherein the light-emitting layer of the first light-emitting device generates green light, and the light-emitting layer of the second light-emitting device generates red light or blue light.

11. The display device according to claim 8, wherein the plurality of sub-pixels further includes a third sub-pixel provided with a third light-emitting device. The first electrode of the third light-emitting device includes a third reflective electrode on the substrate and a fifth transparent electrode on the third reflective electrode, and The fifth microcavity is created by the distance between the third reflective electrode and the second electrode.

12. The display device according to claim 11, wherein the light-emitting layer of the first light-emitting device generates green light, the light-emitting layer of the second light-emitting device generates red light, and the light-emitting layer of the third light-emitting device generates blue light.

13. The display device according to claim 11, wherein the full width at half maximum (FWHM) of the light emitted by the third light-emitting device is smaller than the full WHM of the light emitted by the second light-emitting device, and The full width at half maximum (FWHM) of the light emitted by the second light-emitting device is smaller than that of the light emitted by the first light-emitting device.

14. The display device according to claim 1, wherein the second electrode is a semi-transmissive and semi-reflective electrode.

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