Display device

Abstract

A display device in which each of first to third light emitting devices includes a first electrode disposed on a substrate, a first hole transport layer disposed on the first electrode, and a first light emitting layer disposed on the first hole transport layer, each of the first light emitting device and the second light emitting device includes a first optical layer disposed between the first hole transport layer and the first light emitting layer, and a thickness of the first optical layer of the first light emitting device is the same as a thickness of the first optical layer of the second light emitting device.

Description

Technical Field

[0001] The present disclosure relates to a display device. Background Art

[0002] With the development of the information society, the demand for display devices is increasing. Therefore, various display devices, such as liquid crystal displays (LCDs), plasma display panels (PDPs), and organic light-emitting displays (OLEDs), have been used recently.

[0003] Among display devices, an organic light-emitting display device is a self-emitting type and has advantages such as excellent viewing angles and contrast ratios compared to LCDs. Since it does not require a separate backlight unit, it is possible to be lightweight and thin, and the power consumption is advantageous. In addition, the organic light-emitting display device has the advantages of being able to drive at a low DC voltage, having a fast response speed, and having a particularly low manufacturing cost.

[0004] In addition, an organic light-emitting device used in an organic light-emitting display device includes a plurality of organic layers and a plurality of metal layers, and a process for forming each material layer is required. Recently, research has been conducted to simplify the manufacturing process of organic light-emitting devices. Summary of the Invention

[0005] Accordingly, an object of the present disclosure is to solve the above and other problems. Another object of the present disclosure is to provide an organic light-emitting device having improved device characteristics while simplifying the process and a display device including the organic light-emitting device.

[0006] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, the present invention provides, in one aspect, a display device including: a substrate including a first sub-pixel, a second sub-pixel, and a third sub-pixel; a first light-emitting device disposed in the first sub-pixel; a second light-emitting device disposed in the second sub-pixel; and a third light-emitting device disposed in the third sub-pixel, wherein each of the first to third light-emitting devices includes a first electrode disposed on the substrate, a first hole transport layer disposed on the first electrode, and a first light-emitting layer disposed on the first hole transport layer, each of the first light-emitting device and the second light-emitting device includes a first optical layer disposed between the first hole transport layer and the first light-emitting layer, and the thickness of the first optical layer of the first light-emitting device is the same as the thickness of the first optical layer of the second light-emitting device.

[0007] The further scope of application of the present invention will become apparent from the detailed description given hereinafter. However, the detailed description and specific embodiments, while indicating preferred embodiments of the present invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the present invention will become apparent to those skilled in the art from this detailed description. Description of the Drawings

[0008] The present invention will be more fully understood from the following detailed description and the accompanying drawings, which are given by way of illustration only and thus are not limiting of the present invention, and in which,

[0009] Figure 1 is a cross-sectional view of a plurality of sub-pixels of a display device according to a first embodiment of the present invention.

[0010] Figure 2 is a cross-sectional view of a plurality of sub-pixels of a display device according to a second embodiment of the present invention.

[0011] Figure 3 is a cross-sectional view of a plurality of sub-pixels of a display device according to a third embodiment of the present invention.

[0012] Figure 4 is a cross-sectional view of a plurality of sub-pixels of a display device according to a fourth embodiment of the present invention.

[0013] Figure 5 is a cross-sectional view of a plurality of sub-pixels of a display device according to a fifth embodiment of the present invention.

[0014] Figure 6 is a cross-sectional view of a plurality of sub-pixels of a display device according to a sixth embodiment of the present invention.

[0015] Figure 7 is a cross-sectional view of a plurality of sub-pixels of a display device according to a seventh embodiment of the present invention.

[0016] Figure 8 is a cross-sectional view of a plurality of sub-pixels of a display device according to an eighth embodiment of the present invention.

[0017] Figure 9 is another cross-sectional view of a plurality of sub-pixels of a display device according to a first embodiment of the present invention. Detailed Embodiments

[0018] Advantages and features of the present disclosure and its implementation method will be clarified by the embodiments described below with reference to the accompanying drawings. However, the present disclosure may be implemented in different forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art. In addition, the present disclosure is defined only by the scope of the claims.

[0019] The shapes, sizes, ratios, angles, and quantities disclosed in the drawings used to describe the embodiments of the present disclosure are merely examples, and thus, the present disclosure is not limited to the details shown. Throughout the specification, the same reference numerals denote the same elements. When using "comprising," "having," and "including" described in the present disclosure, another part may be added, unless "only" is used. A term in the singular form may include the plural form, unless stated to the contrary.

[0020] When constructing an element, the element is interpreted to include an error band, although not explicitly described.

[0021] When describing a positional relationship, for example, when the positional relationship is described as "on...," "above...," "under...," and "adjacent to...," one or more parts may be arranged between two other parts, unless "only" or "directly" is used.

[0022] Although terms such as "first," "second," etc. 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. For example, without departing from the scope of the present disclosure, the first element may be referred to as the second element, and similarly, the second element may be referred to as the first element.

[0023] The features of the various embodiments of the present disclosure may be partially or wholly coupled or combined with each other, and may interoperate differently with each other and be technically driven, as can be fully understood by those skilled in the art. The embodiments of the present disclosure may be executed independently of each other, or may be executed together in a mutually dependent relationship. Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings.

[0024] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings.

[0025] Specifically, Figure 1 is a cross-sectional view of a plurality of sub-pixels SP of a display device according to a first embodiment of the present invention.

[0026] Referring to Figure 1 , the substrate 100 may be divided into a plurality of sub-pixels SP. As shown, the plurality of sub-pixels SP may include a first sub-pixel SP1, a second sub-pixel SP2, and a third sub-pixel SP3. Specifically, 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.

[0027] Multiple organic light-emitting devices (OLEDs) can be disposed on a substrate, and may include a first organic light-emitting device (OLED1), a second organic light-emitting device (OLED2), and a third organic light-emitting device (OLED3). The first organic light-emitting device (OLED1) can be disposed in a first sub-pixel (SP1), the second organic light-emitting device (OLED2) can be disposed in a second sub-pixel (SP2), and the third organic light-emitting device (OLED3) can be disposed in a third sub-pixel (SP3).

[0028] In addition, the substrate 100 can be made of glass or plastic, but is not limited thereto. In addition, the display device according to the first embodiment of the present invention can be of a top-emitting type, in which the emitted light is emitted upward. Therefore, as the material of the substrate 100, not only a transparent material but also an opaque material can be used.

[0029] Each of the first organic light-emitting device (OLED1) to the third organic light-emitting device (OLED3) may further include a first electrode 200, a first stack 300, a charge generation layer 400, a second stack 500, and a second electrode 600.

[0030] As Figure 1 shown, the first electrode 200 is disposed on the substrate 100 and can be in each of the first sub-pixel (SP1) to the third sub-pixel (SP3). The first electrode 200 can provide holes for the first stack 300. In addition, the first electrodes 200 of the first organic light-emitting diodes (OLED1) to the third organic light-emitting diodes (OLED3) include the same material and can be formed to have the same or substantially the same thickness, but are not limited thereto.

[0031] In addition, the first electrode 200 can include a transparent conductive material, such as indium tin oxide (ITO) or indium zinc oxide (IZO). Optionally, the first electrode 200 can include a metal material, such as aluminum (Al), silver (Ag), copper (Cu), molybdenum (Mo), titanium (Ti), tungsten (W), or chromium (Cr) or an alloy thereof. In addition, although shown as a single layer, the first electrode 200 can be formed of multiple layers.

[0032] In addition, the first stack 300 of each of the first organic light-emitting diodes (OLED1) to the third organic light-emitting diodes (OLED3) can be disposed on the first electrode 200. In addition, the first stack 300 of each of the first organic light-emitting diodes (OLED1) to the third organic light-emitting diodes (OLED3) can include a first hole injection layer 310, a first hole transport layer 320, a first optical layer 330, a first light-emitting layer 340, and a first electron transport layer 350.

[0033] Among the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3, the first hole injection layer 310 is disposed on the first electrode 200, and holes provided from the first electrode 200 can be easily injected into the first light-emitting layer 340. In addition, the first hole injection layers 310 of the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3 include the same or substantially the same material and can be formed to have the same thickness, but are not limited thereto.

[0034] Among the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3, the first hole transport layer 320 is disposed on the first hole injection layer 310, and holes provided from the first electrode 200 can be easily transported to the first light-emitting layer 340. In addition, the first hole transport layers 320 of the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3 include the same material and can be formed to have the same or substantially the same thickness, but are not limited thereto.

[0035] Among the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3, the first optical layer 330 may be disposed on the first hole transport layer 320. In this case, among the first optical layers 330 of the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3, the thickness of one may be the same as or similar to the thickness of the other, and may be different from the thickness of the other. That is, among the first optical layers 330 of the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3, two first optical layers 330 may have the same or substantially the same thickness, while another first optical layer 330 may have a different thickness.

[0036] Specifically, the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 may be the same or substantially the same. In addition, the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 may be formed to be approximately four times the thickness Ta of the first optical layer 330 of the third organic light-emitting device OLED3. For example, when the thickness Ta of the first optical layer 330 of the third organic light-emitting device OLED3 is about 3 nm, the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 may be greater than 0 nm and less than or equal to 12 nm.

[0037] In addition, the first optical layer 330 of the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3 may include the same material. For example, the first optical layer 330 may include the same material as the first hole injection layer 310 or the first hole transport layer 320. In this case, the first optical layer 330 may assist the holes provided from the first electrode 200 to be easily injected or transported to the first light-emitting layer 340. Alternatively, the first optical layer 330 may be formed of an electron blocking layer material. In this case, the first optical layer 330 may prevent the electrons injected into the first light-emitting layer 340 from leaking through the first hole injection layer 310 or the first hole transport layer 320, thereby improving the light-emitting efficiency of the first light-emitting layer 340 by improving the recombination of holes and electrons in the first light-emitting layer 340.

[0038] Since the first optical layers 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 include the same material and have the same or substantially the same thickness, the first optical layers 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 may be formed simultaneously. That is, the first optical layer 330 may be commonly formed in the first sub-pixel SP1 and the second sub-pixel SP2, and the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 may share the first optical layer 330. Therefore, the process of the organic light-emitting device can be simplified.

[0039] In the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3, the first light-emitting layer 340 may be disposed on the first optical layer 330. More specifically, the first light-emitting layer 340 of the first organic light-emitting device OLED1 may generate red light, the first light-emitting layer 340 of the second organic light-emitting device OLED2 may generate green light, and the first light-emitting layer 340 of the third organic light-emitting device OLED3 may generate blue light.

[0040] In addition to realizing the microcavity characteristics, the thickness of the first light-emitting layer 340 of the third organic light-emitting device OLED3 may be less than the thicknesses of the first light-emitting layers 340 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2, but is not limited thereto.

[0041] In the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3, the first electron transport layer 350 is disposed on the first light-emitting layer 340 to assist the electrons provided from the charge generation layer 400 to be easily transported to the first light-emitting layer 340. In addition, the first electron transport layers 350 of the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3 include the same material and may be formed to have the same or substantially the same thickness, but are not limited thereto.

[0042] In the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3, a charge generation layer 400 is disposed on the first electron transport layer 350, and the charge generation layer 400 may include an n-type charge generation layer 410 and a p-type charge generation layer 420.

[0043] In addition, the n-type charge generation layer 410 is disposed on the first electron transport layer 350 and can supply electrons to the first stack 300. In addition, the n-type charge generation layers 410 of the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3 include the same material and can be formed to have the same or substantially the same thickness, but are not limited thereto.

[0044] As Figure 1 shown, in the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3, the p-type charge generation layer 420 is disposed on the n-type charge generation layer 410 and can supply holes to the second stack 500. In addition, the p-type charge generation layers 420 of the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3 include the same material and can be formed to have the same or substantially the same thickness, but are not limited thereto.

[0045] In addition, in the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3, the second stack 500 may be disposed on the p-type charge generation layer 420. In addition, the second stack 500 of each of the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3 may include a second hole transport layer 510, a second optical layer 520, a second light-emitting layer 530, a hole blocking layer 540, and a second electron transport layer 550.

[0046] In addition, in the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3, the second hole transport layer 510 is disposed on the p-type charge generation layer 420 and assists the holes provided from the p-type charge generation layer 420 to be easily transported to the second light-emitting layer 530. In addition, the second hole transport layers 510 of the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3 may contain the same material as each other and can be formed to have the same or substantially the same thickness, but are not limited thereto. In addition, the second hole transport layer 510 may include the same material as the first hole transport layer 320, but is not limited thereto.

[0047] In addition, in the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3, the second optical layer 520 may be disposed on the second hole transport layer 510. In this case, the thicknesses of the second optical layers 520 of the first organic light-emitting diode OLED1 to the third organic light-emitting diode OLED3 may be different from each other.

[0048] More specifically, the thickness T2 of the second optical layer 520 of the first organic light-emitting device OLED1 may be about five times or more the thickness T3 of the second optical layer 520 of the second organic light-emitting device OLED2. For example, when the thickness T3 of the second optical layer 520 of the second organic light-emitting device OLED2 is greater than 0 nm and less than or equal to 12 nm, the thickness T2 of the second optical layer 520 of the first organic light-emitting device OLED1 may be greater than or equal to 55 nm and less than or equal to 66 nm.

[0049] In addition, as the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 increases, the thickness T2 of the second optical layer 520 of the first organic light-emitting device OLED1 may decrease. As described above, the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 may be greater than 0 nm and less than or equal to 12 nm. As the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 increases from 0 nm to 12 nm, the thickness T2 of the second optical layer 520 of the first organic light-emitting device OLED1 may decrease from 66 nm to 55 nm. In addition, the thickness T2 of the second optical layer 520 of the first organic light-emitting device OLED1 may be greater than or equal to five times the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1. Therefore, by maintaining the sum of the thickness T1 of the first optical layer 330 and the thickness T2 of the second optical layer 520 of the first organic light-emitting device OLED1, the microcavity characteristics can be maintained and fluctuations in device characteristics can be reduced.

[0050] Similarly, as the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 increases, the thickness T3 of the second optical layer 520 of the second organic light-emitting device OLED2 may decrease. As described above, the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 may be greater than 0 nm and less than or equal to 12 nm. As the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 increases from 0 nm to 12 nm, the thickness T3 of the second optical layer 520 of the second organic light-emitting device OLED2 may decrease from 12 nm to 0 nm. Therefore, by maintaining the sum of the thickness T1 of the first optical layer 330 and the thickness T3 of the second optical layer 520 of the second organic light-emitting device OLED2, the microcavity characteristics can be maintained and fluctuations in device characteristics can be reduced.

[0051] In addition, the thickness Tb of the second optical layer 520 of the third organic light-emitting device OLED3 may be about 5 nm. That is, the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 may be formed to be three times the thickness Tb of the second optical layer 520 of the third organic light-emitting device OLED3.

[0052] Among the first organic light emitting diode OLED1 to the third organic light emitting diode OLED3, the second light emitting layer 530 may be disposed on the second optical layer 520. In addition, the second light emitting layer 530 of the first organic light emitting device OLED1 may generate red light, the second light emitting layer 530 of the second organic light emitting device OLED2 may generate green light, and the second light emitting layer 530 of the third organic light emitting device OLED3 may generate blue light.

[0053] In addition, in order to achieve microcavity characteristics, the thickness of the second light emitting layer 530 of the third organic light emitting device OLED3 may be less than the thickness of the second light emitting layer 530 of the first organic light emitting device OLED1 and the second organic light emitting device OLED2, but is not limited thereto.

[0054] Among the first organic light emitting diode OLED1 to the third organic light emitting diode OLED3, a hole blocking layer 540 may be disposed on the second light emitting layer 530. More specifically, the hole blocking layer 540 prevents or at least reduces the leakage of holes injected into the second light emitting layer 530 through the second electron transport layer 550, thereby improving the light emitting efficiency of the second light emitting layer 530 by improving the recombination of holes and electrons in the second light emitting layer 530.

[0055] In addition, among the first organic light emitting diode OLED1 to the third organic light emitting diode OLED3, a second electron transport layer 550 is disposed on the hole blocking layer 540 to assist the electrons provided from the second electrode 600 to be easily transported to the second light emitting layer 530. In addition, the second electron transport layers 550 of the first organic light emitting diode OLED1 to the third organic light emitting diode OLED3 include the same material and may be formed to have the same or substantially the same thickness, but are not limited thereto.

[0056] As Figure 1 shown, among the first organic light emitting diode OLED1 to the third organic light emitting diode OLED3, the second electrode 600 is disposed on the second stack 500 and may be disposed in each of the first sub-pixel SP1 to the third sub-pixel SP3. The second electrode 600 can supply electrons to the second stack 500.

[0057] Since the display device according to the first embodiment of the present invention is configured as a top emission type, the second electrode 600 may include a transparent conductive material such as ITO (IZO) or indium zinc oxide (IZO) to transmit the light emitted from the first stack 300 and the second stack 500 toward the upper side of the display device.

[0058] Accordingly, a first embodiment of the present invention discloses a structure in which a first organic light-emitting device OLED1 and a second organic light-emitting device OLED2 share a first optical layer 330. In addition, as the thickness of the first optical layer 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 increases, the thickness of the second optical layer 520 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 can be reduced. Accordingly, since the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 share the first optical layer 330, the device characteristics of the organic light-emitting device can be maintained while simplifying the process of the organic light-emitting device.

[0059] Next, Figure 2 is a cross-sectional view of a plurality of sub-pixels SP of a display device according to a second embodiment of the present invention.

[0060] Compared with Figure 1 except for the structure of the second optical layer 520, a substantially identical structure is disclosed. Accordingly, the same reference numerals are used for components identical to those of the display device shown in Figure 1 and repeated descriptions are omitted.

[0061] Compared with Figure 1 the first embodiment of Figure 2 the second embodiment of Figure 1 discloses a structure in which the second optical layer 520 of the second organic light-emitting device OLED2 is omitted. Accordingly, compared with Figure 2 the first embodiment of

[0062] Referring to Figure 2 , the first optical layer 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 has the same or substantially the same thickness and can be formed together. In this case, Figure 2 the thickness range of the first optical layer 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 in Figure 1 can be wider than the thickness range of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 in Figure 2 Specifically, Figure 1 the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 in Figure 2 can be greater than 0 nm and less than or equal to 32 nm. That is, compared with

[0063] In addition, the thickness T1 of the first optical layer 330 of the first organic light emitting device OLED1 and the second organic light emitting device OLED2 may be formed to be about 11 times the thickness Ta of the first optical layer 330 of the third organic light emitting device OLED3. For example, the thickness Ta of the first optical layer 330 of the third organic light emitting device OLED3 may be about 3 nm. In addition, the thickness T1 of the first optical layer 330 of the first organic light emitting device OLED1 and the second organic light emitting device OLED2 may be formed to be about seven times the thickness Tb of the second optical layer 520 of the third organic light emitting device OLED3. For example, the thickness Tb of the first optical layer 330 of the third organic light emitting device OLED3 may be about 5 nm.

[0064] In addition, the second optical layer 520 of the first organic light emitting device OLED1 may be disposed on the second hole transport layer 510. In this case, Figure 2 The thickness range of the first optical layer 330 of the first organic light emitting device OLED1 may be greater than Figure 1 The thickness range of the first optical layer 330 of the first organic light emitting device OLED1 is wide. Specifically, the thickness T2 of the second optical layer 520 of the first organic light emitting device OLED1 may be greater than or equal to 34 nm and less than or equal to 66 nm. Figure 1 compared to, Figure 2 The thickness T2 of the second optical layer 520 of the first organic light emitting device OLED1 may be smaller. In addition, the thickness T2 of the second optical layer 520 of the first organic light emitting device OLED1 may be greater than the thickness T1 of the first optical layer 330 of the first and second organic light emitting devices OLED1 and OLED2.

[0065] Since the second organic light emitting device OLED2 does not include the second optical layer 520, the second light emitting layer 530 of the second organic light emitting device OLED2 may be disposed on the second hole transport layer 510. In this case, the thickness T3 of the second light emitting layer 530 of the second organic light emitting device OLED2 may be greater than or equal to 24.5 nm and less than or equal to 40.5 nm. In addition, the thickness of the first light emitting layer 340 of the second organic light emitting device OLED2 may be equal to the thickness T4 of the second light emitting layer 530 of the second organic light emitting device OLED2.

[0066] In this case, since the second optical layer 520 of the first organic light emitting device OLED1 and the second light emitting layer 530 of the second organic light emitting device OLED2 are disposed on the first optical layer 330, as the thickness T1 of the first optical layer 330 of the first organic light emitting device OLED1 and the second organic light emitting device OLED2 increases, the thickness T2 of the second optical layer 520 of the first organic light emitting device OLED1 and the thickness T4 of the second light emitting layer 530 of the second organic light emitting device OLED2 may be reduced. For example, when the thickness T1 of the first optical layer 330 of the first organic light emitting device OLED1 and the second organic light emitting device OLED2 increases from 0 nm to 32 nm, the thickness T2 of the second optical layer 520 of the first organic light emitting device OLED1 may be reduced from 66 nm to 34 nm, and the thickness T4 of the second light emitting layer 530 of the second organic light emitting device OLED2 may be reduced from 40.5 nm to 24.5 nm.

[0067] In short, with Figure 1 compared to, Figure 2 Device characteristics may be maintained by adjusting the thickness T1 of the first optical layer 330 of the first organic light emitting device OLED1 and the second organic light emitting device OLED2, the thickness T2 of the second optical layer 520 of the first organic light emitting device OLED1, and the thickness T4 of the second light emitting layer 530 of the second organic light emitting device OLED2.

[0068] Therefore, even if the second optical layer 520 is omitted in the second organic light emitting device OLED2, the characteristics of the device can be maintained by adjusting the thickness of some layers constituting the first stack 300 and the second stack 500. In addition, since the process of forming the second optical layer 520 in the second organic light emitting device OLED2 can be omitted, the process of the organic light emitting device can be further simplified.

[0069] Figure 3 is a cross-sectional view of a plurality of sub-pixels SP of a display device according to a third embodiment of the present invention.

[0070] and Figure 1 Compared with the first optical layer 330 and the second optical layer 520, the substantially same structure is disclosed. Figure 1 The same components of the illustrated display device are denoted by the same reference numerals, and repeated descriptions are omitted.

[0071] Figure 1 The first embodiment discloses that the first organic light emitting device OLED1 and the second organic light emitting device OLED2 share the first optical layer 330, but Figure 3 The third embodiment discloses that the second organic light emitting device OLED2 and the third organic light emitting device OLED3 share the first optical layer 330 .

[0072] Refer to Figure 3 , the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 has the same or substantially the same thickness and can be formed together. In addition, the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 can be greater than or equal to 1 nm and less than or equal to 6 nm. In addition, the first organic light-emitting device OLED1 may not include the first optical layer 330.

[0073] In addition, the thickness Tc of the second optical layer 520 of the first organic light-emitting device OLED1 can be greater than 60 nm and less than or equal to 66 nm, the thickness T2 of the second optical layer 520 of the second organic light-emitting device OLED2 can be greater than or equal to 6 nm and less than or equal to 11 nm. And the thickness T3 of the second optical layer 520 of the third organic light-emitting device OLED3 can be greater than or equal to 2 nm and less than or equal to 7 nm.

[0074] That is, the thicknesses T2 and T3 of the second optical layer 520 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 including the common first optical layer 330 can be less than the thickness Tc of the second optical layer 520 of the first organic light-emitting device OLED1. In addition, the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 can be less than the thickness T2 of the second optical layer 520 of the second organic light-emitting device OLED2.

[0075] In this case, when the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 increases, in the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3, the thicknesses T2 and T3 of the second optical layer 520 disposed on the first optical layer 330 can decrease. For example, when the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 increases from 1 nm to 6 nm, the thickness T2 of the second optical layer 520 of the second organic light-emitting device OLED2 can decrease from 11 nm to 6 nm, and the thickness T3 of the second optical layer 520 of the third organic light-emitting device OLED3 can decrease from 7 nm to 2 nm. In addition, compared with Figure 1 compared with Figure 3 , the thicknesses of the first optical layer 330 and the second optical layer 520 can be smaller.

[0076] In summary, refer to Figure 1 and Figure 3, the first optical layer 330 may be formed to be selectively shared in at least two of the first sub-pixel SP1 to the third sub-pixel SP3. Therefore, by adjusting the thicknesses of the first optical layer 330 and the second optical layer 520, the process of the organic light-emitting device can be simplified, and the device characteristics of the organic light-emitting device can be maintained. In addition, the first organic light-emitting device OLED1 and the third organic light-emitting device OELD3 may share the first optical layer 330.

[0077] Next, Figure 4 is a cross-sectional view of a plurality of sub-pixels SP of a display device according to a fourth embodiment of the present invention.

[0078] Compared with Figure 3 , except for the structure of the second optical layer 520, substantially the same structure is disclosed. Therefore, the same reference numerals are used for the same components as those of the display device shown in Figure 3 , and repeated descriptions are omitted.

[0079] Compared with Figure 3 of the third embodiment, Figure 4 the fourth embodiment discloses a structure in which the second optical layer 520 is omitted from the second organic light-emitting device OLED2. Therefore, compared with Figure 3 of the third embodiment, in Figure 4 the fourth embodiment, the thicknesses of some layers of the first stack 300 and the second stack 500 can be changed.

[0080] Referring to Figure 4 , the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 has the same or substantially the same thickness and can be formed together. The thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 may be greater than or equal to 1 nm and less than or equal to 7 nm.

[0081] The ratio of the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 to the thickness T3 of the second optical layer 520 of the third organic light-emitting device OLED3 may be 1:7 to 7:1. For example, when the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 increases from 1 nm to 7 nm, the thickness T3 of the second optical layer 520 of the third organic light-emitting device OLED3 may decrease from 7 nm to 1 nm.

[0082] In addition, the thickness Tc of the second optical layer 520 of the first organic light-emitting device OLED1 can be greater than 60 nm and less than or equal to 66 nm. That is, the thickness Tc of the second optical layer 520 of the first organic light-emitting device OLED1 can be approximately 10 times the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3, or approximately 10 times the thickness T3 of the second optical layer 520 of the third organic light-emitting device OLED3.

[0083] Since the second organic light-emitting device OLED2 does not include the second optical layer 520, the second light-emitting layer 530 of the second organic light-emitting device OLED2 can be disposed on the second hole transport layer 510. In this case, the thickness T4 of the second light-emitting layer 530 of the second organic light-emitting device OLED2 can be greater than or equal to 37 nm and less than or equal to 40 nm. In addition, the thickness of the first light-emitting layer 340 of the second organic light-emitting device OLED2 can be equal to the thickness T4 of the second light-emitting layer 530 of the second organic light-emitting device OLED2.

[0084] In this case, since the second optical layer 520 of the third organic light-emitting device OLED3 and the second light-emitting layer 530 of the second organic light-emitting device OLED2 are disposed on the first optical layer 330, as the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 increases, the thickness T3 of the second optical layer 520 of the third organic light-emitting device OLED3 and the thickness T4 of the second light-emitting layer 530 of the second organic light-emitting device OLED2 can be reduced. For example, when the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 increases from 1 nm to 7 nm, the thickness T3 of the second optical layer 520 of the third organic light-emitting device OLED3 can be reduced from 7 nm to 1 nm, and the thickness T4 of the second light-emitting layer 530 of the second organic light-emitting device OLED2 can be reduced from 40 nm to 37 nm.

[0085] In summary, compared with Figure 3 even if the second organic light-emitting device OLED2 omits the second optical layer 520, Figure 4 the characteristics of the device can be maintained by adjusting the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3, the thickness T3 of the second optical layer 520 of the third organic light-emitting device OLED3, and the thickness T4 of the second light-emitting layer 530 of the second organic light-emitting device OLED2.

[0086] Therefore, even if the second optical layer 520 is omitted in the second organic light-emitting device OLED2, the characteristics of the device can be maintained by adjusting the thicknesses of some of the layers constituting the first stack 300 and the second stack 500. In addition, since the process of forming the second optical layer 520 in the second organic light-emitting device OLED2 can be omitted, the process of the organic light-emitting device can be further simplified.

[0087] Figure 5 It is a cross-sectional view of a plurality of sub-pixels SP of a display device according to a fifth embodiment of the present invention.

[0088] Compared with Figure 4 except for the structures of the first optical layer 330 and the second optical layer 520, substantially the same structures are disclosed. Therefore, the same reference numerals are used for the same components as those of the display device shown in Figure 4 and repeated descriptions are omitted.

[0089] Compared with Figure 4 the fourth embodiment of Figure 5 the fifth embodiment of Figure 4 discloses a structure in which the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 share the second optical layer 520. Therefore, compared with Figure 5 the fourth embodiment of

[0090] Referring to Figure 5 the second optical layer 520 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 has the same or substantially the same thickness and can be formed together. The thickness T1 of the second optical layer 520 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 can be greater than or equal to 1 nm and less than or equal to 6 nm.

[0091] The ratio of the thickness T1 of the second optical layer 520 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 to the thickness T3 of the first optical layer 330 of the third organic light-emitting device OLED3 can be 1:7 to 7:1. For example, when the thickness T1 of the second optical layer 520 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 increases from 1 nm to 6 nm, the thickness T3 of the first optical layer 330 of the third organic light-emitting device OLED3 can decrease from 7 nm to 2 nm.

[0092] In addition, the thickness Tc of the second optical layer 520 of the first organic light-emitting device OLED1 may be greater than 60 nm and less than or equal to 66 nm. That is, the thickness Tc of the second optical layer 520 of the first organic light-emitting device OLED1 may be about 10 times the thickness T1 of the second optical layer 520 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3, or may be about 10 times the thickness T3 of the first optical layer 330 of the third organic light-emitting device OLED3.

[0093] Compared with the disclosure of the structure of the second organic light-emitting device OLED2 that does not include the second optical layer 520, Figure 4 the second organic light-emitting device OLED2 may not include the first optical layer 330. Since the second organic light-emitting device OLED2 does not include the first optical layer 330, the first light-emitting layer 340 of the second organic light-emitting device OLED2 may be disposed on the first hole transport layer 320. In this case, the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2 may be greater than or equal to 37.5 nm and less than or equal to 40 nm. In addition, the thickness of the second light-emitting layer 530 of the second organic light-emitting device OLED2 may be equal to the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2. Figure 5

[0094] In this case, as the thickness T1 of the second optical layer 520 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 increases, the thickness T3 of the first optical layer 330 of the third organic light-emitting device OLED3 and the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2 may decrease. For example, when the thickness T1 of the second optical layer 520 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 increases from 1 nm to 6 nm, the thickness T3 of the first optical layer 330 of the third organic light-emitting device OLED3 may decrease from 7 nm to 2 nm, and the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2 may decrease from 40 nm to 37.5 nm.

[0095] In summary, Figure 5 a structure is disclosed in which the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 share the second optical layer 520 instead of the first optical layer 330. That is, a structure in which any one of the first optical layer 330 and the second optical layer 520 is commonly formed in the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 may be disclosed. In addition, the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 or the first organic light-emitting device OLED1 and the third organic light-emitting device OELD3 may share the second optical layer 520 with each other.

[0096] Next, Figure 6 FIG. is a cross-sectional view of a plurality of sub-pixels SP of the display device according to the sixth embodiment of the present invention.

[0097] Figures 1 to 5 A structure in which only one of the first optical layer 330 and the second optical layer 520 is formed in common is disclosed, while Figure 6 the sixth embodiment of discloses a structure in which each of the first optical layer 330 and the second optical layer 520 is formed in common.

[0098] Referring to Figure 6 , the first optical layer 330 that forms the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 in common, and the second optical layer 520 that forms the first organic light-emitting device OLED1 and the third organic light-emitting device OLED3 in common.

[0099] In addition, the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 may be greater than or equal to 1 nm and less than or equal to 8 nm. In addition, the thickness Ta of the first optical layer 330 of the third organic light-emitting device OLED3 may be about 3 nm. That is, the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 may be about three times or less the thickness Ta of the first optical layer 330 of the third organic light-emitting device OLED3.

[0100] In addition, the thickness T2 of the second optical layer 520 of the first organic light-emitting device OLED1 and the third organic light-emitting device OLED3 may be about 5 nm. That is, the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 may be about two times or less the thickness T2 of the second optical layer 520 of the first organic light-emitting device OLED1 and the third organic light-emitting device OLED3. In addition, the second organic light-emitting device OLED2 may not include the second optical layer 520.

[0101] In addition, the thickness T3 of the first light-emitting layer 340 of the first organic light-emitting device OLED1 may be greater than or equal to 62.5 nm and less than or equal to 66 nm, and the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2 may be greater than or equal to 36.5 nm and less than or equal to 40 nm. That is, the thickness T3 of the first light-emitting layer 340 of the first organic light-emitting device OLED1 may be greater than the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2. In addition, the thickness of the second light-emitting layer 530 of the first organic light-emitting device OLED1 may be equal to the thickness T3 of the first light-emitting layer 340 of the first organic light-emitting device OLED1. In addition, the thickness of the second light-emitting layer 530 of the second organic light-emitting device OLED2 may be equal to the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2.

[0102] In this case, as the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 increases, in the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2, the thicknesses T3 and T4 of the first light-emitting layer 340 provided on the first optical layer 330 may decrease. For example, when the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 increases from 1 nm to 8 nm, the thickness T3 of the first light-emitting layer 340 of the first organic light-emitting device OLED1 may decrease from 66 nm to 62.5 nm, and the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2 may decrease from 40 nm to 36.5 nm.

[0103] In summary, Figure 6 The first optical layer 330 that forms the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 together and the second optical layer 520 that forms the first organic light-emitting device OLED1 and the third organic light-emitting device OLED3 together are disclosed. That is, the first organic light-emitting device OLED1 may share both the first optical layer 330 and the second optical layer 520, and the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 may share any one of the first optical layer 330 and the second optical layer 520. Therefore, compared with the structure that shares one optical layer, the process of forming the first optical layer 330 and the second optical layer 520 can be further simplified.

[0104] Figure 7 It is a cross-sectional view of a plurality of sub-pixels SP of a display device according to the seventh embodiment of the present invention.

[0105] Figure 6The sixth embodiment discloses a structure in which the first organic light-emitting device OLED1 shares both the first optical layer 330 and the second optical layer 520, but Figure 7 The seventh embodiment discloses a structure in which the second organic light-emitting device OLED2 shares both the first optical layer 330 and the second optical layer 520.

[0106] Referring to Figure 7 , the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 can be formed jointly, and the second optical layer 520 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 can be formed jointly.

[0107] In addition, the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 can be about 8 nm. In addition, the first organic light-emitting device OLED1 may not include the first optical layer 330.

[0108] In addition, the thickness T2 of the second optical layer 520 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 can be equal to or greater than 4 nm and equal to or less than 20 nm. That is, the thickness T2 of the second optical layer 520 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 can be equal to or greater than 0.5 times the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 and equal to or less than three times thereof. In addition, the third organic light-emitting device OLED3 may not include the second optical layer 520.

[0109] In addition, the thickness T3 of the first light-emitting layer 340 of the first organic light-emitting device OLED1 can be greater than or equal to 59 nm and less than or equal to 67 nm, and the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2 can be greater than or equal to 26.5 nm and less than or equal to 34.5 nm. That is, the thickness T3 of the first light-emitting layer 340 of the first organic light-emitting device OLED1 can be greater than the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2. In addition, the thickness of the second light-emitting layer 530 of the first organic light-emitting device OLED1 can be equal to the thickness T3 of the first light-emitting layer 340 of the first organic light-emitting device OLED1. And, the thickness of the second light-emitting layer 530 of the second organic light-emitting device OLED2 can be equal to the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2. In addition, the thickness T2 of the second optical layer 520 of the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 can be less than the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2.

[0110] In this case, as the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 increases, in the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2, the thicknesses T3 and T4 of the first light-emitting layer 340 provided on the first optical layer 330 can be reduced. For example, when the thickness T1 of the first optical layer 330 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 increases from 4 nm to 20 nm, the thickness T3 of the first light-emitting layer 340 of the first organic light-emitting device OLED1 can be reduced from 67 nm to 59 nm, and the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2 can be reduced from 34.5 nm to 26.5 nm.

[0111] In summary, Figure 7 The first optical layer 330 that forms the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 together and the second optical layer 520 that forms the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 together are disclosed. That is, the second organic light-emitting device OLED2 can share both the first optical layer 330 and the second optical layer 520, and the first organic light-emitting device OLED1 and the third organic light-emitting device OLED3 can share any one of the first optical layer 330 and the second optical layer 520. Therefore, compared with a structure that shares one optical layer, the process of forming the first optical layer 330 and the second optical layer 520 can be further simplified.

[0112] Next, Figure 8 is a cross-sectional view of a plurality of sub-pixels SP of a display device according to an eighth embodiment of the present invention.

[0113] Figure 6 The sixth embodiment of discloses a structure in which the first organic light-emitting device OLED1 shares both the first optical layer 330 and the second optical layer 520, but Figure 8 The eighth embodiment of discloses a structure in which the third organic light-emitting device OLED3 shares both the first optical layer 330 and the second optical layer 520.

[0114] Referring to Figure 8 , the first optical layer 330 of the first organic light-emitting device OLED1 and the third organic light-emitting device OLED3 can be formed together, and the second optical layer 520 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 can be formed together.

[0115] The thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the third organic light-emitting device OLED3 can be greater than or equal to 2 nm and less than or equal to 6 nm. In addition, the second organic light-emitting device OLED2 may not include the first optical layer 330.

[0116] In addition, the thickness T2 of the second optical layer 520 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 can be greater than or equal to 2 nm and less than or equal to 6 nm. The sum of the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the third organic light-emitting device OLED3 and the thickness T2 of the second optical layer 520 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 can be 10 nm or less. That is, when the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the third organic light-emitting device OLED3 increases from 2 nm to 6 nm, the thickness T2 of the second optical layer 520 of the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 can decrease from 6 nm to 2 nm. In addition, the first organic light-emitting device OLED1 may not include the second optical layer 520.

[0117] In addition, the thickness T3 of the first light-emitting layer 340 of the first organic light-emitting device OLED1 can be greater than or equal to 66 nm and less than or equal to 68 nm, and the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2 can be greater than or equal to 37.5 nm and less than or equal to 39.5 nm. That is, the thickness T3 of the first light-emitting layer 340 of the first organic light-emitting device OLED1 can be greater than the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2. In addition, the thickness of the second light-emitting layer 530 of the first organic light-emitting device OLED1 can be equal to the thickness T3 of the first light-emitting layer 340 of the first organic light-emitting device OLED1, and the thickness of the second light-emitting layer 530 of the second organic light-emitting device OLED2 can be equal to the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2.

[0118] In this case, as the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the third organic light-emitting device OLED3 increases, the thickness T3 of the first light-emitting layer 340 of the first organic light-emitting device OLED1 can be decreased, and the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2 can be increased. For example, when the thickness T1 of the first optical layer 330 of the first organic light-emitting device OLED1 and the third organic light-emitting device OLED3 increases from 2 nm to 6 nm, the thickness T3 of the first light-emitting layer 340 of the first organic light-emitting device OLED1 can be decreased from 68 nm to 66 nm, and the thickness T4 of the first light-emitting layer 340 of the second organic light-emitting device OLED2 can be increased from 37.5 nm to 39.5 nm.

[0119] In summary, Figure 8 The first optical layer 330 that forms the first organic light-emitting device OLED1 and the third organic light-emitting device OLED3 together and the second optical layer 520 that forms the second organic light-emitting device OLED2 and the third organic light-emitting device OLED3 together are disclosed. That is, the third organic light-emitting device OLED3 can share both the first optical layer 330 and the second optical layer 520, and the first organic light-emitting device OLED1 and the second organic light-emitting device OLED2 can share either the first optical layer 330 or the second optical layer 520. Therefore, compared with a structure that shares one optical layer, the process of forming the first optical layer 330 and the second optical layer 520 can be further simplified.

[0120] Next, Figure 9 is another cross-sectional view of the display device according to the first embodiment of the present invention. Compared with Figure 1 compared, Figure 9 specifically shows the structure other than the organic light-emitting device OLED.

[0121] Referring to Figure 9 , the display device according to the first embodiment of the present invention may include a substrate 100, a thin-film transistor TR, a planarization layer PLN, a bank, and first to third light-emitting devices OLED1 to OLED3.

[0122] The substrate 100 may be made of a transparent insulating material such as glass, but is not limited thereto.

[0123] In addition, the thin-film transistor TR is disposed on the substrate 100 and may be disposed in each of the first to third sub-pixels SP1 to SP3. The thin-film transistor TR may include a semiconductor layer, a gate electrode, a source electrode, and a drain electrode. In addition, the thin-film transistor TR may disclose a bottom-gate structure in which the semiconductor layer is disposed on the gate electrode or a top-gate structure in which the gate electrode is disposed on the semiconductor layer.

[0124] In addition, a planarization layer PLN may be provided on the thin film transistor TR to compensate for the step difference caused by the thin film transistor TR.

[0125] In addition, the planarization layer PLN may be formed of an organic insulating material such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin.

[0126] The first to third light emitting devices OLED may be provided on the planarization layer PLN. As described above, in Figure 1 each of the first to third light emitting devices OLED may include a first electrode 200, a first stack 300, a charge generation layer 400, a second stack 500, and a second electrode 600.

[0127] In addition, the first electrode 200 may be provided on the planarization layer PLN and may serve as the anode of the display device. As Figure 9 shown, the first electrode 200 may be electrically connected to the drain electrode of the thin film transistor TR through a contact hole formed in the planarization layer PLN.

[0128] In addition, the bank may be provided on the planarization layer PLN and the first electrode 200. The bank may define a light emitting region and a non-light emitting region. That is, the region where the bank is not provided may be the light emitting region, and the region where the bank is provided may be the non-light emitting region.

[0129] The bank may include an organic insulating material such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, etc. Alternatively, the bank may include an inorganic insulating material such as silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), etc. In addition, the bank may include a black dye to absorb light incident from the outside.

[0130] In addition, the first stack 300 may be disposed on the first electrode 200 and may also be disposed on the bank. As described above, in Figure 1 the first stack 300 may include a first hole injection layer 310, a first hole transport layer 320, a first optical layer 330, a first light emitting layer 340, and a first electron transport layer 350.

[0131] In addition, the first hole injection layer 310 and the first hole transport layer 320 may be commonly formed in the first sub-pixel SP1 to the third sub-pixel SP3. Therefore, the first hole injection layer 310 and the first hole transport layer 320 may cover the bank BANK between the first sub-pixel SP1 and the second sub-pixel SP2 and the bank BANK between the second sub-pixel SP2 and the third sub-pixel SP3.

[0132] As in Figure 1In the above description, the first optical layer 330 can be formed in the first sub-pixel SP1 and the second sub-pixel SP2 together. Therefore, the first optical layer 330 of the first sub-pixel SP1 can extend to the second sub-pixel SP2. That is to say, the first optical layers 330 of the first sub-pixel SP1 and the second sub-pixel SP2 are formed together, and the first sub-pixel SP1 and the second sub-pixel SP2 can share the first optical layer 330. Moreover, the first optical layer 330 of the first sub-pixel SP1 and the second sub-pixel SP2 can cover the entire surface of the bank BANK between the first sub-pixel SP1 and the second sub-pixel SP2.

[0133] In addition, the first optical layer 330 provided in the third sub-pixel SP3 can be spaced apart from the first optical layers 330 of the first sub-pixel SP1 and the second sub-pixel SP2. Therefore, the first optical layer 330 of the third sub-pixel SP3 can be provided in the area surrounded by the bank, or can cover a part of the upper surface of the bank. That is, on the upper surface of the bank BANK between the second sub-pixel SP2 and the third sub-pixel SP3, the first optical layers 330 of the first sub-pixel SP1 and the second sub-pixel SP2 and the first optical layer 330 of the third sub-pixel SP3 can be spaced apart from each other.

[0134] The first light-emitting layer 340 can be provided in the first sub-pixel SP1 to the third sub-pixel SP3 respectively.

[0135] In addition, the first electron transport layer 350 and the charge generation layer 400 can be formed in the first sub-pixel SP1 to the third sub-pixel SP3 together. Therefore, the first electron transport layer 350 and the charge generation layer 400 can cover the bank BANK between the first sub-pixel SP1 and the second sub-pixel SP2 and the bank BANK between the second sub-pixel SP2 and the third sub-pixel SP3.

[0136] As Figure 1 described above, the second stack 500 can include a second hole transport layer 510, a second optical layer 520, a second light-emitting layer 530, a hole blocking layer 540, and a second electron transport layer 550.

[0137] The second hole transport layer 510, the hole blocking layer 540, and the second electron transport layer 550 can be formed in the first sub-pixel SP1 to the third sub-pixel SP3 together. In addition, the second optical layer 520 and the second light-emitting layer 530 can be provided in the first sub-pixel SP1 to the third sub-pixel SP3 respectively.

[0138] In summary, since the first optical layer 330 can be formed in the first sub-pixel SP1 and the second sub-pixel SP2 together, the process can be simplified compared with forming the first optical layer 330 in each of the first sub-pixel SP1 and the second sub-pixel SP2.

[0139] According to the present disclosure, the following advantageous effects can be obtained.

[0140] According to the present disclosure, a plurality of light conversion layers can be formed, so that the light efficiency can be improved and the reflectance caused by external light can be reduced.

[0141] It will be apparent to those skilled in the art that the above present disclosure is not limited by the above embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made in the present disclosure without departing from the spirit or scope of the present disclosure. Therefore, the scope of the present disclosure is defined by the appended claims, and all changes or modifications derived from the meaning, scope, and equivalent concepts of the claims are intended to fall within the scope of the present disclosure.

[0142] Cross - reference to related applications

[0143] This application claims the benefit of Korean Patent Application No. 10 - 2023 - 0192774, filed on December 27, 2023, which is incorporated herein by reference in its entirety as if fully set forth herein.

Claims

1. A display device, comprising: A substrate, the substrate comprising a first sub-pixel, a second sub-pixel, and a third sub-pixel; a first light emitting device, the first light emitting device being disposed in the first sub-pixel; a second light emitting device, the second light emitting device being disposed in the second sub-pixel; as well as a third light emitting device, the third light emitting device being arranged in the third sub-pixel, Each of the first light-emitting device, the second light-emitting device and the third light-emitting device includes a first electrode disposed on the substrate, a first hole transport layer disposed on the first electrode, and a first light-emitting layer disposed on the first hole transport layer. wherein each of the first light emitting device and the second light emitting device comprises a first optical layer disposed between the first hole transport layer and the first light emitting layer, and Wherein, the thickness of the first optical layer of the first light emitting device is the same as the thickness of the first optical layer of the second light emitting device.

2. The display device according to claim 1, wherein: The first optical layer of the first light emitting device contacts a lower surface of the first light emitting layer of the first light emitting device.

3. The display device according to claim 1, wherein: The third light emitting device includes a first optical layer disposed between the first hole transport layer and the first light emitting layer, and The thickness of the first optical layer of the third light emitting device is different from the thickness of the first optical layer of the first light emitting device and also different from the thickness of the first optical layer of the second light emitting device.

4. The display device according to claim 1, wherein: The first hole transport layer of the third light emitting device is in contact with the first light emitting layer of the third light emitting device.

5. The display device according to claim 1, wherein: Each of the first light emitting device, the second light emitting device, and the third light emitting device includes a charge generation layer disposed on the first light emitting layer, a second hole transport layer disposed on the charge generation layer, a second optical layer disposed on the second hole transport layer, and a second light emitting layer disposed on the second optical layer, and The thickness of the second optical layer of the first light emitting device, the thickness of the second optical layer of the second light emitting device, and the thickness of the second optical layer of the third light emitting device are different from each other.

6. The display device according to claim 5, wherein: The thickness of the second optical layer of the first light emitting device is greater than the thickness of the second optical layer of the second light emitting device.

7. The display device according to claim 5, wherein: The thickness of the second optical layer of the third light emitting device is smaller than the thickness of the second optical layer of the first light emitting device and is also smaller than the thickness of the second optical layer of the second light emitting device.

8. The display device according to claim 5, wherein: The thickness of the second optical layer of the third light emitting device is greater than the thickness of the second optical layer of the first light emitting device, and greater than the thickness of the second optical layer of the second light emitting device.

9. The display device according to claim 5, wherein: The thickness of the second optical layer of the first light emitting device is different from the thickness of the first optical layer of the first light emitting device.

10. The display device according to claim 1, wherein: Each of the first light emitting device, the second light emitting device and the third light emitting device includes a charge generation layer disposed on the first light emitting layer, a second hole transport layer disposed on the charge generation layer, and a second light emitting layer disposed on the second hole transport layer, wherein the first light emitting device and the third light emitting device include a second optical layer disposed between the second hole transport layer and the second light emitting layer, and The second optical layers of the first light emitting device and the third light emitting device have different thicknesses.

11. The display device according to claim 10, wherein: The second hole transport layer of the second light emitting device is in contact with the second light emitting layer of the second light emitting device.

12. The display device according to claim 10, wherein: The thickness of the second optical layer of the first light emitting device is different from the thickness of the first optical layer of the first light emitting device.

13. The display device according to claim 1, wherein: Each of the first light emitting device, the second light emitting device and the third light emitting device includes a charge generation layer disposed on the first light emitting layer, a second hole transport layer disposed on the charge generation layer, and a second light emitting layer disposed on the second hole transport layer, wherein each of the first light emitting device and the third light emitting device comprises a second optical layer disposed between the second hole transport layer and the second light emitting layer, and The second optical layers of the first light emitting device and the third light emitting device have the same thickness.

14. The display device according to claim 13, wherein: The second hole transport layer of the second light emitting device is in contact with the second light emitting layer of the second light emitting device.

15. The display device according to claim 13, wherein: The thickness of the first light emitting layer of the first light emitting device is greater than the thickness of the first light emitting layer of the second light emitting device.

16. A display device, comprising: A substrate, the substrate comprising a first sub-pixel, a second sub-pixel, and a third sub-pixel; a first light emitting device, the first light emitting device being disposed in the first sub-pixel; a second light emitting device, the second light emitting device being disposed in the second sub-pixel; as well as a third light emitting device, the third light emitting device being arranged in the third sub-pixel, Each of the first light-emitting device, the second light-emitting device and the third light-emitting device includes a first electrode disposed on the substrate, a first hole transport layer disposed on the first electrode, a first light-emitting layer disposed on the first hole transport layer, a charge generation layer disposed on the first light-emitting layer, a second hole transport layer disposed on the charge generation layer, and a second light-emitting layer disposed on the second hole transport layer. wherein each of the first light emitting device and the second light emitting device comprises a first optical layer disposed between the second hole transport layer and the second light emitting layer, and Wherein, the thickness of the first optical layer of the first light emitting device is the same as the thickness of the first optical layer of the second light emitting device.

17. The display device according to claim 16, wherein: The first optical layer contacts a lower surface of the second light emitting layer.

18. The display device according to claim 16, wherein: The first light emitting device includes a second optical layer disposed between the first hole transport layer and the second light emitting layer, and The thickness of the first optical layer of the first light emitting device is different from the thickness of the second optical layer of the first light emitting device.

19. The display device according to claim 16, wherein: The first optical layer is continuously disposed in the first sub-pixel and the second sub-pixel.

20. The display device according to claim 19, wherein: The third light emitting device includes a first optical layer disposed between the first hole transport layer and the first light emitting layer, and The first optical layer disposed in the third sub-pixel is spaced apart from the first optical layer disposed in the first sub-pixel, and is also spaced apart from the first optical layer in the second sub-pixel.

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