Patent ID: 12207520

DETAILED DESCRIPTION

Hereinafter, details related to the above features, technical configurations, and operational effects of the aspects of the present disclosure will be clearly understood by the following detailed description with reference to the drawings, which illustrate some aspects of the present disclosure. Here, the aspects of the present disclosure are provided in order to allow the technical sprit of the present disclosure to be satisfactorily transferred to those skilled in the art, and thus the present disclosure may be embodied in other forms and is not limited to the aspects described below.

In addition, the same or extremely similar elements may be designated by the same reference numerals throughout the specification, and in the drawings, the lengths and thickness of layers and regions may be exaggerated for convenience. It will be understood that, when a first element is referred to as being “on” a second element, although the first element may be disposed on the second element so as to come into contact with the second element, a third element may be interposed between the first element and the second element.

Here, terms such as, for example, “first” and “second” may be used to distinguish any one element with another element. However, the first element and the second element may be arbitrary named according to the convenience of those skilled in the art without departing the technical sprit of the present disclosure.

The terms used in the specification of the present disclosure are merely used in order to describe particular aspects, and are not intended to limit the scope of the present disclosure. For example, an element described in the singular form is intended to include a plurality of elements unless the context clearly indicates otherwise. In addition, in the specification of the present disclosure, it will be further understood that the terms “comprises” and “includes” specify the presence of stated features, integers, steps, operations, elements, components, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or combinations.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example aspects belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

FIG.1is a view schematically showing a display apparatus according to an aspect of the present disclosure.FIG.2is an enlarged view of K region inFIG.1.

Referring toFIGS.1and2, the display apparatus according to the aspect of the present disclosure may include a device substrate100. The device substrate100may include an insulating material. The device substrate100may include a transparent material. For example, the device substrate100may glass or plastic.

A driving circuit and a light-emitting device300may be disposed on the device substrate100. The light-emitting device300may be electrically connected to the driving circuit. The driving circuit may supply a driving current corresponding to a data signal to the light-emitting device300according to a gate signal. For example, the driving circuit may include at least one thin film transistor200. The thin film transistor200may include a semiconductor pattern210, a gate insulating layer220, a gate electrode230, an interlayer insulating layer240, a source electrode250and a drain electrode260.

The semiconductor pattern210may include a semiconductor material. For example, the semiconductor pattern210may include amorphous silicon (a-Si) or polycrystalline silicon (poly-Si). The semiconductor pattern210may be an oxide semiconductor. For example, the semiconductor pattern210may include a metal oxide, such as IGZO.

The semiconductor pattern210may include a source region, a drain region and a channel region. The channel region may be disposed between the source region and the drain region. The source region and the drain region may have a resistance lower than the channel region. For example, the source region and the drain region may include a conductorized region of the oxide semiconductor.

The gate insulating layer220may be disposed on the semiconductor pattern210. The gate insulating layer220may extend beyond the semiconductor pattern210. For example, a side of the semiconductor pattern210may be covered by the gate insulating layer220. The gate insulating layer220may include an insulating material. For example, the gate insulating layer220may include an inorganic insulating material, such as silicon oxide (SiO) and silicon nitride (SiN). The gate insulating layer220may include a material having a high dielectric constant. For example, the gate insulating layer220may include a high-K material, such as hafnium oxide (HfO). The gate insulating layer220may have a multi-layer structure.

The gate electrode230may be disposed on the gate insulating layer220. The gate electrode230may overlap the channel region of the semiconductor pattern210. For example, the gate electrode230may be insulated from the semiconductor pattern210by the gate insulating layer220. The gate electrode230may include a conductive material. For example, the gate electrode230may include a metal, such as aluminum (Al), titanium (Ti), copper (Cu), chrome (Cr), molybdenum (Mo) and tungsten (W). The channel region of the semiconductor pattern210may have electrical conductivity corresponding to a voltage applied to the gate electrode230.

The interlayer insulating layer240may be disposed on the gate electrode230. The interlayer insulating layer240may extend beyond the gate electrode230. For example, a side of the gate electrode230may be covered by the interlayer insulating layer240. The interlayer insulating layer240may be in contact with the gate insulating layer220at the outside of the gate electrode230. For example, the interlayer insulating layer240may extend along the gate insulating layer220. The interlayer insulating layer240may include an insulating material. For example, the interlayer insulating layer240may include an inorganic insulating material, such as silicon oxide (SiO) and silicon nitride (SiN).

The source electrode250may be disposed on the interlayer insulating layer240. The source electrode250may include a conductive material. For example, the source electrode250may include a metal, such as aluminum (Al), titanium (Ti), copper (Cu), chrome (Cr), molybdenum (Mo) and tungsten (W). The source electrode250may be insulated from the gate electrode230by the interlayer insulating layer240. For example, the source electrode250may include a material different from the gate electrode230.

The source electrode250may be electrically connected to the source region of the semiconductor pattern210. For example, the gate insulating layer220and the interlayer insulating layer240may include a source contact hole partially exposing the source region of the semiconductor pattern210. The source electrode250may include a portion overlapping with the source region of the semiconductor pattern210. For example, the source electrode250may be in direct contact with the source region of the semiconductor pattern210in the source contact hole.

The drain electrode260may be disposed on the interlayer insulating layer240. The drain electrode260may include a conductive material. For example, the drain electrode260may include a metal, such as aluminum (Al), titanium (Ti), copper (Cu), chrome (Cr), molybdenum (Mo) and tungsten (W). The drain electrode260may be insulated from the gate electrode230by the interlayer insulating layer240. For example, the drain electrode260may include a material different from the gate electrode230. The drain electrode260may include the same material as the source electrode250.

The drain electrode260may be electrically connected to the drain region of the semiconductor pattern210. The drain electrode260may be spaced away from the source electrode250. For example, the gate insulating layer220and the interlayer insulating layer240may include a drain contact hole partially exposing the drain region of the semiconductor pattern210. The drain electrode260may include a portion overlapping with the drain region of the semiconductor pattern210. For example, the drain electrode260may be in direct contact with the drain region of the semiconductor pattern210in the drain contact hole.

A device buffer layer110may be disposed between the device substrate100and the driving circuit. The device buffer layer110may prevent pollution due to the device substrate100in a process of forming the driving circuit. For example, an upper surface of the device substrate100toward the thin film transistor200may be completely covered by the device buffer layer110. The device buffer layer110may include an insulating material. For example, the device buffer layer110may include an inorganic insulating material, such as silicon oxide (SiO) and silicon nitride (SiN).

A lower passivation layer120may be disposed on the driving circuit. The lower passivation layer120may prevent the damage of the driving circuit due to external impact and moisture. For example, a surface of the thin film transistor200opposite to the device substrate100may be completely covered by the lower passivation layer120. The lower passivation layer120may extend beyond the semiconductor pattern210along the interlayer insulating layer240. The lower passivation layer120may include an insulating material. For example, the lower passivation layer130may include an inorganic insulating material, such as silicon oxide (SiO) and silicon nitride (SiN).

An over-coat layer130may be disposed on the lower passivation layer120. The over-coat layer130may remove a thickness difference due to the driving circuit. For example, an upper surface of the over-coat layer130opposite to the device substrate100may be a flat surface. The over-coat layer130may include an insulating material. The over-coat layer130may include a material different from the lower passivation layer120. For example, the over-coat layer130may include an organic insulating material.

The light-emitting device300may be disposed on the over-coat layer130. The light-emitting device300may emit light displaying a specific color. For example, the light-emitting device300may include a first electrode310, a light-emitting layer320and a second electrode330, which are sequentially stacked.

The first electrode310may be disposed close to the over-coat layer130. The first electrode310may include a conductive material. The first electrode310may include a transparent material. For example, the first electrode310may be a transparent electrode made of a transparent conductive material, such as ITO and IZO.

The first electrode310may be electrically connected to the driving circuit. For example, the lower passivation layer120and the over-coat layer130may include an electrode contact hole partially exposing the drain electrode260of the thin film transistor200. The first electrode310may be connected to the drain electrode250of the thin film transistor200through the electrode contact hole. Thus, in the display apparatus according to the aspect of the present disclosure, the driving current generated by the driving circuit may be provided to the first electrode310of the light-emitting device300. The first electrode310may include a portion overlapping with the drain electrode260of the thin film transistor200. For example, the first electrode310may be in direct contact with the drain electrode260of the thin film transistor200in the electrode contact hole.

The light-emitting layer320may generate light having luminance corresponding to a voltage difference between the first electrode310and the second electrode330. For example, the light-emitting layer320may include an emission material layer (EML) including an emission material. The emission material may include an organic material, an inorganic material or a hybrid material. For example, the display apparatus according to the aspect of the present disclosure may be an organic light-emitting display apparatus including the organic emission material.

The light generated by the light-emitting layer320may display a white color. The light-emitting layer320may include a plurality of the emission material layers. For example, the light-emitting layer320may include a first emission stack321, a second emission stack322, a third emission stack323and a fourth emission stack324, which are sequentially stacked on the first electrode310. Each of the first emission stack321, the second emission stack322, the third emission stack323and the fourth emission stack324may emit light. For example, the light-emitting layer320may include a first charge generation layer329abetween the first emission stack321and the second emission stack322, a second charge generation layer329bbetween the second emission stack322and the third emission stack323, and a third charge generation layer329cbetween the third emission stack323and the fourth emission stack324.

Each of the first charge generation layer329a, the second charge generation layer329band the third charge generation layer329cmay provide electrons or holes to adjacent emission stacks321,322,323and324. For example, each of the first charge generation layer329a, the second charge generation layer329band the third charge generation layer329cmay have a stacked structure of a n-type generating layer329nand a p-type generating layer329p. The n-type generating layer329nand the p-type generating layer329pof the first charge generation layer329amay be arranged in the same order as the n-type generating layer329nand the p-type generating layer329pof the second charge generation layer329band the n-type generating layer329nand the p-type generating layer329pof the third charge generation layer329c. For example, in the display apparatus according to the aspect of the present disclosure, if the first electrode310may function as anode and the second electrode320may function as cathode, the n-type generating layer329nof each charge generation layer329a,329band329cmay be disposed between the first electrode310and the p-type generating layer329pof the corresponding charge generation layer329a,329band329c. Thus, in the display apparatus according to the aspect of the present disclosure, the electrons and the holes may be evenly supplied to each emission stack321,322,323and324.

The first emission stack321disposed between the first electrode310and the first charge generation layer329amay include a hole injection layer321hi, a first hole transport layer321ht, a red emission material layer321re, a first blue emission material layer321beand a first electron transport layer321et, which are sequentially stacked. The first emission stack321may be in direct contact with the first electrode310and the first charge generation layer329a. For example, the first electrode310may be in contact with the hole injection layer321hiof the first emission stack321, and the first charge generation layer329amay be in contact with the first electron transport layer321etof the first emission stack321.

The red emission material layer321remay generate light using the holes supplied through the hole injection layer321hiand the first hole transport layer321ht, and the electrons supplied through the first electron transport layer321et. The red emission material layer321remay generate the light displaying a red color. For example, the light generated by the red emission material layer321remay have a peak wavelength of 640 nm to 720 nm. The red emission material layer321remay include a red dopant and host material. The red dopant of the red emission material layer321remay be a phosphorescent material. For example, the red emission material layer321remay be formed by using CBP(carbazole biphenyl) or mCP(1,3-bis(carbazol-9-yl) as the host material, and being doped with a red dopant including at least one selected from the group consisting of Ir(Piq)3(Tris(1-phenylisoquinoline)iridium(III)), Ir(piq)2(acac)(Bis(1-phenylisoquinoline)(acetylacetonate)iridiumIII)), Ir(btp)2(acac)(Bis)2-benzo[b]thiophen-2-yl-pyridine)(acetylacetonate)iridiumIII)), Ir(BT)2(acac)(Bis(2-phenylbenzothazolato)(acetylacetonate)iridiumIII)).

The first blue emission material layer321bemay generate light using the holes supplied through the hole injection layer321hiand the first hole transport layer321ht, and the electrons supplied through the first electron transport layer321et. The first blue emission material layer321bemay generate the light displaying a blue color. For example, the light generated by the first blue emission material layer321bemay have a peak wavelength of 440 nm to 480 nm. The first blue emission material layer321bemay include a blue dopant and host material. The blue dopant of the first blue emission material layer321bemay be a fluorescent material. For example, the first blue emission material layer321bemay be formed by using at least one selected from the group consisting of an anthracene derivative, a pyrene derivative and perylene derivative as the host material, and being doped with a pyrene-based blue dopant or a boron-based blue dopant.

The first blue emission material layer321bemay be in direct contact with the red emission material layer321re. For example, the energy by recombination of the holes supplied through the hole injection layer321hiand the first hole transport layer321htand the electrons supplied through the first electron transport layer321etmay be provided to the red emission material layer321reand the first blue emission material layer32beof the first emission stack321. The excitons generated by the recombination of the holes and the electrons may be consisted of a singlet exciton in the form of a paired spin and a triplet exciton in the form of an unpaired spin according to the arrangement of the spin. In general, the fluorescent material may emit light using the singlet excitons, and the phosphorescent material may emit light using both the singlet excitons and the triplet excitons. Thus, in the display apparatus according to the aspect of the present disclosure, the blue dopant of the first blue emission material layer321bewhich is a fluorescent material may emit the light using the singlet excitons, and the red dopant of the red emission material layer321rewhich is a phosphorescent material may emit light using the triplet excitons. And, in the display apparatus according to the aspect of the present disclosure, the triplet exciton generated by the host material of the first blue emission material layer321bewhich emits the light having a short wavelength may be used for the emission of the red emission material layer321rewhich emits the light having a long wavelength by Dexter Energy Transfer (DET). Therefore, in the display apparatus according to the aspect of the present disclosure, the first emission stack321may emit both the light displaying the blue color and the light displaying the red color.

The second emission stack322disposed between the first charge generation layer329aand the second charge generation layer329bmay include a second hole transport layer322ht, a second blue emission material layer322beand a second electron transport layer322et, which are sequentially stacked. The second emission stack322may be in direct contact with the first charge generation layer329aand the second charge generation layer329b. For example, the second hole transport layer322htmay be in contact with the first charge generation layer329a, and the second electron transport layer322etmay be in contact with the second charge generation layer329b.

The second blue emission material layer322bemay generate light using the holes supplied through the second hole transport layer322htand the electrons supplied through the second electron transport layer322et. The second blue emission material layer322bemay generate the light displaying a blue color. For example, the light generated by the second blue emission material layer322bemay have a peak wavelength of 440 nm to 480 nm. The second blue emission material layer322bemay include a blue dopant and host material. The blue dopant of the second blue emission material layer322bemay be a fluorescent material. For example, the second blue emission material layer322bemay be formed by using at least one selected from the group consisting of an anthracene derivative, a pyrene derivative and perylene derivative as the host material, and being doped with a pyrene-based blue dopant or a boron-based blue dopant. The second blue emission material layer322bemay include the same blue dopant as the first blue emission material layer321be. For example, the light generated by the second blue emission material layer322bemay have the same peak wavelength as the light generated by the first blue emission material layer321be. Thus, in the display apparatus according to the aspect of the present disclosure, the efficiency and the color purity of the blue color may be improved. The host material of the second blue emission material layer322bemay be the same as the host material of the first blue emission material layer321be.

The third emission stack323disposed between the second charge generation layer329band the third charge generation layer329cmay include a third hole transport layer323ht, a green emission material layer323geand a third electron transport layer323et, which are sequentially stacked. The third emission stack323may be in direct contact with the second charge generation layer329band the third charge generation layer329c. For example, the third hole transport layer323htmay be in contact with the second charge generation layer329b, and the third electron transport layer323etmay be in contact with the third charge generation layer329c.

The green emission material layer323gemay generate light using the holes supplied through the third hole transport layer323htand the electrons supplied through the third electron transport layer323et. The green emission material layer323gemay generate the light displaying a green color. For example, the light generated by the green emission material layer323gemay have a peak wavelength of 520 nm to 560 nm. The green emission material layer323gemay include a green dopant and host material. The green dopant of the green emission material layer323gemay be a phosphorescent material. For example, the green emission material layer323gemay be formed by using CBP(carbazole biphenyl) or mCP(1,3-bis(carbazol-9-yl) as the host material, and being doped with a green dopant including at least one of Ir(ppy)3(fac tris(2-phenylpyridine)iridium), Ir(ppy)2(acac) and Ir(mpyp)3.

The fourth emission stack324disposed between the third charge generation layer329cand the second electrode330may include a fourth hole transport layer324ht, a third blue emission material layer324be, a fourth electron transport layer324etand an electron injection layer324ei, which are sequentially stacked. The fourth emission stack324may be in direct contact with the third charge generation layer329cand the second electrode330. For example, the fourth hole transport layer324htmay be in contact with the third charge generation layer329c, and the electron injection layer324eimay be in contact with the second electrode330.

The third blue emission material layer324bemay generate light using the holes supplied through the fourth hole transport layer324htand the electrons supplied through the fourth electron transport layer324etand the electron injection layer324ei. The third blue emission material layer324bemay generate the light displaying a blue color. For example, the light generated by the third blue emission material layer324bemay have a peak wavelength of 440 nm to 480 nm. The third blue emission material layer324bemay include a blue dopant and host material. The dopant of the third blue emission material layer324bemay be a fluorescent material. For example, the third blue emission material layer324bemay be formed by using at least one selected from the group consisting of an anthracene derivative, a pyrene derivative and perylene derivative as the host material, and being doped with a pyrene-based blue dopant or a boron-based blue dopant. The third blue emission material layer324bemay include the same blue dopant as the second blue emission material layer322be. For example, the light generated by the third blue emission material layer324bemay have the same peak wavelength as the light generated by the second blue emission material layer322be. Thus, in the display apparatus according to the aspect of the present disclosure, the efficiency and the color purity of the blue color may be improved. The host material of the third blue emission material layer324bemay be the same as the host material of the second blue emission material layer322be.

The second electrode330may include a conductive material. The second electrode330may include a material different from the first electrode310. The transmittance of the second electrode330may be lower than the transmittance of the first electrode310. The second electrode330may have a reflectance higher than the first electrode310. For example, the second electrode330may include a metal, such as aluminum (Al) and silver (Ag). Thus, in the display apparatus according to the aspect of the present disclosure, the light generated by the light-emitting layer320may be emitted to outside through the first electrode310and the device substrate100.

A bank insulating layer140may be disposed on the over-coat layer130. The light-emitting device300may be independently controlled by the bank insulating layer140. For example, the bank insulating layer140may cover an edge of the first electrode310. The light-emitting layer320and the second electrode330may be stacked on a portion of the first electrode310exposed by the bank insulating layer140. For example, the bank insulating layer140may define an emission area EA. The bank insulating layer140may include an insulating material. For example, the bank insulating layer140may include an organic insulating material. The bank insulating layer140may include a material different from the over-coat layer130.

The driving circuit may be disposed outside the emission area EA. For example, the driving circuit may overlap the bank insulating layer140. Thus, in the display apparatus according to the aspect of the present disclosure, the light emitted from the light-emitting device300may be not blocked by the driving circuit. That is, in the display apparatus according to the aspect of the present disclosure, the loss of the light due to the driving circuit may be prevented. Therefore, in the display apparatus according to the aspect of the present disclosure, the light extraction efficiency may be increased.

An upper passivation layer150, an encapsulation element400and an encapsulating substrate500may be stacked on the light-emitting device300and the bank insulating layer140. The upper passivation layer150, the encapsulation element400and the encapsulating substrate500may prevent the damage of the light-emitting device300due to the external impact and moisture. For example, the encapsulating substrate500may include a metal, such as aluminum (Al), nickel (Ni) and iron (Fe). The upper passivation layer150and the encapsulation element400may include an insulating material. The encapsulation element400may include a material different from the upper passivation layer150. For example, the upper passivation layer150may include an inorganic insulating material, and the encapsulation element400may include an organic insulating material. The encapsulation element400may include an adhesive material. For example, the encapsulating substrate500may be coupled to the device substrate100in which the light-emitting device300is formed, by the encapsulation element400.

The encapsulation element400may have a multi-layer structure. For example, the encapsulation element400may include a lower encapsulating layer410disposed close to the upper passivation layer150and an upper encapsulating layer420disposed between the lower encapsulating layer410and the encapsulating substrate500. Moisture-absorbing particles may be dispersed in the upper encapsulating layer420. Thus, in the display apparatus according to the aspect of the present disclosure, the deterioration of the light-emitting device300due to the penetration of the external moisture may be prevented by the upper encapsulating layer420, and the stress applied to the light-emitting device300due to the expansion of the moisture-absorbing particles may be relieved by the lower encapsulating layer410.

A color filter600may be disposed between the device substrate100and the light-emitting device300. The color filter600may realize various colors using the light emitted from the light-emitting device300. For example, the color filter600may include a portion overlapping with the emission area EA. The color filter600may be disposed between the lower passivation layer120and the over-coat layer130. Thus, in the display apparatus according to the aspect of the present disclosure, a thickness difference due to the color filter600may be removed by the over-coat layer130.

A below table 1 shows the characteristics of the comparative display device D1 having a stacked structure of a first emission stack including a red emission material layer, a second emission stack including a first blue emission material layer, a third emission stack including a green emission material layer and a fourth emission stack including a second blue emission material layer, and the display device D2 according to the aspect of the present disclosure.

TABLE 1efficiency (cd/A)Color temperature(K)redgreenblueWhiteof white colorD119.746.64.6110.85632D216.446.75.3108.57381

Referring to table 1, the comparative display apparatus D1 has relatively higher the luminous efficiencies of a red color and a white color than the display apparatus D2 according to the aspect of the present disclosure. However, the display apparatus D2 according to the aspect of the present disclosure has relatively higher the luminous efficiency of a blue color and the color temperature of the white color than the comparative display apparatus D1. That is, in the display apparatus D2 according to the aspect of the present disclosure, a deviation between the blue efficiency in which the blue light having a short wavelength is generated and the red efficiency in which the red light having a long wavelength is generated may be reduced by the first emission stack321having a stacked structure of the red emission material layer321reand the first blue emission material layer321be, such that the white balance and the color temperature of the white color may be improved.

Accordingly, the display apparatus according to the aspect of the present disclosure may include the light-emitting device300emitting white light, wherein the light-emitting layer320of the light-emitting device300may include the first emission stack321, the second emission stack322, the third emission stack323and the fourth emission stack324, which are sequentially stacked between the first electrode310and the second electrode330, and wherein the first emission stack321may have a stacked structure of the red emission material layer321reand the first blue emission material layer321be. Thus, in the display apparatus according to the aspect of the present disclosure, the white balance and the color temperature of the white color may be improved. Therefore, in the display apparatus according to the aspect of the present disclosure, the overall luminance and the quality of the image may be improved.

The display apparatus according to the aspect of the present disclosure is described that the second emission stack322includes the second blue emission material layer322be, the third emission stack323includes the green emission material layer323ge, and the fourth emission stack324includes the third blue emission material layer324be. However, in the display apparatus according to another aspect of the present disclosure, the second emission stack322, the third emission stack323and the fourth emission stack324may be variously configured to realize a white color together with the red light and the blue light generated by the first emission stack321. For example, in the display apparatus according to another aspect of the present disclosure, at least one of the second emission stack322, the third emission stack323and the fourth emission stack324may generate light displaying a yellow color, and at least one of the other emission stacks may generate light displaying a cyan color.

The display apparatus according to another aspect of the present disclosure may include a plurality of the emission areas EA, wherein each of the emission areas EA may realize a color different from adjacent emission areas EA. For example, in the display apparatus according to another aspect of the present disclosure, the bank insulating layer140may define a red emission area REA, a white emission area WEA, a green emission area GEA and a blue emission area BEA, which are disposed side by side in a direction, as shown inFIG.3. The driving circuit and the light-emitting device300may be disposed on each emission area REA, WEA, GEA and BEA. The driving circuit and the light-emitting device300of each emission area REA, WEA, GEA and BEA may have the same structure as the driving circuit and the light-emitting device300of adjacent emission area REA, WEA, GEA and BEA. The light-emitting device300on each emission area REA, WEA, GEA and BEA may emit the light displaying a white color. For example, the light-emitting device300on the white emission area WEA, the light-emitting device300on the green emission area GEA and the light-emitting device300on the blue emission area BEA may have the same structure as the light-emitting device300on the red emission area REA. A red color filter600R overlapping with the red emission area REA, a green color filter600G overlapping with the green emission area GEA and a blue color filter600B overlapping with the blue emission area BEA may be disposed between the lower passivation layer120and the over-coat layer130.

FIGS.4A to4Care graphs showing emission spectrum of the light emitted from a red pixel area, a green pixel area or a blue pixel area during low grayscale driving in RWBG display apparatus in which the red pixel area, a white pixel area, the blue pixel area and the green pixel area are repeated.FIGS.5A to5Care graphs showing emission spectrum of the light emitted from a red pixel area, a green pixel area or a blue pixel area during low grayscale driving in RWGB display apparatus in which the red pixel area, a white pixel area, the green pixel area and the blue pixel area are repeated.

Referring toFIGS.4A to4C and5A to5C, compared to the RWBG display device in which the white pixel area is disposed between the red pixel area and the blue pixel area, the light leakage of green color is reduced in the RWGB display device in which the white pixel area is disposed between the red pixel area and the green pixel area.

A below table 2 shows the color gamut according to current density in RWBG display apparatus and RWGB display apparatus.

TABLE 2color gamutcurrent densityDCIBT.2020RWB10mA/cm299.0%81.0%G0.1mA/cm265.6%48.3%RWG10mA/cm299.0%81.0%B0.1mA/cm276.9%56.9%

Referring to table 2, the RWGB display apparatus has the color gamut relatively higher than the RWBG display apparatus at low grayscale driven by a low current density. That is, if red pixel areas, white pixel areas, green pixel areas and blue pixel areas are repeated in a direction, the light leakage of the green color may be reduced, and the color gamut at low grayscale may be improved. Thus, in the display apparatus according to the aspect of the present disclosure, the red pixel areas, the white pixel areas, the green pixel areas and the blue pixel areas may be arranged to be repeated in a direction, such that the deterioration of the image at low grayscale may be minimized.

The display apparatus according to the aspect of the present disclosure is described that the red emission material layer321reis disposed between the first electrode310and the first blue emission material layer321be. However, in the display apparatus according to another aspect of the present disclosure, the first emission stack321may have a stacked structure of the first blue emission material layer321bebeing in contact with the first hole transport layer321htand the red emission material layer321rebeing contact with the first electron transport layer321et, as shown inFIG.6. An upper surface of the first blue emission material layer321betoward the first electron transport layer321etmay be in direct contact with a lower surface of the red emission material layer321retoward the first hole transport layer321ht. Thus, in the display apparatus according to another aspect of the present disclosure, the degree of freedom in a stacking order of the red emission material layer321reand the first blue emission material layer321bemay be improved.

The display apparatus according to the aspect of the present disclosure is described that the first emission stack321being in contact with the first electrode310has a stacked structure of the red emission material layer321reand the first blue emission material layer321be. However, in the display apparatus according to another aspect of the present disclosure, the emission stack having a stacked structure of the red emission material layer and the blue emission material layer may be spaced away from the first electrode. For example, in the display apparatus according to another aspect of the present disclosure, the second emission stack322or the third emission stack323which is disposed between the charge generation layers329a,329band329cmay have a stacked structure of the red emission material layer322reand323reand the blue emission material layer322beand323be, as shown inFIGS.7and8. Alternately, in the display apparatus according to another aspect of the present disclosure, the fourth emission stack324disposed between the third charge generation layer329cand the second electrode330may have a stacked structure of the red emission material layer324reand the blue emission material layer324be, as shown inFIG.9. That is, in the display apparatus according to another aspect of the present disclosure, the degree of freedom in the location of the emission stack having a stacked structure of the red emission material layer and the blue emission material layer may be improved. Therefore, in the display apparatus according to another aspect of the present disclosure, the process efficiency may be improved.

The display apparatus according to the aspect of the present disclosure is described that the light generated by the light-emitting layer320may be emitted to outside through the first electrode310and the device substrate100. However, in the display apparatus according to another aspect of the present disclosure, the second electrode330may have a transmittance higher than the first electrode310. For example, in the display apparatus according to another aspect of the present disclosure, a black matrix810and a color filter820may be disposed side by side between an encapsulation element700covering the light-emitting device300and the encapsulating substrate500, as shown inFIG.10. The encapsulating substrate500may include a transparent material. For example, the encapsulating substrate500may include glass or plastic.

The encapsulation element700may not include moisture absorbing particles. The encapsulating element700may have a stacked structure of layers made of different materials to block the penetration of the external moisture. For example, the encapsulation element700may include a first encapsulating layer710, a second encapsulating layer720and a third encapsulating layer730, which are sequentially stacked, the first encapsulating layer710and the third encapsulating layer730may include an inorganic insulating material, and the second encapsulating layer720may include an organic insulating material. Thus, in the display apparatus according to another aspect of the present disclosure, the damage of the light-emitting device300due to the external moisture and impact may be effectively prevented. A thickness difference due to the light-emitting device300may be removed by the second encapsulating layer720. For example, an upper surface of the encapsulation element700opposite to the device substrate100may be a flat surface.

The color filter820may overlap the light-emitting device300. The black matrix810may overlap the bank insulating layer140. Thus, in the display apparatus according to another aspect of the present disclosure, the decrease of the light extraction efficiency due to the black matrix810may be prevented. And, in the display apparatus according to another aspect of the present disclosure, unnecessary regions may be not recognized by the user. Therefore, in the display apparatus according to another aspect of the present disclosure, the visibility of the realized image may be improved.

A filter capping layer830may be disposed between the encapsulation element700and the black matrix810. The filter capping layer830may extend between the encapsulation element700and the color filter820. For example, the black matrix810and the color filter820may be in direct contact with the encapsulating substrate500. The filter capping layer830may include an insulating material. For example, the filter capping layer830may include an organic insulating material. The lower surface of the filter capping layer830toward the device substrate100may be a flat surface. Thus, in the display apparatus according to another aspect of the present disclosure, an upper surface of the encapsulating substrate500opposite to the device substrate100may be parallel to a lower surface of the device substrate100opposite to the encapsulating substrate500. Therefore, in the display apparatus according to another aspect of the present disclosure, the distortion of the image provided to the user through the encapsulating substrate500may be prevented.

In the display apparatus according to another aspect of the present disclosure, two of the four emission stacks constituting the light-emitting layer may have a stacked structure of the red emission material layer and the blue emission material layer. For example, in the display apparatus according to another aspect of the present disclosure, the first emission stack321being disposed close to the first electrode310may have a stacked structure of a first red emission material layer321reand a first blue emission material layer321be, and the second emission stack322being in direct contact with the first emission stack321may have a stacked structure of a second red emission material layer322reand a second blue emission material layer322be, as shown inFIG.11.

A below table 3 shows the white efficiency, the red efficiency, the green efficiency, and the blue efficiency of an area inclined by 60° compared to the front in a first display apparatus E1 in which only one of the fourth emission stacks has a stacked structure of the red emission material layer and the blue emission material layer and a second display apparatus E2 in which two of the fourth emission stacks has a stacked structure of the red emission material layer and the blue emission material layer.

TABLE 3efficiency(%)whiteredgreenblueE178788172E289919283

Referring to table 3, the second display apparatus E2 may have the white efficiency, the red efficiency, the green efficiency, and the blue efficiency in an area inclined by 60° from the front relatively higher than the first display apparatus E1. Thus, in the display apparatus according to another aspect of the present disclosure in which the first emission stack321and the second emission stack322of the light-emitting layer320have a stacked structure of the red emission material layer321reand322reand the blue emission material layer321beand322be, the color viewing angle may be increased. That is, in the display apparatus according to another aspect of the present disclosure, the rapid deterioration of the image due to a change in the user's location may be prevented. Therefore, in the display apparatus according to another aspect of the present disclosure, the quality of the image may be improved.

A below table 4 shows the deviation in the viewing angle of white color according to a stacking order of the first red emission material layer321reand the first blue emission material layer321beof the first emission stack321and a stacking order of the second red emission material layer322reand the second blue emission material layer322beof the second emission stack322in the display apparatus according to another aspect of the present disclosure. Herein, R-B/R-B means a structure in which the first red emission material layer321re, the first blue emission material layer321be, the second red emission material layer322re, and the second blue emission material layer322beare sequentially stacked on the first electrode310, R-B/B-R means a structure in which the first red emission material layer321re, the first blue emission material layer321be, the second blue emission material layer322beand the second red emission material layer322reare sequentially stacked on the first electrode310, B-R/R-B means a structure in which the first blue emission material layer321be, the first red emission material layer321re, the second red emission material layer322reand the second blue emission material layer322beare sequentially stacked on the first electrode310, and B-RB-R means a structure in which the first blue emission material layer321be, the first red emission material layer321re, the second blue emission material layer322beand the second red emission material layer322reare sequentially stacked on the first electrode310.

TABLE 4R-B/R-BR-B/B-RB-R/R-BB-R/B-Rthe deviation0.0080.0180.0180.028in the viewingangle of white color

Referring to table 4, the deviation in the viewing angle of white color is minimal in the structure in which the first red emission material layer321re, the first blue emission material layer321be, the second blue emission material layer322beand the second red emission material layer322reare sequentially stacked on the first electrode310. Thus, in the display apparatus according to another aspect of the present disclosure, the first emission stack321may include the first red emission material layer321redisposed between the first electrode310and the first blue emission material layer321be, and the second red emission material layer322reand the second blue emission material layer322beof the second emission stack322may have the same stacking order as the first red emission material layer321reand the first blue emission material layer321beof the first emission stack321. Therefore, in the display apparatus according to another aspect of the present disclosure, the degradation of image quality due to viewing angle deviation may be minimized.

In the display apparatus according to another aspect of the present disclosure, the third emission stack323or the fourth emission stack324being spaced away from the first emission stack321having a stacked structure of the first red emission material layer321reand the first blue emission material layer321bemay have a stacked structure of the red emission material layer323reand324reand the blue emission material layer323beand324be, as shown inFIGS.12and13. And, in the display apparatus according to another aspect of the present disclosure, the first emission stack321being in contact with the first electrode310may include only blue emission material layer321be, two of the second emission stack322, the third emission stack323and the fourth emission stack324which are disposed between the first emission stack321and the second electrode330may have a stacked structure of the red emission material layer322re,323reand324reand the blue emission material layer322be,323beand324be. Thus, in the display apparatus according to another aspect of the present disclosure, the degree of freedom m for the configuration of the light-emitting layer320may be improved.

In the result, the display apparatus according to the aspects of the present disclosure may include the light-emitting device on the device substrate, wherein the light-emitting device may include fourth emission stacks, and wherein one of the emission stacks may have a stacked structure of the red emission material layer and the blue emission material layer. Thus, in the display apparatus according to the aspects of the present disclosure, the white balance of the light emitted from each light-emitting device may be improved. And, in the display apparatus according to the aspects of the present disclosure, the color viewing angle of the light emitted from each light-emitting device may be improved. Thereby, in the display apparatus according to the aspects of the present disclosure, the quality of the image provided to the user may be improved.