Organic light-emitting display device and method of preparing the same

An organic light-emitting display device is disclosed. The organic light-emitting display device may include a substrate, an organic light-emitting portion provided on the substrate, a first inorganic film that seals and covers the organic light-emitting portion, and a second inorganic film provided on the first inorganic film and including a low temperature viscosity transition (LVT) inorganic material. A coefficient of thermal expansion (CTE) of the first inorganic film may be smaller than a CTE of the second inorganic film.

INCORPORATION BY REFERENCE OF ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57. This application claims the benefit of Korean Patent Application No. 10-2013-0041257, filed on Apr. 15, 2013, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

The disclosure is directed to organic light-emitting display devices and methods of manufacturing the same, and more particularly to organic light-emitting display devices having improved sealing structures and methods of manufacturing the same.

2. Description of the Related Technology

An organic light-emitting display device includes an organic light-emitting device including a hole injection electrode, an electron injection electrode, and an organic emission layer formed between the hole injection electrode and the electron injection electrode. The organic light-emitting display device is a self-emitting display device that generates light when excitons formed from a combination of holes injected from the hole injection electrode and electrons injected from the electron injection electrode in the organic emission layer drop from an excited state to a ground state.

The organic light-emitting display device that is a self-emitting display device does not require a separate light source, and thus, may be operated at a low voltage and formed as a thin and lightweight structure, and is on the spotlight as a next generation display device due to high quality properties such as wide viewing angles, excellent contrast and quick response. The organic light-emitting device is very vulnerable to external environment, for example, oxygen and moisture, and thus, a sealing structure that seals the organic light-emitting device from the external environment is needed. However, development of a thin organic light-emitting device and/or a flexible organic light-emitting device is still required.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

One or more embodiments of the present disclosure may include an organic light-emitting display device having excellent sealing property and a method of manufacturing the organic light-emitting display device. Additional aspects will be set forth in part in the figures and description which follows and, in part, will be apparent from the figures in combination with the description, or may be learned by practice of the presented embodiments.

In a first aspect, an organic light-emitting display device is provided. The device may include, for example, a substrate, an organic light-emitting portion on the substrate, a first inorganic film covering the organic light-emitting portion, and a second inorganic film on the first inorganic film and including a low temperature viscosity transition inorganic material.

In some embodiments, a coefficient of thermal expansion of the first inorganic film is smaller than a coefficient of thermal expansion of the second inorganic film. In some embodiments, the first inorganic film may include a low temperature viscosity transition inorganic material having a higher viscosity transition temperature than a viscosity transition temperature of the low temperature viscosity transition inorganic material included in the second inorganic film. In some embodiments, the first inorganic film may include a low temperature viscosity transition inorganic material and a dispersed inorganic material dispersed in the first inorganic film. In some embodiments, the dispersed inorganic material may be the same material as the low temperature viscosity transition inorganic material included in the second inorganic film. In some embodiments, the low temperature viscosity transition inorganic material may include a tin oxide. In some embodiments, the low temperature viscosity transition inorganic material may further include a tin oxide and may further include at least one material selected from among a phosphorus oxide, boron phosphate, stannous fluoride, a niobium oxide, and a tungsten oxide. In some embodiments, the low temperature viscosity transition inorganic material includes SnO and may further include at least one material selected from P2O5, BPO4, SnF2, NbO, and WO3. In some embodiments, a viscosity transition temperature of the low temperature viscosity transition inorganic material included in the second inorganic film may be lower than a transition temperature of the organic light-emitting portion. In some embodiments, the first inorganic film includes a Sn—(P,B)—O—F-based low temperature viscosity transition inorganic material. In some embodiments, the second inorganic film may include a Sn—P—O—F-based low temperature viscosity transition inorganic material. In some embodiments, the first inorganic film is the Sn—P—O—F-based low temperature viscosity transition inorganic material, and a ratio of phosphorus (P) to boron (B) of the first inorganic film may be about 9:1 to about 7:3. In some embodiments, a coefficient of thermal expansion of the first inorganic film may be greater than or equal to the coefficient of thermal expansion of the substrate. In some embodiments, the second inorganic film may wrap top and sides of the first inorganic film. In some embodiments, the organic light-emitting device according to an embodiment of the present disclosure may further include a bottom organic layer on a bottom surface of the substrate. In some embodiments, the organic light-emitting device may further include a third inorganic film between the substrate and the organic light-emitting portion. In some embodiments, the organic light-emitting device may further include a protective layer on the organic light-emitting portion.

In another aspect, a method of manufacturing an organic light-emitting display device is provided. The method may include, for example, forming an organic light-emitting portion on a substrate, forming a first inorganic film covering the organic light-emitting portion, and forming a second inorganic film including a low temperature viscosity transition inorganic material on the first inorganic film.

In some embodiments, a coefficient of thermal expansion of the first inorganic film is greater than a coefficient of thermal expansion of the substrate, but smaller than a coefficient of thermal expansion of the second inorganic film. In some embodiments, the forming of the second inorganic film may include, for example, forming a preliminary second inorganic film by providing a low temperature viscosity transition inorganic material on the first inorganic film, and healing including a heat treatment of the preliminary second inorganic film at a temperature greater than or equal to a viscosity transition temperature of the low temperature viscosity transition inorganic material. In some embodiments, the viscosity transition temperature of the low temperature viscosity transition inorganic material may be smaller than a transition temperature of a material comprised in the organic light-emitting portion. In the annealing, the preliminary second inorganic film may be heat treated at a temperature lower than a transition temperature of a material comprised in the organic light-emitting portion. In some embodiments, the annealing may be performed under a vacuum atmosphere or an inert gas atmosphere. In the annealing, the preliminary second inorganic film may be fluidized to infiltrate into pores of the first inorganic film and fill the pores to form a dispersed inorganic material.

In a further aspect, an organic light-emitting display device is provided. The device may include, for example, a substrate, an organic light-emitting portion on the substrate, a first inorganic film covering the organic light-emitting portion and including a first low temperature viscosity transition inorganic material, a second inorganic film provided on the first inorganic film and including a second low viscosity transition inorganic material, and a dispersed inorganic material dispersed in the first inorganic film and including the second low viscosity transition inorganic material.

In some embodiments, a viscosity transition temperature of the second low viscosity transition inorganic material is lower than a viscosity transition temperature of the first low viscosity transition inorganic material. In some embodiments, a coefficient of thermal expansion of the first inorganic film may be greater than a coefficient of thermal expansion of the substrate and smaller than a coefficient of thermal expansion of the second inorganic film. In some embodiments, the first low viscosity transition inorganic material may be a Sn—(P,B)—O—F-based low viscosity transition inorganic material in which a ratio of phosphorus to boron is about 9:1 to about 7:3, and the second inorganic film may include a Sn—P—O—F-based low viscosity transition inorganic material. In some embodiments, a viscosity transition temperature of the second low viscosity transition inorganic material may be lower than a transition temperature of the organic light-emitting portion.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

Reference will now be made in detail to embodiments, examples of which may be illustrated in the accompanying drawings. Like reference numerals refer to the like elements throughout and the descriptions of the like elements are not repeated. Also, a size of each component may be exaggerated for clarity and convenience of the description. Embodiments described below are for illustrative purposes only and thus, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. For example, when a layer is described as provided on “the above”, “upper portion”, or “top” of a substrate or another layer, the layer may exist on another layer via a direct contact, or there may be another layer therebetween.

Also, the terms used in the specification are used only to describe the embodiments and are not used to limit the present disclosure. In the present application, a singular form also includes a plural form unless stated otherwise. The terms “includes” and/or “including” as used herein do not preclude the possibility of additional existence of components, processes, operations and/or devices. Terms such as the first and the second may be used to describe various components; however, the terms should not be construed to limit the components. The terms are only used for distinguishing a component from another component.

FIG. 1Aschematically illustrates a cross-section of an organic light-emitting display device100according to an embodiment of the present disclosure andFIG. 1Billustrates an embodiment of a partial cross-section of I inFIG. 1A. Referring toFIGS. 1A and 1B, the organic light-emitting display device100according to an embodiment of the present disclosure includes a substrate11, an organic light-emitting portion13formed on the substrate11, a first inorganic film14covering the organic light-emitting portion13and a second inorganic film16bprovided on the first inorganic film14. The second inorganic film16bincludes a low temperature viscosity transition (LVT) inorganic material. In the context ofFIG. 1Aand with respect to other embodiments disclosed herein, when a first element is described to “cover” a second element, the first element may entirely or partially overlap the second element. Thus, in some embodiments, the first element “covering” a second element will entirely overlap the second element. While in other embodiments, the first element covering a second element will only partially overlap the second element or will only overlap a portion of the second element.

The substrate11may be formed of a transparent glass material having SiO2as a main ingredient. But, the substrate11is not limited thereto and the substrate11may be formed of various materials such as ceramic, a transparent plastic material, a metal material or the like. On the other hand, when the organic light-emitting display device is a top emission type that emits light in the opposite direction of the substrate11, the substrate11may be non-transparent and a substrate other than a glass substrate or a plastic substrate, such as a metal substrate or a carbon fiber substrate may be used. When an organic light-emitting display device is a flexible display device, the substrate11may be formed of a flexible substrate that is bendable and/or may be formed of a polyimide film.

The organic light-emitting portion13is formed on the substrate11. The organic light-emitting portion13may have a sequentially laminated structure of a first electrode13a, an organic emission layer13b, a second electrode13con the substrate11. The first electrode13aand the second electrode13cmay each perform functions of an anode and a cathode, and may have polarities opposite to each other.

The first electrode13amay be formed on the substrate11and edges of the first electrode13amay be covered by a pixel defining layer13d. When the first electrode13ais an anode, a first electrode material may be selected from among materials having a high work function to facilitate hole injection. The first electrode13amay be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode depending on the particular type of organic light-emitting display device. As the first electrode material, materials that are transparent and have excellent conductivity such as indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), zinc oxide (ZnO), In2O3, or the like may be used. When the first electrode13ais provided as a reflective electrode, the first electrode13amay include a reflective film formed of silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), or a compound thereof, and a transparent film formed of ITO, IZO, ZnO, or In2O3. In some embodiments, the first electrode13amay have a single layer structure or a multi-layer structure having two or more layers. For example, the first electrode13amay have a three-layered structure of ITO/Ag/ITO; but the structure is not limited thereto.

The organic emission layer13bmay be formed on the first electrode13aand/or the pixel defining layer13d. The organic emission layer13bmay be formed of a low molecular weight or a high molecular weight organic material. When the low molecular weight organic material is used, a hole injection layer (HIL, not shown), a hole transport layer (HTL, not shown), an electron transport layer (ETL, not shown), and/or an electron injection layer (EIL, not shown) may be laminated in a singular or a complex structure while having the organic emission layer13bbetween the layers. Various organic materials may be used such as copper phthalocyanine (CuPc), N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB), and tris-8-hydroxyquinoline aluminum (Alq3). The low molecular weight organic materials may be formed by a vacuum deposition method using masks.

When the organic emission layer13bis formed of a high molecular weight organic material, the HTL may be further included from the organic emission layer13bto the anode, and here, PEDOT may be used for the HTL, and poly-phenylenevinylene (PPV)-based and polyfluorene-based high molecular weight organic materials may be used for the emission layer.

The organic emission layer13bmay include, for example, at least one of compounds301,311, and321(as illustrated in Formula 1, Formula 2 and Formula 3, respectively), such as the following:

In some embodiments, the organic emission layers13beach emitting red, green, and blue color light may be provided in a region defined by the pixel defining layer13dto form a subpixel. Also, subpixels each emitting red, green, and blue color light may be used together to form a unit pixel. However, the organic emission layer13bis not limited thereto and may be commonly provided on the entire light-emitting portion13, regardless of the location of the pixel. Here, the organic emission layer13bmay be formed by, for example, vertically laminating or mixing layers including light-emitting materials emitting red, green, and blue color light. Provided that white light may be emitted, a combination of different colors is possible. Also, a color change layer that changes white light into a predetermined color light or a color filter may be further included in the organic light-emitting portion13.

The second electrode13cmay be formed on the organic light-emitting layer13band may be electrically insulated from the organic light-emitting layer13b. The second electrode13cmay be a cathode and here, a metal, an alloy, an electro-conductive compound, and a combination thereof having a low work function may be used as a second electrode-forming metal. For example, Lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or the like may be formed as a thin film to obtain a reflective, a semi-transmissive, or a transmissive electrode. On the other hand, various changes are possible, such as forming a transmissive electrode by using ITO or IZO to obtain a top emission type device.

Although not shown inFIG. 1, the organic light-emitting portion13includes at least one pixel circuit in each pixel, and the pixel circuit may include at least one thin film transistor (not shown) and a capacitor (not shown). The first electrode13amay be operated by electrically connecting to the thin film transistor. The first electrode13amay be patterned in each pixel, and the second electrode13cmay be formed as a common electrode to cover all pixels. In the case of a bottom emission type structure, in which an image is displayed in a direction of the substrate11, the second electrode13cmay be formed with a greater relative thickness to improve emission efficiency in the direction of the substrate11. In the case of a top emission type structure, in which an image is displayed in a direction to the second electrode13c, the second electrode13cmay be formed with a smaller relative thickness such that the second electrode13cmay be a semi-transmissive reflective film, or the second electrode13cmay be formed as a transparent conductor by using materials other than the materials described above. In this case, a reflective film may be further provided on the first electrode13a.

A first inorganic film14and a second inorganic film16bmay prevent leakage of external moisture or oxygen into the organic light-emitting portion13; hence, the first inorganic film14and the second inorganic film16bmay seal the organic light-emitting portion13to block the organic light-emitting portion13from external air.

In some embodiments, the first inorganic film14has a coefficient of thermal expansion (CTE) value smaller than a CTE value of the substrate11and/or the organic light-emitting portion13and the second inorganic film16b.

The second inorganic film16bincludes a low temperature viscosity transition (LVT) inorganic material (hereinafter, referred to as a “LVT inorganic material”). The LVT inorganic material refers to an inorganic material having a low viscosity transition temperature. As used herein, “the viscosity transition temperature” does not refer to a temperature at which a viscosity of the LVT inorganic material completely changes from “solid” to “liquid”, but to the lowest temperature at which fluidity may be provided to the LVT inorganic material.

In some embodiments as described below, the LVT inorganic material may be fluidized and then solidified, wherein a viscosity transition temperature of the LVT inorganic material may be lower than a transition temperature of a material included in the organic light-emitting portion13.

The “transition temperature of a material included in the organic light-emitting portion13” refers to a temperature that may cause a chemical and/or a physical change of a material included in the organic light-emitting portion13. For example, the “transition temperature of a material included in the organic light-emitting portion13” may refer to a glass transition temperature (Tg) of an organic material included in the organic emission layer13bof the organic light-emitting portion13. The glass transition temperature may be inferred from the results of thermal analyses (under N2atmosphere, a temperature range from about 600° C. (10° C./min)-TGA to about 400° C.-DSC, and pan type: Pt pan in a non-reusable aluminum pan (TGA) and a non-reusable aluminum pan (DSC)) by using a thermo gravimetric analysis (TGA) and a differential scanning calorimetry (DSC), and this is well known to one of ordinary skill in the art. For example, the transition temperature may be about 400, 420, 440, 460, 480, 500, 520, 540, 560, 580, 600° C. or any number in between.

The transition temperature of the material included in the organic light-emitting portion13may, for example, exceed 130° C.; however, the transition temperature is not limited thereto, and may be easily measured by a TGA analysis of the material included in the organic light-emitting portion13as described above.

In some embodiments, the transition temperature of the LVT inorganic material may be 80° C. or greater, for example, from about 80° C. to about 130° C.; however, the transition temperature is not limited thereto. For example, the transition temperature may be about 80, 90, 100, 110, 120, 130° C. or any number in between. The LVT inorganic material may be a mixture formed of one type of a compound or two or more types of compounds. The LVT inorganic material may include tin oxide (for example, SnO or SnO2).

When the LVT inorganic material includes SnO, the content of the SnO may be about 20 wt % to about 100 wt %. In some embodiments, the content of the SnO may be about 20, 30, 40, 50, 60, 70, 80, 90 wt % or any value in between. For example, the LVT inorganic material may further include at least one type of phosphorous oxide (for example, P2O5), boron phosphate (BPO4), tin fluoride (for example, SnF2), niobium oxide (for example, NbO), and tungsten oxide (for example, WO3), but the LVT inorganic material is not limited thereto.

For example, the LVT inorganic material may include:

SnO and P2O5;

SnO and BPO4;

but, the LVT inorganic material is not limited thereto.

For example, the LVT inorganic material may have the following composition, but the composition is not limited thereto:

For example, the LVT inorganic material may include SnO (42.5 wt %), SnF2(40 wt %), P2O5(15 wt %), and WO3(2.5 wt %), but the LVT inorganic material is not limited thereto.

When the second inorganic film16bis formed with the above composition, the viscosity transition temperature of the second inorganic film16bmay be lower than the transition temperature of the organic light-emitting portion13to “heal” various defects that may form on the second inorganic film16bduring annealing of the second inorganic film16b, which will be described later.

In some embodiments, the second inorganic film16bmay include a Sn—P—O—F-based LVT inorganic material.

Generally, the viscosity transition temperature of the LVT inorganic material may vary according to components and compositions of materials used to form the LVT inorganic materials, and the components and the compositions may be changed to adjust the viscosity transition temperature.

Also, a coefficient of thermal expansion of the LVT inorganic material may be as high as (100˜300)×10−7/K, and it is known that the lower the viscosity transition temperature of the LVT inorganic material, the higher the coefficient of thermal expansion (CTE).

In some embodiments, CTE values of the substrate11and the organic light-emitting portion13are about (30˜70)×10−7/K which are very different from the CTE value of the LVT inorganic material. The difference in the CTE values generates a difference in temperatures during a sealing process and may add stress to the substrate11and the organic light-emitting portion13, thereby inducing a crack.

A first inorganic film14may have been introduced to control the stress caused by the difference in temperatures generated during the sealing process. A CTE value of the first inorganic film14is smaller than a CTE value of a second inorganic film16b, and may be greater than or equal to the CTE value of the substrate11and/or the organic light-emitting portion13. In some embodiments, the CTE of the first inorganic film14may be greater than or equal to the CTE value of the substrate11and smaller than CTEx2. In some embodiments, the CTE value of the first inorganic film14may be about (70˜100)×10−7/K.

Any inorganic material satisfying the above CTE value may be used to form the first inorganic film14. The first inorganic film14may include a porous inorganic material142in which pores141a(seeFIG. 2B) are formed. The pores141aof the porous inorganic material may be filled with dispersed inorganic materials141b. The dispersed inorganic materials141bmay be formed of the same materials as the second inorganic film16b. The dispersed inorganic materials141bmay be formed when a portion of the second inorganic film16bhas been infiltrated during the annealing of the second inorganic film16b. The first inorganic film14may become denser as the pores141aare filled with the dispersed inorganic materials141b. Accordingly, the first inorganic film14may have improved barrier property to external air including, for example, moisture and/or oxygen.

In some embodiments, the first inorganic film14may include a LVT inorganic material142having a different composition and/or component from the second inorganic film16b. In some embodiments, the first inorganic film14may include a Sn—(P,B)—O—F-based LVT inorganic material142. In this case, the Sn—(P,B)—O—F-based LVT inorganic material142may have been obtained by substituting phosphorus (P) of the Sn—P—O—F-based LVT inorganic material with boron (B). A substitution rate of B may be about 10% to about 30%. The greater the substitution rate of B, the smaller the CTE value of the Sn—(P,B)—O—F-based LVT inorganic material142.

In some embodiments, the first inorganic film14includes the Sn—(P,B)—O—F-based LVT inorganic material142, and the second inorganic film16bmay include the Sn—P—O—F-based LVT inorganic material. In some embodiments, the first inorganic film14may not be fluidized during the annealing for forming the second inorganic film16b, which will be described later.

Optical properties of the first inorganic film14and the second inorganic film16bmay differ from each other. Accordingly, the thickness t1 of the first inorganic film14and the thickness t2 of the second inorganic film16bmay be adjusted to change color and optical properties of the inorganic films14,16b. The first inorganic film14and the second inorganic film16bmay have a light transmission property.

FIG. 2A through 2Dsequentially illustrate a method of manufacturing an organic light-emitting display device100according to an embodiment of the present disclosure. Referring toFIG. 2A, an organic light-emitting portion13is formed on a substrate11. As illustrated inFIG. 1B, the organic light-emitting portion13includes a sequentially laminated structure of a first electrode13a, an organic emission layer13b, a second electrode13con the substrate11. The first electrode13amay be formed by using various deposition methods. The first electrode13amay be patterned to be formed in separate pixels. Thereafter, a pixel defining layer13dmay be formed to cover the first electrode13a. The pixel defining layer13dmay include a polyacrylate-based or a polyimide-based resin, a silica-based inorganic material, or the like. After forming an opening of a predetermined size on the pixel defining layer13d, an organic emission layer13bis formed in a limited region through the opening. Then, the second electrode13cis formed to cover all of the pixels. A protective layer (not shown) may further be formed on the second electrode13c.

Referring toFIG. 2B, a first inorganic film14is formed on the organic light-emitting portion13. The first organic film14may be formed by using resistance heating deposition, sputtering, vacuum deposition, low temperature deposition, electron beam coating, ion plating, or the like. In some embodiments, the first inorganic film14may be formed by a plasma chemical vapor deposition (PCVD) or a plasma ion assisted deposition (PIAD). In some embodiments, the first inorganic film14may provide a Sn—(P,B)—O—F-based LVT inorganic material on the organic light-emitting portion13through sputtering. In greater detail, the sputtering may apply a dual rotary target method, and may use a method in which the substrate11moves and scans the inorganic material. The first inorganic film14may include pores141a.

Referring toFIG. 2C, a preliminary second inorganic film16ais formed on a first inorganic film14. The preliminary second inorganic film16amay be formed by using resistance heating deposition, sputtering, vacuum deposition, low temperature deposition, electron beam coating, ion plating, or a combination thereof. In some embodiments, the preliminary second inorganic film16amay be formed by a plasma chemical vapor deposition (PCVD) or a plasma ion assisted deposition (PIAD). In some embodiments, the preliminary second inorganic film16amay provide a Sn—P—O—F-based LVT inorganic material on an organic light-emitting portion13through sputtering. In greater detail, the sputtering may apply a dual rotary target method, and may use a method in which the substrate11moves and scans the inorganic material.

The preliminary second inorganic film16amay include defects such as deposition components162and pinholes161. A LVT inorganic material deposition component162refers to a LVT inorganic material aggregate particle that did not participate in a deposition when the LVT inorganic material was deposited and the pinhole161refers to an empty region formed because the LVT inorganic material was not provided thereto. A formation of the LVT inorganic material deposition component162may contribute to a formation of the pinhole161.

The above described defects in the pre-inorganic film16amay provide a pathway for external environment materials such as moisture and oxygen during maintenance and operation of an organic light-emitting display device, thereby causing formation of a progressive blind spot and a decrease in lifespan of the organic light-emitting display device.

Accordingly, as illustrated inFIG. 2D, after forming the preliminary second inorganic film16a, an annealing to remove the defects of the preliminary second inorganic film16ais performed.

The annealing is performed at a temperature greater than or equal to a viscosity transition temperature of the LVT inorganic material included in the preliminary second inorganic film16a. The annealing may be performed at a temperature at which the organic light-emitting portion13does not get damaged. For example, the annealing may be performed by heat treating the preliminary second inorganic film16aat a temperature range below the transition temperature of a material included in the organic light-emitting portion13. “The viscosity transition temperature of the LVT inorganic material” may vary according to a composition of the LVT inorganic material and “change in a material included in the organic light-emitting portion13” may vary according to a material used for the organic light-emitting portion13; however, the change in the material included in the organic light-emitting portion13may be inferred by one of ordinary skill in the art based on the composition of the LVT inorganic materials and the materials used for the organic light-emitting portion13. For example, the change in the material included in the organic light-emitting portion13may be determined by evaluating a glass transition temperature (Tg) of an organic material inferred from TGA analysis results of the materials included in the organic light-emitting portion13.

In some embodiments, the annealing may be performed by heat treating the preliminary second inorganic film16aat a temperature of about 80° C. to about 130° C. for one hour to about 3 hours (for example, at a temperature of about 100° C. for 2 hours); but the annealing is not limited thereto. The annealing may be performed for about 1.0, 1.25, 1.5, 1.75, 2.0, 2.25, 2.5, 2.75, or 3.0 hours or any range or time therebetween. The annealing may be performed at a temperature of about 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130° C. or any range or temperature therebetween. When the temperature of the annealing satisfies the above described range, the LVT inorganic material of the preliminary second inorganic film16abecomes fluidized, and a change in the organic light-emitting portion13may be prevented.

In some embodiments, the annealing may be processed in an IR oven under a vacuum atmosphere or an inert gas atmosphere (for example, N2atmosphere or Ar atmosphere)

Due to the annealing, the LVT inorganic material included in the preliminary second inorganic film16amay be fluidized. A fluidized inorganic material may have flowability. Accordingly, the fluidized LVT inorganic material may flow into a first inorganic film14and fill the pores141a(seeFIG. 2B) included in the first inorganic film14to form a dispersed inorganic material141b.

Also, during the annealing, the fluidized LVT inorganic material may flow into and fill pinholes161of the preliminary second inorganic film16aand the deposition components162may be fluidized to flow into and fill the pinholes161. After the heat treatment, the fluidized LVT inorganic material becomes solid again as the temperature drops.

As shown inFIG. 4, defects of the preliminary second inorganic film16amay be removed to form a second inorganic film16bhaving a dense film quality. Also, the pores141aof the first inorganic film14may be filled with the LVT inorganic materials infiltrated from the preliminary second inorganic film16ato form the dispersed inorganic material141b, thereby forming a denser first inorganic film14.

FIG. 3schematically illustrates a cross-section of an organic light-emitting display device200according to another embodiment of the present disclosure. InFIG. 3, like reference numerals represent like elements ofFIG. 1and repeated descriptions are omitted for simplification of the description. Referring toFIG. 3, the organic light-emitting display device200differs from the organic light-emitting display device100ofFIG. 1in that the second inorganic film16bis provided to wrap sides of a first inorganic film14. The second inorganic film16bis provided on top and sides of the first inorganic film14to strengthen barrier properties on the sides.

FIG. 4schematically illustrates a cross-section of an organic light-emitting display device300according to another embodiment of the present disclosure. InFIG. 4, like reference numerals represents like elements ofFIG. 1and repeated descriptions are omitted for simplification of the description. Referring toFIG. 4, the organic light-emitting display device300differs from the organic light-emitting display device100ofFIG. 1in that a bottom organic layer17is provided on a bottom surface of the substrate11. The bottom organic layer17may strengthen bending properties and/or mechanical strength of the substrate11. When the substrate11is formed of a glass material, the bending property may not be good even when a thin substrate11is used. Here, the bottom organic layer17may be provided on the bottom surface of the substrate11to improve the bending property of the substrate11. For example, a bending radius of a glass substrate having a thickness of 0.1 mm is about 10 cm; however, when an acryl organic film having a thickness of about 5 μm is coated on the bottom surface of the substrate11, the substrate11does not break even after the substrate11has been bent for 10,000 times at a bending radius of about 2 cm.

FIG. 5schematically illustrates a cross-section of an organic light-emitting display device400according to another embodiment of the present disclosure. InFIG. 5, like reference numerals represents like elements ofFIG. 1and repeated descriptions are omitted for simplification of the description. Referring toFIG. 5, the organic light-emitting display device400differs from the organic light-emitting display device100ofFIG. 1in that a third inorganic film18is provided between the substrate11and the organic light-emitting portion13. The third inorganic film18may be formed through annealing by using the above-described LVT inorganic material. Although not shown in the drawings, a pixel circuit including a thin film transistor and/or a capacitor may be formed on the third inorganic layer18. In this case, a sealing property of the organic light-emitting portion13may be further improved due to a dense barrier property of the third inorganic layer18. The third inorganic layer18may be useful when a barrier property of the substrate is not good, such as when the substrate is formed of plastic.

FIG. 6schematically illustrates a cross-section of an organic light-emitting display device500according to another embodiment of the present disclosure. InFIG. 6, like reference numerals represents like elements ofFIG. 1and repeated descriptions are omitted for simplification of the description. Referring toFIG. 6, the organic light-emitting display device500differs from the organic light-emitting display device100ofFIG. 1in that a protective layer19may be formed on an organic light-emitting portion13. The protective layer19may prevent damage to the second electrode13cwhen the first inorganic film14and the second inorganic film16bare formed on the organic light-emitting portion13. In some embodiments, the protective layer19may be formed of a material including at least one of LiF, lithium quinolate, and Alq3.

The organic light-emitting display device may include the first inorganic film, and thus, may prevent film cracks that may occur between the substrate and the second inorganic film and/or between the organic light-emitting portion and the second inorganic film. Also, the organic light-emitting display device provides a thin film sealing layer including an inorganic film that has excellent sealing property with respect to the external environment to achieve an organic light-emitting display device having a long lifespan. Accordingly, the organic light-emitting display device may maintain excellent sealing property. Also, the organic light-emitting display device may have an improved bending property and may not destroy the sealing property even when the organic light-emitting display device is bent.