KR20050087444A - Plane white light-emitting source - Google Patents

Abstract

The present invention relates to a high efficiency high stability planar white light emitting device, wherein the device for generating white light is separated into a pair or two or more pairs of transparent electrodes stacked along an electrode surface of a glass or plastic substrate including a transparent or opaque electrode. Inorganic phosphors, organic dyes, organic pigments, nano metals, nano composites, etc., combined with a curing agent and a binder material along the first layer of the light emitting diode and the surface of the substrate or the opposite side of the substrate, respectively, or two or more kinds of excitation coating layers It consists of a 2nd layer provided. Blue, which constitutes white light and is used as an excitation circle, is recognized by being generated from the blue organic light emitting element as the first layer and partially passed through to the transparent excitation coating layer as the second layer, and other white light constituent colors of green, yellow, orange and red Inorganic phosphors, organic dyes, organic pigments, nano metals, nanocomposites, and the like, which are coated in the excitation layer from the blue light source by the organic light emitting element, are generated and recognized by excitation by light energy transfer.

Description

Plane white light-emitting source

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a white light emitting device used for a backlight light source of a liquid crystal display, a full color light emitting device, a lighting fixture signal, and various indicators. More particularly, a part of the blue light generated by a blue organic light emitting device is appropriately selected. The present invention relates to a light emitting device that converts green, yellow, orange, and red to emit white light, and a display device using the same.

The organic light emitting device has a wide viewing angle, high-speed response, and high contrast, so it can be used as a pixel of a television image display or surface light source, and because of its thinness, lightness, and good color, it is attracting attention as a next-generation display. In addition, when a plastic substrate is employed, a curved element may be fabricated, and a device that emits white light may be used as a halo of an organic electroluminescent element or a halo of a liquid crystal display.

The structure of a typical blue organic light emitting diode is an anode layer 110 formed by vacuum deposition of indium tin oxide (ITO) on the transparent substrate 100, as shown in Figure 1, and on the anode layer 110 The hole injection layer 120, the hole transport layer 130, the light emitting layer 140, the electron transport layer 150, the electron injection layer 160, and the cathode layer 170 may be vacuum deposited in this order.

In addition, a general white organic light emitting device uses a hetero multilayer structure including two light emitting layers using complementary colors of cyan, red, blue, and orange, or a mixture of hetero multilayers including three primary light emitting layers of blue, green, and red. An example structure using the above three wavelengths includes an anode layer 110 formed by vacuum deposition of indium tin oxide (ITO) on a transparent substrate 100 as shown in FIG. On the anode layer 110, a hole injection layer 120, a hole transport layer 130, a blue light emitting layer 140a, a green light emitting layer 140b, a red light emitting layer 140c, an electron transporting layer 150, electrons The injection layer 160 and the cathode layer 170 have a structure in which the vacuum deposition.

In the organic EL device configured as described above, electrons are injected from the cathode layer 170, electrons are injected into the emission layer 140 through the electron injection layer 160 and the electron transport layer 150, and the anode layer 110 is disposed. The holes injected from the holes are injected into the light emitting layer 140 through the hole injection layer 120 and the hole transport layer 130, and electrons and holes respectively moved to the light emitting layer 140 are paired with each light emitting layer thus formed. When the exciton of is recombined, blue, green and red light are emitted and mixed to emit white light.

There is a problem in the manufacture of the white organic light emitting device reported in the prior art as follows, evenly distributed red, green, blue for the white light required by the LCD BLU (Back Light Unit) using two wavelengths of complementary color relationship. It is difficult to obtain, the range of color coordinates is short, and it is difficult to satisfy high efficiency full color and display application white light source, and the white organic electroluminescent device using three wavelengths has three wavelengths which are stable by energy transfer from blue to green or green to red. It is difficult to implement, and the conventional white organic light emitting device has a lot of problems in the lifespan and stability of the device because the light emission spectrum is shifted to blue as the driving voltage increases.

Organic electroluminescent materials used in organic electroluminescent devices are largely divided into single molecules and polymer materials, and single molecules are the mainstream commercially available materials. Materials constituting the short-molecular organic electroluminescent device can be divided into a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, a cathode layer. The materials used for the light emitting layer are blue green, red, yellow and orange materials are being developed or in progress. Currently, among these materials, blue light emitting materials have been actively studied to overcome them due to low luminous efficiency and short lifespan. In addition, the development of light blue materials having high luminance and high luminous efficiency used for the development of the white organic electroluminescent device is also emerging.

Conventional blue materials used in the light emitting layer are (4,4'-bis (2,2-diphenyl-ethen-1-yl) diphenyl (DPVBi), bis (styryl) amine (DSA) -based, bis ( 2-methyl-8-quinolinolato) (triphenylsiloxy) aluminum (III) (SAlq), bis (2-methyl-8-quinolinolato) (para-phenolato) aluminum (III) (BAlq ), Bis (salen) zin (II), 1,3-bis [4- (N, N-dimethylamino) phenyl-1,3,4-oxadiazolyl] benzene (OXD8), 3- (biphenyl- 4-yl) -5- (4-dimethylamino) 4- (4-ethylphenyl) -1,2,4-triazole (p-EtTAZ), 3- (4-biphenyl) -4-phenyl-5 -(4-tert-butylphenyl) -1,2,4-triazole (TAZ), 2, 2 ', 7, 7'-tetrakis (non-phenyl-4-yl) -9,9'- Spirofluorene (Spiro-DPVBI), tris (para-ter-phenyl-4-yl) amine (p-TTA), 5,5-bis (dimethylyl boryl) -2,2-bithiophene (BMB-2T ) And perylene, and green light emitting materials include tris (8-quinolinato) aluminum (III) (Alq ₃ ), Almq ₃ (tris (4-methyl-8-quinolinolato) Aluminum (III)), cuma Lean 6 and quinacridone, and the red light emitting material is DCM1 (4-dicyanomethylene-2-methyl-6- (para-dimethylaminostyryl) -4H-pyran), DCM2 (4-dicyanomethylene- 2-methyl-6- (zulolidin-4-yl-vinyl) -4H-pyran), DCJT (4- (dicyanomethylene) -2-methyl-6- (1,1,7,7-tetramethyl Zulolidil-9-enyl) -4H-pyran), DCJTB (4- (dicyanomethylene) -2-tert-butylbutyl-6- (1,1,7,7-tetramethyljulolidyl-9-enyl ) -4H-pyran), DCJTI (4- (dicyanomethylene) -2-isopropyl-6- (1,1,7,7-tetramethylzololidyl-9-enyl) -4H-pyran) and nile Red (Nile red) and the like.

Light-emitting diodes using inorganic phosphors can emit light with vivid colors efficiently, and because they are semiconductor devices, there is no fear of loss, excellent initial driving characteristics and shock resistance, and strong resistance to repetition of ON / OFF lighting. It is widely used as an indicator and a light source, and in recent years, light emitting diodes of various colors using ultra high brightness, high efficiency red, green, and blue inorganic phosphors have been developed, respectively. Light emitting diode (LED) displays have been used. These LEDs are expected to be used more and more because they can operate with less power, have excellent characteristics such as light weight and long life. The white light generated by the LED device is mainly made of a gallium nitride (GaN) -based semiconductor device, and a blue light source, which is a point light source, is partially passed through an epoxy resin layer coated with an inorganic phosphor on the light source. Although blue light is generated by excitation of red or orange, which is a constituent color of white light applied to a transparent epoxy resin layer, it has a limitation in that it cannot produce the planar light source characteristics required for a flat panel display.

The study of white light by LED (Electroluminecent Device) is mainly studied by Nika Chemical Co., Ltd. of Japan, and is a nitride compound semiconductor {In _i Ga _j Al _k N; However, 0≤i, 0≤j, 0≤k, i + j + k; InGaN, including GaN doped with various impurities. The wavelength range of 400-530 nm is yttrium aluminum garnet phosphor {(Y _1-r Gd _r ) ₃ Al ₅ O ₁₂ : Ce; Provided that 0 ≦ r ≦ 1; Some of Al is substituted by Ga and / or In. Finally, yellow phosphors are yttrium aluminum garnet phosphors {Y ₃ (Al _1-s Ga _s ) ₅ O ₁₂ : Ce}, rhenium aluminum garnet phosphors {(Re _1-r Sm _r ) ₃ (Al _1-s Ga _s ) ₅ O ₁₂ : Ce; Provided that 0 ≦ r <, 0 ≦ s ≦ 1; Re is a kind selected from Y and Gd}, a rhenium aluminum garnet phosphor {Re ₃ Al ₅ O ₁₂ : Ce}, a yttrium aluminum phosphor {Y _1-pqr Gd _p Ce _q Sm _r ) ₃ (Al _{1 -s} Ga _s ) ₅ 0 ₁₂ ; However, 0 _{≦ p} ≦ 0.8, 0.003 ≦ q ≦ 0.2, 0.0003 ≦ r ≦ 0.08, 0 ≦ s ≦ 1}, yttrium aluminum phosphor (Y _1-pqr Gd _p Ce _q Sm _r ) ₃ Al ₅ O ₁₂ ; Provided that 0 ≦ p ≦ 0.8, 0.003 ≦ q ≦ 0.2, 0.0003 ≦ r ≦ 0.08} and the rhenium aluminum garnet phosphor {(Re _1-r Sm _r ) ₃ (Al _1-s Ga _s ) ₅ O ₁₂ ; However, 0≤r <1, 0≤s <1 At least one selected from Y and Gd} is used.

At Osram, Japan, yellow Re ₃ (Al: Ga) ₅ O ₁₂ : Ce is used.

Other blue phosphors include (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ C ₁₂ : Eu, an inorganic phosphor with green luminescence properties. ZnS: Cu, Au, Al, green yellow {Y _1-xab Gd _x Tb _a Tm _b ) ₃ (Al _1-y Ga _y ) ₅ O ₁₂ ; However, 0≤x≤1, 0≤y≤1, 0≤a≤0.1, 0≤b≤0.03} and red phosphor {Y _1-p Gd _p ) ₃ (Al _1-xy Ga _x Cr _y ) ₅ O ₁₂ ; However, 0 ≦ p ≦ 0.9, 0 ≦ x ≦ 0.99, 0.001 ≦ y ≦ 0.1}, {Y ₂ O ₂ S: Eu}, and the like.

Since organic dyes or pigments are mostly soluble in epoxy, there are many advantages in controlling the epoxy film of a certain thickness by screen printing or spin coating due to the even dispersibility of the layers. In addition, these pigments or dyes absorb light of the blue organic light emitting device. It is a material with properties that can be excited by

Conventional organic pigments include azo-based insoluble azo pigments, azo lake pigments, condensed azo pigments and metal salt azo pigments, and phthalocyanine-based copper phthalocyanine, halogenated copper phthalocyanine, metal phthalocyanine and copper phthalocyanine lake pigments. Dye lake pigments include acid fuel lakes and basic dye lake pigments. Condensed polycyclic pigments include anthraquinone, thioindigo, perylene, prinon, quinacridone, dioxazine, isoindolinone, isoindolin, Quinaphthalone and the like. Other pigments include nitroso pigments, alizarin, metal complex salt azomethine, aniline black, alkali blue and fluorescence fluorescence.

Conventional organic dyes include direct dyes, acid dyes, mordant dyes, acid dyes, basic dyes, cationic dyes, sulfur dyes, sulfur dyes, vat dyes, soluble dyes, azoic dyes, disperse dyes, reactive dyes, and oxidative dyes. , Organic solvent dyes and fluorescent dyes.

The quantum dots of nano metals and wear composites used in the polymer organic light emitting diodes that are used in the past are spatially located on the backbone of a polymer entangled like a thread, or a functional group of a minor axis that depends on the main axis of the polymer. It is used in hyperbranched form. Visible light energy excited in the conductive polymer is transferred to the quantum dots and emits light at the quantum dots. In addition, by dispersing nano-sized quantum dots in a solvent, ultraviolet light is emitted from the quantum dots by excitation circles. At this time, it shows excellent color purity in various visible light regions according to the nano size of the quantum dots, and thus shows a narrow line width spectral spectrum. Quantum dot materials are mainly nano-sized metals or nanocomposites. Platinum, gold, silver, nickel, magnesium, palladium, etc. are used as nano metals, and nanocomposites include cadmium sulfide (CdS), cadmium selenide (CdSe), zinc sulfide (ZnS), zinc selenide (ZnSe), and indium. Phosphite (InP), titanium oxide (TiO ₂ ), zinc oxide (ZnO), tin oxide (SnO), silicon oxide (SiO ₂ ), magnesium oxide (MgO) and the like.

The present invention has been invented to compensate for the problem of fabricating a white organic light emitting device using the three primary colors of red, green, and blue described above, or using a complementary color relationship, and is a deep blue organic, which is a first layer having high efficiency. In order to obtain efficient white light using the principle that the light emitted from the light emitting device absorbs the inorganic phosphor of the second layer, the organic pigment, the organic dye, the nanocomposite material and the metal quantum dot of the nano metal. A flat white light emitting source using an excitation coating layer that can be absorbed and excited by melting or dispersing in two layers of epoxy resin can be combined with a color projector required by a display device to digest characteristics of LCD backlights, lighting fixtures, and indicators. It can be.

In addition, when fabricating a white light emitting device, when the epoxy excitation coating layer, which is the second layer, is used as a red and green light emitting source, a flat white light source having a long lifetime, high efficiency and high stability can be solved by compensating the disadvantages of the existing first organic light emitting diode. It is possible to prevent the difference in the lifespan of red, green, and blue, and the change in the chromaticity of white light, which occur as the time increases while driving, and also by using an LED (Electroluminescent Device) and an inorganic phosphor. When manufacturing the light emitting device, it is possible to increase the low luminance generated by using the light guide plate and the optical films, and to improve the diversity and stability of chromaticity.

Accordingly, the present invention provides a flat white light emitting device having excellent chromaticity, brightness, high efficiency, and driving stability by using an epoxy excitation layer mainly used in LED white light as a point light source and a high efficiency, high brightness, high stability blue organic light emitting device. Is to provide.

In order to solve the above technical problem, the present invention provides a blue organic light emitting material for a blue organic electroluminescent device represented by the following formula.

(Formula 1)

Al (NQ) ₃

_{(Formula 2)}

BAlq

(Formula 3)

SAlq

(Formula 4)

DCAB

(Formula 5)

DCS

(Formula 6)

DPVBi

Hereinafter, preferred embodiments of the present invention will be described, and the following embodiments described in the present invention are presented to aid the understanding of the present invention, but the present invention is not limited to the following embodiments.

Example 1 and Example 2 describe in detail an example of the manufacturing method of the first layer 200 and the second layer 300, respectively. In addition, Example 3 describes an example of an inorganic phosphor and Examples 4 and 5 describe an example of an organic dye.

Example 1

Representative examples of the blue organic light emitting device as the first layer 200 constituting the white light emitting device of the present invention are as follows.

After the second layer 300 is formed on the opposite side of the glass substrate on which tin indium oxide is deposited, it is transferred to a vacuum deposition apparatus, and then, N, N'-diphenyl -N, N'-bis (1-naph), a hole transport material Til)-(1,1'-biphenyl) -4,4'-diamine (NPB) was vacuum deposited to a thickness of 50 nm at a rate of 0.04 to 0.07 nm per second to form a hole transport layer.

(4,4'-bis (2,2-diphenyl-ethen-1-yl) diphenyl (DPVBi) of Example 2, which is the manufacturing method of the present invention as described above to serve as a light emitting layer on the hole transport layer, 0.03 per second 40 nm is deposited at a rate of ˜0.06 nm, and then tris (8-quinolinato) aluminum (III) (Alq ₃ ) serving as an electron transporting layer is deposited at a rate of 30 nm at a rate of 0.04-0.06 nm per second.

In addition, lithium fluoride (LiF) per second is deposited on the electron transport layer at a rate of 0.02 to 0.03 nm at a rate of 1 nm, and finally, a mask for forming an electrode is placed thereon, followed by deposition of 100 nm at a rate of 0.05 to 0.15 nm per second. An electrode is formed, and the device structure thus formed is shown in FIG. 1.

Example 2

The manufacturing method of the 2nd layer 300 which comprises the white organic light emitting element of this invention is comprised as follows.

In the method of manufacturing the second layer 300, which is an excitation coating layer, an ultrasonic cleaner after mixing an organic / inorganic phosphor, an organic pigment, an organic dye, a quantum dot of a nano-sized metal and a composite material, etc. with a transparent agent, a curing agent, a binder, a solvent, and the like After mixing at room temperature for about 30 minutes, and after the mixing is completed, the mixture is formed into a suspension, a colloidal solution, and the like.

The mixture thus formed is coated with an excitation coating layer using spin coating and screen printing under appropriate conditions and fired in an oven, and the firing temperature is divided into 1 and 2 times at 50 to 150 ° C. for 30 minutes to 2 hours and 1 to 4 hours, respectively. Conduct.

At this time, the total mass-based mixing ratio of the light emitting material of the excitation coating layer used was in the range of 1 to 50%, and the thickness of the final layer after firing was produced in the range of 1 micrometer (μm) to 1 millimeter (mm).

Example 3

An excitation coating layer of the second layer 300 on the opposite side on which indium tin oxide is deposited is manufactured as follows.

Transparent agent (1.00 g), curing agent (1.00 g), binder, para-xylene, yag (YAG; x%, x = 0, 1, 5 and 10) were added to the vial bottle and ultrasonic cleaner for about 30 minutes. Mixing forms a yellow suspension. The suspension formed is coated by the screen printing method and the excitation coating layer is transferred to an oven. The firing temperature is performed at 130 ° C. for 1 hour, and then the substrate temperature is cooled for about 20 minutes. The substrate cooled to room temperature is calcined again at 130 ° C. for about 3 hours.

In the preparation of the first layer 200, a blue organic light emitting diode, which is the first layer 200, was manufactured on the opposite side of the glass substrate on which the second layer 300 was formed.

4 is a light emission spectrum of the white light emitting device manufactured according to the present embodiment, it can be seen that the most excellent white when the composition ratio of YAG is 10% by weight, and YAG, which is an inorganic phosphor of the second layer 300 It can be seen that as the amount of increases, the yellow component of the second layer 300 increases rather than the blue component of the first layer 200 in the emission spectrum.

5 shows the luminance-voltage curve of the present embodiment, which shows the best emission luminance when the composition ratio of YAG is 10% by weight, and exhibits a high emission characteristic of about 32,000 Cd / m ² at about 10V.

Figure 6 shows the current-voltage curve showing the threshold voltage at about 2 V.

Example 4

An excitation coating layer of the second layer 300 on the opposite side on which indium tin oxide is deposited is manufactured as follows.

Add clearing agent (1.00 g), curing agent (1.xg), binder, para-xylene, yellow dye (x%, x = 0, 1, 5, 10, 50 and 100) to the vial bottle and use ultrasonic cleaner After mixing for about 30 minutes, a yellow transparent solution is formed. The formed solution is coated by the spin coating method and the excitation coating layer is transferred to an oven. The firing temperature is performed at 130 ° C. for 1 hour, and then the substrate temperature is cooled for about 20 minutes. The substrate cooled to room temperature is calcined again at 130 ° C. for about 3 hours.

In the preparation of the first layer 200, a blue organic light emitting diode, which is the first layer 200, was manufactured on the opposite side of the glass substrate on which the second layer 300 was formed.

FIG. 7 shows the emission spectrum of the white light emitting device manufactured according to the present embodiment, and as the amount of the yellow dye in the second layer 300 increases, the yellow component increases in the emission spectrum rather than the blue component. When manufacturing a white device using the two wavelengths of the first layer 200 to the second layer 300 shows that it is possible to implement the white through the energy transfer.

Example 5

An excitation coating layer of the second layer 300 on the opposite side on which indium tin oxide is deposited is manufactured as follows.

Translucent (1.00 g), curing agent (1.xg), binder, p-Xylene, orange dye (x%, x = 0, 1, 5, 10, 50 and 100) was added to the vial bottle using an ultrasonic cleaner After about 30 minutes of mixing, an orange clear solution is formed. The formed solution is coated by the spin coating method and the excitation coating layer is transferred to an oven. The firing temperature is performed at 130 ° C. for 1 hour, and then the substrate temperature is cooled for about 20 minutes. The substrate cooled to room temperature is calcined again at 130 ° C. for about 3 hours.

In the preparation of the first layer 200, a blue organic light emitting diode, which is the first layer 200, was manufactured on the opposite side of the glass substrate on which the second layer 300 was formed.

8 is an emission spectrum of the white light emitting device manufactured according to the present embodiment, it can be seen that as the amount of orange dye of the second layer 300 increases, the orange component rather than the blue component increases in the emission spectrum. When fabricating a white device using two wavelengths, it is shown that white can be realized through energy transfer from the first layer 200 to the second layer 300.

The white light emitting device of the present invention is an efficient structure that absorbs a part of a blue organic light emitting source and emits red, green, and orange, which are other constituent colors of white light, through an epoxy layer and transmits some blue light, thereby emitting light of a blue organic light emitting device. As a material, a material having high efficiency and brightness is used, and the epoxy resin layer exhibits a white light emitting device having maximized efficiency by using an excitation material through high blue light absorption.

In particular, this type of light emitting device is a new type of flat white light emitting device that has not been reported so far, and consists of processes suitable for manufacturing a low cost flat white light emitting device.

In addition, according to the method for producing the planar white light presented in the present invention, the manufacturing and purification process is very simple compared to the conventional white organic light emitting device, the white light emitting device of the structure of the present invention is a conventional unreported high brightness, high efficiency It emits white light with high stability and has particularly good optical properties.

In particular, the devices of Examples 3, 4, and 5 show higher luminance and excellent light emission characteristics in the inorganic light emitting devices found so far.

1 is a schematic cross-sectional view showing the structure of a typical blue organic light emitting device

2 is a schematic cross-sectional view showing the structure of a typical three-wavelength white organic light emitting device

3 is a schematic cross-sectional view showing the structure of a white light emitting device produced by the manufacturing method of Example 3 of the present invention;

4 is a light emission spectrum of a white light emitting device according to Embodiment 3 of the present invention.

5 is a luminance-voltage curve of a white light emitting device according to Embodiment 3 of the present invention.

6 is a current-voltage curve of a white light emitting device according to Embodiment 3 of the present invention.

7 is a light emission spectrum of the white light emitting device according to Example 4 of the present invention.

8 is a light emission spectrum of the white light emitting device according to Example 5 of the present invention.

<Description of the symbols for the main parts of the drawings>

10: first layer 20: second layer

100: transparent substrate 110: indium tin oxide anode

120: hole injection layer 130: hole transport layer

140a: blue light emitting layer 140b: green light emitting layer

140c: red light emitting layer 150: electron transport layer

160: electron injection layer 170: cathode layer

Claims (15)

The planar white light source absorbs some blue light energy passing through the organic light emitting element manufactured by the blue-emitting transparent substrate provided as the first layer and the transparent substrate, and includes one, two or more other constituent colors of the white light source, green, yellow, A planar white light emitting device comprising an excitation coating layer provided as a second layer for generating orange and red. A planar white light source absorbs some of the organic light emitting element, which is a first layer made by an opaque substrate including an opaque electrode on a transparent substrate emitting blue light, and some blue light energy passing through the transparent electrode side opposite to the substrate. Or an excitation coating layer which is a second layer that generates green, yellow, orange, and red which are other constituent colors. The method according to claim 1 or 2, The organic light emitting element as the first layer is a flat white light emitting element comprising one or two or more blue excitation circle light emitting layers separated by one or two or more transparent electrodes. The method according to claim 1 or 2, In the case of fabricating an organic light emitting device that is a first layer separated by a pair or two or more transparent electrode electrodes, a method of manufacturing a transparent electrode on an organic thin film may include RF sputter, Grid RF sputter, DC sputter, DC pulse sputter, ALD (atomic layer deposition), A buffer layer composed of one or more ultra thin metals (Al, Ag, Cr, Mg, MgAg, Al / Ag, ..) to minimize damage to the organic thin film using a method such as plasma enhanced atomic layer deposition (PEALD). And a total metal buffer layer having a thickness in the range of 1-20 nanometers (nm). The method according to claim 1 or 2, The organic light emitting element as the first layer includes a blue excitation circular emission layer separated by a pair or two or more transparent electrodes, and includes a light emission layer of green, yellow, orange and red which is one or two or more white light components. A flat white light emitting element. The method according to claim 1 or 2, A flat white light emitting device comprising an aluminum complex compound (Al (NQ) ₃ ) of a blue excitation circle light emitting device as a first layer. The method according to claim 1 or 2, The excitation coating layer, which is the second layer, is a planar white light emitting device comprising one or two or more layers of organic / inorganic phosphors, organic pigments, organic fuels, nano metals and composite materials. The method according to claim 1 or 2, Organic / inorganic phosphors, organic pigments, organic fuels, quantum dots of nanometals and nanocomposites constituting the excitation coating layer, which is the second layer, are mixed and baked by a transparent agent, a curing agent, a binder, and the like, and are based on the total mass of the entire coating layer. The pigment mixing ratio is in the range of 1 to 50%, the firing temperature is in the range of 50 to 150 degrees Celsius, and the firing time is divided into 1 and 2 times, and the flat surface is characterized in that it proceeds for 30 minutes to 2 hours and 1 to 4 hours, respectively. White light emitting device. The method according to claim 1 or 2, Screen printing, spin coating, inkjet printing, a doctor blade, a mold method, etc. are used as a method for forming the excitation coating layer, which is the second layer on the substrate, and the thickness of the final excitation coating layer after firing is 1 micrometer (μm) to 1 Planar white light emitting device, characterized in that in the range of millimeters (mm). The method according to claim 1 or 2, In order to secure optical uniformity of the emitted plane white light, a powder composed of a silicon oxide (SiO ₂ ) component is added to the excitation coating layer, which is the second layer, or photo-patterning the transparent or opaque electrode of the excitation source emission layer into a uniform shape. A flat white light emitting element. The method according to claim 1 or 2, In manufacturing a white light source, a planar white light emitting device comprising forming an excitation coating layer, which is a second layer, by a large area substrate first, and then cutting the substrate to form an organic light emitting device for compatibility with an organic deposition apparatus. The method according to claim 1 or 2, When fabricating a white light source using a transparent or opaque substrate, in order to increase the light efficiency of the transmitted white light and simplify the process, the production of the organic light emitting device as the first layer is performed in advance, and the manufacture of the excitation coating layer as the second layer is performed later. Flat white light emitting device characterized in that. The method according to claim 1 or 2, Transparent substrates for planar white light emitting devices include glass, plastic, PET, PES, PC, thin Si wafers, etc., and opaque substrates include various metal (SUS, Al, Ag, ..) foils, Si wafers, and opaque plastics. And the like, wherein the emission direction of the white light is directed toward the transparent substrate. The method according to claim 1 or 2, A flat white light emitting device comprising an organic / inorganic mixed thin film layer, a stainless steel (SUS) can, a glass can, or the like, in order to prevent infiltration of moisture and oxygen in a device in manufacturing a flat white light source. The method according to claim 1 or 2, In the fabrication of organic light emitting device of a planar white light source, in the case of organic / inorganic mixed thin film lamination, stainless steel (SUS) can, glass can, etc. used for the purpose of preventing the penetration of moisture and oxygen in the device, the light efficiency and moisture of the transmitted white light / Planar white light emitting device, characterized in that the excitation coating layer is formed on the inside (lower layer) or outside of the organic / inorganic mixed thin film lamination or stainless steel (SUS) can, glass can, etc. to increase the inhibition of oxygen penetration.