KR101935892B1 - Phosphorescent light-emitting structure and method of preparing the same - Google Patents

Abstract

A substrate, an organic crystal thin film, an insulating layer disposed on the organic crystal thin film, and a phosphorescent light emitting structure in which a plasmonic metal nanostructure is disposed on the insulating layer and a method for manufacturing the same are disclosed.

Description

A phosphorescent light-emitting structure and a method of preparing the same

A phosphorescent light emitting structure and a manufacturing method thereof.

Organophosphorescent materials are used in a variety of fields such as displays, lighting, or sensors, medical devices, and the like. As organic phosphorescent materials, metal-dependent organic phosphorescent materials have been mainly used.

      However, since such a metal-dependent organic phosphorescent material contains a metal such as a noble metal, it is expensive to manufacture and can not easily obtain various colors and optical characteristics including high-energy blue organic phosphorescence.

      Recently, attention has been paid to optically efficient organophosphorous crystals while reducing costs. Further, there is a need for a novel phosphorescent light emitting structure capable of improving the luminous efficiency of the organophosphorous crystal and a method for producing the same.

One aspect of the present invention is to provide a novel phosphorescent light-emitting structure having improved luminous efficiency by using surface plasmon resonance (SPR) phenomenon.

Another aspect is to provide a method of manufacturing the phosphorescent light emitting structure.

According to one aspect,

Board;

Organic crystalline thin films;

An insulating layer disposed on the organic thin film; And

There is provided a phosphorescent light emitting structure in which a plasmonic metal nanostructure is disposed on the insulating layer.

According to another aspect,

Applying and annealing a solution for forming an organic crystal on a substrate to grow an organic crystal and form a thin film;

Forming a polymer electrolyte insulating layer on the organic thin film; And

And introducing the plasmonic metal nanostructure onto the polymer electrolyte insulating layer to produce a phosphorescent light emitting structure.

According to one aspect of the present invention, there is provided a phosphorescent light emitting structure including a substrate, an organic crystal thin film, an insulating layer disposed on the organic crystal thin film, and a plasmonic metal nano structure disposed on the insulating layer to form a surface plasmon resonance (SPR) The light emitting efficiency can be improved.

1 is a schematic diagram of a phosphorescent light emitting structure according to one embodiment.
2 is a schematic view showing the mechanism of the phosphorescent light emitting structure according to one embodiment.
3 is a schematic view of a method of manufacturing a phosphorescent light emitting structure according to an embodiment.
4A shows a Br6A (phosphorescence) compound and a Br6 (host matrix) compound structure included in the organic thin film according to one embodiment; Figure 4b shows the phosphorescence emission by the formation of a halogen bond between the oxygen of the aldehyde group of Br6A (phosphorescence element) and the bromine atom of Br6 (host matrix); FIG. 4C shows XRD (X-ray diffraction) analysis results of the Br6A / Br6 mixed crystal composing the organic thin film according to one embodiment, and XRD analysis results of each of the simulated Br6A and Br6.
FIG. 5A is an AFM (atomic-force microscopy) morphology and a cross-sectional analysis result of the phosphorescent organic crystal structure according to Comparative Example 1; FIG. FIG. 5B is a result of AFM morphology and cross-sectional analysis of the phosphorescent light emitting structure according to Example 1; FIG. FIG. 5C is a cross-sectional analysis result of the AFM morphology of the phosphorescent light emitting structure according to Comparative Example 5. FIG.
6A to 6C are SEM images of the phosphorescent light emitting structure according to Example 2, Example 4, and Example 6, respectively.
7A is an ultraviolet / visible light absorption spectrum of the same phosphorescent light emitting structure as the phosphorescent light emitting structure according to Examples 1 to 5 except that a quartz substrate is used in place of the silicon wafer substrate; 7B is an ultraviolet / visible light absorption spectrum of the same phosphorescent light emitting structure as the phosphorescent light emitting structure according to Examples 6 to 10; 7C is an ultraviolet / visible light absorption spectrum of the phosphorescent light-emitting structure same as that of the phosphorescent light-emitting structure according to Examples 11 to 15. FIG.
8A is a photoluminescence (PL) spectrum of the same phosphorescent light emitting structure as the phosphorescent light emitting structure according to Examples 1 to 5 except that a quartz substrate is used in place of the silicon wafer substrate; 8B is a photoluminescence (PL) spectrum of the phosphorescent light emitting structure identical to the phosphorescent light emitting structure according to Example 1 and Comparative Examples 2 to 7; 8C is a photoluminescence (PL) spectrum of the same phosphorescent light emitting structure as the phosphorescent light emitting structure according to Example 6 and Comparative Examples 8 to 13; 8D is a photoluminescence (PL) spectrum of the phosphorescent light emitting structure according to Example 11 and Comparative Examples 14 to 19. FIG.
9 shows time-resolved photoluminescence (TRPL) of the same phosphorescent light emitting structure as the phosphorescent light emitting structure according to Example 1, Comparative Example 1 and Comparative Example 2, except that a quartz substrate was used in place of the silicon wafer substrate. The results of the analysis.

Hereinafter, a phosphorescent light emitting structure and a method of manufacturing the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The following is presented as an example, and the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

In the following drawings, each component is exaggerated, omitted, or schematically shown for convenience and clarity of explanation, and the size of each component does not entirely reflect the actual size. Also, in the description of each element, in the case of being described as being formed on "on," " on "means that it is formed directly or through other elements The standards for "on", including all, are described on the basis of drawings. Also, in the description of each component, the term "upper" or "lower" as used in the description of "upper" or "lower" Quot; upper "or" lower "will be described with reference to the drawings.

The term "comprising" is used herein to indicate that it is possible to add and / or intervene other elements, not to exclude other elements unless specifically stated otherwise.

The term "metal nanostructure" as used herein refers to a metal structure of any shape having a nanoscale diameter or / and a long side length unless otherwise specifically stated. The "metal nanostructure" may have a spherical shape, an elliptical shape, a star shape, or a rod shape, but is not limited thereto.

A general metal-free organic phosphorescent material is limited in its choice, and an intrinsically effective phosphorescence efficiency can not be obtained.

The inventors of the present invention provide a novel phosphorescent light-emitting structure having improved luminous efficiency by using pure organic phosphorus as an efficient organic phosphorescent material.

1 is a schematic view of a phosphorescent light emitting structure 10 according to an embodiment.

As shown in FIG. 1, the phosphorescent light emitting structure 10 according to one aspect includes a substrate 1; An organic crystalline thin film 2; An insulating layer (3) disposed on the organic thin film; And a structure in which the plasmonic metal nanostructure 4 is disposed on the insulating layer 3.

The organic thin film layer 2 may be an organic mixed crystal thin film formed of a halogen bond between oxygen of a carbonyl group connected to the first aromatic ring group and halogen atom connected to the second aromatic ring group.

The organic crystals of the organic crystal thin film 2 are "metal-independent phosphorescence" which is an organic phosphorescent material independent of any metal or any organic metal. The organic crystal of the organic thin film 2 may be an organic mixed crystal formed by a halogen bond between oxygen of a carbonyl group connected to the first aromatic ring group and halogen atom which is a heavy atom connected to the second aromatic ring group. These midrangers have the effect of promoting the generation of triplet energy when intercalated into triplet-allowing chormophores. The organic crystals of the organic crystal thin film (2) can be directly contacted with halogen atoms and chromophores, so that the radical effect can be further enhanced. More specifically, this atomic effect can be further enhanced by non-covalent interactions between a halogen bond, i.e., a terminal portion of a halogen bond that is relatively electron deficient and an electron-rich nucleophilic portion. The nucleophilic moiety may be an oxygen atom of a carbonyl group linked to the first aromatic ring group.

The organic thin film (2) may include a compound represented by the following formula (1) and (2)

[Chemical Formula 1]

In Formula 1,

CY1 may be an aromatic cyclic group of C6 to C30;

R ₁ may be a hydrogen atom or a substituted or unsubstituted C1 to C5 alkyl group;

R ₂ and R ₃ independently of each other may be a hydrogen atom, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 alkoxy group, or a combination thereof;

R ₄ may be a halogen atom.

(2)

In Formula 2,

CY2 may be an aromatic cyclic group of C6 to C30;

R ' ₁ may be a halogen atom;

R ' ₂ and R' ₃ may be, independently of each other, a hydrogen atom, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 alkoxy group, or a combination thereof.

The definitions of the substituent (s) used in the above formulas (1) and (2) are as follows.

Which groups the alkyl group used in Formula 1 and Formula 2, the alkoxy "substituted" is an alkyl group of a halogen atom, halogen-substituted C1-C20 (for example: CCF _3, CHCF _2, CH ₂ F, CCl _3, etc.), a hydroxy group, A nitro group, a cyano group, an amino group, an amidino group, a hydrazine, a hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof or an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, C20 aryl group, a C6-C20 heteroaryl group, a C6-C20 arylalkyl group, or a C6-C20 heteroarylalkyl group substituted with at least one substituent selected from the group consisting of an alkyl group, an alkynyl group, a C3-C20 cycloalkyl group, a C6-C20 aryl group,

The C6 to C30 aromatic ring group may include, for example, a phenyl group or a naphthyl group.

The halogen atom includes fluorine, bromine, chlorine, iodine and the like.

The alkyl group of C1 to C5 (C10) refers to a fully saturated branched or unbranched (or straight chain or linear) hydrocarbon having 1-5 carbon atoms, and specific examples thereof include methyl, ethyl, propyl, isobutyl, sec -Butyl, ter-butyl, or neo-butyl, and at least one hydrogen atom in the alkyl group may be substituted with a substituent as defined in the above-mentioned "substitution".

The C1 to C10 alkoxy group refers to an alkyl group bonded to an oxygen atom, and specific examples thereof include methoxy, ethoxy, propoxy and the like. At least one hydrogen atom of the alkoxy group may be the same as defined in the ≪ / RTI >

Specific examples of the compound represented by Formula 1 include 4-bromo-2,5-diheptylbenzylaldehyde, 2,5-dihexyloxy-4-bromobenzylaldehyde, 4-bromo-2,5- Bis (hexylthio) benzylaldehyde, 5-bromo-2,6-bis (hexyloxy) -1-naphthylaldehyde and 4-bromo- , 2,5-dimethoxy-4-bromobenzylaldehyde, 4-bromo-2,5-diahexylbenzylaldehyde, 2,5-dibutyloxy- Pentyloxy-4-bromobenzylaldehyde, 2,5-diheptyloxy-4-bromobenzylaldehyde, or 2,5-dioctyloxy-4-bromobenzylaldehyde.

Specific examples of the compound represented by Formula 2 include 1,4-dibromo-2,5-diheptylbenzene, 2,5-dihexyloxy-1,4-dibromobenzene, -1,4-phenylene) bis (hexylsulfane), 1,5-di-bromo-2,6-bis (hexyloxy) naphthalene, 1,4-dibromo-2,5-dimethoxybenzene 2,5-dibutyloxy-1,4-dibromobenzene, 2,5-dipentyloxy-1,4-dibromobenzene, 2, 5-diheptyloxy-1,4-dibromobenzene, or 2,5-dioctyloxy-1,4-dibromobenzene.

For example, the compound represented by Formula 1 may be 2,5-dihexyloxy-4-bromobenzylaldehyde. For example, the compound represented by Formula 2 may be 2,5-dihexyloxy-1,4-dibromobenzene. This is shown in FIG. 4A, which will be described later, as a Br6A (phosphorescence) compound and a Br6 (host matrix) compound structure, respectively.

The Br6A (phosphorescence) compound and the Br6 (host matrix) compound exhibit phosphorescence emission by forming a halogen bond between the oxygen atom of the aldehyde group of Br6A (phosphor element) and the bromine atom of Br6 (host matrix) in FIG. Br6A (phosphorescence element) forms a halogen bond in the Br6 (host matrix) and is embedded therein to maintain a regular structure.

The mixed crystals of the Br6A (phosphorescence element) compound and the Br6 (host matrix) compound can be excited at the wavelength of the visible light of about 360 nm. The Br6A (phosphorescence element) compound and Br6 (host matrix), a mixed crystal of a compound may represent a blue green spectrum having the maximum phosphorescence peak emission (λ _max) at a wavelength of visible light of about 520nm.

The organic crystal thin film 2 may be a continuous thin film. This continuous thin film can enhance the surface plasmon resonance (SPR) effect by keeping a predetermined distance between the plasmonic metal nanostructure and the organic thin film 2 constant. The surface plasmon resonance may include energy confinement from the electromagnetic field and nano-scale metal amplified at the resonant frequency to the metal-dielectric interface.

The thickness of the organic crystal thin film 2 may be 50 nm to 150 nm and the thickness of the organic crystal thin film may be less than 1%. The organic crystalline thin film 2 may have a uniform thin film within the thickness range. The organic crystal thin film 2 can maintain a near field within the thickness range to further enhance the surface plasmon resonance (SPR) effect.

The insulating layer 3 may be an organic insulating layer, an inorganic insulating layer, or an organic-inorganic hybrid insulating layer. The inorganic insulating layer may include, for example, silica and the like.

The insulating layer 3 may be, for example, an organic insulating layer.

The insulating layer 3 may be, for example, a polymer electrolyte layer in which a cationic polymer and an anionic polymer are alternately laminated. The polymer electrolyte layer is structurally very stable because it is connected between each layer and the layer by electrostatic interaction, hydrogen bonding, or covalent bonding. Further, the polymer electrolyte layer can realize a multi-layered ultra thin film regardless of the size and shape of the substrate 1. [

The cationic polymer may be at least one selected from poly (allylamine), poly (allylamine hydrochloride), polydiallyl dimethyl ammonium, poly (ethylene imine) and poly (acrylamide-co-diallyl dimethyl ammonium) . The anionic polymer may be selected from the group consisting of poly (4-styrenesulfonate), poly (acrylic acid), poly (acrylamide), poly (vinylphosphonic acid), poly (2- acrylamido- , And poly (vinyl sulfonate). By using various kinds of the cationic polymer and the anionic polymer, the ionic strength of the polymer electrolyte layer can be controlled.

The cationic polymer may be, for example, poly (allylamine hydrochloride). The anionic polymer may be, for example, poly (4-styrenesulfonate).

The weight average molecular weight (Mw) of the cationic polymer and the anionic polymer may be 1,000 to 1,000,000, for example, 3,000 to 500,000, for example, 3,000 to 100,000, 70,000.

The thickness of the insulating layer 3 may be 8 to 12 nanometers (nm). The insulating layer 3 may enhance the surface plasmon resonance effect without causing a quenching phenomenon between the plasmonic metallic nanostructure 4 and the organic crystal thin film 2 within the thickness range, have.

2 is a schematic view showing the mechanism of the phosphorescent light emitting structure 10 according to one embodiment. As shown in FIG. 2, the left spherical particle represents a plasmonic metal nanostructure and the right oval particle represents an organic crystal, and the vertical line between the plasmonic metal nanostructure and the organic crystal represents an insulating layer. Within the thickness range of the insulation layer, the phosphorescent light emitting structure 10 according to one embodiment may have a near-field enhancement (NFE) -induced excitation due to the near-field enhancement effect of the embodiment, the phosphorescence efficiency can be improved by the plasmon effect by near-field enhancement (NFE) -induced radiation. Here, the excitation phenomenon due to the near-field enhancement effect is a phenomenon in which the surface plasmon resonance is induced as a result of the interaction of the metal nanostructure and light, and the amplified field generated on the surface stimulates and excites the adjacent phosphorescent material .

The plasmonic metal nanostructure 4 may be one selected from Ag, Au, Al, Cu, Li, Pd, Pt, and alloys thereof. For example, the plasmonic metal nanostructure 4 may be one selected from Ag, Au, and alloys thereof. The plasmonic metal nanostructure 4 may be a phosphorescent material having absorption and emission wavelengths in the visible light region, It is possible to enhance the phosphorescence efficiency of the phosphor.

The plasmonic metal nanostructure 4 has collective oscillation along the electric field of light incident on the surface free electrons of the metal nanostructure when light hγ is applied thereto Thereby forming a surface plasmon. As a result, a very strong local electric field is formed around the plasmonic metal nanostructure 4. At this time, if the phosphorescent material is located near the plasmonic metal nanostructure 4, excitation enhancement due to an increase in light absorption is possible by an electric field formed locally strong around the plasmonic metal nanostructure 4 And the luminous efficiency of the phosphorescent material can be improved. Further, the mutual attracting force between the excited phosphorescent material and the plasmonic metal nanostructures 4 formed with the surface plasmon can lead to emission enhancement that increases the quantum yield inherent in the phosphorescent material.

The average particle size (D50) of the plasmonic metal nanostructure 4 may be 5 to 100 nanometers (nm). For example, the average particle size (D50) of the plasmonic metal nanostructure 4 may be 7 to 70 nanometers (nm).

The average particle diameter (D50) means an average particle diameter (D50) when the plasmonic metal nanostructure (4) is assumed to be spherical.

The average particle size means a particle diameter corresponding to 50% of the smallest particle when the total number of particles is taken as 100% in a distribution curve accumulated from the smallest particle size to the largest particle size. D50 can be measured by methods well known to those skilled in the art and can be measured, for example, with a particle size analyzer or from TEM (transmission electron microscopy) or SEM photographs. As another method, for example, measurement is performed using a dynamic light-scattering measurement apparatus, data analysis is performed, and the number of particles is counted for each size range. From this, the average particle diameter Can easily be obtained.

The density of the plasmonic metal nanostructure 4 on the insulating layer 3 may be 5 to 2000 cells / mm ² . For example, the density of the plasmonic metal nanostructure 4 on the insulating layer 3 may be 10 to 2000 / mm ² . The plasmonic metal nanostructures 4 are uniformly arranged on the insulating layer 3. As the density of the plasmonic metal nanostructure 4 increases, the light absorption / scattering wavelength of the phosphorescent light emitting structure 10 moves to the longer wavelength region. If the plasmonic metal nanostructure 4 has the above density range on the insulating layer 3, the phosphorescent efficiency of the phosphorescent light emitting structure 10 including the same can be improved.

The absorption wavelength of the plasmonic metal nanostructure 4 may overlap with the emission wavelength of the organic thin film 2.

The substrate may include a silicon wafer substrate, a glass substrate, or a quartz substrate, but is not limited thereto, and it is possible to use all substrates available in the art. The thickness of the substrate can also be used within the range of thicknesses used in the art.

3 is a schematic view of a method of manufacturing a phosphorescent light emitting structure according to an embodiment.

As shown in FIG. 3, a method of manufacturing a phosphorescent light emitting structure according to another aspect includes: applying a solution for forming an organic crystal on a substrate and annealing the organic solution to grow organic crystals and forming a thin film; Forming a polymer electrolyte insulating layer on the organic thin film; And introducing a plasmonic metal nanostructure on the polymer electrolyte insulating layer to produce a phosphorescent light emitting structure.

First, the substrate 11 is prepared. The substrate 11 may include a silicon wafer substrate, a glass substrate, or a quartz substrate. But any substrate available in the art can be used without being limited thereto. For example, the substrate 11 may be a silicon wafer substrate having a predetermined thickness.

A solution 12 for forming an organic crystal is prepared. The solution for forming an organic crystal (12) may include a compound represented by the following formula (1) and (2)

[Chemical Formula 1]

In Formula 1,

CY1 may be an aromatic cyclic group of C6 to C30;

R ₁ may be a hydrogen atom or a substituted or unsubstituted C1 to C5 alkyl group;

R ₂ and R ₃ independently of each other may be a hydrogen atom, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 alkoxy group, or a combination thereof;

R ₄ may be a halogen atom.

(2)

In Formula 2,

CY2 may be an aromatic cyclic group of C6 to C30;

R ' ₁ may be a halogen atom;

R ' ₂ and R' ₃ may be, independently of each other, a hydrogen atom, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 alkoxy group, or a combination thereof.

The definition of the substituent (s) used in the above-mentioned formulas (1) and (2) and the kind of these specific compounds are the same as those described above, and the description thereof will be omitted.

The solution 12 for forming an organic crystal is applied on the substrate 11. (Step I) The coating method may be spin coating, spray coating, drop coating, dip coating, or deposition. The deposition method may include physical vapor deposition or chemical vapor deposition. For example, the organic solution 12 for forming an organic crystal can be spin-coated on the substrate 11 at a predetermined speed of several hundred nanometers.

Next, the organic crystal film 12 'coated with the solution 12 for forming an organic crystal is annealed on the substrate 11. (Step II) The annealing process may be performed at 70 ° C. in an air atmosphere have. It is possible to form a uniform and continuous thin film having a predetermined thickness by growing organic crystals without adjusting the concentration and / or the dropping rate of the solution 12 for forming an organic crystal under the annealing treatment atmosphere and temperature. Accordingly, the surface plasmon resonance (SPR) effect can be improved and the luminous efficiency of the phosphorescent light emitting structure including the same can be improved.

Next, a polymer electrolyte insulating layer 13 is formed on the organic thin film 12 ''. (Step III) In the step of forming the polymer electrolyte insulating layer 13, the organic thin film 12 '' The polymer electrolyte insulating layer 13 can be formed by a layer-by-layer assembly method. For example, the step of forming the polymer electrolyte insulating layer 13 may be performed by using an immersion-based layer-by-layer self-assembly procedure on the organic thin film 12 ' The electrolyte insulating layer 13 can be formed.

The polymer electrolyte insulating layer 13 can alternately laminate the cationic polymer and the anionic polymer.

The cationic polymer may be at least one selected from poly (allylamine), poly (allylamine hydrochloride), polydiallyl dimethyl ammonium, poly (ethylene imine) and poly (acrylamide-co-diallyl dimethyl ammonium) . The anionic polymer may be selected from the group consisting of poly (4-styrenesulfonate), poly (acrylic acid), poly (acrylamide), poly (vinylphosphonic acid), poly (2- acrylamido- , And poly (vinyl sulfonate).

The cationic polymer may be, for example, poly (allylamine hydrochloride). The anionic polymer may be, for example, poly (4-styrenesulfonate).

The weight average molecular weight (Mw) of the cationic polymer and the anionic polymer may be 1,000 to 1,000,000, for example, 3,000 to 500,000, for example, 3,000 to 100,000, 70,000.

As the cationic polymer, poly (allylamine hydrochloride) and poly (4-styrenesulfonate) as the anionic polymer can be assembled into one double layer, and there is no limitation in the assembling order. For example, poly (4-styrenesulfonate) as the anionic polymer at the bottom and poly (allylamine hydrochloride) as the cationic polymer at the top can be disposed.

The thickness of the polymer electrolyte insulating layer 13 may be 8 to 12 nanometers (nm).

The polymer electrolyte insulating layer 3 improves the surface plasmon resonance effect without causing a quenching phenomenon between the plasmonic metallic nanostructure 4 and the organic crystal thin film 2 within the thickness range, .

Next, a plasmonic metal nanostructure 14 is introduced onto the polymer electrolyte insulating layer 13 to prepare a phosphorescent light emitting structure. (Step IV)

The plasmonic metal nanostructures 14 may be introduced as a layer arranged in a line. The step of introducing the plasmonic metal nanostructure 14 can be adsorbed onto the polymer electrolyte insulating layer 13 by electrostatic interaction. For example, the substrate on which the polymer electrolyte insulating layer 13 is formed is immersed in a suspension having citric acid anion on its surface for about 15 minutes to 120 minutes to form a poly (allylamine Hydrochloric acid) can be adsorbed on the polymer electrolyte insulating layer 13 on which the polymer electrolyte membrane 13 is disposed.

Hereinafter, examples and comparative examples of the present invention will be described. However, the following examples are only illustrative of the present invention, and the present invention is not limited to the following examples.

[Example]

All reagents used in Preparative Example 1 below were purchased from Sigma-Aldrich without further purification. NMR spectra were obtained using a Varian Inova (500) with a deuterated solvent from Cambridge Isotope Labs, Inc.

Manufacturing example  One: Br6  And Br6A  synthesis

Dihydroxy-1,4-dibromobenzene and Br6A (2,5-dihexyloxy-4-bromobenzylaldehyde) organic crystals from 2,5-dihydroxy 1,4-dibenzene using the following reaction scheme 1 And purified by column chromatography with an eluent of ethylene acetate: hexane (1:30), followed by recrystallization from methanol and acetonitrile.

   <Reaction scheme 1>

For Br6A, &lt; 1 &gt; H NMR (500 MHz, d6-DMSO); (t, 2H), 1.73 (m 4H), 1.42 (m 4H), 1.30 (m 8H), 0.87 (s 1H) (m 6H).

Manufacturing example  2: Au nanoparticles ( Average particle diameter (D50)): 55 nm) containing suspension

A solution of 198 mL of deionized water and 2 mL of 1 wt.% Of gold (III) chloride (HAuCl ₄ .3H ₂ O, 99.999%) was heated at 130 ° C with vigorous stirring. Then 1.4 ml of a 1% by weight aqueous solution of sodium citrate (99%) (~ 10 mg / ml) was quickly added to the mixture and the aqueous sodium citrate (99%) solution was boiled under continuous stirring for 30 minutes to give a pale pink And Au nanoparticles (average particle diameter (D50)) having a surface of citric acid anion attached thereto: 55 nm) were obtained.

Manufacturing example  3: Ag  Nanoparticles ( Average particle diameter (D50)): 7 nm) containing suspension

3 mg of NaBH ₄ (99%) and 12 mg of sodium citrate were dissolved in 148 ml of deionized water and heated at 60 캜 in a dark room for 30 minutes with vigorous stirring. Then, 2 mL of 23.5 mM silver nitrate (AgNO ₃ ,> 99.8%) solution was added dropwise to the mixture, and the temperature was raised to 90 ° C. The pH of the solution was adjusted to 10.5 with 0.1 M sodium hydroxide and heating was continued for 20 minutes until the color of the solution changed to yellow. Thereafter, Ag nanoparticles (average particle diameter (D50)) having a citric acid anion attached to the surface of the yellow color: 7 nm) were obtained.

Manufacturing example  4: Ag  Nanoparticles ( Average particle diameter (D50)): 70 nm) containing suspension

Silver nitrate (AgNO ₃ , > 99.8%) was dissolved in 150 mL of deionized water and the silver nitrate aqueous solution was heated until boiling. Then, 3 mL of a 1 wt% aqueous solution of sodium citrate was added to the boiled solution and boiled for 1 hour. Thereafter, a suspension containing Ag nanoparticles (average particle diameter (D50)): 70 nm with citric acid anion attached to the surface of the yellow color was obtained.

Example  1: Preparation of phosphorescent light emitting structure

On the silicon wafer substrate, a solution for forming organic crystals, in which 1 wt% of Br6A / Br6 (1: 1 equiv.) Mixed organic crystals dissolved in hexane solvent was added at a concentration of 5 mg / mL, was spin- (Step I)

A silicon wafer substrate coated with a solution for forming Br6A / Br6 (1: 1 equiv.) Organic crystals was placed on a hot plate and annealed at 70 DEG C in an air atmosphere to obtain Br6A / Br6 (1: 1 equiv.) Mixed organic crystals And a thin film having a thickness of about 90 nm was formed. (Step II)

The thin film of Br6A / Br6 (1: 1 equiv.) Mixed organic crystals was dissolved in a solution of 0.5 (70,000 g / mol) of poly (4-styrene sulfonate) (PSS) having a negative charge (Mw: 70,000 g / mol) dissolved in 3.3 mM sodium chloride (4-styrenesulfonate) before use was repeated by repeating the steps of immersing and washing in a 0.5 mg / mL solution of poly (allylamine hydrochloride) (PAH) (Mw: 17,500 g / mol) (PSS) solution and poly (allylamine hydrochloride) (PAH) solution were adjusted to 0.5 mg / mL.

Then, the polymer electrolyte of the PSS / PAH double layer was immersed on the Br6A / Br6 (1: 1 equiv.) Mixed organic crystal thin film using an immersion-based layer-by-layer self-assembly procedure A polyelectrolyte insulating layer having a thickness of about 9.6 nm was formed by alternately stacking poly (4-styrenesulfonate) (PSS) having negative charge and poly (allylamine hydrochloride) (PAH) having positive charge. Step III)

The thickness of the polymer electrolyte layer of the PSS / PAH double layer was calculated using Winspall software (RES-TEC, Germany) using a complex refractive index of 1.45 and a dielectric constant of 2.0125. This is presumed to have the same value as the optical constant value of the PSS and the PAH.

The substrate on which the polymer electrolyte insulating layer was formed was immersed in a suspension containing Au nanoparticles (average particle diameter (D50)) of 55 nm prepared in Preparation Example 2 for about 15 minutes. Au nanoparticles having citric acid anion attached to the surface are adsorbed on poly (allylamine hydrochloride) (PAH) having positive charge of the polymer electrolyte insulating layer to form plasmonic Au nanoparticles (average particle diameter (D50)): 55 nm) was disposed on the light-emitting layer. (Step IV)

A method of manufacturing the phosphorescent light emitting structure is schematically illustrated in FIG.

Example  2 to 5: Preparation of phosphorescent light emitting structure

The substrate having the polymer electrolyte insulating layer formed thereon was immersed in a suspension containing Au nanoparticles (average particle diameter (D50)) prepared in Production Example 2 in the step IV above for about 15 minutes, followed by drying for about 45 minutes, 90 minutes, and 120 minutes, respectively, to prepare a phosphorescent light-emitting structure.

Example  6: Preparation of phosphorescent light emitting structure

(Average particle diameter (D50)) of 7 nm prepared in Production Example 3 was used instead of the suspension containing Au nanoparticles (average particle diameter (D50)) (55 nm) prepared in Production Example 2 in the step IV) (The average particle diameter (D50)): 7 nm) was disposed on the substrate having the polymer electrolyte insulating layer formed thereon by immersing the substrate in the suspension for about 15 minutes to prepare a phosphorescent light-emitting structure having the same structure as in Example 1 To prepare a phosphorescent light-emitting structure.

Example  7 to 10: Preparation of phosphorescent light emitting structure

The substrate having the polymer electrolyte insulating layer formed on the Ag nanoparticle-containing suspension having the citric acid anion attached to the surface in the step IV was immersed for about 45 minutes, 60 minutes, 90 minutes, and 120 minutes, respectively, instead of immersing the substrate for about 15 minutes , A phosphorescent light-emitting structure was prepared in the same manner as in Example 6.

Example  11: Preparation of phosphorescent light emitting structure

(Average particle diameter (D50)): 70 nm) prepared in Production Example 4 was used instead of the suspension containing Au nanoparticles (average particle diameter (D50)) (55 nm) (The average particle diameter (D50)): 70 nm) was disposed on the substrate having the polymer electrolyte insulating layer formed thereon for about 15 minutes to prepare a phosphorescent light-emitting structure having the same structure as that of Example 1 To prepare a phosphorescent light-emitting structure.

Examples 12 to 15: Preparation of phosphorescent light emitting structure

The substrate having the polymer electrolyte insulating layer formed on the Ag nanoparticle-containing suspension having the citric acid anion attached to the surface in the step IV was immersed for about 45 minutes, 60 minutes, 90 minutes, and 120 minutes, respectively, instead of immersing the substrate for about 15 minutes , A phosphorescent light-emitting structure was prepared in the same manner as in Example 11.

Comparative Example  1: Preparation of phosphorescent organic crystal structure

On the silicon wafer substrate, a solution for forming organic crystals, in which 1 wt% of Br6A / Br6 (1: 1 equiv.) Mixed organic crystals dissolved in hexane solvent was added at a concentration of 5 mg / mL, was spin- And then dried at room temperature to prepare an uneven phosphorescent organic crystal structure having a thickness of about 60 nm to 120 nm.

Comparative Example  2 to 7: Preparation of phosphorescent light emitting structure

In step III, the PSS / PAH bilayer polymer electrolyte was immersed on the Br6A / Br6 (1: 1 equiv.) Mixed organic crystal thin film using an immersion-based layer-by-layer self-assembly procedure (4-styrene sulfonate) (PSS) having negative charge and poly (allylamine hydrochloride) (PAH) having positive charge were alternately laminated in six layers instead of one layer, two layers, four layers, eight layers, Except that a polyelectrolyte insulating layer having a thickness of about 1.6 nm, a thickness of about 3.2 nm, a thickness of about 6.4 nm, a thickness of about 12.8 nm, a thickness of about 16.0 nm, and a thickness of about 19.2 nm, , A phosphorescent light-emitting structure was prepared in the same manner as in Example 1.

Comparative Example  8 to 13: Preparation of phosphorescent light emitting structure

In step III, the PSS / PAH bilayer polymer electrolyte was immersed on the Br6A / Br6 (1: 1 equiv.) Mixed organic crystal thin film using an immersion-based layer-by-layer self-assembly procedure (4-styrene sulfonate) (PSS) having negative charge and poly (allylamine hydrochloride) (PAH) having positive charge were alternately laminated in six layers instead of one layer, two layers, four layers, eight layers, Except that a polyelectrolyte insulating layer having a thickness of about 1.6 nm, a thickness of about 3.2 nm, a thickness of about 6.4 nm, a thickness of about 12.8 nm, a thickness of about 16.0 nm, and a thickness of about 19.2 nm, , A phosphorescent light-emitting structure was prepared in the same manner as in Example 6.

Comparative Example  14 to 19: Preparation of phosphorescent light emitting structure

In step III, the PSS / PAH bilayer polymer electrolyte was immersed on the Br6A / Br6 (1: 1 equiv.) Mixed organic crystal thin film using an immersion-based layer-by-layer self-assembly procedure (4-styrene sulfonate) (PSS) having negative charge and poly (allylamine hydrochloride) (PAH) having positive charge were alternately laminated in six layers instead of one layer, two layers, four layers, eight layers, Except that a polyelectrolyte insulating layer having a thickness of about 1.6 nm, a thickness of about 3.2 nm, a thickness of about 6.4 nm, a thickness of about 12.8 nm, a thickness of about 16.0 nm, and a thickness of about 19.2 nm, , A phosphorescent light-emitting structure was prepared in the same manner as in Example 11.

Analysis example  One: XRD  analysis

XRD analysis experiments were performed on the Br6A / Br6 (1: 1 equiv.) Mixed organic crystals used in Example 1 and the Br6 and Br6A organic crystals synthesized by Preparation Example 1. [ The results are shown in Fig. 4C.

The analysis of Br6 and Br6A organic crystals synthesized in Preparation Example 1 was simulated using FeliX32 software. The Br6A / Br6 (1: 1 equiv.) Mixed organic crystals used in Example 1 were tested using a Rigaku RINT2200HF + diffractometer using CuKradiation (1.540598A).

 Referring to FIG. 4C, the Br6A / Br6 (1: 1 equiv.) Mixed organic crystals used in Example 1 contained both the Br6A organic crystals and the peaks that appeared in the Br6A organic crystals between diffraction angles 2? And it can be confirmed that it is maintained regularly.

Analysis example  2: AFM (Atomic-force microscopy) analysis

AFM analysis experiments were carried out on the phosphorescent organic crystal structure of Comparative Example 1, the phosphorescent light emitting structure of Example 1, and the phosphorescent light emitting structure of Comparative Example 3. The results of the morphology and the cross-sectional analysis thereof according to the results of the AFM analysis are shown in FIGS. 5A and 5B.

Experiments were performed using AFM (Digital Instrument, Dimension 3100).

5A and 5B, the phosphorescent light emitting structure according to Example 1 is formed with a uniform organic crystal thin film having a thickness of about 90 nm and a thickness variation of less than 1%. In comparison, the phosphorescent organic crystal structure according to Comparative Example 1 has a non-uniform organic crystal film with a thickness of about 60 nm to 120 nm.

Referring to FIG. 5C, the phosphorescent light emitting structure according to Comparative Example 5 is formed with an organic crystal thin film having a thickness of about 12.2 nm.

Analysis example  3: SEM  analysis

SEM analysis experiments were conducted on the phosphorescent light emitting structures according to Examples 2, 4, and 6. JSM-7600F (10.0kV, x10,000) manufactured by JEOL Co. was used as the SEM analyzer. The results are shown in Figs. 6A to 6C.

6A to 6C, the phosphorescent light emitting structures according to Example 2, Example 4, and Example 6 were 13 / mm ² , 45 / mm ² , and 70 / mm ² , respectively. From this, it can be confirmed that the density of the Au nanoparticles disposed on the polymer electrolyte insulating layer is increased as the time for immersing the substrate on which the polymer electrolyte insulating layer is formed in the suspension containing the anion of citrate anion on the surface is increased .

Analysis example  4: Ultraviolet / visible light absorption spectrum analysis

Ultraviolet / visible light absorption spectrum analysis experiments were carried out on the phosphorescent light emitting structures according to Examples 1 to 15. The results are shown in Figs. 7A to 7C.

Ultraviolet / visible light absorption spectrum analysis was carried out using Agilent Inc., Cary 5000.

      7A shows a phosphorescent light emitting structure (plasmonic Au nanoparticles (average particle diameter (D50)): 55 nm) which is the same as the phosphorescent light emitting structure according to Examples 1 to 5 showed an absorbance peak at a wavelength of about 540 nm, (Plasmonic Ag nanoparticles (average particle diameter (D50)): 7 nm), which is the same as the phosphorescent light emitting structure according to Examples 6 to 10, exhibited an absorbance peak at a wavelength of about 394 nm, and FIG. The phosphorescent light emitting structure (plasmonic Ag nanoparticles (average particle diameter (D50)): 70 nm) identical to the phosphorescent light emitting structure according to Examples 11 to 15 exhibited an absorbance peak at a wavelength of about 422 nm.

Analysis example  5: Photoluminescence (Photoluminescence; PL ) Spectrum

      Phosphorescent light emitting structure similar to the phosphorescent light emitting structure according to Examples 1 to 5 and Comparative Examples 2 to 7 except that a quartz substrate was used in place of the silicon wafer substrate, the phosphorescent light emitting structure according to Example 6, and Comparative Examples 8 to A photoluminescence (PL) spectrum analysis experiment of the same phosphorescent light emitting structure as the phosphorescent light emitting structure according to Example 13, and the same phosphorescent light emitting structure as the phosphorescent light emitting structure according to Example 11 and Comparative Examples 14 to 19 was performed.

   Photoluminescence (PL) spectra (@ 298 K) were measured using Photon Technologies International (PTI) and QuantaMaster 400 scanning spectrofluorimeter.

 Referring to FIG. 8A, the same phosphorescent light emitting structure as the phosphorescent light emitting structure according to Examples 1 to 5 exhibits a photo-emission peak at a wavelength of about 520 to 540 nm. Referring to FIGS. 8B to 8D, The phosphorescent light emitting structure identical to the phosphorescent light emitting structure according to Example 6 and Example 11 had the same phosphorescence structure as the phosphorescent light emitting structure according to Comparative Examples 2 to 7, Comparative Examples 8 to 13, and Comparative Examples 14 to 19 It can be confirmed that it has excellent photoluminescence characteristics as compared with the light emitting structure.

Analysis example  6: Time-sharing light emission (Time-Resolved Photoluminescence: TRPL ) analysis

Phosphorescent light emitting structures similar to those of the phosphorescent light emitting structure according to Example 1 and Comparative Example 2 and phosphorescent organic crystal structures similar to those of the phosphorescent organic crystal structure according to Comparative Example 1 were obtained in the same manner as in Example 1 and Comparative Example 2 except that a quartz substrate was used in place of the silicon wafer substrate. Time-resolved photoluminescence (TRPL) analysis was performed. The results are shown in Fig. 9 and Table 1.

The quantum efficiency of photoluminescence was obtained by using PTI and Quanta Master with integrating sphere. The photoluminescence quantum efficiency was calculated using Equation 1 below.

<Formula 1>

(%) = [(Number of photons emitted (color)) / (number of photons absorbed) x 100]

The phosphorescence lifetime (ms) data was collected using PTI LaserStrobe and calculated on FeliX32 with the PTI device.

On the other hand, the Absolute PL quantum efficiency ? _PL is found by the following equation (2).

      <Formula 2>

_Wherein N _emission represents the emission photon number from the sample, N _absorption represents the number of photons absorbed by the sample _{,? Represents the} calibration coefficient for the measurement setup,? Represents the wavelength , h denotes the Planck's constant, c denotes the speed of light, I _em ( λ ) denotes the PL intensity from the sample, I _ex ( λ ) denotes the intensity of the excitation laser, I ' _ex ( ? ) _Represents the intensity of the sample-containing excitation laser.

division Photoluminescence quantum efficiency (%) Life (ms) Example 1 63.4 7.92 Comparative Example 1 52.2 8.13 Comparative Example 2 2.0 6.42

9 and Table 1, the photoluminescence quantum efficiency of the same phosphorescent light emitting structure as that of the phosphorescent light emitting structure according to Example 1 was the same as that of the phosphorescent organic crystal structure according to Comparative Example 1 and the phosphorescence organic crystal structure according to Comparative Example 2 It can be confirmed that it is superior to the same phosphorescent light emitting structure as the light emitting structure. The lifetime characteristics of the same phosphorescent light emitting structure as the phosphorescent light emitting structure according to Example 1 were similar to those of the phosphorescent organic crystal structure similar to the phosphorescent organic crystal structure according to Comparative Example 1 and were similar to those of the phosphorescent light emitting structure according to Comparative Example 2 It can be confirmed that it is superior.

1, 11: Substrate 2, 12 ": Organic crystal thin film
3, 13: Polymer electrolyte insulating layer 4, 14: Plasmonic metal nano structure
10: phosphorescent light-emitting structure 12: solution for organic crystal formation
12 ': Organic crystal film 100: Hot plate

Claims (20)

Board;
Organic crystalline thin films;
An insulating layer disposed on the organic thin film; And
A plasmonic metal nanostructure is disposed on the insulating layer,
Wherein the insulating layer is an organic insulating layer, and the insulating layer has a thickness of 8 to 12 nanometers (nm). The method according to claim 1,
Wherein the organic thin film is an organic mixed crystal thin film formed by a halogen bond between oxygen of a carbonyl group connected to a first aromatic ring group and a halogen atom connected to a second aromatic ring group. The method according to claim 1,
Wherein the organic thin film comprises a compound represented by the following Chemical Formula 1 and Chemical Formula 2:
[Chemical Formula 1]

In Formula 1,
CY1 is an aromatic cyclic group of C6 to C30;
R ₁ is a hydrogen atom or a substituted or unsubstituted C1 to C5 alkyl group;
R ₂ and R ₃ are each independently a hydrogen atom, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 alkoxy group, or a combination thereof;
R ₄ is a halogen atom.
(2)

In Formula 2,
CY2 is an aromatic cyclic group of C6 to C30;
R ' ₁ is a halogen atom;
R ' ₂ and R' ₃ are each independently a hydrogen atom, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 alkoxy group, or a combination thereof. The method according to claim 1,
Wherein the organic thin film is a thin film having a continuous shape. The method according to claim 1,
Wherein the organic crystal thin film has a thickness of 50 nm to 150 nm and the organic crystal thin film has a thickness deviation of less than 1%. delete The method according to claim 1,
Wherein the insulating layer is a polymer electrolyte layer. The method according to claim 1,
Wherein the insulating layer is a polymer electrolyte layer in which a polymer having a positive charge and a polymer having a negative charge are alternately laminated. delete The method according to claim 1,
Wherein the plasmonic metal nanostructure is one selected from Ag, Au, Al, Cu, Li, Pd, Pt, and alloys thereof. The method according to claim 1,
Wherein the average particle size (D50) of the plasmonic metal nanostructure is 5 to 100 nanometers (nm). The method according to claim 1,
And the density of the plasmonic metal nanostructure on the insulating layer is 5 to 2000 cells / mm ² . The method according to claim 1,
Wherein an absorption wavelength of the plasmonic metal nanostructure overlaps an emission wavelength of the organic thin film. The method according to claim 1,
Wherein the substrate comprises a silicon wafer substrate, a glass substrate, or a quartz substrate. Applying and annealing a solution for forming an organic crystal on a substrate to grow an organic crystal and form a thin film;
Forming a polymer electrolyte insulating layer on the organic thin film; And
And introducing a plasmonic metal nanostructure onto the polymer electrolyte insulating layer to prepare a phosphorescent light emitting structure,
Wherein the polyelectrolyte insulation layer has a thickness of 8 to 12 nanometers (nm). 16. The method of claim 15,
Wherein the solution for forming an organic crystal comprises a compound represented by the following Chemical Formula 1 and Chemical Formula 2:
[Chemical Formula 1]

In Formula 1,
CY1 is an aromatic cyclic group of C6 to C30;
R ₁ is a hydrogen atom or a substituted or unsubstituted C1 to C5 alkyl group;
R ₂ and R ₃ are each independently a hydrogen atom, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 alkoxy group, or a combination thereof;
R ₄ is a halogen atom.
(2)

In Formula 2,
CY2 is an aromatic cyclic group of C6 to C30;
R ' ₁ is a halogen atom;
R ' ₂ and R' ₃ are each independently a hydrogen atom, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 alkoxy group, or a combination thereof. 16. The method of claim 15,
Wherein the coating method is a spin coating method, a spray coating method, a drop coating method, a dip coating method, or a vapor deposition method. 16. The method of claim 15,
Wherein the annealing treatment is performed at 70 캜 in an air atmosphere. 16. The method of claim 15,
Wherein the step of forming the polymer electrolyte insulating layer comprises forming a polymer electrolyte insulating layer on the organic thin film by a layer-by-layer assembly method. 16. The method of claim 15,
Wherein the step of introducing the plasmonic metal nanostructure is adsorbed onto the polymer electrolyte insulating layer by electrostatic interaction.

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