KR20090114886A - Fluorescence Enhancement OLED using Surface Plasmon Resonance - Google Patents

Abstract

PURPOSE: A fluorescence enhancement OLED using surface plasmon resonance is provided to increase optical power efficiency by adding the conductive spacer layer on the surface of metallic thin film. CONSTITUTION: The metal lower part - electrode layer(11) is arranged on the surface of the substrate(10). The metallic thin film lower part layer(12) is arranged on the surface of the metal lower part - electrode layer. The organic EL component layer(13) is arranged on the surface of the metallic thin film lower part layer. The metallic foil upper layer(15) is arranged on the organic EL component layer. The conductive spacer layer(16) is arranged on the surface of the metallic thin film lower part layer. The metal upper part - electrode layer(17) is arranged in the conductive spacer floor.

Description

Fluorescence Enhancement OLED using Surface Plasmon Resonance

The present invention relates to an organic light emitting diode (OLED), and more particularly to an organic light emitting diode having a fluorescence enhancement effect using surface plasmon resonance.

An organic light emitting diode (OLED) is an electronic device that emits light in response to an applied potential. An organic light emitting diode is a device that emits light by reacting to an applied potential and is described in Tang et al., C.W.Tang, S.A.VanSlyke, Applied Physics Letters. 51, 913 (1987) 'and commonly assigned US Pat. No. 4,769,292. Thereafter, an organic EL element layer including a plurality of polymer materials was presented and device performance was improved.

A typical OLED device 100 comprises a substrate 10, a reflective under-electrode layer 11, organic EL elements 13, 14 and a transparent top-electrode layer 17, as shown in FIG. (13, 14) includes one or more sublayers including a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer and an electron injection layer. Here, the reflective bottom-electrode is the anode and the transparent top-electrode layer is the cathode. It is also possible for the anode and cathode to be interchangeable, and the fluorescence emitted from inside the device is passed through both the substrate and the transparent top-electrode and output.

One important feature of OLED devices is their luminance output efficacy. This parameter determines how much current or voltage is needed to induce delivery of the desired light output. OLED devices have a long life inversely with the operating current, so the higher the luminance output efficiency at the same light output, the longer it can be used, and much research is being conducted to improve the luminance efficiency and color quality of such OLED devices.

It is an object of the present invention to provide a fluorescently enhanced OLED device with improved brightness efficiency and color quality.

Another object of the present invention is to provide a fluorescently enhanced OLED device with a simple and easy process.

It is another object of the present invention to provide a fluorescently enhanced OLED device capable of top emission in order to prevent a decrease in luminance output efficacy due to TFT blocking.

According to the present invention for achieving the above object, a fluorescently enhanced OLED device comprises: a substrate; A metal lower electrode layer disposed on a surface of the substrate; A metal thin film underlayer disposed on a surface of the metal under-electrode layer; An organic EL element layer disposed on a surface of the metal thin film underlayer; A metal thin film upper layer disposed on the organic EL element layer; A conductive spacer layer disposed on a surface of the metal thin film upper layer; And a metal top-electrode layer disposed on the conductive spacer layer.

Here, at least one of the metal lower electrode layer and the metal upper electrode layer is opaque and reflective, and the material of the opaque and reflective electrode layer is selected from at least one of Ag, Au, Al, and the metal thin film upper layer and the lower layer are opaque. And at least one of Ag, Au, and Al, which are reflective, and adjust the material and thickness of the metal thin film upper layer and the lower layer, the position, and the thickness of the organic EL element layer to enhance the light emission output compared to a similar device without fluorescence enhancement. It is preferable to be.

Further, it is preferable that one of the metal lower electrode layer and the metal upper electrode layer is opaque and reflective, the other is transparent, and the material of the transparent electrode layer is selected from ITO.

In addition, it is preferable that the metal lower electrode layer is ITO, the metal upper electrode layer is Ag, and the thickness thereof is 10 to 100 nm.

In addition, both the metal thin film upper layer and the metal thin film lower layer may be Ag, Au, or Al, and the thickness of the thin film may be 2 to 30 nm.

Further, the metal thin film underlayer between the metal under-electrode layer and the organic EL element layer can be removed.

The metal lower electrode layer may be an anode, and the metal upper electrode layer may be a cathode.

Alternatively, the metal lower electrode layer may be a cathode, and the metal upper electrode layer may be an anode.

Preferably, the conductive spacer layer disposed between the upper metal thin film upper layer and the metal upper-electrode layer is made of an organic material and may have a thickness of 5 to 50 nm.

In another aspect of the present invention, a metal thin film layer deposited on the top surface of the device metal lower electrode layer is used to further improve the performance of the fluorescence enhanced OLED device.

The fluorescently enhanced OLED device according to the invention is basically designed for bottom emission but can be used as the top emission device in some cases. The opaque reflective electrode layer disposed on the top of the spacer is selected and used as Ag, Au, Al. When the metal deposition thickness is 20 nm or less, it is translucent and the fluorescence enhanced by the surface plasmon resonance is also transmitted to the top. You can output

According to the OLED device fabrication structure according to the present invention, a metal thin film electrode disposed on one surface of a metal lower electrode layer disposed on one surface of the substrate is deposited, and a metal thin film top disposed on an organic EL element and the metal thin film By adding a conductive spacer layer disposed on the upper one surface, fluorescence generated near the bottom of the surface of the upper portion of the metal thin film is transferred to the metal thin film-transparent conductive spacer-metal upper electrode structure, and the fluorescence is interposed between the spacers in the near region. By interacting with the metal upper electrode, which maintains a certain distance, it is possible to manufacture a fluorescent-enhanced OLED which increases the light output efficiency while the reinforcing action occurs.

In addition, the OLED device using the above-described fluorescence enhancement phenomenon uses electron vibration due to the generation of surface plasmon occurring at the boundary between the organic EL element layer and the metal thin film. The frequency is determined, and the optical efficiency due to the surface plasmon is increased and the frequency width is narrow at the fluorescence enhancement frequency, thereby making it possible to manufacture OLED devices with improved color quality.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings and the contents described in the accompanying drawings. However, the present invention is not limited or limited by the following examples.

A method for improving the luminance output efficacy of OLED devices is to use Fluorescence enhancement through surface plasmons of metal thin films. The phenomenon in which fluorescence generated at a close distance from the surface of a metal thin film is enhanced by surface plasmons has been described in the prior art 'Science. 302, 77 (2003), 'Physical Review Letters. 96, 113002 (2006) '.

Nazin et al. (Science. 302, 77 (2003)) have introduced light through a scanning tunneling microscope into a metal-molecule-metal linkage in the near field and incident light. Through the experiment to induce light emission after the molecules on the metal substrate transition to the excited state. This experiment identifies trends between molecular luminescence through incident light and surface plasmon transfer light that occurs between the molecular-metal linkages.

Anger et al. (Physical Review Letters. 96, 113002 (2006)) confirmed the phenomenon that fluorescence was enhanced by surface plasmons after applying an organic polymer on the surface of a metal substrate. When the laser is incident on the lower surface of the metal substrate, the distance between the substrate and the metal particles is controlled in the range of tens of nanometers, and the interaction between the light incident in the near field and the plasmon radioactive / non-radioactive transition is identified. According to the size of the particles, the fluorescence enhancement phenomenon occurs more than five times theoretically confirmed that the experimental agreement.

These documents have revealed that the metal-molecule-metal junction form induces the interaction between surface plasmon and luminescent light in the region near the sub-wavelength range, and thus enhances the fluorescence emission phenomenon. There is no attempt to check.

K.Okamoto et al. (Nature. 3,601 (2004)) disclose photoluminescence (LUM) by combining light emitted from quantum wells of InGaN light emitting elements (InGaN LEDs) with plasmons on the surface of metal electrodes. Photoluminescence was enhanced by 14 times at the highest point. Select a metal whose surface plasmon frequency between the bandgap of the quantum well and the electrode-spacer is close to each other and emit light because energy transfer by recombination of electrons and hole pairs in the quantum well affects the vibration of electrons caused by the electrode metal surface plasmon The frequency and luminescence intensity were found to increase. However, in this study, the energy due to the recombination of electrons and holes in the quantum well is transferred to the electrode surface plasmon to increase the luminescence intensity, whereas in the present invention, the fluorescence emitted from the lower surface of the metal thin film between the organic layers forms plasmon on the electrode surface. The difference is that the metal electrode increases the light emission intensity by interacting in the near region with the transparent conductive spacer therebetween. The structure is similar because each of InGaN and a metal thin film is inserted among the devices, but Okamoto et al. Used it as a quantum well emitter, and it is not an organic light emitting device unlike the present invention.

2 shows an embodiment of a fluorescently enhanced OLED device according to the present invention, illustrating an example of a structure of a fluorescently enhanced OLED device without a bottom metal thin film.

Referring to the drawings, the fluorescence-enhanced OLED device structure according to the present invention is the substrate 10, the metal lower-electrode 11, the organic EL element layers 13, 14 and the metal upper-electrode layer, like the conventional OLED device structure. (17), and the organic EL element layers 13 and 14 include one or more sublayers of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. In this case, the fluorescence-enhanced OLED device structure according to the present invention enhances fluorescence emitting around the surface by depositing a metal thin film (metal thin film upper layer) 15 on the surface of the organic EL element layers 13 and 14. The conductive transparent electrode spacer layer 16 is disposed on the metal thin film upper layer 15. Conductive spacer layer 16 is composed of an organic material, the thickness may be implemented from 5 to 50nm.

Figure 3 shows another embodiment of the fluorescently enhanced OLED device according to the present invention, by depositing a metal thin film layer 12 on the top surface of the metal bottom-electrode 11 of Figure 2 to the microcavity (Micro Cavity) effect Fluorescence generated inside the device is efficiently emitted through the glass substrate.

Both the metal lower electrode layer 11 and the metal upper electrode layer 17 may be made of an opaque and reflective material made of Ag, Au, Al, or an alloy of two or more thereof. Alternatively, one of the metal lower electrode layer 11 and the metal upper electrode layer 17 may be made of an opaque and reflective material, and the other may be made of a transparent material such as indium tin oxide (ITO). For example, the metal lower electrode layer 11 may be formed of ITO, and the metal upper electrode layer 17 may be formed of Ag having a thickness of 10 to 100 nm. In addition, the metal lower electrode layer 11 may be an anode, and the metal upper electrode layer 17 may be implemented as a cathode, or vice versa.

In addition, the metal thin film lower layer 12 and the metal thin film upper layer 15 may be implemented with at least one of opaque and reflective Ag, Au, Al, and the material, thickness, position and organic EL element layers 13, 14. The thickness of is adjusted to enhance the luminescence output compared to similar devices without fluorescence enhancement (see FIG. 1). Here, the thickness of the metal thin film lower layer 12 or the metal thin film upper layer 15 is preferably implemented in 2 to 30nm.

1 to 3, the substrate 10 is made of glass, and the reflective metal upper-electrode layer 17 is assumed to be made of a cathode of Ag having a thickness of 15 nm. In addition, it is assumed that the organic EL element layers 13 and 14 include an NPB hole transport layer and a light emitting layer. In addition, it is assumed that the fluorescent light source emitting light inside the device has an output independent of the electrical characteristics of the entire OLED. It is also assumed that the transparent conductive spacer layer is 10 nm thick. This assumption facilitates the evaluation of the fluorescence-enhancing structure itself properties of the metal-molecule-metal linkage independent of the specific properties of the emitter so that the conclusion can be applied to any emitter as a whole.

The position of the light emitting source due to the OLED device electrical properties is an important factor for the performance of the overall device. In the present invention, the energy level according to the OLED planar multilayer device internal constituent material causes a difference in energy levels between the EL element layer, the upper metal thin film and the transparent conductive spacer layer, and induced electron-hole recombination to occur at the upper metal thin film boundary. The fluorescence-enhanced OLED of surface plasmon thus assumes that the dipole light source is located at the top surface of the organic EL element layer and the metal thin film boundary.

In the present invention, to confirm the fluorescence emission enhancement through the surface plasmon and to establish the device structure, the simulation was performed using the Finite Difference Time Domain (FDTD) method, and as a basis for comparing the performance of the device, the normal emitted power, total emitted power, Far Field is set, and Equation 1, Equation 2 and Equation 3 are used to obtain each.

Equation 1

Where

는 이중 쌍극자 광원에서 복사되는 빛의 포인팅 벡터이고,

Is the pointing vector of light radiated from the dipole light source,

는 표면에 직교 성분 벡터이고,

Is a vector of orthogonal components on the surface,

Gaussian filter is a function in which the ratio of input and output values varies according to the angle value in Equation 1, and is described in Equation 3,

는 OLED 디바이스 기판 아래 monitor를 이용해 표면과 직교 방향으로 입사되는 전기장에 의한 값으로 파장의 함수로 주어진다.

Is the value of the wavelength given by the electric field incident in the direction perpendicular to the surface using a monitor underneath the OLED device substrate.

Equation 2

Where

는 2차원 시뮬레이션 영역의 한 지점에 통과하며 감지되는 에너지의 포인 팅 벡터이다.

Is the pointing vector of the energy detected as it passes through a point in the two-dimensional simulation domain.

Equation 3

Where

σ is a value of 50% of the angle that is set as the viewing angle when the normal emittied light is measured by the monitor in front of the OLED element substrate.

Fluorescent light sources used a dual dipole model, and a monitor was measured at each location to measure the energy passing through a specific point in the two-dimensional simulation area, and measured the total emitted power output from all directions through the device. Normal emitted power is the ratio of the energy delivered to the device front constant viewing angle to the total energy output from the light source in the simulation area and used as an important criterion for comparing the performance in the device structure design. It was used as a reference for comparing the angular characteristics of the OLED output light.

The efficacy of the present invention to enhance OLED device output with enhanced fluorescence emission through surface plasmons is illustrated in the examples below. In an embodiment based on theoretical prediction, the emission spectrum by a given device is predicted by interpreting Maxwell's equation that emits dipoles of random orientation in a planar multilayer device, and uses the FDTD method to interpret Maxwell's equation. did. The dipole emission spectrum was assumed as a function of having a Gaussian distribution at a particular frequency. In each layer, the model is measured by spectroscopic ellipsometry or described in 'Handbook of Optical Constants of Solids, EDPalik, Academic Press (1985)', 'Handbook of Optical Constants of Solids II, EDPalik, Academic Press (1991) '] use the wavelength dependent composite refractive index.

Next, two comparative devices: (a) an OLED device without a metal thin film between the organic EL constituent layers (see FIG. 1), and (b) an OLED device with a metal thin film for fluorescence enhancement through surface plasmons By comparing (see FIG. 2), the theoretically predicted luminance output of the bottom-surface plasmon enhanced OLED device as shown in FIG. 3 according to the present invention is compared.

The calculated results are summarized in Table 1. In these results, when the metal thin film is deposited on the upper and lower surfaces of the organic EL element layer, the output is enhanced compared with the OLED device 100 which is not deposited with the metal thin film. The orientation of the dual dipole fluorescent light source was set to TE and TM, and in each case, the output was calculated by the above equation (1) within the viewing angle range of the front surface of the glass substrates of the OLED devices 100 and 102 to obtain Normal Emitted Power. The peak heights in Table 1 are expressed in arbitrary units where the first value is for the TM orientation and the second value is for the TE orientation and is applied to the results table of all examples below. Electromagnetic vibration of the boundary between the metal thin film and the organic layer occurs at the surface plasmon frequency, and the fluorescence is enhanced, so the peak position and the height are changed in the calculation results below.

TABLE 1

device Board Anode (ITO) nm Metal thin film bottom nm NPB nm Alq3 nm Metal thin film top nm Transparent conductive spacer nm Cathode (Ag) nm Peak position nm Peak height (arbitrary unit) Calculation result drawing 100 Glass 150 0 75 80 0 0 15 568 0.016, 0.032 Figure 4 102a Glass 150 5 75 65 10 10 15 750 0.083, 0.180 Figure 5

Next, the light output advantage according to the thickness of the organic EL element layer in the OLED device 102 of the present invention is described.

When the thickness of the organic EL element layers 13 and 14 at the bottom surface of the upper surface of the metal thin film layer 15 was reduced from 140 nm to 135 nm, the peak position of the Normal Emitted Power was 730 nm, and the peak height was 0.181 for the TM. We can calculate that TE is strengthened 2-3 times to 0.361. The organic material in the process is a slow deposition rate is easy to control the thickness of about 5nm. In addition, when the sum of the thicknesses of NPB and Alq3, that is, the thickness of the organic EL element layer is constant, the tendency of the position and height of the Normal Emitted Power peak is similarly predicted in the calculation.

TABLE 2

device Board Anode (ITO) nm Metal thin film bottom nm NPB nm Alq3 nm Metal thin film top nm Transparent conductive spacer nm Cathode (Ag) nm Peak position nm Peak height (arbitrary unit) Calculation result drawing 102a Glass 150 5 75 65 10 10 15 750 0.083, 0.180 Figure 5 102b Glass 150 5 60 75 10 10 15 730 0.181, 0.361 Figure 6

Next are three comparative devices: (a) an OLED device 102c with a thickness of 15 nm transparent conductive spacers and a metal thin film as compared to (a) an OLED device 102b with a thickness of 10 nm transparent transparent spacers and a metal thin film. ), And (c) the theoretically predicted Normal Emitted Power of OLED device 102d with a thickness of 15 nm of transparent conductive spacers and 20 nm of metal thin film top thickness.

In a study by P.Anger et al., 'Physical Review Letters 96,113002 (2006)', the fluorescence enhancement is shown as a function of the distance between the metal particles and the organic thin film sandwiching the dielectric, and fluorescence occurs. The reinforcing effect is large when the distance between the organic thin film portion and the metal particles is between 0 and 20 nm.

Comparing the devices in Table 3, the total thickness of the NPB and Alq3 layers was kept constant, and the thicknesses of the metal thin film upper layer 15 and the transparent conductive spacer 16 were increased by 5 nm or 10 nm and 5 nm, respectively. The OLED device is expected to have a blue shift at the peak position of 725 nm and increase the peak height to 0.255 and 0.510 for TM and TE, respectively. In the case where the thickness of the metal thin film upper layer 15 was 15 nm and 20 nm, the peak position and height of the normal emission power were not different from each other.

TABLE 3

device Board Anode (ITO) nm Metal thin film bottom nm NPB nm Alq3 nm Metal thin film top nm Transparent conductive spacer nm Cathode (Ag) nm Peak position nm Peak height (arbitrary unit) Calculation result drawing 102b Glass 150 5 60 75 10 10 15 730 0.181, 0.361 Figure 6 102c Glass 150 5 50 85 15 15 15 725 0.255, 0.510 Figure 7 102d Glass 150 5 50 85 20 15 15 725 0.255, 0.510 Figure 8

Next, the thicknesses of the three comparative devices, namely, the upper portion of the metal thin film and the transparent conductive spacer, are constant at 20 nm and 15 nm, and under the condition that the thickness of the organic EL element layer is constant, (a) an OLED having a thickness of the lower portion of the metal thin film is 10 nm. The normal emitted power of the devices 102f, (b) the OLED device 102e having a thickness of 5 nm under the metal thin film and (c) the OLED device 102g having a thickness of 15 nm under the metal thin film was calculated.

When the thickness of the lower portion of the metal thin film is 5 nm, respectively, the peak height is nearly doubled and the position is slightly shifted at 10 nm and 15 nm, respectively. The thickness of the metal thin film upper layer, the transparent conductive spacer, the cathode, and the organic EL element layer were changed in peak when the metal thin film thickness was changed under constant conditions, and the fluorescence generated between the metal thin film upper-transparent conductive spacer-cathode It is calculated that the light due to the emission enhancement phenomenon outputs different peak values depending on the thickness due to the coupling phenomenon with the metal thin film on the upper surface of the anode. In addition, when the thickness of the lower portion of the metal thin film is 10nm and 15nm, that is, having a thickness of more than 10nm, the peak position and height of the Normal Emitted Power was not agile and calculated as a constant value.

TABLE 4

device Board Anode (ITO) nm Metal thin film bottom nm NPB nm Alq3 nm Metal thin film top nm Transparent conductive spacer nm Cathode (Ag) nm Peak position nm Peak height (arbitrary unit) Calculation result drawing 102e Glass 150 5 60 70 20 15 15 740 0.210, 0.420 Figure 9 102f Glass 150 10 60 70 20 15 15 720 0.407, 0.819 Figure 10 102 g Glass 150 15 60 70 20 15 15 735 0.417, 0.830 Figure 11

The results expressed in respective wavelength functions are as shown in FIGS. 4 to 11.

토르의 진공하에서 가열 보트로부터 승화시켜 침착시켰다. Fluorescence enhanced OLED is manufactured as follows. The glass substrate was coated with a 150 nm thick anode layer composed of ITO by a DC sputtering process at an Ar pressure of about 4 mTorr. The layers below are in order

Sublimate and deposit from a heating boat under vacuum of Thor.

(1) a 15 nm thick metal thin film underlayer consisting of Ag;

(2) a 60 nm thick hole transport layer consisting of N, N'-di (naphthalen-1-yl) -N, N'-diphenyl-benzidine (NPB);

(3) a 70 nm thick electron transport layer (also serving as a light emitting layer) consisting of tris (8-hydroxyquinoline) aluminum (III) (Alq3);

(4) a 20 nm thick metal thin film upper layer composed of Ag;

(5) a 15 nm thick transparent conductive spacer layer consisting of tris (8-hydroxyquinoline) aluminum (III) (Alq3); And

(6) A 15 nm thick metal electrode upper layer made of Ag.

After depositing these layers, the device was transferred from the deposition chamber into a dry box for encapsulation. The completed device structure is referred to as glass / ITO / Ag / NPB / Alq3 / Ag / Alq3 / Ag / Alq3.

The light output of the device, determined by the surface plasmon frequency between the metal upper electrode layer and the organic spacer constituent material, is characterized by the detail and thickness of the organic EL element layer, the composition and thickness of the bottom of the metal thin film disposed on one surface of the electrode layer, the organic Fluorescent red OLEDs and blue OLEDs with relatively low light efficiency and short lifetime can be controlled by determining the composition and thickness of the top of the metal thin film disposed on the EL element, and the composition and thickness of the conductive spacer layer disposed on one surface of the metal thin film. Can improve the performance.

K.Okamoto et al. (Nature. 3,601 (2004), S. Wedge, et al. (Optics Express. 12, 16 (2004), patterning sub-wavelength widths on metal surfaces for surface plasmon formation. Unlike the process in the research, in the present invention, by using only a method of planar deposition of a metal thin film on a conventional OLED structure, it is easy and easy to manufacture a fluorescent-enhanced OLED by reducing the fine and vacuum processes and increasing the yield. Designed.

Considering the entire display system connected to the TFT and driver including the panel, the bottom emitting OLED reduces the light output by TFT blocking. The light output reduced by TFT blocking is unavoidable when using the OLED of the bottom emission type, and according to another aspect of the present invention, to overcome this, it is manufactured to be applied to the top emission type fluorescent enhanced OLED device. . The upper metal electrode involved in fluorescence enhancement is located at a distance of several tens of nanometers or less from the upper metal thin film with an organic spacer interposed therebetween. Does not occur. When opaque and reflective metals Ag, Au, and Al are deposited with a thin thickness of several tens of nanometers or less, they have semi-transparent characteristics that can transmit light generated inside the device. Fluorescence-enhanced OLED devices fabricated as devices can also be used as devices for top emission. In order to use the upper light emitting device, the device structure of the present invention is used as it is, but the lower portion of the metal thin film disposed on one surface of the lower metal electrode layer is removed, and the anode and the cathode are used in the same manner as the lower light emitting device.

Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and the present invention is not limited to the specific embodiments of the present invention without departing from the spirit of the present invention as claimed in the claims. Anyone skilled in the art can make various modifications, as well as such modifications are within the scope of the claims.

1 is a schematic cross-sectional view of a typical OLED device structure used as a comparison group.

2 is a schematic cross-sectional view of a fluorescence enhanced OLED device structure without a bottom metal thin film.

3 is a schematic cross-sectional view of the structure of a fluorescently enhanced OLED device of the present invention with a bottom metal thin film.

4 shows the result of the normal emitted power of the device 100 as a function of the wavelength.

5 shows the result of the normal emitted power of the device 102a as a function of wavelength.

6 shows the result of the normal emitted power of the device 102b as a function of wavelength.

7 shows the result of the normal emitted power of the device 102c as a function of wavelength.

8 shows the result of the normal emitted power of the device 102d as a function of wavelength.

9 shows the result of the wavelength of the normal emitted power of the device 102e.

FIG. 10 shows the result of the normal emitted power of the device 102f as a function of wavelength.

11 shows the result of the normal emitted power of the device 102g as a function of wavelength.

Explanation of symbols for the main parts of the drawings

10: Substrate

11: lower electrode layer

12: metal thin film underlayer

13: organic EL element layer (I)

14: organic EL element layer (II)

15: metal thin film upper layer

16: transparent conductive spacer layer

17: top-electrode layer

Claims (9)

Board; A metal lower electrode layer disposed on a surface of the substrate; A metal thin film underlayer disposed on a surface of the metal under-electrode layer; An organic EL element layer disposed on a surface of the metal thin film underlayer; A metal thin film upper layer disposed on the organic EL element layer; A conductive spacer layer disposed on a surface of the metal thin film upper layer; And And a metal top-electrode layer disposed on the conductive spacer layer. The method of claim 1, At least one of the metal lower electrode layer and the metal upper electrode layer is opaque and reflective, and the material of the opaque and reflective electrode layer is selected from at least one of Ag, Au, Al, and the metal thin film upper layer and the lower layer are opaque and reflective. At least one of adult Ag, Au, and Al, wherein the material, thickness, position, and thickness of the organic EL element layer of the metal thin film upper and lower layers are adjusted to enhance luminescence output compared to similar devices without fluorescence enhancement. Characterized by a fluorescently enhanced OLED device. The method of claim 1, Wherein one of the metal bottom electrode layer and the metal top electrode layer is opaque and reflective, the other is transparent, and the material of the transparent electrode layer is selected from ITO. The method of claim 3, wherein Wherein said metal bottom electrode layer is ITO, said metal top electrode layer is Ag and has a thickness of 10 to 100 nm. The method of claim 1, Wherein both the metal thin film upper layer and the metal thin film lower layer are Ag, Au or Al, and the thickness of the thin film is 2 to 30 nm. The method of claim 1, Wherein said metal bottom-electrode layer is an anode and said metal top-electrode layer is a cathode. The method of claim 1, Wherein said metal bottom-electrode layer is a cathode and said metal top-electrode layer is an anode. The method of claim 1, The conductive spacer layer disposed between the upper metal thin film upper layer and the metal upper-electrode layer is composed of organic material and has a thickness of 5 to 50 nm. Board; A metal lower electrode layer disposed on a surface of the substrate; An organic EL element layer disposed on a surface of the metal lower electrode layer; A metal thin film upper layer disposed on the organic EL element layer; A conductive spacer layer disposed on a surface of the metal thin film upper layer; And And a metal top-electrode layer disposed on the conductive spacer layer.

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