Organic el lighting device

Abstract

Provided is an organic EL lighting device capable of suppressing light emission in a blue region compared to the prior art. The organic EL device is provided with a substrate, an anode, a blue fluorescent light-emitting unit, a green-red phosphorescent light-emitting unit, and a cathode, and the organic EL device is configured such that a blue fluorescent light-emitting layer of the blue fluorescent light-emitting unit contains a phosphorescent material.

Description

Technical Field

[0001] The present invention relates to an organic EL lighting device. Background Art

[0002] Organic EL lighting devices are semiconductor devices that convert electrical energy into light energy. Because they can emit thin, soft, diffuse light in a planar pattern, they have attracted attention as a light source to replace incandescent and fluorescent lamps, and extensive research has been carried out in recent years.

[0003] In order to popularize organic EL lighting devices, further improvements in efficiency, brightness, color rendering, device life, and biological effects have been required in recent years.

[0004] For example, as described in non-patent document 1, Brainard et al. reported in 2001 that the suppression of human melatonin secretion was affected by the blue luminescence spectrum on the short-wavelength side, regardless of whether the illuminance was high or minimum, and was also slightly dependent on the spectrum in the 460nm region on the long-wavelength side of the blue. Later, Thapan et al. reported that this situation was related to photosensitive retinal ganglion cells (ipRGCs) containing substances such as melanopsin.

[0005] Furthermore, Non-Patent Document 2 also describes the relationship between the blue region spectrum and melatonin secretion suppression in humans.

[0006] Patent Document 1 discloses an organic EL element that emits white light of low color temperature with suppressed emission in the blue region and emits white light of high color rendering with practical power efficiency.

[0007] It is explained that this organic EL element has little irritation to the eyes associated with the secretion of melatonin in a nighttime living environment and is therefore suitable as lighting that can help improve sleep quality.

[0008] In this organic EL element, the problem of poor power efficiency is addressed by suppressing light emission in the blue region. The green and red phosphorescent units are sufficiently far away from the reflective cathode to reduce their susceptibility to plasmon loss, thereby achieving improved efficiency.

[0009] Furthermore, in order to reduce the blue emission intensity and achieve a distance from the blackbody radiation curve of duv0.02 or less, the hole transport layer on the blue cell side is used as an adjustment layer.

[0010] On the other hand, Patent Document 1 does not describe the life of the device.

[0011] Patent Document 1: International Publication No. 2022 / 092131

[0012] Non-patent document 1: Hatori & Panda: The emerging roles of melanopsin in behavioral adaptation to light, Trends in Molecular Medicine, 16-10, pp. 435-446 (2010)

[0013] Non-patent document 2: Shigekazu Higuchi. Light and melatonin suppression in humans. Japanese Journal of Chronobiology. (2008) vol. 14, no. 1, pp. 6-13.

[0014] However, as methods for suppressing light emission in the blue region in an organic EL element, there are methods of reducing the film thickness of the blue region and reducing the content of the blue light-emitting material. However, these methods also have the problem of shortening the life of the blue region. Summary of the Invention

[0015] Therefore, an object of the present invention is to provide an organic EL lighting device capable of suppressing light emission in the blue region compared to conventional devices.

[0016] One aspect of the present invention for solving the above-mentioned problems is an organic EL lighting device, which includes an organic EL device, the organic EL device having a substrate, an anode, a blue fluorescent light-emitting unit, a green and red phosphorescent light-emitting unit and a cathode, and the organic EL device is constructed so that the blue fluorescent light-emitting layer of the blue fluorescent light-emitting unit includes at least a fluorescent light-emitting main material and a phosphorescent material.

[0017] According to this aspect, energy transfer occurs from the phosphorescent material in the triplet excited state generated in the blue fluorescent light-emitting layer to the fluorescent host material, causing a portion of the fluorescent host material to enter a pseudo-triplet excited state, and non-radiative deactivation occurs in a portion of the fluorescent host material. As a result, the intensity of blue light from the blue fluorescent light-emitting layer of the blue fluorescent light-emitting unit decreases compared to a case where no phosphorescent material is added, and a reduction in device life can be suppressed.

[0018] In a preferred aspect, the maximum emission wavelength of the phosphorescent material is 450 nm to 650 nm.

[0019] According to this aspect, while reducing the intensity of blue light from the organic EL device, it is possible to suppress a reduction in the life of the device.

[0020] Preferably, the amount of the phosphor material in the blue fluorescent light-emitting layer is 0.3 wt % or more.

[0021] According to this aspect, while the intensity of blue light from the organic EL device is sufficiently reduced, a reduction in the life of the device can be suppressed.

[0022] In a preferred aspect, a charge generation layer is provided between the blue fluorescent light-emitting unit and the green-red phosphorescent light-emitting unit, and the amount of the phosphorescent material in the blue fluorescent light-emitting layer is 0.1 wt % or more and less than 0.3 wt %.

[0023] According to this aspect, as the content of the phosphor material changes, the ratio of the deactivation process changes, so the intensity of the blue light can be controlled without changing the film thickness.

[0024] Preferably, white light having a Melanopic Ratio of 0.5 or less is emitted, wherein the white light has a color temperature of 2000K to 3000K, a duv from a blackbody radiation curve of 0.02 or less, and a color reproducibility of 80 or more.

[0025] According to this aspect, the visual recognition load for objects, including color tones, is reduced, making it easier on the eyes in a nighttime living environment and reducing eye stimulation related to melatonin secretion and production, thereby contributing to improved sleep quality.

[0026] In a preferred aspect, the triplet excited state energy level of the fluorescent host material of the blue fluorescent light-emitting layer is deeper than the triplet excited state energy level of the phosphorescent material.

[0027] A preferred aspect includes the organic EL device and a blue light source capable of emitting blue light that complements the light emitted by the organic EL device.

[0028] In a preferred aspect, the blue light source is a blue OLED or a blue LED.

[0029] According to these aspects, color adjustment at a high color temperature can be performed.

[0030] According to the organic EL lighting device of the present invention, while reducing the intensity of blue light, it is also possible to suppress a reduction in the life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a cross-sectional view of a main portion of the organic EL lighting device according to the first embodiment of the present invention, with hatching omitted for easier understanding.

[0032] Figure 2 : is the total luminous flux spectrum of the organic EL lighting device of Example 1.

[0033] Figure 3 This is the change in peak intensity of blue light of the organic EL lighting device of Example 1 during heating and power-on.

[0034] Figure 4This is the correlated color temperature change of the organic EL lighting device of Example 1 during heating and power-on.

[0035] Figure 5 : is the total luminous flux spectrum of the organic EL lighting device of Example 2.

[0036] Figure 6 This is the change in peak intensity of blue light of the organic EL lighting device of Example 2 during heating and power-on.

[0037] Figure 7 This is the correlated color temperature change of the organic EL lighting device of Example 2 during heating and power-on.

[0038] Figure 8 : is the total luminous flux spectrum of the organic EL lighting device of Example 3.

[0039] Figure 9 This is the change in peak intensity of blue light of the organic EL lighting device of Example 3 during heating and power-on.

[0040] Figure 10 This is the correlated color temperature change of the organic EL lighting device of Example 3 during heating and power-on.

[0041] Figure 11 : is the total luminous flux spectrum of the organic EL lighting device of Example 4.

[0042] Figure 12 : is the total luminous flux spectrum of the organic EL lighting device of Example 5.

[0043] Figure 13 : is the total luminous flux spectrum of the organic EL lighting device of Example 6.

[0044] Figure 14 : is the total luminous flux spectrum of the organic EL lighting device of Example 7.

[0045] Figure 15 : is the total luminous flux spectrum of the organic EL lighting device of Comparative Example 1.

[0046] Figure 16 This is a change in the peak intensity of blue light of the organic EL lighting device of Comparative Example 1 during heating and power-on.

[0047] Figure 17 This is the correlated color temperature change of the organic EL lighting device of Comparative Example 1 during heating and power-on.

[0048] Figure 18 4 is a cross-sectional structural diagram of the organic EL lighting devices of Examples 1 to 7 and Comparative Example 1. DETAILED DESCRIPTION

[0049] Hereinafter, embodiments of the present invention will be described in detail.

[0050] (Organic EL lighting device 10)

[0051] like Figure 1 As described above, the organic EL lighting apparatus 10 according to the first embodiment of the present invention includes the organic EL device 25 having the light exit surface 20 and the back surface 21 as two main surfaces and emitting white light from the light emitting region 7 on the light exit surface 20 side.

[0052] The organic EL device 25 is a member having a planar expansion, and is preferably a plate-shaped member.

[0053] From the viewpoint of suppressing the occurrence of DS (dark spots) and shortening the device life, the organic EL device 25 is preferably as follows: Figure 1 As shown in FIG. 2 , the sealing layer 5 is provided to cover the entire surface of the light emitting region 7 on the back surface 21 side when viewed from above.

[0054] like Figure 1 Thus, the organic EL device 25 includes the substrate 1 , the anode 2 , the light-emitting functional layer 3 , and the cathode 4 in order from the light-emitting surface 20 side toward the back surface 21 side, and the overlapping portion thereof coincides with the light-emitting region 7 in plan view.

[0055] The light-emitting functional layer 3 preferably includes at least a blue fluorescent light-emitting unit 3A and a green-red phosphorescent light-emitting unit 3B in order from the substrate 1 side. Figure 1 In this way, the charge generation layer 3C is included between the blue fluorescent light-emitting unit 3A and the green and red phosphorescent light-emitting unit 3B.

[0056] The light-emitting functional layer 3 is mainly composed of an organic compound, and generally known materials such as low-molecular pigment materials and conjugated polymer materials used in organic EL devices can be used.

[0057] The light-emitting functional layer 3 can be formed by any appropriate known method such as vacuum deposition, sputtering, CVD, or various coating methods. From the perspective of achieving high-performance devices, vacuum deposition is preferred.

[0058] The white light emitted from the light emitting surface 20 of the organic EL device 25 preferably has a Melanopic Ratio value, which is an indicator related to the suppression of melatonin secretion, of 0.5 or less.

[0059] The white light emitted from the light exit surface 20 of the organic EL device 25 preferably has a color temperature of 2000K to 3000K.

[0060] It is preferable that the white light emitted from the light exit surface 20 of the organic EL device 25 has a coordinate duv in the CIE 1931 chromaticity coordinate system that is at a distance of 0.02 or less from the blackbody radiation curve.

[0061] It is preferable that the white light emitted from the light exit surface 20 of the organic EL device 25 has an Ra value related to color reproducibility, that is, an average color rendering index Ra of 80 or more.

[0062] The organic EL lighting apparatus 10 may also use a blue light source composed of a blue OLED or a blue LED in addition to the organic EL device 25 .

[0063] That is, the organic EL lighting device 10 may include a blue light source separately from the organic EL device 25 , and the organic EL device 25 and the blue light source may be arranged on the same plane.

[0064] In this case, the blue light source is preferably capable of emitting blue light that complements the white light that is the irradiation light of the organic EL device 25 .

[0065] (Substrate 1)

[0066] The substrate 1 is a member having a planar extension and made of a light-transmitting material.

[0067] The substrate 1 may be, for example, a glass substrate or a resin film substrate. From the viewpoint of suppressing the intrusion of moisture into the organic EL lighting device 10 , which may cause performance degradation, a glass substrate is preferable.

[0068] Alternatively, the base material 1 may be a flexible substrate.

[0069] (Anode 2)

[0070] As the material of the anode 2, transparent conductive metal oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), and zinc oxide (ZnO) can be used. From the perspective of achieving high-performance devices, highly transparent ITO or IZO is preferred.

[0071] (Blue fluorescent light emitting unit 3A)

[0072] The blue fluorescent light-emitting unit 3A includes a blue fluorescent light-emitting layer 32 that emits blue light, and has a hole transporting surface and an electron transporting surface as two surfaces.

[0073] like Figure 1 In this way, the blue fluorescent light-emitting unit 3A preferably includes a hole injection layer 30 , a hole transport layer 31 , a blue fluorescent light-emitting layer 32 , an electron transport layer 33 , and an electron injection layer 34 in this order from the anode 2 side.

[0074] (Charge Generation Layer 3C)

[0075] The charge generation layer 3C has a function of connecting the blue fluorescent light-emitting unit 3A and the green and red phosphorescent light-emitting unit 3B.

[0076] Specifically, the charge generation layer 3C has a function of injecting electrons toward the blue fluorescent light-emitting unit 3A side and injecting holes toward the green and red phosphorescent light-emitting unit 3B side when the organic EL lighting device 10 is powered on.

[0077] (Green-red phosphorescent light-emitting unit 3B)

[0078] The green-red phosphorescent light-emitting unit 3B includes a green-red phosphorescent mixed light-emitting layer 37 that emits green light and red light, and has two surfaces: a hole transporting surface and an electron transporting surface.

[0079] The green-red phosphorescent mixed light-emitting layer 37 includes a green phosphorescent material, a red phosphorescent material and a phosphorescent host material.

[0080] like Figure 1 Thus, the green-red phosphorescent light-emitting unit 3B preferably includes, in order from the anode 2 side (charge generation layer 3C side), a hole injection layer 35 , a hole transport layer 36 , a green-red phosphorescent mixed light-emitting layer 37 , an electron transport layer 38 , and an electron injection layer 39 .

[0081] (Hole Injection Layers 30 and 35)

[0082] The hole injection layer 30 is a layer that takes in holes from the anode 2 and injects the holes into the hole transport layer 31 , for example.

[0083] The hole injection layer 35 is a layer that takes in holes from the charge generation layer 3C, for example, and injects the holes into the hole transport layer 36 .

[0084] Furthermore, from the viewpoint of improving the brightness by improving the transparency of the hole injection layers 30 and 35 , the hole injection layers 30 and 35 may preferably be made of a hole transport material doped with an electron accepting dopant.

[0085] The average thickness of the hole injection layers 30 and 35 is preferably 0.1 nm or more and 20 nm or less.

[0086] (Hole transport material)

[0087] As the hole transporting material, for example, a triphenylamine compound, a carbazole compound, or the like can be used.

[0088] (Electron-Accepting Dopant)

[0089] As the electron-accepting dopant, a tetracyanoquinodimethane compound, molybdenum oxide (MoO 3 ), tungsten oxide (WO 3 ), vanadium oxide (V 2 O 5 ) or the like can be used.

[0090] (Hole Transport Layers 31 and 36)

[0091] The hole transport layer 31 is a layer that efficiently transports holes from the hole injection layer 30 side to the blue fluorescent light-emitting layer 32 and restricts the movement of electrons to the anode 2 side.

[0092] The hole transport layer 36 efficiently transports holes from the hole injection layer 35 side to the green-red phosphorescent mixed light-emitting layer 37 and restricts the movement of electrons to the charge generation layer 3C side (anode 2 side).

[0093] As the material of the hole transport layers 31 and 36 , a known hole transport material can be used.

[0094] The average thickness of the hole transport layers 31 and 36 is preferably 1 nm or more and 200 nm or less.

[0095] (Blue fluorescent light-emitting layer 32)

[0096] The blue fluorescent light-emitting layer 32 includes a blue fluorescent light-emitting material, a phosphorescent material (phosphorescent material), and a fluorescent light-emitting host material. The fluorescent light-emitting host material is an electron-transporting host material.

[0097] The thickness of the blue fluorescent light-emitting layer 32 is preferably 1 nm to 40 nm, and more preferably has a light emission peak at 470 nm or less.

[0098] The triplet excited state energy level of the fluorescent host material of the blue fluorescent light-emitting layer 32 is preferably deeper than that of the phosphorescent material from the viewpoint of efficiently placing a portion of the fluorescent host material in a pseudo triplet excited state.

[0099] (blue fluorescent material)

[0100] As the blue fluorescent light-emitting material, perylene 4,4'-bis(9-ethyl-3-carbazolylvinyl)-1,1-biphenyl (BCzVBi), 4,4'-bis[4-(di-p-triamino)phenylvinyl]biphenyl (DPAVBi), or the like can be used.

[0101] (Phosphorescent material)

[0102] The phosphorescent material preferably has a maximum emission wavelength of 450 nm to 650 nm.

[0103] The amount of the phosphorescent material added to the blue fluorescent light-emitting layer 32 is not particularly limited, but is preferably 0.1 wt % or more, more preferably 0.2 wt % or more, further preferably 0.3 wt % or more, and particularly preferably 0.5 wt % or more from the viewpoint of suppressing light emission in the blue region.

[0104] From the perspective of maintaining sufficient blue light emission, the amount of phosphorescent material added to the blue fluorescent light-emitting layer 32 is preferably 1 wt % or less, more preferably 0.7 wt % or less, and even more preferably 0.6 wt % or less.

[0105] From the viewpoint of obtaining a good average color rendering index Ra, the amount of the phosphorescent material added to the blue fluorescent light-emitting layer 32 is preferably less than 0.6 wt %, and preferably 0.1 wt % or more and less than 0.3 wt %.

[0106] As red phosphorescent materials, iridium complexes such as (bzq)2Ir(acac), (btp)2Ir(acac), Ir(bzq)3, and Ir(piq)3 can be used.

[0107] As a green phosphorescent material, iridium complexes such as (ppy)2Ir(acac) and Ir(ppy)3 can be used.

[0108] As a blue phosphorescent material, iridium complexes such as FIrpic, FIr6, and Ir(Fppy)3 can be used.

[0109] (Electron Transport Layers 33 and 38)

[0110] The electron transport layer 33 efficiently transports electrons from the electron injection layer 34 side to the blue fluorescent light-emitting layer 32 and restricts the movement of electrons to the cathode 4 side (charge generation layer 3C side).

[0111] The electron transport layer 38 efficiently transports electrons from the electron injection layer 39 side to the green-red phosphorescent mixed light-emitting layer 37 and restricts the movement of electrons to the cathode 4 side.

[0112] As the material of the electron transport layers 33 and 38 , a known electron transport material can be used.

[0113] The average thickness of the electron transport layers 33 and 38 is preferably 1 nm or more and 200 nm or less.

[0114] (Electron Injection Layers 34 and 39)

[0115] The electron injection layer 34 is a layer that takes in electrons from the charge generation layer 3C and injects the electrons into the electron transport layer 33 , for example.

[0116] The electron injection layer 39 is a layer that takes in electrons from the cathode 4 and injects the electrons into the electron transport layer 38 , for example.

[0117] From the viewpoint of improving the brightness by improving the transparency of the electron injection layers 34 and 39 , the electron injection layers 34 and 39 can also preferably be made of a material obtained by doping an electron-donating dopant with an electron-transporting material.

[0118] The average thickness of the electron injection layers 34 and 39 is preferably 0.1 nm or more and 20 nm or less.

[0119] (Electron transport material)

[0120] As the electron transport material, for example, quinoline metal complexes, anthracene compounds, oxadiazole compounds, triazole compounds, phenanthroline compounds, silole compounds, etc. can be used.

[0121] (Electron-donating dopant)

[0122] As the electron-donating dopant, alkali metals, alkaline earth metals, rare earth metals, compounds of these metals, phthalocyanine complexes having these metals as the central metal, dihydroimidazole compounds, and the like can be used.

[0123] (Cathode 4)

[0124] The cathode 4 can be formed using various metal materials, but a white glossy metal is preferred, and silver (Ag) and aluminum (Al) are more preferred.

[0125] (Outcoupling layer)

[0126] In order to improve the angle-dependent optical properties of brightness and color, e.g. Figure 1 In this manner, the organic EL lighting device 10 preferably includes an outcoupling layer 6 (OCL) on the outermost surface of a region including at least the light emitting region 7 on the light emitting surface 20 side.

[0127] Example

[0128] Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.

[0129] In addition, the present invention is not limited to the following embodiments, and can be implemented with appropriate changes within the scope of the present invention.

[0130] (Example 1)

[0131] In Example 1, a Figure 18 A cross-sectional structural diagram of an organic EL lighting device.

[0132] Specifically, an indium tin oxide (ITO) layer is formed as anode 2 on the device formation surface of a glass substrate serving as base material 1. Next, a blue fluorescent light-emitting unit 3A, a charge generation layer, a green and red phosphorescent light-emitting unit 3B, and an aluminum (Al) layer serving as cathode 4 are sequentially formed on this ITO layer, thereby fabricating a two-stage stacked device consisting of anode 2 / blue fluorescent light-emitting unit 3A / charge generation layer / green and red phosphorescent light-emitting unit 3B / cathode 4.

[0133] Here, the blue fluorescent light-emitting layer of the blue fluorescent light-emitting unit 3A includes a fluorescent light-emitting main material, a blue fluorescent light-emitting material, and a phosphorescent material with a maximum emission wavelength of 600nm~650nm, and contains 0.6wt% of the phosphorescent material relative to the mass of the combined fluorescent light-emitting main material and the blue fluorescent light-emitting material.

[0134] (Example 2)

[0135] The organic EL lighting device of Example 2 is the same as that of Example 1, except that the maximum wavelength of light emitted by the phosphorescent material included in the blue fluorescent light-emitting layer is 500 nm to 600 nm.

[0136] (Example 3)

[0137] The organic EL lighting device of Example 3 is the same as that of Example 1, except that the maximum wavelength of light emitted by the phosphorescent material included in the blue fluorescent light-emitting layer is 450 nm to 500 nm.

[0138] (Example 4)

[0139] The organic EL lighting device of Example 4 is the same as that of Example 1 except that the amount of the phosphorescent material contained in the blue fluorescent light-emitting layer is 0.3 wt % relative to the mass of the combined fluorescent host material and the blue fluorescent light-emitting material.

[0140] (Example 5)

[0141] The organic EL lighting device of Example 5 is the same as that of Example 1 except that the amount of the phosphorescent material contained in the blue fluorescent light-emitting layer is 0.2 wt % relative to the mass of the combined fluorescent host material and the blue fluorescent light-emitting material.

[0142] (Example 6)

[0143] In the organic EL lighting device of Example 6, the same as Example 1 is used except that the maximum emission wavelength of the phosphorescent material contained in the blue fluorescent light-emitting layer is 450nm~500nm and the added amount of the phosphorescent material is 0.3wt% relative to the mass of the combined fluorescent light-emitting host material and the blue fluorescent light-emitting material.

[0144] (Example 7)

[0145] In the organic EL lighting device of Example 7, the same as Example 1 is used except that the maximum emission wavelength of the phosphorescent material contained in the blue fluorescent light-emitting layer is 450nm~500nm and the added amount of the phosphorescent material is 0.2wt% relative to the mass of the combined fluorescent light-emitting host material and the blue fluorescent light-emitting material.

[0146] (Comparative Example 1)

[0147] The organic EL lighting device of Comparative Example 1 is the same as that of Example 1, except that the blue fluorescent light-emitting layer of the blue fluorescent light-emitting unit 3A does not contain a phosphorescent material.

[0148] (Evaluation of total luminous flux spectrum)

[0149] The total luminous flux spectrum was measured using a total luminous flux measurement system (Ø12 inch HM manufactured by OTSUKA ELECTRONICS) in accordance with JIS C 7801 at a current density of 3 mA / cm 2 Lighted and measured.

[0150] (TCP evaluation)

[0151] The total luminous flux was measured by the above system in accordance with JIS Z 8725 at a current density of 3 mA / cm 2 Light up and measure, and calculate the correlated color temperature TCP.

[0152] (duv's evaluation)

[0153] The total luminous flux was measured by the above system in accordance with JIS Z 8725 at a current density of 3 mA / cm 2 Light it up and measure, and calculate the distance duv from the blackbody radiation curve.

[0154] (Ra's evaluation)

[0155] The total luminous flux was measured by the above system in accordance with JIS Z 8726 at a current density of 3 mA / cm 2 Light up and measure, and calculate the color rendering index Ra.

[0156] (Evaluation of Melanopic Ratio)

[0157] The total luminous flux was measured by the above system with a current density of 3 mA / cm 2 The total luminous flux spectrum was illuminated and measured, and the Melanopic Ratio value was simulated using the Tool Box published by The WELL Building Standard (https: / / resources.wellcertified.com / tools / well-building-standard-v2 / ).

[0158] (Evaluation of blue light peak intensity)

[0159] The luminance was measured by a spectroradiometer (CS-2000 manufactured by Konica Minolta) at a current density of 3 mA / cm 2The light was turned on and the radiation spectrum was measured, and the relative luminous intensity of the luminous peak observed in the 430nm to 490nm region was evaluated.

[0160] Table 1 shows the wavelengths and addition concentrations of the phosphorescent materials of Examples 1 to 7 and Comparative Example 1, as well as the measured TCP (K), duv, Ra, Melanopic Ratio values, and blue light peak intensity (%).

[0161] [Table 1]

[0162] Table 1

[0163]

[0164] [Table 2]

[0165] Table 2

[0166]

[0167] Figure 2 In the organic EL lighting device of Example 1, the current density is 3 mA / cm 2 Total luminous flux spectrum after lighting.

[0168] According to the Figure 2 The correlated color temperature TCP of the organic EL lighting device of Example 1 calculated from the spectrum is 2702K, the deviation duv from blackbody radiation is 0.012, the color reproducibility Ra is 81, and the Melanopic Ratio value is 0.335.

[0169] If the blue light peak intensity of the organic EL lighting device of Comparative Example 1 described later is 100%, the blue light peak intensity of the organic EL lighting device of Example 1 is 18%.

[0170] Figure 3 In the organic EL lighting device of Example 1, the current density is 10 mA / cm at 85°C. 2 The change in the peak intensity of blue light when heating and power were applied was performed below.

[0171] If the blue light peak intensity of the organic EL lighting device of Example 1 before the start of heating and energization is set to 100%, the blue light peak intensity after 300 hours of heating and energization is 89%, and the blue light peak intensity change rate is 11%.

[0172] Figure 4 In the organic EL lighting device of Example 1, the current density is 10 mA / cm at 85°C. 2 The correlated color temperature changes when heating is applied are shown in the figure.

[0173] The change in correlated color temperature from before the start of heating energization to 300 hours after the heating energization of the organic EL lighting device of Example 1 was 41K.

[0174] Figure 5 In the organic EL lighting device of Example 2, the current density is 3 mA / cm 2 Total luminous flux spectrum when lit.

[0175] As in Example 1, calculations were performed based on the total luminous flux spectrum of the organic EL lighting device of Example 2. The results showed that the correlated color temperature TCP was 2797 K, duv was 0.009, Ra was 83, and the Melanopic Ratio was 0.384.

[0176] If the peak intensity of blue light of the organic EL lighting device of Comparative Example 1 is set to 100%, the peak intensity of blue light of the organic EL lighting device of Example 2 is 24%.

[0177] Figure 6 In the organic EL lighting device of Example 2, the current density is 10 mA / cm at 85°C. 2 The change in the peak intensity of blue light when heating and power were applied was performed below.

[0178] If the blue light peak intensity of the organic EL lighting device of Example 2 before the start of heating and energization is set to 100%, the blue light peak intensity after 300 hours of heating and energization is 87%, and the blue light peak intensity change rate is 13%.

[0179] Figure 7 In the organic EL lighting device of Example 2, the current density is 10 mA / cm at 85°C. 2 The correlated color temperature changes when heating is applied are shown in the figure.

[0180] The change in correlated color temperature from before the start of heating energization to 300 hours after the heating energization of the organic EL lighting device of Example 2 was 14K.

[0181] Figure 8 In the organic EL lighting device of Example 3, the current density is 3 mA / cm 2 Total luminous flux spectrum when lit.

[0182] As in Example 1, calculations were performed based on the total luminous flux spectrum of the organic EL lighting device of Example 3. The results showed that the correlated color temperature TCP was 2827 K, duv was 0.009, Ra was 84, and the Melanopic Ratio was 0.401.

[0183] If the peak intensity of blue light of the organic EL lighting device of Comparative Example 1 is set to 100%, the peak intensity of blue light of the organic EL lighting device of Example 3 is 28%.

[0184] Figure 9 In the organic EL lighting device of Example 3, the current density was 10 mA / cm at 85°C. 2 The change in the peak intensity of blue light when heating and power were applied was performed below.

[0185] If the blue light peak intensity of the organic EL lighting device of Example 3 before the start of heating and energization is set to 100%, the blue light peak intensity after 300 hours of heating and energization is 84%, and the blue light peak intensity change rate is 16%.

[0186] Figure 10 In the organic EL lighting device of Example 3, the current density was 10 mA / cm at 85°C. 2 The correlated color temperature changes when heating is applied are shown in the figure.

[0187] The change in correlated color temperature from before the start of heating energization to 300 hours after heating energization of the organic EL lighting device of Example 3 was 29K.

[0188] Figure 11 In the organic EL lighting device of Example 4, the current density is 3 mA / cm 2 Total luminous flux spectrum when lit.

[0189] As in Example 1, calculations were performed based on the total luminous flux spectrum of the organic EL lighting device of Example 4. The results showed that the correlated color temperature TCP was 2959 K, duv was 0.009, Ra was 84, and the Melanopic Ratio was 0.439.

[0190] If the peak intensity of blue light of the organic EL lighting device of Comparative Example 1 is set to 100%, the peak intensity of blue light of the organic EL lighting device of Example 4 is 35%.

[0191] Figure 12 In the organic EL lighting device of Example 5, the current density is 3 mA / cm 2 Total luminous flux spectrum when lit.

[0192] As in Example 1, calculations were performed based on the total luminous flux spectrum of the organic EL lighting device of Example 5. The results showed that the correlated color temperature TCP was 3127 K, duv was 0.006, Ra was 86, and the Melanopic Ratio was 0.512.

[0193] If the peak intensity of blue light of the organic EL lighting device of Comparative Example 1 is set to 100%, the peak intensity of blue light of the organic EL lighting device of Example 5 is 47%.

[0194] Figure 13 In the organic EL lighting device of Example 6, the current density is 3 mA / cm 2 Total luminous flux spectrum when lit.

[0195] As in Example 1, calculations were performed based on the total luminous flux spectrum of the organic EL lighting device of Example 6. The results showed that the correlated color temperature TCP was 3109 K, duv was 0.006, Ra was 86, and the Melanopic Ratio was 0.509.

[0196] If the peak intensity of blue light of the organic EL lighting device of Comparative Example 1 is set to 100%, the peak intensity of blue light of the organic EL lighting device of Example 6 is 47%.

[0197] Figure 14 In the organic EL lighting device of Example 7, the current density is 3 mA / cm 2 Total luminous flux spectrum when lit.

[0198] As in Example 1, calculations were performed based on the total luminous flux spectrum of the organic EL lighting device of Example 7. The results showed that the correlated color temperature TCP was 3224 K, duv was 0.003, Ra was 90, and the Melanopic Ratio was 0.579.

[0199] If the peak intensity of blue light of the organic EL lighting device of Comparative Example 1 is set to 100%, the peak intensity of blue light of the organic EL lighting device of Example 7 is 58%.

[0200] Figure 15 In the organic EL lighting device of Comparative Example 1, the current density is 3 mA / cm 2 Total luminous flux spectrum when lit.

[0201] Calculations were performed similarly to Example 1 based on the total luminous flux spectrum of the organic EL lighting device of Comparative Example 1. The results showed that the correlated color temperature TCP was 3753 K, duv was -0.004, Ra was 93, and the Melanopic Ratio was 0.784.

[0202] Figure 16 In the organic EL lighting device of Comparative Example 1, the current density was 10 mA / cm at 85°C. 2 The change in the peak intensity of blue light when heating and power were applied was performed below.

[0203] Assuming the blue light peak intensity of the organic EL lighting device of Comparative Example 1 before the start of heating and energization is 100%, the blue light peak intensity after 300 hours of heating and energization is 74%, and the blue light peak intensity change rate is 26%.

[0204] Figure 17 In the organic EL lighting device of Comparative Example 1, the current density was 10 mA / cm at 85°C. 2 The color temperature changes when heating and power are turned on are shown below.

[0205] The change in correlated color temperature from before the start of heating energization to 300 hours after heating energization of the organic EL lighting device of Comparative Example 1 was -338K.

[0206] From Table 1 and Figure 2 (Total luminous flux spectrum of Example 1), Figure 5 (Total luminous flux spectrum of Example 2), Figure 8 (Total luminous flux spectrum of Example 3) and Figure 15 (Total luminous flux spectrum of Comparative Example 1) The following can be seen.

[0207] By adding 0.6 wt % of a phosphorescent material having a maximum emission wavelength of 450 nm to 650 nm to the blue fluorescent light-emitting layer of the blue fluorescent light-emitting unit 3A, the peak intensity of blue light near a wavelength of 460 nm can be sufficiently suppressed.

[0208] From Table 2 and Figure 3 (Change in peak intensity of blue light during heating and power-on in Example 1) Figure 6 (Change in peak intensity of blue light during heating and power-on in Example 2) Figure 9 (Change in peak intensity of blue light during heating and power-on in Example 3) and Figure 16 (Change in Peak Intensity of Blue Light During Heating Power-On in Comparative Example 1) The following was found.

[0209] By adding 0.6 wt % of a phosphorescent material having a maximum emission wavelength of 450 nm to 650 nm to the blue fluorescent light emitting layer of the blue fluorescent light emitting unit 3A, changes in the peak intensity of blue light during heating and energization can be suppressed, and reduction in device life can be suppressed.

[0210] From Table 2 and Figure 4 (Change in correlated color temperature during heating in Example 1) Figure 7 (Change in correlated color temperature during heating in Example 2) Figure 10 (Correlated color temperature change during heating power-on in Example 3) and Figure 17 (Change in Correlated Color Temperature During Heating Power Application in Comparative Example 1) The following was found.

[0211] By adding 0.6 wt % of a phosphorescent material having a maximum emission wavelength of 450 nm to 650 nm to the blue fluorescent light-emitting layer of the blue fluorescent light-emitting unit 3A, changes in correlated color temperature during heating and energization can be suppressed, thereby preventing a reduction in device life.

[0212] From Table 1 and Figure 2 (Total luminous flux spectrum of Example 1), Figure 8 (Total luminous flux spectrum of Example 3), Figure 11 (Total luminous flux spectrum of Example 4), Figure 12 (Total luminous flux spectrum of Example 5), Figure 13 (Total luminous flux spectrum of Example 6) and Figure 14 (Total luminous flux spectrum of Example 7) The following can be seen.

[0213] By adding 0.2 wt % to 0.6 wt % of a phosphorescent material having maximum emission wavelengths of 450 nm to 500 nm and 600 nm to 650 nm to the blue fluorescent light-emitting layer of the blue fluorescent light-emitting unit 3A, the peak intensity of blue light around 460 nm can be suppressed.

[0214] In addition, based on the above results and Figure 5 In Example 2 shown, the blue light peak intensity around 460 nm can also be controlled. It is estimated that the blue light peak intensity around 460 nm can also be controlled when 0.2 wt % to 0.6 wt % of a 500 nm to 600 nm phosphorescent material is added.

[0215] As described above, in the organic EL lighting devices of Examples 1 to 3 of the present invention, compared with the organic EL lighting device of Comparative Example 1, while suppressing the peak intensity of blue light to 18 to 28%, the change in peak intensity of blue light and the change in color temperature caused by 300 hours of heating and power-on can be suppressed, and the reduction in the life of the device can be suppressed.

[0216] Furthermore, in the organic EL lighting devices of Examples 1 to 7 of the present invention, the peak intensity of blue light can be controlled simply by adjusting the amount of phosphorescent material added without changing the film thickness.

[0217] Description of Reference Numerals

[0218] 1...substrate; 2...anode; 3A...blue fluorescent light-emitting unit; 3B...green and red phosphorescent light-emitting unit; 3C...charge generation layer; 4...cathode; 10...organic EL lighting device; 25...organic EL device; 32...blue fluorescent light-emitting layer.

Claims

1. An organic EL lighting device comprising an organic EL device, wherein the organic EL device comprises a substrate, an anode, a blue fluorescent light-emitting unit, a green and red phosphorescent light-emitting unit, and a cathode, wherein: The organic EL device is configured such that the blue fluorescent light-emitting layer of the blue fluorescent light-emitting unit includes a fluorescent light-emitting host material and a phosphor material.

2. The organic EL lighting device according to claim 1, wherein The maximum wavelength of light emission of the phosphorescent material is 450nm to 650nm.

3. The organic EL lighting device according to claim 1 or 2, wherein: The amount of the phosphor material in the blue fluorescent light-emitting layer is greater than 0.3 wt %.

4. The organic EL lighting device according to claim 1 or 2, wherein: A charge generation layer is provided between the blue fluorescent light-emitting unit and the green and red phosphorescent light-emitting unit. The amount of the phosphor material in the blue fluorescent light-emitting layer is greater than or equal to 0.1 wt % and less than 0.3 wt %.

5. The organic EL lighting device according to claim 1, wherein Emits white light with a Melanopic Ratio value of 0.5 or less. The white light is configured to have a color temperature of 2000K to 3000K, a duv from a blackbody radiation curve of 0.02 or less, and a color reproducibility of 80 or more.

6. The organic EL lighting device according to claim 1, wherein The triplet excited state energy level of the fluorescent host material of the blue fluorescent light-emitting layer is deeper than the triplet excited state energy level of the phosphorescent material.

7. The organic EL lighting device according to claim 1, wherein The organic EL device and a blue light source are provided. The blue light source can emit blue light that complements the light emitted by the organic EL device.

8. The organic EL lighting device according to claim 7, wherein The blue light source is a blue OLED or a blue LED.

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