JP2008311103A - Manufacturing method of display device, and the display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a display device, capable of improving characteristics of an organic layer, when the organic layer is formed by a heat transfer method. <P>SOLUTION: A light-emitting layer 15C is formed by carrying out a plurality of times of transfer processes, by sequentially using a plurality of donor substrates, having respectively a transfer layer of a thickness which is made by dividing in the thickness direction the light-emitting layer 15C. Even when the distribution of concentration ratio (doping concentration ratio) of two or more kinds of materials (host material and dopant material) contained in each transfer layer is nonuniform in the thickness direction at the time of transfer, unevenness in the thickness direction of the distribution of dope concentration ratio as a whole for the light-emitting layer 15C is reduced, as compared with a conventional method in which the light-emitting layer 15C is formed by a single transfer process. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a display device by a thermal transfer method and a display device.

  As one method for producing an organic light-emitting element, a pattern production method using thermal transfer is disclosed (for example, Patent Document 1). In the thermal transfer method, a donor element in which a transfer layer containing a luminescent material is formed on a support material is formed, and this donor element is placed opposite to a transfer substrate for forming an organic light emitting element, and radiation is emitted in a reduced pressure environment. In this method, the transfer layer is transferred to the transfer substrate by irradiation. Conventionally, in order to form organic light emitting elements of three colors of red, green, and blue, transfer is generally performed three times in the same manner as the number of luminescent colors, but a method using a blue common layer (for example, patent document) 2) is also disclosed.

  For example, Patent Document 3 discloses a method in which a light-emitting layer including a host material and a guest material (dopant material) is formed by the thermal transfer method.

JP 2002-110350 A Japanese Patent Laying-Open No. 2005-235741 JP 2006-309955 A

  By the way, as disclosed in Patent Document 3, when a light emitting layer containing a host material and a dopant material is formed by a thermal transfer method, the transfer material transferred onto the transfer substrate has a host material and a dopant material. The concentration ratio (dope concentration ratio) is biased in the thickness direction and becomes non-uniform. This is because, due to the difference in molecular weight between the host material and the dopant material, a difference occurs in the scattering rate with respect to heat at the time of transfer, which causes the dopant ratio in the transferred layer after transfer to deviate from the desired ratio. It is believed that there is. Thus, when the dope concentration ratio is non-uniform in the thickness direction, the light emission efficiency in the light emitting layer is lowered and the light emission characteristics are deteriorated.

  Note that the deterioration of the characteristics of the organic layer due to the uneven thickness ratio distribution in the thickness direction is caused by other organic layers (for example, a hole transport layer or an electron transport layer) containing two or more materials in the organic light emitting device. In the case of the layer), it is considered that the same occurs when formed by the thermal transfer method.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a display device manufacturing method and a display device capable of improving characteristics of the organic layer when the organic layer is formed by a thermal transfer method. Is to provide.

In the display device manufacturing method of the present invention, the display region of the substrate to be transferred has a first electrode, a light emitting layer, an organic layer made of a multilayer film made of two or more materials, and a second electrode in order. The step of forming an organic light-emitting element and forming at least one of the organic layers composed of a multilayer film includes the following steps (A) to (C):
(A) Donor substrate formation step of forming at least a photothermal conversion layer on a common substrate on a region corresponding to a display region of a transfer substrate (B) A transfer layer containing the material of the one layer is formed on the photothermal conversion layer Step of forming transfer layer (C) The donor substrate and the transfer substrate are aligned with the transfer layer facing the transfer substrate, and the transfer layer is transferred to the transfer substrate by irradiating the donor substrate with radiation. Transfer step In the donor substrate forming step and the transfer layer forming step, a plurality of donor substrates each having a transfer layer having a thickness obtained by dividing the one layer in the thickness direction are formed, and the plurality of donor substrates are sequentially used. The one layer is formed by performing the transfer step a plurality of times.

  In the method for manufacturing a display device of the present invention, one layer is formed by sequentially performing a plurality of transfer processes using a plurality of donor substrates each having a transfer layer having a thickness obtained by dividing one layer in the thickness direction. Therefore, this one layer is constituted by a plurality of transfer layers laminated in the thickness direction, and the thickness of each transfer layer is compared with the case where one layer is formed by a single transfer process. Relatively thin. Thereby, even when the distribution of concentration ratios of two or more materials contained in each transfer layer is nonuniform in the thickness direction during transfer, one layer is formed by a single transfer process. In comparison, the nonuniformity in the thickness direction of the concentration ratio distribution is reduced as a whole layer.

  The display device of the present invention includes an organic light-emitting element that includes a first electrode, a light-emitting layer, an organic layer composed of a multilayer film made of two or more materials, and a second electrode in order in a display region of a transfer substrate. A donor substrate having a photothermal conversion layer in a region corresponding to the display region of the transfer substrate is formed on at least one of the organic layers formed of the multilayer film on the common substrate; After forming the transfer layer containing the material of the one layer on the photothermal conversion layer, align the donor substrate and the transfer substrate with the transfer layer facing the transfer substrate, and irradiate the donor substrate with radiation. The transfer layer is formed by transferring the transfer layer onto a substrate to be transferred, and the one layer is composed of a plurality of the transfer layers stacked in the thickness direction.

  In the display device of the present invention, one layer formed by irradiating the donor substrate with radiation and transferring the transfer layer to the transfer substrate is composed of a plurality of transfer layers stacked in the thickness direction. Therefore, the thickness of each transfer layer is relatively thin as compared with the case where this one layer is constituted by a single transfer layer. As a result, even when the distribution of concentration ratios of two or more materials contained in each transfer layer is non-uniform in the thickness direction, one layer is one compared to the case where one layer is composed of a single transfer layer. As a whole layer, the nonuniformity in the thickness direction of the concentration ratio distribution is reduced.

  According to the method for manufacturing a display device of the present invention, one layer is formed by performing a transfer process a plurality of times by sequentially using a plurality of donor substrates each having a transfer layer having a thickness obtained by dividing one layer in the thickness direction. Since it is formed, one layer is formed by a single transfer process even when the distribution of the concentration ratio of two or more materials contained in each transfer layer is not uniform in the thickness direction during transfer. Compared with the case where it is done, the nonuniformity in the thickness direction of the distribution of the concentration ratio of the entire layer can be reduced. Therefore, when the organic layer is formed by a thermal transfer method, the characteristics of the organic layer can be improved.

  In particular, when the light-emitting layer, which is the one layer, is formed so as to include the host material and the dopant material, and the light-emitting layer is formed by performing the transfer process a plurality of times using a plurality of donor substrates sequentially. Can reduce non-uniformity in the thickness direction of the distribution of the doping concentration ratio of the entire light emitting layer. Therefore, when the light emitting layer is formed by a thermal transfer method, the light emission characteristics can be improved.

  According to the display device of the present invention, one layer formed by irradiating the donor substrate with radiation and transferring the transfer layer to the transfer substrate is composed of a plurality of transfer layers stacked in the thickness direction. Therefore, even when the distribution of the concentration ratio of two or more materials contained in each transfer layer is non-uniform in the thickness direction, one layer is composed of a single transfer layer In comparison, it is possible to reduce the non-uniformity in the thickness direction of the concentration ratio distribution as a whole layer. Therefore, when the organic layer is formed by a thermal transfer method, the characteristics of the organic layer can be improved.

  In particular, when the light emitting layer as the one layer is composed of a plurality of transfer layers including a host material and a dopant material and laminated in the thickness direction, the doping concentration ratio of the entire light emitting layer It is possible to reduce non-uniformity in the thickness direction of the distribution. Therefore, when the light emitting layer is formed by a thermal transfer method, the light emission characteristics can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a configuration of a display device according to an embodiment of the present invention. This display device is used as an ultra-thin organic light emitting color display device or the like. For example, a plurality of organic light emitting elements 10R, 10G, and 10B described later are arranged in a matrix on a transfer substrate 11 made of glass. A display area 110 is formed, and a signal line driving circuit 120 and a scanning line driving circuit 130 which are drivers for displaying images are formed around the display area 110.

  A pixel drive circuit 140 is formed in the display area 110. FIG. 2 illustrates an example of the pixel driving circuit 140. The pixel driving circuit 140 is formed below the first electrode 15 described later, and includes a driving transistor Tr1 and a writing transistor Tr2, a capacitor (holding capacitor) Cs therebetween, a first power supply line (Vcc), and a second power source line (Vcc). This is an active drive circuit having an organic light emitting element 10R (or 10G, 10B) connected in series to the drive transistor Tr1 between power supply lines (GND). The driving transistor Tr1 and the writing transistor Tr2 are configured by a general thin film transistor (TFT (Thin Film Transistor)), and the configuration may be, for example, an inverted staggered structure (so-called bottom gate type) or a staggered structure (top gate type). There is no particular limitation.

  In the pixel driving circuit 140, a plurality of signal lines 120A are arranged in the column direction, and a plurality of scanning lines 130A are arranged in the row direction. An intersection between each signal line 120A and each scanning line 130A corresponds to one of the organic light emitting elements 10R, 10G, and 10B (sub pixel). Each signal line 120A is connected to the signal line drive circuit 120, and an image signal is supplied from the signal line drive circuit 120 to the source electrode of the write transistor Tr2 via the signal line 120A. Each scanning line 130A is connected to the scanning line driving circuit 130, and a scanning signal is sequentially supplied from the scanning line driving circuit 130 to the gate electrode of the writing transistor Tr2 via the scanning line 130A.

  FIG. 3 illustrates an example of a planar configuration of the display area 110. In the display area 110, an organic light emitting element 10R that generates red light, an organic light emitting element 10G that generates green light, and an organic light emitting element 10B that generates blue light are sequentially formed in a matrix. Has been. The organic light emitting elements 10R, 10G, and 10B have a rectangular planar shape, and a combination of adjacent organic light emitting elements 10R, 10G, and 10B constitutes one pixel (pixel) 10. The pixel pitch is, for example, 300 μm.

  4 shows in detail the cross-sectional configuration of the organic light emitting devices 10R, 10G, and 10B shown in FIG. The organic light emitting elements 10R, 10G, and 10B are respectively arranged from the substrate 11 side from the driving transistor Tr1 of the pixel driving circuit 140, the planarization insulating film 12, the first electrode 13 as an anode, the interelectrode insulating film 14, and the like. The organic layer 15 including the light emitting layer 15 </ b> C and the second electrode 16 as a cathode are stacked in this order.

  Such organic light emitting devices 10R, 10G, and 10B are covered with a protective film 17 such as silicon nitride (SiNx), and further, a sealing substrate 30 made of glass or the like with an adhesive layer 20 interposed between the protective film 17 and the like. Is sealed by being bonded over the entire surface.

  The drive transistor Tr1 is electrically connected to the first electrode 13 through a connection hole 12A provided in the planarization insulating film 12.

The planarization insulating film 12 is for planarizing the surface of the transferred substrate 11 on which the pixel driving circuit 140 is formed, and is formed of a material having a high pattern accuracy because a minute connection hole 12A is formed. Preferably it is. Examples of the constituent material of the planarization insulating film 12 include an organic material such as polyimide or an inorganic material such as silicon oxide (SiO ₂ ).

  The first electrode 13 is made of, for example, ITO (indium / tin composite oxide).

  The interelectrode insulating film 14 is used to ensure insulation between the first electrode 13 and the second electrode 16 and to accurately form the light emitting region in a desired shape. For example, the interelectrode insulating film 14 is made of a photosensitive resin such as polyimide. ing. The interelectrode insulating film 14 is provided with an opening corresponding to the light emitting region. The organic layer 15 and the second electrode 16 may be continuously provided not only on the light emitting region but also on the interelectrode insulating film 14, but light emission occurs in the opening of the interelectrode insulating film 14. Only.

For example, as shown in FIG. 5, the organic layer 15 has a configuration in which a hole injection layer 15A, a hole transport layer 15B, a light emitting layer 15C, and an electron transport layer 15D are stacked in this order from the first electrode 13 side. Of these, layers other than the light emitting layer 15C may be provided as necessary. The organic layer 15 may have a different configuration depending on the emission color of the organic light emitting elements 10R, 10G, and 10B. The hole injection layer 15A is a buffer layer for increasing hole injection efficiency and preventing leakage. The hole transport layer 15B is for increasing the efficiency of transporting holes to the light emitting layer 15C. The light emitting layer 15C generates light by applying an electric field to recombine electrons and holes. As will be described later in detail, the light emitting layer 15C includes a host material having charge transporting properties and a dopant material (guest material) having light emitting properties. The electron transport layer 15D is for increasing the efficiency of electron transport to the light emitting layer 15C. An electron injection layer (not shown) made of LiF, Li ₂ O, or the like may be provided between the electron transport layer 15D and the second electrode 16, for example, having a thickness of about 0.3 nm.

The hole injection layer 15A of the organic light emitting device 10R has, for example, a thickness of 5 nm to 300 nm and is 4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA) or 4 , 4 ′, 4 ″ -tris (2-naphthylphenylamino) triphenylamine (2-TNATA). The hole transport layer 15B of the organic light emitting device 10R has, for example, a thickness of 5 nm or more and 300 nm or less, and is composed of bis [(N-naphthyl) -N-phenyl] benzidine (α-NPD). The light emitting layer 15C of the organic light emitting element 10R has a thickness of 10 nm to 100 nm, for example, and is a dopant material for 9,10-di- (2-naphthyl) anthracene (ADN) (host material) which is a host material. 2,6≡bis [4′≡methoxydiphenylamino) styryl] ≡1,5≡dicyanonaphthalene (BSN) 30% by weight. The electron transport layer 15D of the organic light emitting element 10R has, for example, a thickness of 5 nm or more and 300 nm or less, and is composed of 8≡hydroxyquinoline aluminum (Alq ₃ ).

The hole injection layer 15A of the organic light emitting element 10G has, for example, a thickness of 5 nm to 300 nm and is made of m-MTDATA or 2-TNATA. The hole transport layer 15 </ b> B of the organic light emitting element 10 </ b> G has, for example, a thickness of 5 nm to 300 nm and is configured by α-NPD. The light emitting layer 15C of the organic light emitting element 10G has a thickness of 10 nm to 100 nm, for example, and is configured by mixing 5% by volume of coumarin 6 (Coumarin 6) as a dopant material with ADN as a host material. The electron transport layer 15D of the organic light emitting element 10G has a thickness of 5 nm to 300 nm, for example, and is made of Alq ₃ .

The hole injection layer 15A of the organic light emitting element 10B has, for example, a thickness of 5 nm to 300 nm, and is made of m-MTDATA or 2-TNATA. The hole transport layer 15B of the organic light emitting element 10B has, for example, a thickness of 5 nm to 300 nm and is made of α-NPD. The light emitting layer 15C of the organic light emitting element 10B has a thickness of 10 nm or more and 100 nm or less, for example, ADN as a host material, and 4,4′≡bis [2≡ {4≡ (N, N≡diphenyl) as a dopant material. Amino) phenyl} vinyl] biphenyl (DPAVBi) mixed with 2.5% by weight. The electron transport layer 15D of the organic light emitting element 10B has a thickness of 5 nm to 300 nm, for example, and is made of Alq ₃ .

  FIGS. 6A and 6B each show a detailed cross-sectional configuration example of the light emitting layer 15 shown in FIG. Specifically, in FIG. 6A, the light emitting layer 15C is composed of two transfer layers 15C1 and 15C2 (stacked in order from the hole transport layer 15B side) stacked in the thickness direction, In FIG. 6B, the light emitting layer 15C is composed of four transfer layers 15C1 to 15C4 (stacked in order from the hole transport layer 15B side) stacked in the thickness direction. That is, in the light emitting layer 15C shown in FIGS. 6A and 6B, the light emitting layer is constituted by a plurality of transfer layers that are divided and laminated in the thickness direction. Further, in each of these transfer layers 15C1 to C4, the concentration ratio (doping concentration ratio) between the host material and the dopant material is biased in the thickness direction and becomes non-uniform (in the drawing, the portion shown in dark is the doping concentration) (A region with a high ratio is shown, and a thin portion indicates a region with a low doping concentration ratio.) Specifically, the concentration of the dopant material is lower on the hole transport layer 15B side than on the electron transport layer 15D side, whereby the doping concentration ratio is also higher on the hole transport layer 15B side than on the electron transport layer 15D side. Is lower. This is because, due to the difference in molecular weight between the host material and the dopant material, a difference occurs in the scattering rate with respect to heat during transfer, which will be described later, and the dopant ratio in the transfer layer after transfer deviates from the desired ratio. It is believed that there is.

  For example, the second electrode 16 has a thickness of 5 nm or more and 50 nm or less, and is made of a single element or alloy of a metal element such as aluminum (Al), magnesium (Mg), calcium (Ca), or sodium (Na). Among these, an alloy of magnesium and silver (MgAg alloy) or an alloy of aluminum (Al) and lithium (Li) (AlLi alloy) is preferable.

The protective film 17 is for preventing moisture and the like from entering the organic layer 15 and is made of a material having low permeability and water absorption and has a sufficient thickness. Further, the protective film 17 is made of a material having a high transmittance with respect to the light generated in the light emitting layer 15C and having a transmittance of, for example, 80% or more. For example, the protective film 17 has a thickness of about 2 μm to 3 μm and is made of an inorganic amorphous insulating material. Specifically, amorphous silicon (α-Si), amorphous silicon carbide (α-SiC), amorphous silicon nitride (α-Si _1-x N _x ), and amorphous carbon (α-C) are preferable. Since these inorganic amorphous insulating materials do not constitute grains, the water permeability is low and a good protective film 17 is obtained. The protective film 17 may be made of a transparent conductive material such as ITO.

  The adhesive layer 20 is made of, for example, a thermosetting resin or an ultraviolet curable resin.

  The sealing substrate 30 is positioned on the second electrode 16 side of the organic light emitting elements 10R, 10G, and 10B, and seals the organic light emitting elements 10R, 10G, and 10B together with the adhesive layer 20, and emits organic light. It is made of a material such as glass that is transparent to the light generated by the elements 10R, 10G, and 10B. For example, a color filter 31 is provided on the sealing substrate 30, and the light generated in the organic light emitting elements 10R, 10G, and 10B is extracted and reflected by the organic light emitting elements 10R, 10G, and 10B and the wiring therebetween. It absorbs extraneous light and improves contrast.

  The color filter 31 may be provided on either side of the sealing substrate 30, but is preferably provided on the organic light emitting elements 10R, 10G, and 10B side. This is because the color filter 31 is not exposed on the surface and can be protected by the adhesive layer 20. Further, since the distance between the light emitting layer 15C and the color filter 31 is narrowed, it is possible to prevent light emitted from the light emitting layer 15C from entering the adjacent color filter 31 and causing color mixing. Because. The color filter 31 includes a red filter, a green filter, and a blue filter (all not shown), and is sequentially arranged corresponding to the organic light emitting elements 10R, 10G, and 10B.

  Each of the red filter, the green filter, and the blue filter is, for example, rectangular and has no gap. These red filter, green filter and blue filter are each composed of a resin mixed with a pigment, and by selecting the pigment, the light transmittance in the target red, green or blue wavelength region is high, The light transmittance in the wavelength range is adjusted to be low.

  This display device can be manufactured, for example, as follows.

  FIG. 7 shows a part of the flow of the manufacturing method of the display device, and FIGS. 8 to 13 show the manufacturing method of the display device in the order of steps. The display device manufacturing method shown in FIG. 7 corresponds to a manufacturing method in the case where the light emitting layer is constituted by two transfer layers, such as the light emitting layer 15C shown in FIG. 6A. Similarly, FIGS. 12A and 12B show the case where the light emitting layer is composed of two transfer layers. On the other hand, FIGS. 13A to 13D show a case where the light emitting layer is constituted by four transfer layers, for example, as in the light emitting layer 15C shown in FIG. 6B.

(Transfer substrate input)
First, a transfer substrate 11 made of the above-described material is prepared, a pixel drive circuit 140 including a drive transistor Tr1 is formed on the transfer substrate 11, and then a planarization insulation is performed by applying a photosensitive resin to the entire surface. A film 12 is formed, and the planarization insulating film 12 is patterned into a predetermined shape by exposure and development, and a connection hole 12A is formed and baked.

  Next, the first electrode 13 made of the above-described material is formed by, for example, sputtering, and is formed into a predetermined shape by, for example, dry etching. Note that an alignment mark used for alignment with the donor substrate in a transfer process described later is formed at a predetermined position of the transfer substrate 11.

  Subsequently, a photosensitive resin is applied over the entire surface of the substrate 11 to be transferred, an opening is provided corresponding to the light emitting region by, for example, photolithography, and baking is performed, whereby the interelectrode insulating film 14 is formed.

(Hole injection layer and hole transport layer deposition)
After that, the hole injection layer 15A and the hole transport layer 15B made of the above-described thickness and material are sequentially formed by, for example, vapor deposition.

  After forming the hole injection layer 15A and the hole transport layer 15B, the light emitting layer 15C is formed by a thermal transfer method using a donor substrate. The step of forming the light emitting layer 15C includes a donor substrate forming step, a transfer layer forming step, and a transfer step, as will be described below. Although details will be described later in this embodiment, a plurality of donor substrates each having a transfer layer having a thickness obtained by dividing the light emitting layer 15C in the thickness direction are formed in the donor substrate forming step and the transfer layer forming step. At the same time, the light emitting layer 15C is formed by performing the transfer process a plurality of times by sequentially using the plurality of donor substrates.

(Donor substrate formation process)
FIG. 8 shows the configuration of the donor substrate, FIG. 8A shows the planar configuration of the donor substrate, and FIG. 8B is taken along the line II-II in FIG. 8A. It represents an arrow cross-sectional configuration. For example, the donor substrate 40 has a stacked structure in which an absorption layer 42, a photothermal conversion layer 43, a protective layer 44, and a transfer layer 50 are sequentially stacked on a common substrate 41.

  The common substrate 41 is made of a material having high rigidity that can be aligned with the substrate 11 to be transferred and a material having high transparency to laser light, for example, glass.

  The absorption layer 42 is for increasing the absorption efficiency of the laser light by the photothermal conversion layer 43, and is made of, for example, amorphous silicon (a-Si). The thickness of the absorption layer 42 is desirably set so as to have the lowest reflectance in accordance with the constituent material of the photothermal conversion layer 43. For example, when the photothermal conversion layer 43 is made of molybdenum (Mo), the thickness is 34 nm to It is preferably about 35 nm. Note that the absorption layer 42 is not necessarily provided.

  The photothermal conversion layer 43 is made of a metal material having a high absorption rate such as molybdenum (Mo), titanium (Ti), chromium (Cr), or an alloy containing these. The thickness of the light-to-heat conversion layer 43 is desirably such that light does not pass through, for example, 100 nm. The photothermal conversion layer 43 is for forming the light emitting layer 15 </ b> C in the display area 110 of the non-transfer substrate 11, and is formed in the area 41 </ b> A corresponding to the display area 110 of the non-transfer substrate 11.

The protective layer 44 is for preventing oxidation and alteration of the photothermal conversion layer 43 and enhancing the characteristics of the light emitting layer 15C. For example, the protective layer 44 is made of silicon nitride (SiNx), silicon dioxide (SiO ₂ ), or ITO. Yes. The thickness of the protective layer 44 is preferably such that the light-to-heat conversion layer 43 can be well protected, for example, about 100 nm. Note that the protective layer 44 is not necessarily provided.

  The donor substrate 40 can be manufactured, for example, as follows.

  First, an amorphous silicon film (not shown) is formed on the common substrate 41 made of the above-described material by the CVD (Chemical Vapor Deposition) method, for example, with the above-described thickness. Next, for example, a molybdenum film (not shown) is formed on the amorphous silicon film by the sputtering method, for example, with the above-described thickness. Subsequently, the amorphous silicon film and the molybdenum film are selectively removed by, for example, a lithography technique, and the absorption layer 42 and the photothermal conversion layer 43 are formed in the region 41A. On the photothermal conversion layer 43, for example, by the CVD method described above. The protective layer 44 made of the thickness and material is uniformly formed.

(Transfer layer formation process)
Next, three donor substrates 40R, 40G, and 40B (40G and 40B are not shown) are prepared in the same manner as the number of luminescent colors, and as shown in FIG. On the conversion layer 43, the transfer layer 50 (in the case of the donor substrate 40R, the transfer layer 50R) including the material of the light emitting layer 15C of the organic light emitting element 10R described above is formed.

  Similarly, although not shown, a transfer layer 50G including the material of the light emitting layer 15C of the organic light emitting element 10G is formed on the donor substrate 40G, and the transfer including the material of the light emitting layer 15C of the organic light emitting element 10B is performed on the donor substrate 40B. Layer 50B is formed.

  Here, in the present embodiment, in the donor substrate forming process and the transfer layer forming process, the donor substrates 40R, 40G, and 40B for each emission color are shown in FIGS. 6A and 6B, for example. As described above, the transfer layers having thicknesses obtained by dividing the light emitting layers 15C of the organic light emitting elements 10R, 10G, and 10B in the thickness direction (for example, the two transfer layers 15C1 and 15C2 in FIG. A plurality of donor substrates each having four transfer layers 15C1 to 15C4) in (B) (in the case of FIG. 6A, two donor substrates for each emission color, in the case of FIG. 6B, each Four donor substrates for the emission color are prepared (step S101 in FIG. 7).

(Transfer process)
After that, the donor substrate 40R and the transfer substrate 11 are aligned with the transfer layer 50R facing the transfer substrate 11, the two substrates are depressurized and brought into close contact with each other, and the laser beam is emitted from the common substrate 41 side of the donor substrate 40R. Irradiate. The laser light is absorbed by the light-to-heat conversion layer 43, and as shown in FIGS. 9 and 10, the transfer layer 50 R is selectively applied to the display area 110 of the substrate 11 to be transferred with a cutting width D of, for example, 100 μm. The light emitting layer 15C of the organic light emitting element 10R is formed.

  Similarly, as shown in FIG. 11, the light emitting layer 15C of the organic light emitting element 10G is formed and the light emitting layer 15C of the organic light emitting element 10B is formed.

  Here, in this embodiment, for example, as shown in FIGS. 12A and 12B and FIGS. 13A to 13D, each emission color produced in the donor substrate forming step and the transfer layer forming step. The light emitting layers 15C of the organic light emitting devices 10R, 10G, and 10B are formed by sequentially performing a plurality of such transfer processes using a plurality of donor substrates (step S101) for the substrate (steps S102 to S102 in FIG. S105). Specifically, as shown in FIG. 6A, when the light emitting layer 15C is formed by two transfer layers 15C1 and 15C2, first, a transfer layer (transfer layer 15C1) of the transfer substrate 11 and the first donor substrate. Are aligned with each other (step S102), and a first transfer process is performed by irradiating a laser beam, whereby the hole transport layer 15B is formed as shown in FIG. Then, the transfer layer 15C1 is formed (step S103). Next, the transfer substrate 11 and the transfer layer (corresponding to the transfer layer 15C2) of the second donor substrate are faced to perform alignment (step S104), and a second transfer process is performed by irradiating laser light. Thus, as shown in FIG. 12B, the transfer layer 15C2 is formed on the transfer layer 15C1 (step S105). In this way, the light emitting layer 15C shown in FIG. 6A is formed. As shown in FIG. 6B, when the light emitting layer 15C is formed by the four transfer layers 15C1 to 15C4, the transfer process is performed four times in the same manner, so that FIGS. The light emitting layer 15C is formed as shown in FIG.

  After forming the light emitting layer 15C of the organic light emitting devices 10R, 10G, and 10B, the electron transport layer 15D, the electron injection layer (not shown), and the second electrode 16 are formed by, for example, vapor deposition. In this way, the organic light emitting elements 10R, 10G, and 10B are formed.

  After the organic light emitting elements 10R, 10G, and 10B are formed, the protective film 17 made of the above-described material is formed thereon. As a method for forming the protective film 17, a film forming method in which the energy of the film forming particles is small to such an extent that the protective film 17 is not affected, for example, a vapor deposition method or a CVD method is preferable. Further, it is desirable that the protective film 17 be performed continuously with the formation of the second electrode 16 without exposing the second electrode 16 to the atmosphere. It is because it can suppress that the organic layer 15 deteriorates with the water | moisture content or oxygen in air | atmosphere. Further, in order to prevent a decrease in luminance due to deterioration of the organic layer 15, the film forming temperature of the protective film 17 is set to room temperature, and in order to prevent the protective film 17 from being peeled off, the film stress is minimized. It is desirable to film.

(Post-process)
Next, it progresses to a post process. Here, for example, a red filter material is formed on the sealing substrate 30 made of the above-described material by applying a red filter material by spin coating or the like, and patterning and baking by a photolithography technique. Subsequently, similarly to the red filter, a blue filter and a green filter are sequentially formed.

  After that, an adhesive layer 20 is formed on the protective film 17, and the sealing substrate 30 is bonded with the adhesive layer 20 in between. In that case, it is preferable to arrange | position the surface in which the color filter 31 of the sealing substrate 30 was formed in the organic light emitting element 10R, 10G, 10B side. Thus, the display device shown in FIG. 1 is completed.

  In the display device thus obtained, a scanning signal is supplied to each pixel from the scanning line driving circuit 130 via the gate electrode of the writing transistor Tr2, and an image signal is supplied from the signal line driving circuit 120 to the writing transistor. It is held in the holding capacitor Cs via Tr2. That is, the driving transistor Tr1 is controlled to be turned on / off in accordance with the signal held in the holding capacitor Cs, whereby the driving current Id is injected into each of the organic light emitting elements 10R, 10G, and 10B, so that holes, electrons, Recombine to emit light. This light is transmitted through the second electrode 16, the color filter 31 and the sealing substrate 30 and extracted.

  Here, in the present embodiment, a plurality of transfer layers (in which a light emitting layer 15C formed by irradiating the donor substrate 40 with radiation and transferring the transfer layer 50 to the transfer substrate 11 is laminated in the thickness direction). Compared with the conventional case (corresponding to a comparative example shown in FIG. 14A described later) in which the light emitting layer 15C is configured by a single transfer layer. The thickness of each transfer layer is relatively thin. As a result, even when the concentration ratio distribution (dope concentration ratio) of two or more kinds of materials (host material and dopant material) included in each transfer layer is non-uniform in the thickness direction, the light emitting layer 15C is a single transfer. Compared with the case where the layers are configured (comparative example), the non-uniformity in the thickness direction of the distribution of the doping concentration ratio is reduced as the entire light emitting layer 15C.

  Here, FIGS. 14A to 14E show cross-sectional configurations of the light emitting layers according to the comparative example and the reference example. Specifically, FIG. 14A shows a light emitting layer 105C according to a comparative example (consisting of a single transfer layer), and FIG. 14B shows a light emitting layer 205C according to Reference Example 1 (deposition method). 14C shows a light emitting layer 305C according to Reference Example 2 (transfer layer 305C1 formed by vapor deposition at a doping concentration ratio = 7% and a doping concentration ratio = 12%). 14 (D) shows a light emitting layer 405C according to Reference Example 3 (dope concentration ratio = 12% and formed by the vapor deposition method). 405C1 and a transfer layer 405C2 formed by vapor deposition at a doping concentration ratio = 7%), FIG. 14E shows a light emitting layer 505C according to Reference Example 4 (doping concentration ratio = 7%). Formed by vapor deposition method Transfer layer 505C1, transfer layer 505C2 formed by vapor deposition at a doping concentration ratio = 10%, and transfer layer 505C3 formed by vapor deposition at a doping concentration ratio = 12%), respectively) Represents. 15 corresponds to Example 1 (corresponding to the light-emitting layer 15C having the cross-sectional configuration shown in FIG. 6A) and Example 2 (corresponding to the light-emitting layer 15C having the cross-sectional configuration shown in FIG. 6B). The light emission efficiency of the light emitting layer according to Comparative Example and Reference Example 1 is expressed in relation to the wavelength (nm) of the emitted light. FIG. 16A shows the luminous efficiency of the light emitting layers according to Reference Examples 1 to 4 in relation to the wavelength (nm) of the emitted light. FIG. 16B shows the reference example. 1 represents the time variation (lifetime characteristics; LT characteristics) of the light emission luminance of the light emitting layers according to 1 to 4 respectively. In addition, these Examples 1, 2, a comparative example, and reference examples 1-4 are each about the organic light emitting element which has a green light emitting layer.

  First, from FIG. 15, the light emission efficiency is improved in Examples 1 and 2 in which the light emitting layer 15C is constituted by a plurality of transfer layers, compared to the comparative example in which the light emitting layer 105C is constituted by a single transfer layer. It can be seen that the light emitting layer 205C is approaching the value of the luminous efficiency of Reference Example 1 formed by vapor deposition. Note that the luminous efficiency of the light emitting layer formed by the vapor deposition method is higher than that of the light emitting layer formed by the thermal transfer method. In the vapor deposition method, the non-uniformity in the thickness direction of the dope concentration ratio as in the case of the thermal transfer method is present. This is probably because it hardly occurs. Further, as indicated by an arrow P1 in the figure, the light emitting layer 15C is laminated in the thickness direction as compared with the first embodiment in which the light emitting layer 15C is composed of two transfer layers 15C1 and 15C2 laminated in the thickness direction. In Example 2 configured by the four transfer layers 15C1 to 15C4 thus formed, the light emission efficiency was further improved, so that the number of transfer layers (the number of transfer processes) constituting the light emitting layer 15C increased. Since the thickness of each transfer layer becomes thinner, it can be seen that the non-uniformity in the thickness direction of the distribution of the doping concentration ratio of the entire light emitting layer 15C is further reduced.

  16A and 16B, the doping concentration in the thickness direction in the light emitting layer 305C and the light emitting layer 505C is compared with that in Reference Example 1 in which the doping concentration ratio in the thickness direction in the light emitting layer 205C is uniform. In Reference Examples 2 and 4 in which the ratio is non-uniform, the light emission efficiency and life characteristics are deteriorated, whereas in Reference Example 3 in which the thickness concentration in the light emitting layer 405C is non-uniform, the light emission efficiency and Since the lifetime characteristics are hardly deteriorated, at least in the green light-emitting layer, the hole transport layer 15B side (first electrode 13 side) is more than the doping concentration ratio on the electron transport layer 15D side (second electrode 16 side). It can be seen that the higher the dope concentration ratio, the better the light emission efficiency and life characteristics. This is because at least in the green light-emitting layer, the thickness region contributing to light emission is considered to be on the hole transport layer 15B side (first electrode 13 side).

  Therefore, from the results of FIGS. 16A and 16B, for example, as shown in FIGS. 17A and 17B, when performing the transfer process a plurality of times, it contributes to light emission in the light emitting layer 15C. If the thin transfer layer is selectively transferred in the thickness region (in this case, the thickness region on the hole transport layer 15B side), the thickness of the dope concentration ratio distribution is selectively selected in the thickness region contributing to light emission. It is considered that the non-uniformity in direction is reduced and the light emission characteristics are further improved.

  Thus, according to the method for manufacturing the display device of the present embodiment, the transfer process is performed a plurality of times by sequentially using a plurality of donor substrates each having a transfer layer having a thickness obtained by dividing the light emitting layer 15C in the thickness direction. Since the light emitting layer 15C is thus formed, the concentration ratio distribution (dope concentration ratio) of two or more kinds of materials (host material and dopant material) contained in each transfer layer is in the thickness direction during transfer. Even in the case of non-uniformity, compared with the conventional case where the light emitting layer 15C is formed by a single transfer process (the above comparative example), the nonuniformity in the thickness direction of the distribution of the doping concentration ratio of the entire light emitting layer 15C is reduced. Can be reduced. Therefore, when the light emitting layer 15C is formed by the thermal transfer method, it is possible to improve the light emission characteristics.

  Further, in the donor substrate forming step and the transfer layer forming step, a plurality of donor substrates are selectively transferred so that a thin transfer layer is selectively transferred in a thickness region contributing to light emission in the light emitting layer 15C when the transfer step is performed a plurality of times. In this way, in the thickness region contributing to light emission, the nonuniformity in the thickness direction of the distribution of the doping concentration ratio can be selectively reduced, and the light emission characteristics can be further improved. Specifically, in the case of the light emitting layer 15C (green light emitting layer) of the organic light emitting element 10G which is a green light emitting element, the thickness is selected in the thickness region on the first electrode 13 side (hole transport layer 15B side) of the light emitting layer 15C. If a plurality of donor substrates are formed so that an extremely thin transfer layer is transferred, the light emission characteristics of the organic light emitting element 10G can be further improved.

  Further, according to the display device of the present embodiment, the light emitting layer 15C formed by irradiating the donor substrate 40 with radiation and transferring the transfer layer 50 to the transfer substrate 11 is laminated in the thickness direction. Since it is composed of a plurality of transfer layers (transfer layers 15C1, 15C2, etc.), the concentration ratio distribution (dope concentration ratio) of two or more materials (host material and dopant material) contained in each transfer layer Even when the light emitting layer 15C is non-uniform in the thickness direction, the distribution of the doping concentration ratio of the light emitting layer 15C as a whole is non-uniform in the thickness direction as compared with the case where the light emitting layer 15C is composed of a single transfer layer (comparative example). Can be reduced. Therefore, when the light emitting layer 15C is formed by the thermal transfer method, it is possible to improve the light emission characteristics.

  In addition, when the transfer layer is selectively thinned in the thickness region contributing to light emission in the light emitting layer 15C, the distribution of the doping concentration ratio is selectively distributed in the thickness region contributing to light emission. The nonuniformity in the thickness direction can be reduced, and the light emission characteristics can be further improved.

(Modules and application examples)
Hereinafter, application examples of the display device described in each of the above-described embodiments will be described. The display device in each of the above embodiments is a television device, a digital camera, a notebook personal computer, a mobile terminal device such as a mobile phone, or a video camera, such as an externally input video signal or an internally generated video signal. The present invention can be applied to display devices for electronic devices in various fields that display images or videos.

(module)
The display device of each of the above embodiments is incorporated into various electronic devices such as application examples 1 to 5 described later, for example, as a module as illustrated in FIG. In this module, for example, a region 210 exposed from the sealing substrate 30 and the adhesive layer 20 is provided on one side of the transfer substrate 11, and the signal line driving circuit 120 and the scanning line driving circuit 130 are provided in the exposed region 210. The wiring is extended to form an external connection terminal (not shown). The external connection terminal may be provided with a flexible printed circuit (FPC) 220 for signal input / output.

(Application example 1)
FIG. 19 illustrates an appearance of a television device to which the display device of each of the above embodiments is applied. The television apparatus has, for example, a video display screen unit 300 including a front panel 310 and a filter glass 320, and the video display screen unit 300 is configured by the display device according to each of the above embodiments. .

(Application example 2)
FIG. 20 shows the appearance of a digital camera to which the display device of each of the above embodiments is applied. The digital camera includes, for example, a flash light emitting unit 410, a display unit 420, a menu switch 430, and a shutter button 440. The display unit 420 is configured by the display device according to each of the above embodiments. Yes.

(Application example 3)
FIG. 21 shows an appearance of a notebook personal computer to which the display device of each of the above embodiments is applied. The notebook personal computer has, for example, a main body 510, a keyboard 520 for inputting characters and the like, and a display unit 530 for displaying an image. The display unit 530 is a display according to each of the above embodiments. It is comprised by the apparatus.

(Application example 4)
FIG. 22 shows the appearance of a video camera to which the display device of each of the above embodiments is applied. This video camera has, for example, a main body 610, a subject photographing lens 620 provided on the front side surface of the main body 610, a start / stop switch 630 at the time of photographing, and a display 640. Reference numeral 640 denotes the display device according to each of the above embodiments.

(Application example 5)
FIG. 23 shows the appearance of a mobile phone to which the display device of each of the above embodiments is applied. For example, the mobile phone is obtained by connecting an upper housing 710 and a lower housing 720 with a connecting portion (hinge portion) 730, and includes a display 740, a sub-display 750, a picture light 760, and a camera 770. Yes. The display 740 or the sub-display 750 is configured by the display device according to each of the above embodiments.

  While the present invention has been described with reference to the embodiments and examples, the present invention is not limited to these embodiments and the like, and various modifications are possible. For example, in the above-described embodiment and the like, the case of irradiating laser light in the transfer step has been described, but other radiation such as a lamp may be irradiated.

  Further, in the above-described embodiment and the like, the case where the transfer is performed three times in the same manner as the number of emitted colors has been described, but only the red and green light emitting layers 15C are formed by the thermal transfer method, and then the blue common layer is entirely deposited by the vapor deposition method. A film may be formed. At this time, in the organic light emitting device 10R, the light emitting layer 15C including the red light emitting material and the blue common layer including the blue light emitting material are formed. However, energy transfer occurs in red having the lowest energy level, and red light emission occurs. Becomes dominant. In the organic light emitting device 10G, a light emitting layer 15C containing a green light emitting material and a blue common layer containing a blue light emitting material are formed. Energy transfer occurs in green having a lower energy level, and green light emission is dominant. It becomes. Since the organic light emitting device 10B has only the blue common layer, blue light emission occurs.

  In the above-described embodiment and the like, the organic light emitting elements are organic light emitting elements 10R (red light emitting elements) having a red light emitting layer 15C, organic light emitting elements 10G (green light emitting elements) having a green light emitting layer 15C, and blue light emitting elements. The organic light-emitting element 10B (blue light-emitting element) having the light-emitting layer 15C is formed, and the light-emitting layers 15C of red, green, and blue are formed by performing the transfer process a plurality of times using a plurality of donor substrates sequentially. However, at least the green light emitting layer 15C of the red, green and blue light emitting layers 15C may be formed by a plurality of transfer processes. This is because the green light emitting layer 15C originally has a higher doping concentration ratio than the red or blue light emitting layer 15C. Therefore, if the present invention is applied to such a green light emitting layer 15C, the red or blue light emitting layer is used. This is because the light emission characteristics can be further improved as compared with the case of applying only at 15C.

  For the same reason, for example, the number of transfer steps when forming the green light-emitting layer 15C is the same as the number of transfer steps when forming the red light-emitting layer 15C and the time when forming the blue light-emitting layer 15C. If a plurality of donor substrates are formed so as to be larger than the number of transfer steps, the number of transfer steps when forming the green light emitting layer 15C is the transfer when forming the red or blue light emitting layer 15C. Compared with the case where the number of steps is smaller than that, the light emission characteristics can be further improved.

  In the above-described embodiment and the like, the case where the transfer process is performed a plurality of times using a plurality of donor substrates sequentially when forming in the light emitting layer 15C of the organic layers 15 included in the organic light emitting element has been described. If the organic layer other than the light emitting layer 15C (such as the hole injection layer 15A, the hole transport layer 15B, or the electron transport layer 15D) is also configured to include two or more types of materials, The present invention can be applied when another organic layer is formed by the transfer process used. When comprised in this way, the characteristic deterioration of the organic layer by the thickness direction nonuniformity of the distribution of the density | concentration ratio of two or more materials in another organic layer can be reduced, and the characteristic which the organic layer has is improved. It becomes possible.

  Furthermore, for example, the material and thickness of each layer described in the above embodiments and the like, or the film formation method, film formation conditions, and laser light irradiation conditions are not limited, and may be other materials and thicknesses. Alternatively, other film forming methods, film forming conditions, and irradiation conditions may be used. For example, the first electrode 13 may be made of IZO (indium / zinc composite oxide) in addition to ITO. Moreover, you may comprise the 1st electrode 13 with a reflective electrode. In that case, the first electrode 13 has a thickness of, for example, 100 nm or more and 1000 nm or less, and it is desirable that the first electrode 13 has a reflectance as high as possible in order to increase the light emission efficiency. For example, the material constituting the first electrode 13 is a metal such as chromium (Cr), gold (Au), platinum (Pt), nickel (Ni), copper (Cu), tungsten (W), or silver (Ag). An elemental element or an alloy is mentioned. Further, for example, the first electrode 13 may have a dielectric multilayer film.

  In addition, for example, in the above-described embodiment, the first electrode 13, the organic layer 15, and the second electrode 16 are sequentially stacked on the transfer substrate 11 from the transfer substrate 11 side, and the sealing substrate The case where light is extracted from the side 30 has been described. However, the second electrode 16, the organic layer 15, and the first electrode 13 are placed on the transfer substrate 11 on the transfer substrate 11 by reversing the stacking order. It is also possible to stack the layers in order from the side and take out light from the side of the substrate 11 to be transferred.

  Furthermore, for example, in the above-described embodiment, the case where the first electrode 13 is an anode and the second electrode 16 is a cathode has been described. However, the anode and the cathode are reversed, and the first electrode 13 is a cathode, The electrode 16 may be an anode. Further, the first electrode 13 is a cathode and the second electrode 16 is an anode, and the second electrode 16, the organic layer 15, and the first electrode 13 are stacked on the transfer substrate 11 in this order from the transfer substrate 11 side. In addition, light can be extracted from the transfer substrate 11 side.

In addition, in the above-described embodiment and the like, the configuration of the organic light emitting elements 10R, 10G, and 10B has been specifically described. However, it is not necessary to provide all layers, and other layers are further provided. Also good. For example, between the first electrode 13 and the organic layer 15, chromium oxide (III) (Cr ₂ O ₃ ), ITO (Indium-Tin Oxide: mixed oxide film of indium (In) and tin (Sn)), etc. A hole injecting thin film layer may be provided.

  Furthermore, in the above-described embodiment and the like, the case where the second electrode 16 is configured by a semi-transmissive electrode and the light generated in the light emitting layer 15C is extracted from the second electrode 16 side has been described. You may make it take out from the 1 electrode 13 side. In this case, it is desirable to increase the luminous efficiency so that the second electrode 16 has as high a reflectance as possible.

  In addition, in each of the above embodiments and the like, the case of an active matrix display device has been described, but the present invention can also be applied to a passive matrix display device. Furthermore, the configuration of the pixel driving circuit for active matrix driving is not limited to that described in the above embodiments and the like, and a capacitor and a transistor may be added as necessary. In that case, a necessary driving circuit may be added in addition to the signal line driving circuit 120 and the scanning line driving circuit 130 described above in accordance with the change of the pixel driving circuit.

It is a figure showing the structure of the display apparatus which concerns on the 1st Embodiment of this invention. It is a figure showing an example of the pixel drive circuit shown in FIG. It is a top view showing the structure of the display area shown in FIG. It is sectional drawing showing the structure of the organic light emitting element shown in FIG. It is sectional drawing showing the detailed structure of the organic layer shown in FIG. It is sectional drawing showing an example of the detailed structure of the light emitting layer shown in FIG. It is a flowchart showing a part of process of the manufacturing method of the display apparatus shown in FIG. FIG. 8 is a plan view and a cross-sectional view illustrating a configuration of a donor substrate used in the manufacturing method illustrated in FIG. 7. It is a figure for demonstrating a transfer process. It is a figure for demonstrating the process following FIG. It is a figure for demonstrating the process following FIG. It is sectional drawing for demonstrating an example of the process of dividing and forming a light emitting layer. It is sectional drawing for demonstrating the other example of the process of dividing and forming a light emitting layer. It is sectional drawing showing the structure of the light emitting layer which concerns on a comparative example and a reference example. FIG. 6 is a characteristic diagram showing the luminous efficiency of the light emitting layers according to Examples 1 and 2, Comparative Example and Reference Example 1. It is a characteristic view showing the time change of the luminous efficiency of the light emitting layer which concerns on the reference examples 1-4, and light emission luminance. It is sectional drawing showing the structure of the light emitting layer which concerns on the modification of this invention. It is a top view showing schematic structure of the module containing the display apparatus of each said embodiment. It is a perspective view showing the external appearance of the application example 1 of the display apparatus of each said embodiment. (A) is a perspective view showing the external appearance seen from the front side of the application example 2, (B) is a perspective view showing the external appearance seen from the back side. 12 is a perspective view illustrating an appearance of application example 3. FIG. 14 is a perspective view illustrating an appearance of application example 4. FIG. (A) is a front view of the application example 5 in an open state, (B) is a side view thereof, (C) is a front view in a closed state, (D) is a left side view, and (E) is a right side view, (F) is a top view and (G) is a bottom view.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Pixel, 10R, 10G, 10B ... Organic light emitting element, 11 ... Transfer substrate, 12 ... Planarization insulating film, 13 ... First electrode, 14 ... Interelectrode insulating film, 15 ... Organic layer, 15A ... Hole injection 15B ... hole transport layer, 15C ... light emitting layer, 15C1-15C4 ... transfer layer (light emitting layer), 15D ... electron transport layer, 16 ... second electrode, 17 ... protective film, 20 ... adhesive layer, 30 ... sealing Stopping substrate, 31 ... color filter, 40 ... donor substrate, 41 ... common substrate, 42 ... absorption layer, 43 ... photothermal conversion layer, 44 ... protective layer, 50R, 50G, 50B ... transfer layer.

Claims (9)

Manufacture of a display device in which a display region of a transfer substrate includes a first electrode, a light emitting layer, an organic layer made of a multilayer film made of two or more materials, and an organic light emitting element having a second electrode in order A method,
The step of forming at least one of the organic layers composed of the multilayer film is as follows:
On the common substrate, a donor substrate forming step of forming at least a photothermal conversion layer in a region corresponding to the display region of the transfer substrate;
A transfer layer forming step of forming a transfer layer containing the material of the one layer on the photothermal conversion layer;
A transfer step in which the donor substrate and the transfer substrate are aligned with the transfer layer facing the transfer substrate, and the transfer layer is transferred to the transfer substrate by irradiating the donor substrate with radiation. And including
In the donor substrate forming step and the transfer layer forming step, a plurality of donor substrates each having a transfer layer having a thickness obtained by dividing the one layer in the thickness direction are formed, and the plurality of donor substrates are sequentially used. The method for manufacturing a display device, wherein the one layer is formed by performing the transfer step a plurality of times. The light emitting layer as the one layer is formed so as to include a host material and a dopant material, and the light emitting layer is formed by performing the transfer step a plurality of times using the plurality of donor substrates sequentially. The manufacturing method of the display device according to claim 1, wherein In the donor substrate forming step and the transfer layer forming step, the plurality of the transfer layers are selectively transferred in a thickness region contributing to light emission in the light emitting layer when the transfer step is performed a plurality of times. A method for manufacturing a display device according to claim 2, wherein the donor substrate is formed. The organic light emitting device is formed of a red light emitting device having a red light emitting layer, a green light emitting device having a green light emitting layer, and a blue light emitting device having a blue light emitting layer,
The at least green light-emitting layer among the red light-emitting layer, the green light-emitting layer, and the blue light-emitting layer is formed by performing the transfer step a plurality of times using the plurality of donor substrates sequentially. 3. A method for manufacturing the display device according to 2. In the donor substrate forming step and the transfer layer forming step, a thin transfer layer is selectively transferred in the thickness region on the first electrode side of the green light emitting layer when the transfer step is performed a plurality of times. The method for manufacturing a display device according to claim 4, wherein the plurality of donor substrates are formed. The red light emitting layer, the green light emitting layer, and the blue light emitting layer are respectively formed by performing the transfer step a plurality of times using the plurality of donor substrates sequentially,
The number of transfer steps when forming the green light emitting layer is larger than the number of transfer steps when forming the red light emitting layer and the number of transfer steps when forming the blue light emitting layer. The method for manufacturing a display device according to claim 4, wherein the plurality of donor substrates are formed. A display device comprising a display region of a substrate to be transferred, which includes a first electrode, a light emitting layer, an organic layer composed of a multilayer film made of two or more materials, and an organic light emitting element sequentially having a second electrode. And
At least one of the multilayer organic layers is formed on a common substrate by forming a donor substrate having a photothermal conversion layer in a region corresponding to a display region of the transfer substrate, and on the photothermal conversion layer. After forming the transfer layer including the material of the one layer, the donor substrate and the transfer target substrate are aligned with the transfer layer facing the transfer target substrate, and the donor substrate is irradiated with radiation. The transfer layer is formed by transferring the transfer layer to the transfer substrate,
The one layer is constituted by a plurality of the transfer layers laminated in the thickness direction. The display device according to claim 7, wherein the light-emitting layer that is the one layer includes a host material and a dopant material, and includes a plurality of the transfer layers stacked in a thickness direction. The display device according to claim 8, wherein the transfer layer is selectively thinned in a thickness region contributing to light emission in the light emitting layer.

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