KR102364411B1 - Quantum dot light-emitting device, method of fabricating the same and display device including quantum dot light-emitting device - Google Patents

Abstract

The present invention provides a quantum dot light-emitting device capable of presenting overall effect and improving emission performance by a quantum dot by reducing the number of times of a patterning process for a quantum dot layer, a method of fabricating the same, and a display device including the quantum dot light-emitting device. The quantum dot light-emitting device may comprise a first pixel region, a second pixel region, and a third pixel region to generate light of different colors, respectively. The quantum dot light-emitting device may include a layered structure provided between first and second electrode members spaced from each other to convert electric energy into optical energy. The layered structure may include: a first quantum dot light emitting part arranged corresponding to a first pixel region to include a first quantum dot for emitting light of a first color; a second quantum dot light emitting part arranged corresponding to a second pixel region to include a second quantum dot for emitting light of a second color; and an inorganic common layer provided through the first pixel region, the second pixel region, and the third pixel region. The inorganic common layer may include a first region corresponding to the third pixel region and a second region corresponding to the second pixel region and the second pixel region. The first region may be a third color light emitting part.

Description

Quantum dot light-emitting device, manufacturing method thereof, and display device including quantum dot light-emitting device {Quantum dot light-emitting device, method of fabricating the same and display device including quantum dot light-emitting device}

The present invention relates to a light emitting device, a display device, and a manufacturing method thereof, and more particularly, to a quantum dot light emitting device, a manufacturing method thereof, and a display device including the quantum dot light emitting device.

A quantum dot is a crystalline semiconductor having a size of several to several tens of nanometers, and may be composed of hundreds to thousands of atoms. Because quantum dots are very small in size, they have a large surface area per unit volume, and most atoms can exist on the crystal surface. Since these quantum dots have discontinuous energy levels due to the quantum confinement effect, they may exhibit optical/electrical properties different from those of bulk semiconductors having continuous energy bands.

Recently, research has been conducted to apply quantum dots to various optical and electronic devices. In particular, interest in quantum dot light emitting devices using the electroluminescence phenomenon of quantum dots is increasing. The quantum dot light emitting device can be used as a high-efficiency and low-power light emitting device, and in particular, it is attracting attention as one of the next-generation light emitting devices due to its narrow emission spectrum and easy wavelength control characteristics.

However, in manufacturing a full-color display device using a self-luminous type quantum dot light-emitting device, that is, a self-emitting quantum dot light-emitting diode (QLED), a solution process-based Since the patterning step of the quantum dot layer must be applied several times, the manufacturing process is difficult and the performance of the quantum dot layer is deteriorated. Although various solution process methods including inkjet printing have been developed, the quantum dot layer patterned first is subjected to a number of solvents and ultraviolet rays ( UV ray), the quantum dot layer may be damaged or severe performance degradation may occur. In addition, if the solution process is performed several times, the exposure time of the quantum dots to air increases, which may adversely affect the stability of the quantum dots. Accordingly, for the practical industrialization of self-luminous QLEDs, a technology capable of minimizing the exposure time of the quantum dot layer to external light, air, solvent, etc. and easily securing the performance and stability of the quantum dot layer is required.

The technical problem to be achieved by the present invention is to provide a quantum dot light emitting device having a configuration capable of reducing the number of patterning processes of the quantum dot layer, thereby obtaining various effects, and at the same time improving the light emitting performance by the quantum dot, and a method for manufacturing the same.

In addition, the technical problem to be achieved by the present invention is to provide a quantum dot display device to which the quantum dot light emitting device is applied and a method for manufacturing the same.

The problem to be solved by the present invention is not limited to the problems mentioned above, and other problems not mentioned will be understood by those skilled in the art from the following description.

According to an embodiment of the present invention, a quantum dot light emitting device including a first pixel region, a second pixel region, and a third pixel region emitting light of different colors, wherein the first electrode member and the second electrode are spaced apart from each other It is disposed between the members and has a stacked structure for converting electrical energy supplied through the first and second electrode members into optical energy, wherein the stacked structure is disposed to correspond to the first pixel area, a first quantum dot light emitting unit containing a first quantum dot for light emission of a first color; a second quantum dot light emitting unit disposed to correspond to the second pixel area and containing a second quantum dot for emitting a second color; and an organic common layer commonly provided over the first pixel area, the second pixel area, and the third pixel area, wherein the organic common layer is a third pixel area corresponding to the third pixel area. A quantum dot light emitting device is provided, comprising a first region and a second region corresponding to the first pixel region and the second pixel region, wherein the first region is a third color light emitting unit.

The first pixel area may be a red pixel area, the second pixel area may be a green pixel area, and the third pixel area may be a blue pixel area. The first quantum dot light emitting part may be a red quantum dot light emitting part, the second quantum dot light emitting part may be a green quantum dot light emitting part, and the third color light emitting part may be a blue light emitting part.

The second region of the organic common layer may be a substantially non-emission region.

The second region of the organic common layer may function as a charge transport region or an exciton transport region with respect to the first quantum dot light emitting unit and the second quantum dot light emitting unit.

The organic common layer may have a shape extending to the third pixel area while covering upper surfaces of each of the first quantum dot light emitting part and the second quantum dot light emitting part.

The organic common layer may not contain quantum dots.

The organic common layer may be entirely made of the same material in the first pixel area, the second pixel area, and the third pixel area.

The organic common layer may include a host material and a dopant material for blue light emission.

The first quantum dot light emitting unit, the second quantum dot light emitting unit, and the organic common layer may constitute a first stacked body, and the stacked structure may include a hole transport layer provided between the first electrode member and the first stacked body. ; and an electron transport layer provided between the second electrode member and the first laminate.

The stacked structure may include a hole injection layer provided between the first electrode member and the hole transport layer; and an electron injection layer provided between the second electrode member and the electron transport layer. It may further include at least one of.

The electron transport layer may contact the organic common layer.

According to another embodiment of the present invention, a quantum dot display device having the above-described quantum dot light emitting device is provided.

According to another embodiment of the present invention, there is provided a method of manufacturing a quantum dot light emitting device including a first pixel region, a second pixel region, and a third pixel region emitting light of different colors, the method comprising the steps of: forming a first electrode member ; forming a stacked structure on the first electrode member; and forming a second electrode member on the laminated structure, wherein the forming of the laminated structure includes a first quantum dot disposed corresponding to the first pixel area and containing a first quantum dot for emitting light of a first color. forming a first quantum dot light emitting unit and a second quantum dot light emitting unit disposed to correspond to the second pixel area and containing a second quantum dot for light emission of a second color; and forming an organic common layer commonly provided over the first pixel area, the second pixel area, and the third pixel area, wherein the organic common layer is a first corresponding to the third pixel area. There is provided a method of manufacturing a quantum dot light emitting device comprising a region and a second region corresponding to the first pixel region and the second pixel region, wherein the first region is a third color light emitting unit.

The first pixel area may be a red pixel area, the second pixel area may be a green pixel area, and the third pixel area may be a blue pixel area. The first quantum dot light emitting part may be a red quantum dot light emitting part, the second quantum dot light emitting part may be a green quantum dot light emitting part, and the third color light emitting part may be a blue light emitting part.

The second region of the organic common layer may be a substantially non-emission region, and may act as a charge transport region or an exciton transport region with respect to the first quantum dot light emitting unit and the second quantum dot light emitting unit.

The organic common layer may be formed to extend to the third pixel area while covering upper surfaces of each of the first quantum dot light emitting part and the second quantum dot light emitting part.

The organic common layer may be formed without a process of patterning in units of pixel areas.

The first quantum dot light emitting unit, the second quantum dot light emitting unit, and the organic common layer may constitute a first stacked body, and the forming of the stacked structure may be performed between the first electrode member and the first stacked body. forming a hole transport layer; and forming an electron transport layer between the second electrode member and the first laminate.

The forming of the stacked structure may include: forming a hole injection layer between the first electrode member and the hole transport layer; and forming an electron injection layer between the second electrode member and the electron transport layer. It may further include at least one of.

The electron transport layer may be formed to contact the organic common layer.

According to another embodiment of the present invention, a quantum dot light emitting device including a first pixel region and a second pixel region emitting light of different colors, the quantum dot light emitting device disposed between the first electrode member and the second electrode member spaced apart from each other and a stacked structure for converting electrical energy supplied through the first and second electrode members into optical energy, wherein the stacked structure is disposed to correspond to the first pixel area and emits light of a first color a first quantum dot light emitting unit containing a first quantum dot for; and an organic common layer commonly provided over the first pixel area and the second pixel area, wherein the organic common layer includes a first area corresponding to the second pixel area and the first area A quantum dot light emitting device having a second area corresponding to the pixel area, wherein the first area is a second color light emitting part is provided.

The first pixel area may be a red pixel area or a green pixel area, and the second pixel area may be a blue pixel area. The first quantum dot light emitting unit may be a red quantum dot light emitting unit or a green quantum dot light emitting unit, and the second color light emitting unit may be a blue light emitting unit.

According to embodiments of the present invention, a quantum dot light emitting device having a configuration that can obtain various effects by reducing the number of patterning processes of the quantum dot layer and further improve the light emitting performance by the quantum dot, and a quantum dot display device to which the same is applied can be implemented.

In particular, if the method according to the embodiments is used, in manufacturing a full-color display device including red, green, and blue pixels, the cost is reduced and production by omitting the patterning process for the blue pixels. It can have the effect of greatly reducing the required time. In addition, through energy transfer (ie, Forster resonant energy transfer) from the organic common layer having a large bandgap to the quantum dot layer having a relatively small bandgap, the performance of the quantum dot layer pixel may be improved.

1 is a perspective view showing a quantum dot light-emitting device according to an embodiment of the present invention.
2A to 2D are cross-sectional views illustrating a method of manufacturing a quantum dot light emitting device according to an embodiment of the present invention.
3 is a cross-sectional view illustrating a red light emitting device that may correspond to a first unit light emitting device applied to a first pixel region of a quantum dot light emitting device according to an embodiment of the present invention.
4 is a cross-sectional view showing a green light emitting device that may correspond to a second unit light emitting device applied to a second pixel area of a quantum dot light emitting device according to an embodiment of the present invention.
5 is a cross-sectional view illustrating a blue light emitting device that may correspond to a third unit light emitting device unit applied to a third pixel region of a quantum dot light emitting device according to an embodiment of the present invention.
6 is a graph showing electroluminescence (EL) spectral characteristics of a quantum dot light emitting device according to an embodiment of the present invention.

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

Examples of the present invention to be described below are provided to more clearly explain the present invention to those of ordinary skill in the art, and the scope of the present invention is not limited by the following examples, The embodiment may be modified in many different forms.

The terminology used herein is used to describe specific embodiments, not to limit the present invention. As used herein, terms in the singular form may include the plural form unless the context clearly dictates otherwise. Also, as used herein, the terms “comprise” and/or “comprising” refer to a referenced shape, step, number, action, member, element, and/or group that specifies the existence of these groups. and does not exclude the presence or addition of one or more other shapes, steps, numbers, acts, elements, elements, and/or groups thereof. In addition, as used herein, the term “connection” not only means that certain members are directly connected, but also includes indirectly connected members with other members interposed therebetween.

In addition, in the present specification, when a member is said to be located "on" another member, this includes not only a case in which a member is in contact with another member but also a case in which another member is present between the two members. As used herein, the term “and/or” includes any one and any combination of one or more of those listed items. In addition, as used herein, terms such as "about", "substantially", etc. are used in the meaning of the range or close to the numerical value or degree, in consideration of inherent manufacturing and material tolerances, and to help the understanding of the present application The exact or absolute figures provided for this purpose are used to prevent the infringer from using the mentioned disclosure unfairly.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The size or thickness of the regions or parts shown in the accompanying drawings may be slightly exaggerated for clarity and convenience of description. Like reference numerals refer to like elements throughout the detailed description.

1 is a perspective view showing a quantum dot light-emitting device according to an embodiment of the present invention.

Referring to FIG. 1 , the quantum dot light emitting device according to the present embodiment may include a first pixel region P1 , a second pixel region P2 , and a third pixel region P3 emitting light of different colors. there is. Each of the pixel regions P1, P2, and P3 may be referred to as a sub-pixel region. The first pixel area P1 may be a red pixel area, the second pixel area P2 may be a green pixel area, and the third pixel area P3 may be a blue pixel area. The following description of FIG. 1 exemplifies a case in which the first pixel area P1 is a red pixel area, the second pixel area P2 is a green pixel area, and the third pixel area P3 is a blue pixel area. do. However, the arrangement of the sub-pixel area may be variously designed and modified, and the present invention is also applied to such a modified example.

A quantum dot light emitting device according to an embodiment may include a first electrode member 110 and a second electrode member 190 that are spaced apart from each other. In addition, the quantum dot light emitting device is disposed between the first electrode member 110 and the second electrode member 190 and has a stacked structure S10 for converting electrical energy supplied through these 110 and 190 into optical energy. may include

The first electrode member 110 may be provided on the substrate 100 , the stacked structure S10 may be provided on the first electrode member 110 , and the second electrode member may be provided on the stacked structure S10 . 190 may be provided. The substrate 100 may be a transparent substrate such as a glass substrate. In addition to glass, other materials such as transparent polymer may be applied as the material of the substrate 100 . The first electrode member 110 may include a plurality of first electrode elements 10 . The plurality of first electrode elements 10 may be arranged side by side, for example extending in a first direction. The plurality of first electrode elements 10 may be arranged to respectively correspond to the plurality of pixel regions P1 , P2 , P3 . The second electrode member 190 may include a plurality of second electrode elements 20 . The plurality of second electrode elements 20 may be arranged side by side, for example extending in the second direction. Here, the second direction may be a direction perpendicular to the first direction. Accordingly, the plurality of second electrode elements 20 may intersect perpendicularly with respect to the first plurality of electrode elements 10 . However, the arrangement direction of the plurality of second electrode elements 20 may be different. For example, the second plurality of electrode elements 20 may extend in the same direction as the first plurality of electrode elements 10 .

The stacked structure S10 disposed between the first electrode member 110 and the second electrode member 190 includes the red quantum dot light emitting unit 140 and the second pixel area ( S10 ) disposed to correspond to the first pixel area P1 . It may include a green quantum dot light emitting unit 150 disposed to correspond to P2). The red quantum dot light emitting unit 140 may contain a first quantum dot for light emission of a first color, for example, red. The green quantum dot light emitting unit 150 may contain a second quantum dot for light emission of a second color, for example, green.

In addition, the stacked structure S10 may include an organic common layer 160 commonly provided over the first pixel area P1, the second pixel area P2, and the third pixel area P3. can The organic common layer 160 includes a first area 1 corresponding to the third pixel area P3 and a second area 2 corresponding to the first pixel area P1 and the second pixel area P2 . can do. The first region 1 of the organic common layer 160 may be a “blue light emitting part”.

The organic common layer 160 may include a host material and a dopant material for blue light emission. That is, the organic common layer 160 may have a host-dopant system, and may include an organic dopant emitting blue light and an organic host capable of controlling the light emission.

The organic common layer 160 may be entirely made of the same material in the first pixel area P1 , the second pixel area P2 , and the third pixel area P3 . The organic common layer 160 may form a continuous one-layer structure over the first pixel area P1 , the second pixel area P2 , and the third pixel area P3 . The organic common layer 160 may have a shape extending to the third pixel area P3 while covering the upper surfaces of the red quantum dot light emitting part 140 and the green quantum dot light emitting part 150 , respectively. Accordingly, the organic common layer 160 may contact the upper surface of each of the red quantum dot light emitting unit 140 and the green quantum dot light emitting unit 150 , and in the third pixel area P3 , separate quantum dot light emission in contact with the upper and lower surfaces. It can exist without wealth. The organic common layer 160 may be an organic material layer that does not contain quantum dots.

The first region 1 corresponding to the third pixel region P3 of the organic common layer 160 may act as a “blue light emitting part”. In the exemplary embodiment of the present invention, the above-described "blue light emitting part" may be implemented by using the organic common layer 160 without providing the "third quantum dot light emitting part" in the third pixel region P3. Accordingly, in manufacturing a full-color display, a patterning process (a quantum dot layer patterning process) for the third pixel area P3 may be omitted. As such, by omitting the patterning process for one pixel (ie, P3 ), it is possible to obtain the effect of simplifying the process, reducing the cost, and significantly reducing the production time. In addition, it is possible to suppress various problems that may occur when the patterning step of the quantum dot layer is applied several times, that is, the performance of the quantum dot layer is deteriorated or the stability is lowered. Therefore, according to an embodiment of the present invention, it may be advantageous to secure the performance and stability of the red quantum dot emission layer 140 and the green quantum dot emission layer 150 .

Meanwhile, the second region 2 corresponding to the first pixel region P1 and the second pixel region P2 of the organic common layer 160 may be a “substantially non-emissive region”. In the second region 2 of the organic common layer 160 , the function of blue light emission may not be substantially expressed. Instead, the second region 2 of the organic common layer 160 is a charge transport region (ie, a charge transport layer) or an exciton transport region (ie, a charge transport region) with respect to the red quantum dot emitter 140 and the green quantum dot emitter 150 . exciton transport layer). Accordingly, the light emitting performance of the red quantum dot light emitting unit 140 and the green quantum dot light emitting unit 150 may be improved by the second region 2 of the organic common layer 160 .

Energy generated in the second region 2 of the organic common layer 160 is transferred to the red quantum dot light emitting unit 140 and the green quantum dot light emitting unit 150 , so that the red quantum dot light emitting unit 140 has red light emission performance. and improving the green light emission performance of the green quantum dot light emitting unit 150 . This energy transfer may be a “Forster resonant energy transfer”. When the organic common layer 160 is an organic common layer (blue organic common layer) for blue light emission, the red/green quantum dot light emitting unit 140 having a relatively small bandgap in the blue organic common layer having a large bandgap. 150), Felster resonance energy transfer can easily occur, and through this, the performance of the quantum dot layer pixels (ie, P1, P2) can be improved. In this regard, even when excitons related to blue light emission occur in the organic common layer 160 (eg, a blue organic common layer), the excitons are transferred to the red/green quantum dot light emitting units 140 and 150 to emit red light. and green light emission efficiency may be improved. Energy generated from the organic common layer 160 (eg, blue organic common layer) is relatively high, and the energy (ie, light energy) to be generated from the red/green quantum dot light emitting units 140 and 150 is relatively low. For this reason, improvement in luminous performance/efficiency by energy transfer can be easily achieved.

When it is assumed that the red quantum dot light emitting part 140 , the green quantum dot light emitting part 150 , and the organic common layer 160 constitute one "first stacked body", the stacked structure S10 is the first electrode member 110 . and the hole transport layer 130 provided between the first stacked body and the electron transport layer 170 provided between the second electrode member 190 and the first stacked body. In addition, the stacked structure S10 includes the hole injection layer 120 provided between the first electrode member 110 and the hole transport layer 130 and the electrons provided between the second electrode member 190 and the electron transport layer 170 . At least one of the injection layer 180 may be further included. For example, as shown in FIG. 1, on the first electrode member 110, the hole injection layer 120, the hole transport layer 130, the first laminate (ie, 140 + 150 + 160), the electron transport layer ( 170), the electron injection layer 180, and the second electrode member 190 may be sequentially provided. In this case, the red quantum dot light emitting unit 140 and the green quantum dot light emitting unit 150 may be provided on the upper surface of the hole transport layer 130 , respectively, while covering the red quantum dot light emitting unit 140 and the green quantum dot light emitting unit 150 . An organic common layer 160 extending to the third pixel area P3 may be provided. In the third pixel region P3 , the organic common layer 160 may contact the top surface of the hole transport layer 130 . In addition, the electron transport layer 170 may be provided on the organic common layer 160 . Accordingly, the electron transport layer 170 may contact the organic common layer 160 . In addition, the organic common layer 160 may be provided between the electron transport layer 170 and the quantum dot light emitting units 140 and 150 .

The quantum dot light emitting device according to the present embodiment may have a structure in which light generated in the first pixel region P1, the second pixel region P2, and the third pixel region P3 is emitted (emitted) toward the substrate 100. there is. In this case, the supply of holes for light emission may be made from the lower side of the first stacked body (ie, 140 + 150 + 160), and the supply of electrons for light emission may be from the bottom of the first stacked body (ie, 140 + 150 + 160). ) from above. The organic common layer 160 may be disposed on the side where the electron transport layer 170 is provided, and the second region 2 of the organic common layer 160 may serve to transport electrons. When having such an arrangement structure, the second region 2 of the organic common layer 160 may efficiently perform an energy transfer function. That is, since transport of the battery may be performed faster than transport of holes, it may be preferable for the second region 2 of the organic common layer 160 to transport electrons rather than holes. In addition, even when blue light or related energy is generated in the second region 2 of the organic common layer 160 , the blue light or related energy passes through the red/green quantum dot light emitting units 140 and 150 below it. It can play a role in causing energy transfer and improving the performance/efficiency of red and green light emission. In addition, the function of blue light emission may not be substantially expressed in the second region 2 of the organic common layer 160 .

The quantum dot light emitting device according to the embodiment described with reference to FIG. 1 may be applied to a quantum dot display device. Accordingly, the quantum dot display device according to the embodiment of the present invention may have the configurations described with reference to FIG. 1 .

2A to 2D are cross-sectional views illustrating a method of manufacturing a quantum dot light emitting device according to an embodiment of the present invention. A method of manufacturing a quantum dot light emitting device, which will be described below with reference to FIGS. 2A to 2D , may be understood in connection with the content described above with reference to FIG. 1 .

Referring to FIG. 2A , the first electrode member 111 may be formed on a predetermined substrate 101 . The substrate 101 may be a transparent substrate such as a glass substrate. In addition to glass, other materials such as transparent polymer may be applied as the material of the substrate 101 . The first electrode member 111 may comprise a plurality of first electrode elements 11 . The plurality of first electrode elements 11 may be arranged side by side, for example extending in the first direction. The plurality of first electrode elements 11 may be arranged to respectively correspond to the plurality of pixel regions P1 , P2 , P3 .

Next, the hole injection layer 121 and the hole transport layer 131 may be sequentially formed on the first electrode member 111 . The hole injection layer 121 and the hole transport layer 131 may be entirely formed to cover the plurality of pixel areas P1 , P2 , and P3 .

Although not shown, the space between the plurality of first electrode elements 11 may be filled with an insulating material in some cases. Alternatively, a portion of the hole injection layer 121 may be provided to fill the space between the plurality of first electrode elements 11 .

The first pixel area P1 may be a red pixel area, the second pixel area P2 may be a green pixel area, and the third pixel area P3 may be a blue pixel area. The following description is based on a case in which the first pixel area P1 is a red pixel area, the second pixel area P2 is a green pixel area, and the third pixel area P3 is a blue pixel area.

Referring to FIG. 2B , a red quantum dot light emitting unit 141 disposed to correspond to the first pixel area P1 and a green quantum dot light emitting unit disposed to correspond to the second pixel area P2 on the hole transport layer 131 ( 151) can be formed respectively. The red quantum dot light emitting unit 141 may contain a first quantum dot for emitting a first color (ie, red). The green quantum dot light emitting unit 151 may contain a second quantum dot for emitting a second color (ie, green). The red quantum dot light emitting part 141 may be formed through a panning process using a solution process. Similarly, the green quantum dot light emitting part 151 may be formed through a panning process using a solution process. The red quantum dot light emitting part 141 may be formed first, and the green quantum dot light emitting part 151 may be formed later, or vice versa. In FIG. 2B , the red quantum dot light emitting unit 141 and the green quantum dot light emitting unit 151 are shown in contact with each other, but in some cases, they may be slightly spaced apart.

Referring to FIG. 2C , an organic common layer 161 covering the red quantum dot emission part 141 and the green quantum dot emission part 151 may be formed on the hole transport layer 131 . In other words, the organic common layer 161 commonly provided over the first pixel area P1 , the second pixel area P2 , and the third pixel area P3 may be formed. The organic common layer 161 may be formed without a process of patterning in units of pixel areas. Accordingly, a separate mask may not be used when the organic common layer 161 is formed. For example, the organic common layer 161 may be formed by a thermal evaporation process or by other processes.

The organic common layer 161 includes a first region ( 1 in FIG. 1 ) corresponding to the third pixel region P3 and a second region ( FIG. 1 ) corresponding to the first pixel region P1 and the second pixel region P2 . 1 of 2) can be provided. The first region ( 1 in FIG. 1 ) of the organic common layer 161 corresponding to the third pixel region P3 may be a “blue light emitting part”. The second region ( 2 of FIG. 1 ) of the organic common layer 161 corresponding to the first pixel region P1 and the second pixel region P2 may be a “substantially non-emissive region”.

The organic common layer 161 may include a host material and a dopant material for blue light emission. That is, the organic common layer 161 may have a host-dopant system, and may include an organic dopant emitting blue light and an organic host capable of controlling the emission thereof. The organic common layer 161 may be entirely made of the same material in the first pixel area P1 , the second pixel area P2 , and the third pixel area P3 . The organic common layer 161 may form a continuous one-layer structure over the first pixel area P1 , the second pixel area P2 , and the third pixel area P3 . The organic common layer 161 may extend to the third pixel region P3 while covering the upper surfaces of the red quantum dot light emitting part 141 and the green quantum dot light emitting part 151 . Accordingly, the organic common layer 161 may contact the upper surfaces of each of the red quantum dot light emitting unit 141 and the green quantum dot light emitting unit 151 , and in the third pixel area P3 , separate quantum dot light emission in contact with the upper and lower surfaces. It can exist without wealth. The organic common layer 161 may be an organic material layer that does not contain quantum dots.

Referring to FIG. 2D , an electron transport layer 171 and an electron injection layer 181 may be sequentially formed on the organic common layer 161 . The electron transport layer 171 and the electron injection layer 181 may be entirely formed to cover the plurality of pixel areas P1 , P2 , and P3 .

Next, the second electrode member 191 may be formed on the electron injection layer 181 . The second electrode member 191 may comprise a plurality of second electrode elements 21 . Herein, for convenience, although the plurality of second electrode elements 21 are illustrated in a form extending in the same direction as the plurality of first electrode elements 11 , the plurality of second electrode elements 21 are the plurality of first electrode elements It may have a structure extending in a direction different from that of (11), that is, in the second direction. The plurality of second electrode elements 21 may extend in a direction perpendicular to the plurality of first electrode elements 11 .

The first area ( 1 of FIG. 1 ) corresponding to the third pixel area P3 of the organic common layer 161 may act as a "blue light emitting part". In the embodiment of the present invention, the "blue light emitting part" may be implemented by using the organic common layer 161 without providing the "third quantum dot light emitting part" in the third pixel region P3. Accordingly, in manufacturing a full-color display, a patterning process (a quantum dot layer patterning process) for the third pixel area P3 may be omitted. As such, by omitting the patterning process for one pixel (ie, P3 ), it is possible to obtain the effect of simplifying the process, reducing the cost, and significantly reducing the production time. In addition, it is possible to suppress various problems that may occur when the patterning step of the quantum dot layer is applied several times, that is, the performance of the quantum dot layer is deteriorated or the stability is lowered. Therefore, according to an embodiment of the present invention, it may be advantageous to secure the performance and stability of the red quantum dot emission layer 141 and the green quantum dot emission layer 151 .

Meanwhile, the second region ( 2 of FIG. 1 ) corresponding to the first pixel region P1 and the second pixel region P2 of the organic common layer 161 may be a “substantially non-emission region”. In the second region ( 2 of FIG. 1 ) of the organic common layer 161 , the function of blue light emission may not be substantially expressed. Instead, the second region ( 2 in FIG. 1 ) of the organic common layer 161 is a charge transport region (ie, a charge transport layer) or exciton transport with respect to the red quantum dot light emitting part 140 and the green quantum dot light emitting part 150 . It can act as a region (ie, an exciton transport layer). Energy transfer may occur in the second region ( 2 of FIG. 1 ) of the organic common layer 161 to the red quantum dot light emitting part 140 and the green quantum dot light emitting part 150 . Accordingly, the light emitting performance and efficiency of the red quantum dot light emitting unit 141 and the green quantum dot light emitting unit 151 may be improved by the second region (2 of FIG. 1 ) of the organic common layer 161 . Details related thereto are the same as those described for the second region 2 of the organic common layer 160 in FIG. 1 , and thus a repeated description thereof will be omitted.

In addition, in the structure of FIG. 2D , at least one of the hole injection layer 121 and the electron injection layer 181 may not be provided. In addition, at least one of the hole transport layer 131 and the electron transport layer 171 may not be provided. In addition, the structure of FIG. 2D may be variously changed.

The method of manufacturing a quantum dot light emitting device according to the embodiment described with reference to FIGS. 2A to 2D may be applied to a method of manufacturing a quantum dot display device. Accordingly, the method of manufacturing a quantum dot display device according to an embodiment of the present invention may include the processes described with reference to FIGS. 2A to 2D.

3 is a cross-sectional view illustrating a red light emitting device that may correspond to a first unit light emitting device applied to a first pixel region of a quantum dot light emitting device according to an embodiment of the present invention.

Referring to FIG. 3 , the red light emitting device that may correspond to the first unit light emitting device portion of the quantum dot light emitting device according to the embodiment includes a substrate 100a, a first electrode 110a, a hole injection layer 120a, and a hole transport layer. 130a, a red quantum dot emission layer 140a, an organic common layer 160a, an electron transport layer 170a, an electron injection layer 180a, and a second electrode 190a may be included.

The first electrode 110a may be a positive electrode, that is, a positive electrode. As the first electrode 110a, for example, indium tin oxide (ITO) having a thickness of about 150 nm may be applied. The first electrode 110a may be patterned on the substrate 100a. The substrate 100a may be, for example, a glass substrate having a thickness of about 0.7 mm. The substrate 100a was cleaned in an ultrasonic bath for about 15 minutes each with acetone, deionized water, and isopropyl alcohol before device fabrication, and an oven at a temperature of about 120° C. It can be used after storing it for about 12 hours or more.

Thereafter, in order to remove the residue on the substrate 100a on which the first electrode 110a is formed and to make it hydrophilic, the surface of the substrate 100a on which the first electrode 110a is formed is coated with UV-ozone. The surface treatment may be performed for about 15 minutes, and the hole injection layer 120a may be formed thereon. As the hole injection layer 120a, PEDOT:PSS, that is, poly(ethylenedioxythiophene):polystyrene sulphonate may be applied. The hole injection layer 120a may be formed by spin coating. The spin coating, for example, may be performed for 60 seconds at a speed of 3000 rpm and an acceleration condition of 4 seconds. During the spin coating, for example, a PEDOT:PSS solution may be permeated using a polyvinylidene fluoride (PVDF) filter having a pore size of about 0.45 μm, and then the permeated solution may be used. The device portion on which the spin coating layer is formed may be heat-treated on a hot plate, for example, at a temperature of about 150° C. for about 30 minutes. The thickness of the hole injection layer 120a formed in this way may be about 45 nm. The hole injection layer 120a may perform a role similar to an electrode due to the characteristics of PEDOT:PSS having high electrical conductivity, and hole injection through the hole injection layer 120a may be smoothly performed.

After the heat treatment is completed, the device part may be moved into a glove box filled with argon (Ar), and then the hole transport layer 130a may be formed on the hole injection layer 120a. PVK, that is, poly(9-vinylcarbazole) may be applied as the hole transport layer 130a. The hole transport layer 130a may also be formed by spin coating. In this case, the spin coating may be performed for about 30 seconds at a speed of 4000 rpm. PVK used for spin coating may be in the form of a solution (ie, PVK solution) having a concentration of 20 mg/mL dissolved in chlorobenzene, and PTFE (polytetrafluoroethylene) having a pore size of about 0.2 μm during spin coating It can be used by passing the solution through a filter. The hole transport layer 130a formed in this way may have a thickness of about 50 nm.

Next, a red quantum dot emission layer 140a may be formed on the hole transport layer 130a. The red quantum dot emission layer 140a may be formed of red quantum dots, for example, CdZnSe/ZnS QDs. In this case, 9 mg/mL of red CdZnSe/ZnS QD dispersed in hexane was transmitted through the PVDF filter, spin-coated at a speed of about 4000 rpm for 30 seconds, and then heated to a temperature of about 75° C. on a hot plate. Heat treatment can be performed for about 30 minutes. The thickness of the stacked red quantum dot emission layer 140a may be about 30 nm.

Thereafter, the organic common layer 160a, the electron transport layer 170a, the electron injection layer 180a, and the second electrode 190a may be sequentially formed on the red quantum dot emission layer 140a by a vacuum thermal evaporation method. The organic common layer 160a may be a blue organic common layer including an organic material for blue light emission. The organic common layer 160a applies a host-dopant system and may be formed to include an organic dopant emitting blue light and an organic host capable of controlling the emission of the blue dopant. For example, the organic common layer 160a may include Firpic as a blue phosphorescent dopant. As a material of the electron transport layer 170a, an organic material having high electron mobility and an energy level capable of smoothly injecting electrons into the organic common layer 160a may be used. As a material of the electron injection layer 180a, an organic material capable of smoothly moving electrons to the electron transport layer 170a by adjusting a vacuum energy level may be used. For example, lithium fluoride may be used. there is. As the material of the second electrode 190a, a metal material having a high reflectivity and reflecting light generated inside the device in the direction of the substrate 100a may be used. For example, aluminum (Al) may be used. Accordingly, the second electrode 190a may be a reflective electrode, and light generated inside the device may be emitted toward the substrate 100a.

The red light emitting device of FIG. 3 is a first unit light emitting device part (ie, a red light emitting device part) applied to the first pixel region (P1 of FIGS. 1 and 2D ) of the quantum dot light emitting device according to an embodiment of the present invention. can correspond to However, specific materials, process conditions, thickness, etc. of the red light emitting device described with reference to FIG. 3 are merely exemplary and may be variously changed.

4 is a cross-sectional view illustrating a green light emitting device that may correspond to a second unit light emitting device unit applied to a second pixel area of a quantum dot light emitting device according to an embodiment of the present invention.

Referring to FIG. 4 , the green light emitting device that may correspond to the second unit light emitting device portion of the quantum dot light emitting device according to the embodiment includes a substrate 100a, a first electrode 110a, a hole injection layer 120a, and a hole transport layer. 130a, a green quantum dot emission layer 150a, an organic common layer 160a, an electron transport layer 170a, an electron injection layer 180a, and a second electrode 190a may be included.

The green light emitting device of FIG. 4 is different from the red light emitting device of FIG. 3 in the material of the quantum dot light emitting layer, and other components may be the same. The green quantum dot emission layer 150a of FIG. 4 may include green quantum dots, for example, CdZnSeS/ZnS QDs. In this case, 9 mg/mL of green CdZnSeS/ZnS QD dispersed in hexane was passed through the PVDF filter, spin-coated at a speed of about 4000 rpm for 30 seconds, and then heated to a temperature of about 75° C. on a hot plate. Heat treatment can be performed for about 30 minutes. The thickness of the stacked green quantum dot emission layer 150a may be, for example, about 30 nm. However, the material, formation conditions, thickness, etc. of the green quantum dot light emitting layer 150a are merely exemplary and may be variously changed.

The green light emitting device of FIG. 4 corresponds to the second unit light emitting device part (ie, the green light emitting device part) applied to the second pixel area (P2 of FIGS. 1 and 2D ) of the quantum dot light emitting device according to the embodiment of the present invention. can be

5 is a cross-sectional view illustrating a blue light emitting device that may correspond to a third unit light emitting device unit applied to a third pixel region of a quantum dot light emitting device according to an embodiment of the present invention.

Referring to FIG. 5 , the blue light emitting device that may correspond to the third unit light emitting device portion of the quantum dot light emitting device according to the embodiment includes a substrate 100a, a first electrode 110a, a hole injection layer 120a, and a hole transport layer. 130a, an organic common layer 160a, an electron transport layer 170a, an electron injection layer 180a, and a second electrode 190a may be included. Here, the organic common layer 160a may be a blue light emitting layer (ie, a blue organic light emitting layer). The device structure of FIG. 5 may correspond to or be substantially similar to the structure of FIG. 3 except for the red quantum dot emission layer 140a. Compared to the red light emitting device of FIG. 3 , the device of FIG. 5 may have the same structure, materials, and manufacturing method except for the red quantum dot light emitting layer 140a.

The blue light emitting device of FIG. 5 corresponds to the third unit light emitting device part (ie, the blue light emitting device part) applied to the third pixel region (P3 of FIGS. 1 and 2D ) of the quantum dot light emitting device according to the embodiment of the present invention. can be

6 is a graph showing electroluminescence (EL) spectral characteristics of a quantum dot light emitting device according to an embodiment of the present invention. 6 is a result of evaluating the electroluminescence (EL) characteristics of the devices of FIGS. 3, 4 and 5 . This evaluation result may correspond to the result of the quantum dot light emitting device of FIG. 1 in which the devices of FIGS. 3, 4 and 5 are combined. Electrical characteristics were measured while flowing a current to each device in FIGS. 3, 4 and 5 with a Keithley 237 source meter, and the amount of light was measured using a Keithley 2000 multimeter, silicon photodiode and photomultiplier tube. In addition, electroluminescence (EL) spectra were measured using a Konica Minolta CS 2000.

Referring to FIG. 6 , it can be seen that red (R), green (G), and blue (B) emission peaks that are clearly distinguished appear. In the case of the red light emitting device and the green light emitting device, it can be seen that the blue light emitting component is sufficiently suppressed to have little effect on the color purity of each. Also, it can be seen that only the blue light emitting component generated from the blue dopant is observed in the blue light emitting device. Accordingly, even when an organic common layer commonly applied to three pixel areas is used as in the embodiment of the present invention, a full-color display by R/G/B light emission is possible, and improved light emission is achieved. It may be possible to implement a quantum dot display with performance and efficiency.

As described above, according to the embodiment of the present invention, various effects can be obtained by reducing the number of patterning processes of the quantum dot layer, and the quantum dot light emitting device having a configuration that can further improve the light emitting performance by the quantum dot and A quantum dot display device to which this is applied can be implemented. In particular, if the method according to the embodiments is used, in manufacturing a full-color display device including red, green, and blue pixels, the cost is reduced and production by omitting the patterning process for the blue pixels. It can have the effect of greatly reducing the required time. In addition, through energy transfer (ie, Forster resonant energy transfer) from the organic common layer having a large bandgap to the quantum dot layer having a relatively small bandgap, the performance of the quantum dot layer pixel may be improved.

Additionally, in the above embodiment, the case where the quantum dot light emitting device includes three pixel regions P1, P2, and P3 has been mainly described, but in other embodiments, the quantum dot light emitting device has two pixel regions as a basic unit. may include For example, the quantum dot light emitting device according to the embodiment may include a first pixel region and a second pixel region emitting light of different colors, and disposed between the first electrode member and the second electrode member spaced apart from each other. a stacked structure, wherein the stacked structure is disposed to correspond to the first pixel area, and includes a first quantum dot light emitting unit containing a first quantum dot for emitting a first color, and the first pixel area; An organic common layer commonly provided over the second pixel area may be included. Here, the organic common layer may include a first area corresponding to the second pixel area and a second area corresponding to the first pixel area, and the first area may be a second color light emitting part. Here, the first pixel area may be, for example, a red pixel area or a green pixel area, and the second pixel area may be, for example, a blue pixel area. The first quantum dot light emitting unit may be, for example, a red quantum dot light emitting unit or a green quantum dot light emitting unit, and the second color light emitting unit may be, for example, a blue light emitting unit. According to another embodiment, the quantum dot light emitting device may include four or more pixel areas as a basic unit.

In the present specification, preferred embodiments of the present invention have been disclosed, and although specific terms are used, these are only used in a general sense to easily explain the technical content of the present invention and help the understanding of the present invention, and to limit the scope of the present invention. It is not meant to be limiting. It is apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein. For those of ordinary skill in the art, a quantum dot light emitting device according to the embodiment described with reference to FIGS. 1 to 6 and a method for manufacturing the same and a display device including the quantum dot light emitting device, the technical spirit of the present invention does not deviate It will be appreciated that various substitutions, changes, and modifications can be made without departing from the scope. As a specific example, it will be appreciated that the colors corresponding to each of the first pixel area P1 , the second pixel area P2 , and the third pixel area P3 may be variously changed in the above-described embodiment. In addition, it will be appreciated that the quantum dot light emitting device according to the embodiment can be applied not only to a display device, but also to a QLED-based lighting device. Therefore, the scope of the invention should not be determined by the described embodiments, but should be determined by the technical idea described in the claims.

* Explanation of symbols for the main parts of the drawing *
100, 101: substrate 110, 111: first electrode member
120, 121: hole injection layer 130, 131: hole transport layer
140, 141: red quantum dot light emitting unit 150, 151: green quantum dot light emitting unit
160, 161: organic common layer 170, 171: electron transport layer
180, 181: electron injection layer 190, 191: second electrode member
P1: first pixel area P2: second pixel area
P3: third pixel area S10: stacked structure

Claims (22)

A quantum dot light emitting device comprising a first pixel region, a second pixel region, and a third pixel region emitting light of different colors, the quantum dot light emitting device comprising:
It is disposed between the first electrode member and the second electrode member spaced apart from each other and has a laminated structure for converting electrical energy supplied through the first and second electrode members into optical energy,
The layered structure is
a first quantum dot light emitting unit disposed to correspond to the first pixel area and containing a first quantum dot for emitting a first color;
a second quantum dot light emitting unit disposed to correspond to the second pixel area and containing a second quantum dot for emitting a second color; and
an organic common layer commonly provided over the first pixel area, the second pixel area, and the third pixel area;
The organic common layer includes a first area corresponding to the third pixel area and a second area corresponding to the first pixel area and the second pixel area, the first area being a third color light emitting part, and the second region is a substantially non-luminescent region;
The organic common layer is provided to directly contact each of the first quantum dot light emitting part and the second quantum dot light emitting part,
The second region of the organic common layer serves as an exciton transfer region with respect to the first quantum dot light emitting unit and the second quantum dot light emitting unit,
In the second region of the organic common layer, Felster resonance energy transfer occurs to each of the first quantum dot light emitting unit and the second quantum dot light emitting unit, and in the second area of the organic common layer The generated exciton is transferred to each of the first quantum dot light emitting unit and the second quantum dot light emitting unit, so that the light emitting efficiency of the first color and the light emitting efficiency of the second color are increased. The method of claim 1,
the first pixel area is a red pixel area, the second pixel area is a green pixel area, and the third pixel area is a blue pixel area;
The first quantum dot light emitting part is a red quantum dot light emitting part, the second quantum dot light emitting part is a green quantum dot light emitting part, and the third color light emitting part is a blue light emitting quantum dot light emitting device. delete The method of claim 1,
The second region of the organic common layer serves as a charge transport region for the first quantum dot light emitting unit and the second quantum dot light emitting unit. The method of claim 1,
The organic common layer is a quantum dot light emitting device having a shape extending to the third pixel area while covering the upper surfaces of each of the first quantum dot light emitting part and the second quantum dot light emitting part. The method of claim 1,
The organic common layer is a quantum dot light emitting device that does not contain a quantum dot. The method of claim 1,
The organic common layer is a quantum dot light emitting device formed of the same material in the first pixel region, the second pixel region, and the third pixel region. The method of claim 1,
The organic common layer is a quantum dot light emitting device including a host material and a dopant material for blue light emission. The method of claim 1,
The first quantum dot light emitting unit, the second quantum dot light emitting unit, and the organic common layer constitute a first laminate,
The stacked structure may include a hole transport layer provided between the first electrode member and the first stacked body; and an electron transport layer provided between the second electrode member and the first laminate,
The hole transport layer is formed as one continuous layer over the first, second, and third pixel regions, and the organic common layer is in direct contact with the hole transport layer formed as the continuous one layer. 10. The method of claim 9,
The stacked structure may include a hole injection layer provided between the first electrode member and the hole transport layer; and an electron injection layer provided between the second electrode member and the electron transport layer. A quantum dot light emitting device further comprising at least one of. 10. The method of claim 9,
The electron transport layer is a quantum dot light emitting device in contact with the organic common layer. A quantum dot display device comprising the quantum dot light emitting device according to any one of claims 1, 2, 4 to 11. A method of manufacturing a quantum dot light emitting device comprising a first pixel region, a second pixel region, and a third pixel region emitting light of different colors, the method comprising:
forming a first electrode member;
forming a stacked structure on the first electrode member; and
forming a second electrode member on the laminated structure;
Forming the laminated structure comprises:
a first quantum dot light emitting unit disposed to correspond to the first pixel area and containing a first quantum dot for light emission of a first color, and a second quantum dot disposed to correspond to the second pixel area and for light emission of a second color; Forming a second quantum dot light emitting unit containing; and
forming an organic common layer commonly provided over the first pixel area, the second pixel area, and the third pixel area;
The organic common layer includes a first area corresponding to the third pixel area and a second area corresponding to the first pixel area and the second pixel area, the first area being a third color light emitting part, and the second region is a substantially non-luminescent region;
The organic common layer is provided to directly contact each of the first quantum dot light emitting part and the second quantum dot light emitting part,
The second region of the organic common layer serves as an exciton transfer region with respect to the first quantum dot light emitting unit and the second quantum dot light emitting unit,
In the second region of the organic common layer, Felster resonance energy transfer occurs to each of the first quantum dot light emitting unit and the second quantum dot light emitting unit, and in the second area of the organic common layer The generated exciton is transferred to each of the first quantum dot light emitting unit and the second quantum dot light emitting unit to increase the light emitting efficiency of the first color and the light emitting efficiency of the second color. 14. The method of claim 13,
the first pixel area is a red pixel area, the second pixel area is a green pixel area, and the third pixel area is a blue pixel area;
The first quantum dot light emitting part is a red quantum dot light emitting part, the second quantum dot light emitting part is a green quantum dot light emitting part, and the third color light emitting part is a blue light emitting part. 14. The method of claim 13,
The second region of the organic common layer serves as a charge transport region for the first quantum dot light emitting unit and the second quantum dot light emitting unit. 14. The method of claim 13,
The organic common layer is formed to extend to the third pixel area while covering upper surfaces of each of the first quantum dot light emitting part and the second quantum dot light emitting part. 14. The method of claim 13,
The method of manufacturing a quantum dot light emitting device in which the organic common layer is formed without a process of patterning in units of pixel areas. 14. The method of claim 13,
The first quantum dot light emitting unit, the second quantum dot light emitting unit, and the organic common layer constitute a first laminate,
Forming the laminated structure comprises:
forming a hole transport layer between the first electrode member and the first laminate; and
Further comprising the step of forming an electron transport layer between the second electrode member and the first laminate,
The hole transport layer is formed as one continuous layer over the first, second and third pixel regions, and the organic common layer is in direct contact with the hole transport layer formed as the continuous one layer of the quantum dot light emitting device. manufacturing method. 19. The method of claim 18,
Forming the laminated structure comprises:
forming a hole injection layer between the first electrode member and the hole transport layer; and
forming an electron injection layer between the second electrode member and the electron transport layer; A method of manufacturing a quantum dot light emitting device further comprising at least one of. 19. The method of claim 18,
The electron transport layer is a method of manufacturing a quantum dot light emitting device is formed to contact the organic common layer. A quantum dot light emitting device comprising a first pixel region and a second pixel region emitting light of different colors, the quantum dot light emitting device comprising:
It is disposed between the first electrode member and the second electrode member spaced apart from each other and has a laminated structure for converting electrical energy supplied through the first and second electrode members into optical energy,
The layered structure is
a first quantum dot light emitting unit disposed to correspond to the first pixel area and containing a first quantum dot for emitting a first color; and
an organic common layer provided in common over the first pixel area and the second pixel area;
The organic common layer includes a first area corresponding to the second pixel area and a second area corresponding to the first pixel area, the first area being a second color light emitting part, and the second area being substantially It is a non-luminous area,
The organic common layer is provided to directly contact the first quantum dot light emitting part,
The second region of the organic common layer serves as an exciton transfer region with respect to the first quantum dot light emitting unit,
Felster resonance energy transfer occurs from the second region of the organic common layer to the first quantum dot light emitting unit, and excitons generated in the second region of the organic common layer emit the first quantum dot Quantum dot light emitting device configured to be transferred to the second color to increase the luminous efficiency of the first color. 22. The method of claim 21,
the first pixel area is a red pixel area or a green pixel area, the second pixel area is a blue pixel area;
The first quantum dot light emitting part is a red quantum dot light emitting part or a green quantum dot light emitting part, and the second color light emitting part is a blue light emitting part.

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