KR102467812B1 - Display devices and methods of manufacturing display devices - Google Patents

Abstract

The display device includes a pixel definition including a substrate, a pixel electrode disposed on the substrate, an electrochromic material disposed on the substrate, partially covering the pixel electrode, and reversibly changed between a transparent state and an opaque state by a color change. It may include a film, a light emitting layer disposed on the pixel electrode, and a common electrode disposed on the light emitting layer and the pixel defining layer.

Description

Display device and manufacturing method of the display device {DISPLAY DEVICES AND METHODS OF MANUFACTURING DISPLAY DEVICES}

The present invention relates to a display device, and more particularly, to display devices including a pixel defining layer containing an electrochromic material and methods of manufacturing such display devices.

Display devices have been used as a medium for transmitting information, and demand for such display devices is steadily increasing. Conventional display devices have opaque screens capable of displaying images in only one direction. However, recently, a transparent display device capable of displaying an image of an object positioned on the front and/or rear surface of the display device by allowing light incident from the front and/or rear surface of the display device to pass through the display device has been developed.

Such a transparent display device includes a plurality of pixels corresponding to pixel electrodes disposed on a substrate, and the plurality of pixels may be distinguished by a pixel defining layer. The pixel-defining layer substantially covers a peripheral portion of the pixel electrode and exposes a central portion of the pixel electrode.

In a conventional transparent display device, when the pixel defining layer is transparent, an image of an object located on the front and/or rear surface of the display device may be displayed, but the contrast ratio of the image displayed by the display device may be lowered. . Also, when the pixel-defining layer is opaque, the contrast ratio of the image displayed by the display device is improved, but images of objects positioned on the front and/or rear surface of the display device cannot be displayed.

One object of the present invention is to provide a display device including a pixel defining layer that can variably change between a transparent state and an opaque state through color change.

Another object of the present invention is to provide a method of manufacturing a display device including a changeable pixel defining layer capable of variably changing between a transparent state and an opaque state through color change.

However, the objects of the present invention are not limited to these objects, and may be expanded in various ways without departing from the spirit and scope of the present invention.

In order to achieve one object of the present invention described above, a display device according to exemplary embodiments includes a substrate, a pixel electrode disposed on the substrate, a pixel electrode disposed on the substrate and partially covering the pixel electrode, and a color A pixel defining layer including an electrochromic material that is reversibly changed between a transparent state and an opaque state by change, a light emitting layer disposed on the pixel electrode, and a common electrode disposed on the light emitting layer and the pixel defining layer. can

In example embodiments, the pixel defining layer may cause the color change to be transparent or black.

In example embodiments, the display device further includes a first electrode disposed under the pixel defining layer, and a second electrode disposed on the pixel defining layer and facing the first electrode; The pixel defining layer may cause the color change by a first electric field generated between the first electrode and the second electrode.

In example embodiments, the electrochromic material is transparent when the first electric field is not generated between the first electrode and the second electrode, and the first electric field is formed between the first electrode and the second electrode. 1 Black color can be displayed when an electric field is generated.

In example embodiments, the display device may further include a first insulating layer disposed between the first electrode and the pixel electrode and electrically insulating the first electrode from the pixel electrode.

In example embodiments, the first insulating layer may include an electrochromic material that changes color to transparent or black by a second electric field generated between the first electrode and the pixel electrode.

In example embodiments, the first insulating layer may be integrally formed with the pixel defining layer.

In example embodiments, the display device may further include a second insulating layer disposed between the second electrode and the common electrode and electrically insulating the second electrode from the common electrode.

In example embodiments, the second insulating layer may include an electrochromic material that changes color to transparent or black by a third electric field generated between the second electrode and the common electrode.

In example embodiments, the first electrode and the pixel electrode may be positioned on the same level above the substrate.

In example embodiments, the second electrode may be disposed below the common electrode.

In example embodiments, the display device may be changed into the transparent state in which the pixel defining layer transmits external light and the opaque state in which external light is blocked by the first electric field.

In example embodiments, the electrochromic material may include a polymer compound including a functional group, and the functional group may include perfluorocyclobutane, a hydroxy group, an amino group, an alkyl amino group, an aryl amino group, a heteroarylamino group, It may include one or more selected from the group consisting of a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group, an aryl group, an aryl alkyl group, a heteroaryl group, and a heterocyclic group.

In order to achieve another object of the present invention described above, in the method of manufacturing a display device according to example embodiments, after providing a substrate, a pixel electrode may be formed on the substrate. A pixel defining layer including an electrochromic material that partially covers the pixel electrode and is reversibly changed between a transparent state and an opaque state by color change may be formed on the substrate. An emission layer may be formed on the pixel electrode, and a common electrode may be formed on the emission layer and the pixel defining layer.

In example embodiments, a first electrode may be formed on the substrate, and a second electrode facing the first electrode and generating an electric field between the first electrode may be formed on the pixel defining layer. can

In example embodiments, a first insulating layer electrically insulating the first electrode and the pixel electrode may be formed between the first electrode and the pixel electrode.

In example embodiments, a second insulating layer electrically insulating the second electrode and the common electrode may be formed between the second electrode and the common electrode.

In example embodiments, the pixel electrode and the first electrode may be formed at the same time.

In example embodiments, the electrochromic material may include a polymer compound including a functional group, and the functional group may include perfluorocyclobutane, a hydroxy group, an amino group, an alkyl amino group, an aryl amino group, a heteroarylamino group, It may include one or more selected from the group consisting of a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group, an aryl group, an aryl alkyl group, a heteroaryl group, and a heterocyclic group.

Since the display device according to exemplary embodiments of the present invention may include a pixel defining layer that can variably change between a transparent state and an opaque state, transmittance of external light can be increased in the transparent state, and the transmittance of external light can be increased in the opaque state. The contrast ratio of the image displayed by the display device can be improved. In addition, in the manufacturing method of the display device according to the exemplary embodiments of the present invention, since the pixel electrode and the first electrode are formed at the same time, manufacturing cost and manufacturing time can be reduced.

However, the effects of the present invention are not limited to the above-mentioned effects, and may be expanded in various ways without departing from the spirit and scope of the present invention.

1 is a plan view illustrating a display device according to exemplary embodiments of the present invention.
2 and 3 are cross-sectional views illustrating a display device according to exemplary embodiments of the present invention.
4 is a cross-sectional view illustrating a display device according to other exemplary embodiments of the present disclosure.
5 to 12 are cross-sectional views illustrating a method of manufacturing a display device according to exemplary embodiments of the present invention.

Hereinafter, display devices and methods of manufacturing the display devices according to exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In the accompanying drawings, the same or similar reference numerals are used for like elements.

1 is a plan view illustrating a display device according to exemplary embodiments of the present invention. For example, FIG. 1 may be a plan view illustrating a part of a display device according to exemplary embodiments of the present invention.

Referring to FIG. 1 , a display device 100 according to exemplary embodiments of the present invention may have a display area in which a plurality of pixels may be repeatedly disposed. For example, the plurality of pixels may be arranged in the display area in a matrix structure that is repeatedly arranged along a first direction and a second direction substantially orthogonal to the first direction. The arrangement of pixels is not limited thereto, and the pixels may be arranged in various ways according to the configuration of the display device 100 .

The plurality of pixels may include a red pixel Pr, a green pixel Pg, and a blue pixel Pb disposed adjacent to each other. Here, an image may be displayed in the display area by combining light emitted from the red pixel Pr, the green pixel Pg, and the blue pixel Pb.

2 and 3 are cross-sectional views illustrating a display device according to exemplary embodiments of the present invention. For example, FIGS. 2 and 3 may be cross-sectional views illustrating the display device taken along line II′ of FIG. 1 .

Referring to FIG. 2 , a display device 100 according to example embodiments may include a substrate 110 , a pixel circuit, a light emitting structure, a pixel defining layer 170 , and the like. In example embodiments, the display device 100 may additionally include a first electrode 160, a second electrode 180, a first insulating layer 165, a second insulating layer 185, and the like. .

The substrate 110 may include a transparent substrate such as a glass substrate, a quartz substrate, or a transparent plastic substrate. Optionally, the substrate 110 may be made of a flexible substrate.

A buffer layer 115 may be disposed on the substrate 110 . The buffer layer 115 can prevent diffusion of impurities generated from the substrate 110 and can control a heat transfer rate during a crystallization process for forming the active pattern 120 . In addition, the buffer layer 115 may serve to substantially planarize the surface of the substrate 110 . For example, the buffer layer 115 may include a silicon compound such as silicon oxide (SiOx), silicon nitride (SiNx), or silicon oxynitride (SiOxNy). The buffer layer 115 may have a single-layer structure or a multi-layer structure including a silicon compound. However, such a buffer layer 115 is not essential and may not be formed in consideration of the type of substrate 110, process conditions of the display device 100, and the like.

The pixel circuit may supply voltage or current to the light emitting structure to generate light from the light emitting structure. For example, the pixel circuit may include a plurality of transistors and a plurality of capacitors. Although one transistor is shown in FIG. 2 for convenience, the pixel circuit may include a plurality of transistors and at least one capacitor.

Each of the transistors may include an active pattern 120 , a gate electrode 130 , a source electrode 140 and a drain electrode 145 .

An active pattern 120 may be disposed on the buffer layer 115 . The active pattern 120 may be made of polysilicon. A source region 121 and a drain region 122 containing impurities may be formed on opposite sides of the active pattern 120 , and a channel not doped with impurities may be formed between the source region 121 and the drain region 122 . An area 123 may be defined.

A gate insulating layer 125 substantially covering the active pattern 120 may be disposed on the buffer layer 115 . For example, the gate insulating layer 125 may include a silicon compound such as silicon oxide, silicon nitride, or silicon oxynitride. The gate insulating layer 125 may have a single-layer structure or a multi-layer structure containing a silicon compound.

A gate electrode 130 may be disposed on the gate insulating layer 125 . Here, the gate electrode 130 may be positioned on at least a portion of the active pattern 120, for example, the upper portion of the channel region 123. For example, the gate electrode 130 may include aluminum (Al), silver (Ag), tungsten (W), copper (Cu), nickel (Ni), chromium (Cr), molybdenum (Mo), titanium (Ti), It may include a metal such as platinum (Pt), tantalum (Ta), neodymium (Nd), scandium (Sc), alloys of the metals, or nitrides of the metals. These may be used alone or in combination of two or more.

An interlayer insulating layer 135 substantially covering the gate electrode 130 may be disposed on the gate insulating layer 125 . For example, the interlayer insulating layer 135 may include a silicon compound such as silicon oxide, silicon nitride, or silicon oxynitride. The interlayer insulating film 135 may have a single-layer structure or a multi-layer structure containing a silicon compound. First contact holes exposing the source region 121 and the drain region 122 of the active pattern 120 may be provided in the gate insulating layer 125 and the interlayer insulating layer 135 .

A source electrode 140 and a drain electrode 145 may be disposed on the interlayer insulating layer 135 . The source electrode 140 and the drain electrode 145 may be electrically connected to the source region 121 and the drain region 122 of the active pattern 120 through the first contact holes, respectively. For example, the source electrode 140 and the drain electrode 145 may be formed of aluminum (Al), silver (Ag), tungsten (W), copper (Cu), nickel (Ni), chromium (Cr), or molybdenum (Mo). ), titanium (Ti), platinum (Pt), tantalum (Ta), neodymium (Nd), scandium (Sc), alloys of the metals, or nitrides of the metals. These may be used alone or in combination of two or more.

An insulating layer 150 substantially covering the source electrode 140 and the drain electrode 145 may be disposed on the interlayer insulating layer 135 . A second contact hole exposing the drain electrode 145 of the transistor may be provided in the insulating layer 150, and the pixel electrode 155 may come into contact with the drain electrode 145 while filling the second contact hole. . In other embodiments, a via structure electrically connecting the pixel electrode 155 and the drain electrode 145 may be provided in the insulating layer 150 . For example, a contact (not shown) made of a conductive material may be disposed in the second contact hole, and the pixel electrode 155 and the drain electrode 145 may contact upper and lower portions of the contact, respectively. . In addition, the insulating layer 150 may substantially serve as a planarization layer for upper structures. For example, the insulating layer 150 may include an organic material such as polyimide, epoxy resin, acrylic resin, or polyester.

The light emitting structure may include a pixel electrode 155 , a light emitting layer 175 , a common electrode 190 , and the like. In example embodiments, the light emitting layer 175 may include an organic light emitting layer.

A pixel electrode 155 may be disposed on the insulating layer 150 . As described above, the pixel electrode 155 may be in contact with the drain electrode 145 while filling the second contact hole, or may be electrically connected to the drain electrode 145 through the contact provided in the second contact hole. can be connected In example embodiments, as shown in FIG. 1 , the pixel electrode 155 may be independently disposed for each pixel. For example, the pixel electrode 155 may include a metal such as aluminum, silver, tungsten, copper, nickel, chromium, molybdenum, titanium, platinum, tantalum, neodymium, scandium, or an alloy of these metals. According to other embodiments, the pixel electrode 155 may include a transparent conductive material. For example, the pixel electrode 155 may include indium tin compound (ITO), indium zinc compound (IZO), zinc oxide, or indium oxide. Optionally, the pixel electrode 155 may have a multilayer structure including the transparent conductive material and the metal.

A first electrode 160 may be disposed on the insulating layer 150 . For example, as shown in FIG. 1 , the first electrode 160 may be disposed adjacent to and surrounding the plurality of pixels. For example, the first electrode 160 may include a metal such as aluminum, silver, tungsten, copper, nickel, chromium, molybdenum, titanium, platinum, tantalum, neodymium, scandium, or alloys of these metals. According to other exemplary embodiments, the first electrode 160 may include a transparent conductive material. For example, the first electrode 160 may include indium tin compound (ITO), indium zinc compound (IZO), zinc oxide, or indium oxide. Optionally, the first electrode 160 may have a multilayer structure including the transparent conductive material and the metal.

In example embodiments, the first electrode 160 and the pixel electrode 155 may be disposed on substantially the same level above the substrate 110 . In this case, the first electrode 160 and the pixel electrode 155 may include substantially the same material.

A first insulating layer 165 may be disposed on the insulating layer 150 . The first insulating layer 165 may be disposed between the first electrode 160 and the pixel electrode 155 to electrically insulate the first electrode 160 and the pixel electrode 155 . For example, as shown in FIG. 1 , the first insulating layer 165 may be disposed to substantially surround the pixel electrode 155 . For example, the first insulating layer 165 may include an organic material such as polyimide, epoxy resin, acrylic resin, or polyester.

A pixel defining layer 170 partially covering the pixel electrode 155 may be disposed on the first electrode 160 and the first insulating layer 165 . In other words, the first electrode 160 and the first insulating layer 165 may be positioned below the bottom surface of the pixel defining layer 170 . For example, the pixel defining layer 170 may expose a central portion of the pixel electrode 155 while covering a peripheral portion of the pixel electrode 155 . Accordingly, a pixel opening exposing a central portion of the pixel electrode 155 may be provided in the pixel defining layer 170 .

The pixel defining layer 170 includes an electrochromic material capable of changing color from transparent to substantially black by a first electric field generated between the first electrode 160 and the subsequent second electrode 180. can do. Accordingly, the pixel defining layer 170 may change from a transparent state to an opaque state. In such an electrochromic material, optical properties of the material may be reversibly changed by electrochemical oxidation and reduction reactions. For example, the electrochromic material may be transparent when an electric field is not applied, but may exhibit a predetermined color when an electric field is applied. In addition, the electrochromic material may exhibit a predetermined color when an electric field is not applied, but may become transparent when an electric field is applied. In example embodiments, the electrochromic material may be transparent when the first electric field is not generated between the first electrode 160 and the second electrode 180, and the first electric field is generated. In some cases, it may be substantially black.

In exemplary embodiments, any material capable of causing a color change from transparent to substantially black by the first electric field may be used as the electrochromic material without limitation. Examples of the applicable electrochromic material include a compound containing a viologen group and a polymer compound containing a functional group. Here, the functional group is a perfluorocyclobutane, a hydroxy group, an amino group, an alkyl amino group, an aryl amino group, a heteroaryl amino group, a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group, an aryl group, an aryl alkyl group, a heteroaryl group, and a heterocyclic group. It may include one or more selected from the group consisting of groups.

A second electrode 180 may be disposed on the pixel defining layer 170 . For example, the second electrode 180 may be positioned on the upper surface of the pixel defining layer 170 . In this case, the second electrode 180 may substantially face the first electrode 160 through the pixel defining layer 170 . Accordingly, the first electrode 160 and the second electrode 180 may substantially correspond to each other with the pixel defining layer 170 at the center, and the first electrode 160 and/or the second electrode 180 may The first electric field may be generated between the first electrode 160 and the second electrode 180 according to the applied voltage. For example, the second electrode 180 may include a metal such as aluminum, silver, tungsten, copper, nickel, chromium, molybdenum, titanium, platinum, tantalum, neodymium, scandium, or alloys of these metals. According to other embodiments, the second electrode 180 may include a transparent conductive material. For example, the second electrode 180 may include indium tin compound (ITO), indium zinc compound (IZO), zinc oxide, or indium oxide. Optionally, the second electrode 180 may have a multilayer structure including the transparent conductive material and the metal.

In the display device 100 according to example embodiments, the pixel defining layer 170 transmits external light by the first electric field generated between the first electrode 160 and the second electrode 180. It can be changed into a transparent state that can be used and an opaque state that can substantially block external light. For example, as shown in FIG. 2 , when the first electric field is not generated between the first electrode 160 and the second electrode 180, the pixel defining layer 170 containing the electrochromic material This may be transparent, and thus external light incident on the display device 100 passes through the pixel defining layer 170, so that the display device 100 can operate in a transparent mode. In addition, as shown in FIG. 3 , when the first electric field is generated between the first electrode 160 and the second electrode 180, the pixel defining layer 170 including the electrochromic material is substantially Black color may be displayed, and thus external light incident on the display device 100 is substantially blocked by the pixel defining layer 170 , so that the display device 100 may be operated in an opaque mode.

A second insulating layer 185 substantially covering the second electrode 180 may be disposed on the pixel defining layer 170 . The second insulating layer 185 may be disposed between the second electrode 180 and the common electrode 190 to electrically insulate the second electrode 180 and the common electrode 190 . In example embodiments, the second insulating layer 185 may cover the side surface and top surface of the second electrode 180 . For example, the second insulating layer 185 may include an organic material such as polyimide, epoxy resin, acrylic resin, or polyester.

An emission layer 175 may be disposed on the pixel electrode 155 exposed by the pixel opening of the pixel defining layer 170 . The light emitting layer 175 may include an organic light emitting layer in which light is emitted by combining holes and electrons respectively injected from the pixel electrode 155 and the common electrode 190 . In example embodiments, the light emitting layer 175 may further include a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. can

The hole injection layer may be disposed on the pixel electrode 155 , and the hole transport layer may be disposed on the hole injection layer. The organic emission layer may be disposed on the hole transport layer. The organic emission layer may include a host material excited by holes and electrons, and a dopant material that increases luminous efficiency through energy absorption and emission. The electron transport layer may be disposed on the organic emission layer, and the electron injection layer may be disposed on the electron transport layer.

A common electrode 190 may be disposed on the light emitting layer 175 and the second insulating layer 185 . In this case, the second electrode 180 may be positioned below the common electrode 190 . The common electrode 190 may substantially face the pixel electrode 155 through the light emitting layer 175 . The common electrode 190 may be shared by a plurality of pixels. For example, the common electrode 190 may include aluminum (Al), silver (Ag), tungsten (W), copper (Cu), nickel (Ni), chromium (Cr), molybdenum (Mo), titanium (Ti), A metal having a relatively low work function, such as platinum (Pt), tantalum (Ta), neodymium (Nd), or scandium (Sc), or alloys of these metals may be included.

4 is a cross-sectional view illustrating a display device according to other exemplary embodiments of the present disclosure. For example, FIG. 4 may be a cross-sectional view illustrating the display device taken along line II′ of FIG. 1 .

Referring to FIG. 4 , a display device 200 according to other exemplary embodiments of the present disclosure may include a substrate 210 , a pixel circuit, a light emitting structure, a pixel defining layer 270 , and the like. In example embodiments, the display device 200 may additionally include a first electrode 260, a second electrode 280, a first insulating layer 265, a second insulating layer 285, and the like. . In the display device illustrated in FIG. 4 , redundant descriptions of elements substantially the same as or similar to those described with reference to FIGS. 2 and 3 will be omitted.

A first insulating layer 265 may be disposed on the insulating layer 250 . The first insulating layer 265 may be disposed between the first electrode 260 and the pixel electrode 255 to electrically insulate the first electrode 260 and the pixel electrode 255 . For example, as shown in FIG. 1 , the first insulating layer 265 may be disposed to substantially surround the pixel electrode 255 .

In example embodiments, the first insulating layer 265 may be formed between the first electrode 260 and the pixel electrode 255 according to a voltage applied to the first electrode 260 and/or the pixel electrode 255 . It may include an electrochromic material capable of causing a color change to transparent or substantially black by the generated second electric field. For example, the electrochromic material may be transparent when the second electric field is not generated between the first electrode 260 and the pixel electrode 255, and may be substantially black when the second electric field is generated. color can be displayed. Here, the first insulating layer 265 may be substantially integrally formed with the pixel defining layer 270 .

A second insulating layer 285 substantially covering the second electrode 280 may be disposed on the pixel defining layer 270 . The second insulating layer 285 may be disposed between the second electrode 280 and the common electrode 290 to electrically insulate the second electrode 280 and the common electrode 290 . For example, the second insulating layer 285 may cover the side surface and top surface of the second electrode 280 .

In example embodiments, the second insulating layer 285 may be formed between the second electrode 280 and the common electrode 290 according to a voltage applied to the second electrode 280 and/or the common electrode 290 . It may include an electrochromic material capable of causing a color change to transparent or substantially black by the generated third electric field. For example, the electrochromic material may be transparent when the third electric field is not generated between the second electrode 280 and the common electrode 290, and may be substantially black when the third electric field is generated. color can be displayed.

5 to 12 are cross-sectional views illustrating a method of manufacturing a display device according to exemplary embodiments of the present invention.

Referring to FIG. 5 , a buffer layer 115 may be formed on the substrate 110 . The buffer layer 115 may be formed using a chemical vapor deposition (CVD) process, a plasma enhanced chemical vapor deposition (PECVD) process, a high-density plasma-chemical vapor deposition (HDP-CVD) process, or the like. For example, the buffer layer 115 may be formed on the substrate 110 by loading the substrate 110 into a process chamber and introducing a silicon oxide precursor, a nitrogen source gas, or a carrier gas.

An active pattern 120 may be formed on the buffer layer 115 . For example, the active pattern 120 may be formed on the buffer layer 115 by forming a semiconductor layer using amorphous silicon or polysilicon on the buffer layer 115 and then patterning the semiconductor layer through an etching process. can Optionally, after forming a semiconductor film on the buffer film 115, a crystallization process such as a low-temperature polysilicon (LTPS) process or a laser crystallization process may be performed. Also, the active pattern 120 may be formed using an oxide semiconductor such as IGZO, ZTO, or ITZO.

After the gate insulating layer 125 is formed on the buffer layer 115 while covering the active pattern 120 , the gate electrode 130 may be formed on the gate insulating layer 125 . For example, after forming the first conductive layer on the gate insulating layer 125 , the gate electrode 130 may be formed on the gate insulating layer 125 by patterning the first conductive layer using an etching process. In this case, the first conductive layer may be formed using a metal, alloy, or metal nitride. Also, the first conductive layer may be formed by stacking a plurality of metal layers. The gate electrode 130 may be positioned to substantially overlap the active pattern 120 with the gate insulating layer 125 interposed therebetween.

In example embodiments, impurities are implanted into the active pattern 120 using the gate electrode 130 as an ion implantation mask to form a source region 121 and a drain region 122 on opposite sides of the active pattern 120 . ) can be formed.

After forming an interlayer insulating film 135 covering the gate electrode 130 on the gate insulating film 125, the interlayer insulating film 135 and the gate insulating film 125 are partially etched to partially expose the active pattern 120. First contact holes may be formed. For example, the first contact holes may be formed by partially etching the interlayer insulating layer 135 and the gate insulating layer 125 using an etching process using a mask or a photolithography process.

A source electrode 140 and a drain electrode 145 contacting the active pattern 120 may be formed through the interlayer insulating layer 135 and the gate insulating layer 125 . For example, after forming a second conductive layer on the interlayer insulating layer 135 while filling the first contact holes, the second conductive layer may be patterned to form the source electrode 140 and the drain electrode 145. . Here, the second conductive layer may be formed using a metal, alloy, or metal nitride. Also, the second conductive layer may be formed by stacking a plurality of metal layers.

After forming the insulating film 150 on the interlayer insulating film 135 while covering the source electrode 140 and the drain electrode 145, the insulating film 150 is partially etched to partially expose the drain electrode 145. 2 contact holes may be formed. For example, the insulating layer 150 may be formed using an organic material such as polyimide, epoxy resin, acrylic resin, or polyester. In this case, the insulating layer 150 may be formed to a thickness sufficient to have a substantially flat upper surface. The insulating layer 150 may be formed using, for example, a spin coating process or a printing process. In addition, the second contact hole may be formed by partially etching the insulating layer 150 using an etching process using a mask or a photolithography process.

A third conductive layer 154 may be formed on the insulating layer 150 while filling the second contact hole. For example, the third conductive layer 154 may be formed using a metal material such as aluminum, silver, tungsten, copper, nickel, chromium, molybdenum, titanium, platinum, tantalum, neodymium, scandium, or an alloy of these metals. have. Optionally, the third conductive layer 154 may be formed using a transparent conductive material such as ITO, IZO, zinc oxide or indium oxide.

Referring to FIG. 6 , the pixel electrode 155 and the first electrode 160 may be formed by patterning the third conductive layer 154 . For example, the pixel electrode 155 and the first electrode 160 may be simultaneously formed on the insulating layer 150 by patterning the third conductive layer 154 using an etching process. Accordingly, since a separate process for forming the first electrode 160 is not required, manufacturing cost and manufacturing time can be reduced.

Referring to FIG. 7 , a first insulating layer 165 electrically insulating the first electrode 160 and the pixel electrode 155 may be formed on the insulating film 150 . For example, the first insulating layer 165 may be formed using an organic material such as polyimide, epoxy resin, acrylic resin, or polyester. In this case, the first insulating layer 165 may be formed to cover the exposed top surface of the insulating film 150 and side surfaces of the first electrode 160 and the pixel electrode 155 .

Referring to FIG. 8 , a pixel defining layer 170 may be formed on the first electrode 160 and the first insulating layer 165 to partially cover the pixel electrode 155 . For example, by an electric field generated between the first electrode 160 and the subsequent second electrode 180 on the pixel electrode 155, the first electrode 160, and the first insulating layer 165, the transparent After forming a preliminary pixel defining layer using an electrochromic material capable of causing a color change such as substantially black, and then patterning the preliminary pixel defining layer through an etching process, the first electrode 160 and the first insulating layer ( 165 , a pixel defining layer 170 may be formed.

In exemplary embodiments, any material capable of causing a color change from transparent to substantially black by the first electric field may be used as the electrochromic material without limitation. Examples of the applicable electrochromic material include a compound containing a viologen group and a polymer compound containing a functional group. Here, the functional group is a perfluorocyclobutane, a hydroxy group, an amino group, an alkyl amino group, an aryl amino group, a heteroaryl amino group, a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group, an aryl group, an aryl alkyl group, a heteroaryl group, and a heterocyclic group. It may include one or more selected from the group consisting of groups.

Referring to FIG. 9 , a light emitting layer 175 may be formed on the pixel electrode 155 . The light emitting layer 175 may be formed on the pixel electrode 155 using, for example, an organic light emitting material for emitting red, green, or blue light. For example, the light emitting layer 175 may be formed by a spin coating process, a roll printing process, or a nozzle using a fine metal mask (FMM) including openings exposing regions where red, green, and blue pixels are to be formed. It may be formed through a printing process, an inkjet printing process, or the like. Accordingly, an organic light emitting layer including the organic light emitting material may be formed for each pixel.

In some embodiments, before forming the organic emission layer, a hole transport layer may be further formed using a hole transport material. In addition, an electron transport layer may be further formed on the organic light emitting layer using the electron transport material. The hole transport layer and the electron transport layer may be formed along surfaces of the pixel defining layer 170 and the pixel electrode 155 to be commonly provided to a plurality of pixels. Alternatively, the hole transport layer and the electron transport layer may be patterned for each pixel through a process similar to that of the organic light emitting layer.

Referring to FIG. 10 , a second electrode 180 may be formed on the pixel defining layer 170 . For example, by forming a fourth conductive layer on the pixel defining layer 170 and the light emitting layer 175 and then patterning the fourth conductive layer using an etching process, the second electrode ( 180) can be formed. In this case, the second electrode 180 may be positioned to substantially overlap the first electrode 160 with the pixel defining layer 170 interposed therebetween.

Referring to FIG. 11 , a second insulating layer 185 electrically insulating the second electrode 180 and the common electrode 190 may be formed on the insulating film 150 . For example, the second insulating layer 185 may be formed using an organic material such as polyimide, epoxy resin, acrylic resin, or polyester. In this case, the second insulating layer 185 may be formed to cover the side surface and top surface of the second electrode 180 .

12, on the light emitting layer 175 and the second insulating layer 185, for example, aluminum, silver, tungsten, copper, nickel, chromium, molybdenum, titanium, platinum, tantalum, neodymium, scandium, etc. The common electrode 190 may be formed by depositing a metal material having a low work function or an alloy of these metals. The common electrode 190 may be formed by depositing the metal material through, for example, a sputtering process.

In the above, display devices and manufacturing methods of the display devices according to embodiments of the present invention have been described with reference to the drawings, but the described embodiments are exemplary and the technical spirit of the present invention described in the claims below is provided. It may be modified and changed by those skilled in the art to the extent that it does not deviate.

The present invention can be variously applied to electronic devices having a display device. For example, the present invention can be applied to computers, notebooks, mobile phones, smart phones, smart pads, PMPs, PDAs, MP3 players, digital cameras, video camcorders, and the like.

100: display device 110: substrate
155: pixel electrode 160: first electrode
165: first insulating layer 170: pixel defining layer
175: light emitting layer 180: second electrode
185: second insulating layer 190: common electrode

Claims (20)

Board;
a pixel electrode disposed on the substrate;
a pixel defining layer disposed on the substrate, partially covering the pixel electrode, and including an electrochromic material that is reversibly changed between a transparent state and an opaque state by color change;
a light emitting layer disposed on the pixel electrode;
a common electrode disposed on the light emitting layer and the pixel defining layer;
a first electrode disposed on the same layer as the pixel electrode between the substrate and the pixel defining layer; and
and a second electrode disposed between the pixel defining layer and the common electrode and facing the first electrode. The display device of claim 1 , wherein the pixel defining layer causes the color change to be transparent or black. The display device of claim 1 , wherein the pixel defining layer causes the color change by a first electric field generated between the first electrode and the second electrode. The electrochromic material of claim 3 , wherein the electrochromic material is transparent when the first electric field is not generated between the first electrode and the second electrode, and the first electric field is generated between the first electrode and the second electrode. A display device characterized in that it displays black when is generated. The display device of claim 3 , further comprising a first insulating layer disposed between the first electrode and the pixel electrode and electrically insulating the first electrode from the pixel electrode. 6 . The display device of claim 5 , wherein the first insulating layer includes an electrochromic material that changes color to transparent or black by a second electric field generated between the first electrode and the pixel electrode. . The display device of claim 5 , wherein the first insulating layer is integrally formed with the pixel defining layer. The display device of claim 3 , further comprising a second insulating layer disposed between the second electrode and the common electrode and electrically insulating the second electrode from the common electrode. 9. The display device of claim 8, wherein the second insulating layer includes an electrochromic material that changes color to transparent or black by a third electric field generated between the second electrode and the common electrode. . The display device of claim 3 , wherein the first electrode and the pixel electrode are located on the same level above the substrate. The display device of claim 3 , wherein the second electrode is disposed below the common electrode. The display device according to claim 3 , wherein the pixel defining layer is changed into the transparent state in which external light is transmitted and the opaque state in which external light is blocked by the first electric field. The display device of claim 1 , wherein the electrochromic material comprises a polymer compound including a functional group. 14. The method of claim 13, wherein the functional group is perfluorocyclobutane, a hydroxy group, an amino group, an alkyl amino group, an aryl amino group, a heteroaryl amino group, a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group, an aryl group, an aryl alkyl group, a heteroaryl group. A display device comprising at least one selected from the group consisting of a group and a heterocyclic group. providing a substrate;
forming a pixel electrode on the substrate;
forming a pixel defining layer on the substrate that partially covers the pixel electrode and includes an electrochromic material that is reversibly changed between a transparent state and an opaque state by color change;
forming a light emitting layer on the pixel electrode;
forming a common electrode on the light emitting layer and the pixel defining layer;
forming a first electrode disposed on the same layer as the pixel electrode between the substrate and the pixel defining layer; and
and forming a second electrode opposite the first electrode between the pixel defining layer and the common electrode. The method of claim 15 , wherein an electric field is generated between the second electrode and the first electrode. The method of claim 16 , further comprising forming a first insulating layer between the first electrode and the pixel electrode to electrically insulate the first electrode from the pixel electrode. . The method of claim 16 , further comprising forming a second insulating layer between the second electrode and the common electrode to electrically insulate the second electrode from the common electrode. . 17. The method of claim 16, wherein the pixel electrode and the first electrode are formed at the same time. 16. The method of claim 15, wherein the electrochromic material includes a polymer compound including a functional group, and the functional group is a perfluorocyclobutane, a hydroxyl group, an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a cyano group, or an alkyl group. , A method of manufacturing a display device comprising at least one selected from the group consisting of a cycloalkyl group, an alkoxy group, an aryl group, an aryl alkyl group, a heteroaryl group, and a heterocyclic group.

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