KR20180022074A - polarizing variable device and manufacturing method thereof - Google Patents

Abstract

The present application relates to a polarization-variable device and a manufacturing method thereof. According to the present invention, the polarization-variable device can perform selective polarization separation of a desired wavelength band by simply changing a driving voltage. According to the present invention, the polarization-variable device includes a first substrate, a second substrate, and a polarization separation layer located between the first substrate and the second substrate and including a first region including a metal line and a second region including a conductive light blocking particle.

Description

[0001] The present invention relates to a polarizing variable device and a manufacturing method thereof,

The present application relates to a polarization variable element, its use, and a method of manufacturing the same.

A line grating polarizer is a type of optical element that guides unpolarized light into linearly polarized light having a specific vibration direction. In general, a line grating polarizer has a structure in which a plurality of stripe patterns are arranged parallel to each other on a light-transmitting substrate. When the pitch of the stripe patterns is sufficiently shorter than the wavelength of incident light, an electric field vector orthogonal to the stripe pattern (I.e., p-polarized light) is transmitted, and a component having an electric field vector parallel to the stripe pattern (i.e., s-polarized light) is reflected or absorbed so that polarization is induced.

 Conventionally, a line grating polarizer using mainly aluminum has been used as such a grating polarizer. An example of a prior art related to a linear grating polarizer using aluminum is Korean Patent Publication No. 2002-0035587 (Patent Document 1).

In the case of such a wire grid polarizer, the period of the metal wire (pitch) should be considerably shorter than the wavelength of the incident light so that the extinction ratio of the polarizer becomes higher. However, the shorter the period of the metal wire is, Has come. However, with the recent development of semiconductor manufacturing equipment and exposure technology, it becomes possible to manufacture fine patterns, and it is possible to manufacture a nanowire grid polarizer that operates in visible light. However, there are still difficulties and problems in the manufacturing process.

Patent Document 1: Korean Patent Publication No. 2002-0035587

The present invention provides a polarization variable element and a method of manufacturing the same, which are capable of selective polarization separation in a desired wavelength band according to application conditions of an external electric field.

The present application also provides the use of the above-mentioned polarization variable element.

The present application relates to a polarization variable element and a method of manufacturing the same.

The present application is based on the idea that a conductive light blocking particle capable of moving toward a metal line when an external electric field is applied is placed in a region where a metal line of the polarization separation layer is not formed and the same effect It is possible to provide a polarization variable element capable of selectively separating a desired wavelength band by reflection and polarization, and a method of manufacturing the same.

In the case of using the polarization variable element according to the present application, it is possible to effectively implement the cut-off mode or the polarization mode effectively by merely setting the external field application or the electric field range. In particular, without complicated processes for designing the pitches of the metal lines, There is an advantage that the wavelengths of the band and the infrared region can be selectively reflected.

The term " normal cut-off mode " means a drive mode of a polarization variable element to which no external electric field is applied. For example, the transmittance of light having a wavelength of 400 nm or more to the polarization variable element is 30% Or less, 10% or less, or 5% or less.

The term " polarization mode " used herein means a drive mode of a polarization variable element to which an external electric field is applied, and may mean, for example, a mode in which the polarization degree calculated by the following equation 1 is 0.3 or more, 0.4 or more, or 0.5 or more .

[Equation 1]

D ₁ = (Tc ₁ -Tp ₁ ) / (Tc ₁ + Tp ₁ )

Wherein Tc ₁ is a transmittance of the light having a wavelength of 400 nm or more polarized in a direction orthogonal to the metal line to the polarization variable element and Tp ₁ is a transmittance of the light having a wavelength of 400 nm or more polarized in a direction parallel to the metal line, And the transmittance for the variable element.

Fig. 1 schematically shows the structure of the polarization variable element of the present application.

As shown in FIG. 1, the polarization variable element according to the present application includes a first substrate 100 and a second substrate 300; And a first region (201) between the first substrate (100) and the second substrate (300) and including a metal line arranged with a pitch of 1 占 퐉 to 100 占 퐉 and a conductive light blocking particle And a polarized light separating layer 200 including a second region 202. The polarization variable element having the structure as shown in FIG. 1 can selectively implement a normal cutoff mode and a polarization mode depending on whether an external electric field is applied or not.

The first substrate of the present application serves as a support for forming a polarized light separation layer on the upper portion. The first substrate may have a transmittance of 60% or more or 70% or more for a visible light region such as a polymer film or a glass film Film or the like can be exemplified.

More specifically, the polymer film may be a polyethylene terephthalate film, a polycarbonate film, a polypropylene film, a polyethylene film, a polystyrene film, a polyepoxy film, a cyclic olefin polymer (COP) film, a cyclic olefin copolymer ) Film and a film composed of a combination of components constituting the film.

The glass film may be a quartz film, an ultraviolet blocking glass, or the like, but is not limited thereto.

The thickness of the first substrate may be in the range of, for example, 1 탆 to 100 탆, 3 탆 to 80 탆, or 5 탆 to 50 탆.

The second substrate serves to support an electrode layer, which will be described later, and is laminated with the first substrate. For example, the material used for the polymer film of the first substrate can be adopted without any limitations.

The polarization variable element according to the present application includes a polarization separation layer between a first substrate and a second substrate.

The polarized light separating layer further includes a first region including a metal line and a second region including the conductive light blocking particles.

1, the first region of the polarization separation layer may be composed of a plurality of metal lines, and the regions of the void space formed by the joints of the second substrate in addition to the first region may be the second region . The second region includes conductive light blocking particles.

The polarization variable element according to the present application is characterized in that the conductive light blocking particles are contained in the second region of the polarized light separating layer and the conductive light blocking particles are randomly distributed in the second region depending on whether an external electric field is applied , Or near a metal line, through which a normally cut-off or polarization mode can be selectively implemented.

The polarized light separating layer includes a metal wire. The metal line reflects a polarized component in a direction parallel to the metal line among the incident light and transmits a polarized component in a direction orthogonal to the metal line. The material is typically used in a wide grid polarizer Materials forming the metal lines of the polarization separation layer can be used without limitation.

In one example, the metal wire may comprise any metal selected from the group consisting of aluminum, copper, chromium, platinum, gold, silver, nickel, and alloys thereof.

The metal line may be present in the polarization separation layer with a predetermined pitch, height and line width to perform the polarization splitting function.

The term pitch (p) in the present application may mean the sum of the spacing between the plurality of metal lines and the line width of the metal line, as shown in Fig. 2, and the term height h may range from the portion in contact with the first substrate, , And the term line width (w) may mean the length of the metal wire in the transverse direction.

In one example, the pitch of the metal lines may be in the range of 1 占 퐉 to 100 占 퐉. In the case of the polarization variable element according to the present application, the metal wire can be arranged so as to have any pitch in the above range because it is an element for selectively polarizing and separating the wavelengths of the visible light region or more. In another example, the pitch of the metal lines may be in the range of 1 占 퐉 to 50 占 퐉, 1 占 퐉 to 30 占 퐉, 1 to 15 占 퐉, or 1 to 10 占 퐉.

In one example, the height of the metal line may be in the range of 10 nm to 5,000 nm, 20 nm to 1,000 nm, or 30 nm to 500 nm. If the height of the metal line is excessively high, the pitch-to-height ratio may not be suitable for selectively polarizing the wavelength of visible light, and if the height is too small, problems in fabrication may arise and polarization efficiency may be impaired .

In one example, the line width of the metal line may be in the range of 10 nm to 2,000 nm, 10 nm to 1,000 nm, or 10 nm to 500 nm. If the line width of the metal wire is too thick, the selective polarization function depending on whether an external electric field is applied or not may not be properly developed under the same pitch value, and a metal wire having an excessively thin line width may deteriorate the manufacturing easiness.

In addition to the pitch, height, and line width of the metal line, the numerical values such as the aspect ratio or the fill factor are set such that the polarization variable element including the polarization separation layer including the metal line can secure a polarization characteristic of a desired visible light wavelength or more Range, and can be freely designed and changed by those skilled in the art within a range that satisfies the pitch, height, and line width.

The polarized light separating layer also includes a second region. The second region includes conductive light blocking particles.

As shown in FIG. 1, the second region refers to a region where the second substrate formed with the electrode layer is joined to the first substrate, and also refers to an empty space other than the first region including the metal line in the polarization separation layer .

The term " conductive light-shielding particles " as used herein refers to particles having a transmittance of 30% or less with respect to a wavelength of visible light or more, and the surface thereof is negatively charged or positively charged. When an external electric field is applied via an electrode layer and a metal wire Means a particle which moves to the vicinity of a metal line and plays a role of realizing the same effect as a metal wire is substantially thickened.

In one example, the conductive light blocking particles may be dispersed in the second region.

As described above, since the surface of the conductive light-shielding particles is negatively charged or positively charged, they may be aggregated or scattered by their own attractive or repulsive force. The conductive light-shielding particles included in the second region according to the present application May have the same charge characteristics and may be dispersed at a predetermined interval by self repulsive force.

In one example, the conductive light blocking particles may be negatively charged or positively charged particles.

The method of making the electroconductive light blocking particles negative or positive may include, for example, coating a material capable of imparting negative charge or positive charge characteristics to the light blocking particles.

In a specific example, the conductive light-shielding particles comprise a core comprising a light-shielding material and a particle of a core / shell structure surrounding the core and comprising a shell in which an organic compound or a coordination compound is positively or negatively charged. . The organic compound may include, for example, a carboxyl group, an ester group, or an acyl group, and the coordination compound may include, but is not limited to, an amine group, a thiol group, or a phosphine group.

The conductive light blocking particles may have a particle diameter of 1 mu m or less. When the particle diameter of the conductive light blocking particles is more than 1 탆, the particles can not be uniformly dispersed in the second region, and thus the driving of the polarization variable element may not be possible.

In another example, the particle diameter of the conductive light blocking particles may be in the range of 0.001 mu m to 0.1 mu m or 0.001 mu m to 0.01 mu m.

Examples of the conductive light blocking particles include, but are not limited to, conductive carbon black, conductive graphite, or conductive carbon nanotubes.

The conductive carbon black, the conductive graphite or the conductive carbon nanotube may be coated on a known carbon black, graphite or carbon nanotube, for example, by coating a compound capable of imparting positive or negative charge characteristics, such as the organic compound or coordination compound, Or the like may be imparted with a chargeability on the surface thereof.

The conductive light blocking particles may be contained in the second region at a predetermined volume ratio. If the volume of the conductive light blocking particles occupies an excessively large amount of voids in the second region, a normal blocking mode is implemented irrespective of whether an external electric field is applied or not, and desired polarization separation characteristics can not be secured. In addition, when the volume of the conductive light blocking particles occupies an excessively small space in the second region, the degree of polarization with respect to a desired wavelength band may be greatly reduced.

In one example, the conductive light blocking particles may be present in the second region in an amount that can occupy a volume ratio of 0.5% to 30% of the total volume of the second region in the polarization separation layer. Polarized light separation characteristics for a desired wavelength band, specifically, a wavelength band of visible light or more can be ensured according to whether an external electric field is applied within the volume ratio range. Particularly, when the conductive light-shielding particles are included in the second region within the volume ratio range, there may be an advantage that the polarization separation characteristics with respect to the wavelength band of the desired visible light or higher can be secured even under a low external electric field application condition.

In another example, the conductive light blocking particles may be present in the second region in an amount that can account for 0.5% to 25% or 0.5% to 20% by volume of the total volume of the second region in the polarization separation layer.

The second region of the polarized light separating layer may further include a dispersion medium for dispersing the conductive light blocking particles.

The dispersion medium is a composition for dispersing the conductive light shielding particles in the second region, and the kind thereof can be used without limitation as a known solvent capable of performing the above-mentioned role.

In one example, the dispersion medium is a solvent capable of forming a solution in an emulsion state such that the conductive light shielding particles of the second region may be effectively dispersed in the second region, for example, polyethylene glycol or polypropylene glycol or the like But is not limited thereto.

The polarization variable element according to the present application further includes an electrode layer. The electrode layer may also be in contact with the polarization separation layer.

More specifically, as shown in FIG. 1, the electrode layer 400 is formed on the lower surface of the second substrate 300, and may be in contact with the polarization separation layer 200. In addition, the second region 202 can be formed due to the contact between the polarization separation layer 200 and the electrode layer 400.

The electrode layer serves as an anode or a cathode together with a metal wire, and may include, for example, a conductive polymer, a conductive metal, a conductive nanowire, or ITO (Indium Tin Oxide).

The electrode layer may be, for example, a coating layer formed by coating any one of the above materials, or a deposition layer formed by depositing any one of the above materials.

In a specific example, the electrode layer may be, but is not limited to, a deposition layer comprising ITO.

The electrode layer serves as a metal line and an electrode in the above-described polarization separation layer, and is capable of applying an external electric field to the polarization variable element. In addition, the amount of the conductive light blocking particles adhering to the metal wire is changed according to the intensity of the external electric field, thereby achieving the same effect as substantially changing the thickness of the metal wire, and ultimately, It is possible to selectively perform polarization separation.

In one example, the polarization variable element according to the present application may have a polarization degree calculated from the following equation (2) in the range of 0.50 to 0.98 when the external electric field is applied within a range of 10V to 1000V.

[Equation 2]

D ₂ = (Tc ₂ -Tp ₂ ) / (Tc ₂ + Tp ₂ )

Wherein Tc ₂ is the transmittance of the light having a wavelength of 400 nm or more polarized in a direction orthogonal to the metal line to the polarization variable element and Tp ₂ is the transmittance of the light having a wavelength of 400 nm or more polarized in a direction parallel to the metal line, And the transmittance for the variable element.

In another example, the degree of polarization calculated by equation (2) may be in the range of 0.60 to 0.98 or 0.70 to 0.98.

By including the predetermined amount of the conductive light blocking particles in the second region of the polarized light separating layer according to the present application, it is possible to achieve the above-described polarization degree under a low driving voltage, for example, an external electric field within a range of 10 V to 100 V can do.

The present application also relates to a method of manufacturing a polarization variable element. According to the method for manufacturing a polarization variable element according to the present application, a polarization variable element capable of selectively implementing a normal blocking mode and a polarization mode can be manufactured depending on whether an external electric field is applied. Such a polarization variable element is, for example, Window or the like.

That is, the present application is directed to a light-emitting device comprising a first substrate, a first substrate on which a metal line is formed, and a second region of the polarization separation layer including a second region other than the first region, And a method of manufacturing a polarization variable element which realizes a normally cutoff mode or a polarization mode depending on whether an external electric field is applied or not.

The method of manufacturing a polarization variable element according to the present application includes the step of positioning a conductive light blocking particle in a second region of the polarization separation layer where a metal line is not formed, Mode can be implemented.

The method of positioning the conductive light blocking particles in the second region of the polarized light separating layer includes, for example, forming a metal line on the first substrate and then forming a solution containing the conductive light blocking particles in a region where the metal line is not formed Lt; / RTI >

In another example, a method of positioning the conductive light blocking particles in the second region of the polarization splitting layer includes forming a metal line on the first substrate, forming an electrode layer on the second substrate, 2 substrate with the conductive light blocking particles in a state of being joined together.

The content of the conductive light blocking particles in the solution containing the conductive light blocking particles may be, for example, in the range of 0.5 wt% to 30 wt%.

In another example, the content of the conductive light blocking particles in the solution containing the conductive light blocking particles may be, for example, in the range of 0.5 wt% to 25 wt% or 0.5 wt% to 20 wt%.

The method of manufacturing a polarization-variable element according to the present application may further comprise the step of joining a first substrate on which a polarization separation layer is formed and a second substrate on which an electrode layer is formed.

The laminating step may be performed before or after placing the conductive light blocking particles in the second region of the polarized light separating layer.

Forming a metal line on the first substrate before the lapping step to form a polarized light separation layer including a first region including a metal line and a second region formed in addition to the first region, Forming an electrode layer on the substrate, and so on.

A method of forming a metal line having a polarization separating characteristic on the first substrate is known, and for example, a method disclosed in International Publication No. WO2013-095062 can be used without limitation.

When the above steps are performed, the conductive light blocking particles may be located in the second region. In addition, when the conductive light blocking particles are positioned in the second region as described above, the polarization variable element can selectively implement the blocking mode and the polarization mode.

More specifically, in the case where an external electric field is not applied, the conductive light blocking particles may be dispersed in the second region by the repulsive force of the second region, and due to the light blocking property of the light blocking particles, By blocking light transmitted through the device, a normal blocking mode of the polarization variable element can be realized.

In addition, when an external electric field is applied via the electrode layer and the metal line, the conductive light blocking particles move to the vicinity of the metal line, and the same effect as that in which the pitch between the metal lines is substantially reduced can be realized. A polarization mode can be realized.

In one example, when the external electric field is applied within a range of 10 V to 100 V, the polarization variable element produced according to the above method may have a polarization degree calculated by the following formula 2 within the range of 0.50 to 0.98.

[Equation 2]

D ₂ = (Tc ₂ -Tp ₂ ) / (Tc ₂ + Tp ₂ )

Tc ₂ is the transmittance of the light having a wavelength of 400 nm or more polarized in a direction orthogonal to the metal line to the polarization variable element and Tp ₂ is the transmittance of the light having a wavelength of 400 nm or more polarized in the direction parallel to the metal line, And the transmittance for the variable element.

The method of manufacturing a polarization variable element according to the present application may further include the step of sealing the side surface after laminating the first substrate and the second substrate.

The present application is also directed to the use of a polarization variable element, for example a smart window comprising a polarization variable element.

The light of a desired wavelength band can be polarized and separated according to whether or not the external light-receiving element of the polarization-changing element according to the present application is applied.

In particular, the polarization variable element according to the present application can selectively polarize and split light having a wavelength in the visible light band through application of an electric field without designing a complex polarization separation layer.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram showing a structure of a polarization variable element according to the present application. FIG.
2 is a view for explaining the pitch, the height and the line width of the metal lines in the polarization separation layer according to the present application.
3 shows a photomicrograph of a light-variable element at a driving voltage of 20V.
Fig. 4 shows a photomicrograph of a light-variable element at a driving voltage of 40V.

Hereinafter, the polarization variable element according to the present application will be described in more detail with reference to examples and comparative examples, but the following examples are only examples according to the present application, and the technical idea of the present application is not limited. To those of ordinary skill in the art.

Example  1 - Fabrication of polarization-variable device

A PET substrate on which ITO was deposited and a quartz substrate on which an aluminum electrode line was formed with a pitch of about 5 mu m were laminated and a solution (carbon black: Isopar G, carbon black) containing carbon black particles whose surfaces were negatively charged Particle content: 3.5 wt%) was injected, and the side was sealed with a sealant to prepare a polarization variable element having the structure as shown in Fig. The height of the aluminum electrode line in the polarization variable element is 1 mu m and the width is 50 nm.

Experimental Example  1. Microphotograph of the polarization-variable device according to driving voltage

In order to observe whether or not the conductive light blocking particles were gathered around the metal line according to the driving voltage of the polarization variable element according to Example 1, microscope images at 20 V and 40 V were measured respectively, and the results are shown in Figs. 3 and 4 Respectively.

As shown in FIGS. 3 and 4, as the driving voltage is increased, it is confirmed that the carbon black particles having negative charges are gathered around the metal line, and as the voltage increases, substantially the same effect as the pitch value of the metal line decreases Can be achieved.

100: first substrate
200: polarization separating layer
201: first region
202: second region
300: second substrate

Claims (15)

A first substrate and a second substrate; And
A polarized light separating layer disposed between the first substrate and the second substrate and including a first region including a metal line disposed at a pitch of 1 탆 to 100 탆 and a second region including conductive light blocking particles, , And which implements a normal blocking mode or a polarization mode depending on whether an external electric field is applied or not. The method according to claim 1,
And the pitch of the metal wire is in the range of 1 占 퐉 to 50 占 퐉. The method according to claim 1,
Wherein the line width of the metal line is in the range of 10 nm to 2,000 nm. The method according to claim 1,
Wherein the metal line comprises any one metal selected from the group consisting of aluminum, copper, chromium, platinum, gold, silver, nickel, and alloys thereof. The method according to claim 1,
Wherein the conductive light blocking particles are conductive carbon black, graphite or carbon nanotubes. The method according to claim 1,
Wherein the conductive light blocking particles have a particle diameter of 1 占 퐉 or less. The method according to claim 1,
Wherein the conductive light blocking particles are present in the second region in an amount that can occupy a volume ratio of 0.1% to 30% of the total volume of the second region in the polarization separation layer. The method according to claim 1,
And the second region further comprises a dispersion medium for dispersing the conductive light blocking particles. The method according to claim 1,
Further comprising an electrode layer existing between the first substrate and the second substrate, wherein the electrode layer is in contact with the polarization separation layer. 10. The method of claim 9,
The electrode layer is a deposition layer comprising a conductive polymer, a conductive metal, a conductive nanowire, or ITO (Indium Tin Oxide). The method according to claim 1,
Wherein a polarization degree calculated by the following formula 2 is within a range of 0.50 to 0.98 when an external electric field is applied within a range of 10 V to 100 V:
[Equation 2]
D ₂ = (Tc ₂ -Tp ₂ ) / (Tc ₂ + Tp ₂ )
Wherein Tc ₂ is the transmittance of the light having a wavelength of 400 nm or more polarized in a direction orthogonal to the metal line to the polarization variable element and Tp ₂ is the transmittance of the light having a wavelength of 400 nm or more polarized in a direction parallel to the metal line, And the transmittance for the variable element. And the step of positioning the conductive light blocking particles in the second region of the polarization splitting layer which is formed on the first substrate and includes a first region where a metal line is formed and a second region formed in addition to the first region And implementing a normally cutoff mode or a polarization mode depending on whether an external electric field is applied or not. 13. The method of claim 12,
And joining a first substrate on which a polarization separation layer is formed and a second substrate on which an electrode layer is formed. 13. The method of claim 12,
Wherein a polarization degree calculated by the following formula 2 is within a range of 0.50 to 0.98 when an external electric field is applied within a range of 10 V to 100 V:
[Equation 2]
D ₂ = (Tc ₂ -Tp ₂ ) / (Tc ₂ + Tp ₂ )
Wherein Tc ₂ is the transmittance of the light having a wavelength of 400 nm or more polarized in a direction orthogonal to the metal line to the polarization variable element and Tp ₂ is the transmittance of the light having a wavelength of 400 nm or more polarized in a direction parallel to the metal line, And the transmittance for the variable element. A smart window comprising the polarization variable element of claim 1.

Images