KR102089293B1 - Third order resonance-based high color purity structural color filter - Google Patents

Abstract

A structural color color filter is disclosed. The structural color filter includes a first reflective layer, a second reflective layer facing the first reflective layer, a first resonance layer disposed between the first reflective layer and the second reflective layer, and a second resonance disposed between the first and second reflective layers. And an absorption layer disposed between the first resonant layer and the second resonant layer. The structural color color filter can emit light of high purity color.

Description

THIRD ORDER RESONANCE-BASED HIGH COLOR PURITY STRUCTURAL COLOR FILTER}

The present invention relates to a structural color filter that can significantly improve color purity and lower the angle dependence of the incident angle.

Color filters are used in various areas such as liquid crystal display technology, optical measurement systems, light emitting diodes, CMOS image sensors, and the like. However, conventionally, color filters based on organic dyes or chemical pigments have been mainly used. Since dyes or pigments are sensitive to continuous UV irradiation, high temperature and moisture, organic dyes or chemical pigments are used. ), Etc., there is a problem that the performance is rapidly deteriorated. In addition, in order to reduce the pixel size in such a conventional color filter, there is a problem that a complicated and highly accurate alignment process is essential.

In order to solve the above problems of a color filter based on a conventional organic dye or a chemical pigment, a structural color filter has recently received a lot of attention. This structural color filter has the potential to achieve high efficiency, high resolution, small pixel size, long-term stability, and nonphotobleaching.

As one of these structural color filters, a Fabry-Perot interference based filter is under development. The Fabry-Perot interference-based filter has a structure in which a resonant layer is disposed between two reflective surfaces, and only a light having a specific wavelength passes through a multiple interference phenomenon inside the resonant layer by the reflective surfaces. It functions as a color filter.

In the conventional Fabry-Perot interference-based structural color filter, in order to increase the color purity, the thickness of the metal layer forming the reflective surface must be increased, but in this case, a transmission efficiency decreases. Therefore, there is a need to develop a technology capable of improving color purity without changing the thickness of the metal layer.

An object of the present invention is to provide a structural color filter capable of emitting high-purity light using tertiary resonance by having a resonant layer with an absorber layer inserted therein.

Structure color filter according to an embodiment of the present invention includes a first reflective layer; A second reflective layer facing the first reflective layer; A first resonance layer disposed between the first reflective layer and the second reflective layer; A second resonant layer disposed between the first resonant layer and the second reflective layer; And an absorption layer disposed between the first resonance layer and the second resonance layer.

In one embodiment, each of the first reflective layer and the second reflective layer may independently include one or more metal thin films selected from the group consisting of silver (Ag), aluminum (Al), and gold (Au).

In one embodiment, one surface of the first resonant layer is in contact with one surface of the first reflective layer to form an interface, and one surface of the second resonant layer is in contact with one surface of the second reflective layer to form an interface. have.

In one embodiment, each of the first and second resonant layers is independently a group consisting of zinc sulfide (ZnS), zinc selenide (ZnSe), titanium oxide (TiO ₂ ), and tantalum oxide (Ta ₂ O ₅ ) It may be formed of a single material selected from. For example, the first resonance layer and the second resonance layer may be formed of the same material, and in this case, the thickness of the first resonance layer may be the same as the thickness of the second resonance layer.

In one embodiment, the absorption layer is one selected from the group consisting of germanium (Ge), silicon (Si), titanium (Ti), titanium nitride (TiN), nickel (Ni), tungsten (W), and chromium (Cr). It may have a single-layer structure formed of the above material or a multi-layer stacked structure. In one embodiment, the absorption layer may have a thickness of 5 to 30 nm.

In one embodiment, the structural color filter may emit light having a third resonant wavelength among light incident from the outside.

In one embodiment, the structural color filter may further include an anti-reflection layer disposed on the reflective layer disposed in a direction in which external light is incident among the first and second reflective layers. In this case, the anti-reflection layer may be formed of one material selected from the group consisting of zinc sulfide (ZnS), zinc selenide (ZnSe), titanium oxide (TiO ₂ ), and tantalum oxide (Ta ₂ O ₅ ).

In one embodiment, the structural color filter may be a transmissive color filter that selectively transmits light corresponding to a third resonant wavelength among external light.

In one embodiment, the structural color filter may be a reflective color filter that selectively reflects light corresponding to a third resonant wavelength among external light. In this case, the reflective layer disposed below the first and second reflective layers based on the direction in which the external light is incident may be thicker than the remaining reflective layers.

In one embodiment, the structural color filter may further include a substrate disposed under the first reflective layer to support it.

In one embodiment, the substrate may be formed of a glass, metal, semiconductor, ceramic or polymer material.

According to the color filter of the structural color of the present invention, since the light of a specific wavelength is emitted by using a single tertiary resonance instead of the primary resonance, high purity light having a narrow half width can be emitted. In addition, since the absorber layer is disposed in the middle of the resonant layer, high-order resonance other than the third-order resonance can be suppressed, thereby resolving the problem that the color purity is lowered by emitting light at the other higher-order resonance frequency.

1 is a cross-sectional view for explaining a structural color filter according to an embodiment of the present invention.
2A and 2B have a layered structure of “anti-reflection layer (ZnS) / reflection layer (Ag) / resonance layer (ZnS) / reflection layer (Ag)”, and the thickness of the resonant layer is set so that a third resonance occurs at a wavelength of 630 nm Irradiance (square of absolute value of electric field) at the simulated 3rd resonance for the transmissive structural color filter according to the comparative example (if the 3rd resonance occurs at the wavelength of 630nm, the 5th resonance occurs at the wavelength of 450nm) and These graphs show the irradiance profiles at the fifth resonance.
3A and 3B show a transmissive structural color filter according to an embodiment having the same structure as the structural color filter of the comparative example, except that a 10 nm thick germanium (Ge) absorbing layer is inserted in the middle of the resonant layer (ZnS). These graphs show the irradiance profile at the simulated third resonance and the irradiance profile at the fifth resonance, respectively.
4 is a red, green and blue transmissive structural color filter according to a comparative example having a stacked structure of “anti-reflection layer (ZnS) / reflection layer (Ag) / resonance layer (ZnS) / reflection layer (Ag) / substrate (glass)” The simulated transmission spectrum for the fields is shown.
5 is a red, green and blue transmissive structural color filter according to an embodiment having the same structure as a structural color filter according to a comparative example, except that a germanium (Ge) absorbing layer is inserted in the middle of the resonant layer (ZnS). It is a simulated transmission spectrum.
6 is a color space coordinate obtained by calculating transmission spectra of red, green, and blue transmissive structural color filters according to the embodiment of FIG. 5 in a CIE chromaticity diagram.
7 and 8 are graphs showing the light transmission efficiency at the third resonant wavelength according to the thickness of the absorption layer in the transmissive red structure color filter.
9A to 9C show cross-sectional views, measurement transmission spectra, and sample pictures of a structural color filter manufactured according to an embodiment, respectively.
10A to 10C are graphs showing changes in resonance frequency according to a change in incident angle of TM polarized light for blue, green, and red structural color filters having the structure shown in FIG. 9A.
11A to 11C are graphs showing changes in resonance frequency according to a change in incident angle of unpolarized light for blue, green, and red structural color filters having the structure shown in FIG. 9A.
12 are graphs showing a transmission spectrum of a transmissive red structural color filter according to the material of the absorption layer.
13 is a graph showing transmission spectra of transmission type blue, green, and red color filters formed on a flexible substrate.
14 are photographs of the structural color color filters.
15A to 15C and FIGS. 16A and 16B are graphs showing changes in transmittance and tertiary resonance wavelength according to changes in the bending curvature radius of the structural color filters.
17 is a graph showing the change in transmittance according to the number of repetitions of the bending test.
18A is a reflective yellow structure color filter, “ZnS (45 nm) /, according to a comparative example having a stacked structure of“ ZnS (35 nm) / Ag (45 nm) / ZnS (140 nm) / Ag (150 nm) ” Reflective magenta structure color filter and “ZnS (55nm) / Ag (45nm) / ZnS (230nm)” according to a comparative example having a stacked structure of Ag (45nm) / ZnS (180nm) / Ag (150nm) / Ag (150 nm) ”shows a reflection spectrum of a reflective cyan color filter according to a comparative example.
18B is a reflective yellow structure according to an embodiment having a stacked structure of “ZnS (35 nm) / Ag (45 nm) / ZnS (70 nm) / Ge (5 nm) / ZnS (70 nm) / Ag (150 nm)” Color color filter, reflective magenta according to an embodiment having a layered structure of “ZnS (45 nm) / Ag (45 nm) / ZnS (90 nm) / Ge (5 nm) / ZnS (90 nm) / Ag (150 nm)” Structural color color filter and reflective cyan according to an embodiment having a layered structure of “ZnS (55 nm) / Ag (45 nm) / ZnS (115 nm) / Ge (10 nm) / ZnS (115 nm) / Ag (150 nm)” ) Structure color It shows the reflection spectrum of the color filter.
FIG. 19 illustrates the change of the third resonant wavelength according to the change in the incident angle of TM and TE polarized light in the reflective yellow, magenta, and cyan color filters according to the embodiment of FIG. 18B. These are graphs.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention can be applied to various changes and may have various forms, and specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosure form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing each drawing, similar reference numerals are used for similar components. In the accompanying drawings, the dimensions of the structures are shown to be enlarged than the actual for clarity of the present invention.

Terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "include" or "have" are intended to indicate the presence of features, numbers, steps, actions, elements or combinations thereof described herein, one or more other features or numbers. It should be understood that it does not preclude the existence or addition possibility of steps, steps, elements, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. Terms such as those defined in a commonly used dictionary should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Does not.

1 is a cross-sectional view for explaining a structural color filter according to an embodiment of the present invention.

1, the structural color filter 100 according to an embodiment of the present invention includes a substrate 110, a first reflective layer 120a, a second reflective layer 120b, a first resonant layer 130a, and a second The resonance layer 130b and the absorption layer 140 may be included. The structural color color filter 100 may be a transmissive color filter or a reflective color filter.

The material of the substrate 110 is not particularly limited. However, when the structural color filter 100 is a transmissive color filter, the substrate 110 may be formed of a transparent material. For example, when the structural color filter 100 is a transmissive color filter, the substrate 110 may be formed of a glass or polymer material. In one embodiment, when the transmissive structural color filter 100 is applied to a flexible device, the substrate 110 may be formed of a transparent polymer material. On the other hand, when the structural color filter 100 is a reflective color filter, the material of the substrate 100 is not particularly limited, and may be formed of not only the glass or polymer material, but also metal, semiconductor, and ceramic materials. It might be.

The first reflective layer 120a may be disposed on the substrate 110, and the second reflective layer 120b may be disposed apart from the first reflective layer 120a on the first reflective layer 120a. have. The first and second reflective layers 120a and 120b may be formed of a metal material having high reflectivity to light in the visible region. For example, the first and second reflective layers 120a and 120b may independently include one or more metal thin films selected from silver (Ag), aluminum (Al), and gold (Au).

When the structural color color filter 100 is a reflective color filter, the first reflective layer 120a may be formed to be relatively thick to absorb light having a resonant wavelength, and the structural color color filter 100 may In the case of a transmissive color filter, the first reflective layer 120a may be formed relatively thin.

The first resonant layer 130a may be disposed between the first reflective layer 120a and the second reflective layer 120b, and the second resonant layer 130b may include the first resonant layer 130a and the It may be disposed between the second reflective layer (120b). In one embodiment, the lower surface of the first resonant layer 130a may contact the first reflective layer 120a to form an interface, and the upper surface of the second resonant layer 130b may be the second reflective layer. In contact with (120b) it can form an interface.

The first and second resonant layers 130a and 130b may have a high refractive index and be formed of a transparent dielectric material. For example, the first and second resonant layers 130a and 130b independently of each other include zinc sulfide (ZnS), zinc selenide (ZnSe), titanium oxide (TiO ₂ ), and tantalum oxide (Ta ₂ O ₅ ). It may be formed of one material selected from. The material of the first resonant layer 130a and the material of the second resonant layer 130b are preferably identical to each other, but may be different.

In one embodiment, the thickness of the first resonance layer 130a and the thickness of the second resonance layer 130b may be the same. Alternatively, the thickness of the first resonance layer 130a and the thickness of the second resonance layer 130b may be different.

The light incident into the first and second resonant layers 130a and 130b is a specific wavelength, for example, a resonant wavelength due to repetitive reflection and interference caused by the first and second reflective layers 120a and 120b. Can be emitted outside. At this time, the wavelength of the emitted light may be determined by the thickness and refractive index of the first and second resonant layers 130a and 130b.

In one embodiment, when the structural color color filter 100 is a transmissive color filter, the structural color color filter 100 may emit one of red light, green light, and blue light. In this case, the first and The entire thickness of the second resonant layers 130a and 130b may be the thickest when the red light is emitted and the thinnest when the blue light is emitted. In an embodiment, when the first and second resonant layers 130a and 130b are both formed of zinc sulfide (ZnS) and the structural color filter 100 is a red light filter, the first and second resonant layers Each of (130a, 130b) may be formed to a thickness of 115nm. In addition, when the first and second resonant layers 130a and 130b are both formed of zinc sulfide (ZnS) and the structural color filter 100 is a green light filter, the first and second resonant layers 130a and 130b ) Each may be formed to a thickness of 90nm. In addition, when the first and second resonant layers 130a and 130b are both formed of zinc sulfide (ZnS) and the structural color filter 100 is a blue light filter, the first and second resonant layers 130a, 130b) Each may be formed to a thickness of 70 nm.

On the other hand, the structural color filter 100 according to the present invention may emit light having a high-order resonant frequency rather than primary resonance, and emit light having a high purity color, that is, a light having a narrow half width. To this end, the thickness of the first and second resonant layers 130a and 130b may be thicker than the thickness of the resonant layer of a conventional Fabry-Perot based structural color filter required for primary resonance. In one embodiment, the structural color filter 100 according to the present invention may emit light of high purity color using a third order resonance.

The absorbing layer 140 may be disposed between the first resonant layer 130a and the second resonant layer 130b. The absorption layer 140 may be formed of a material having high absorption of light in the visible region. For example, the absorption layer 140 is a single layer formed of germanium (Ge), silicon (Si), titanium (Ti), titanium nitride (TiN), nickel (Ni), tungsten (W), chromium (Cr), etc. Or it may have a multilayer structure.

The absorption layer 140 absorbs light having a fifth-order resonance frequency higher than the third-order resonance used by the structural color filter 100 according to the present invention to suppress the fifth-order resonance, thereby improving color purity. . In one embodiment, when the thickness of the absorbing layer 140 is thick, since the effective refractive index of the entire resonant layers 130a and 130b is affected and the light emission efficiency is reduced, the absorbing layer 140 is about 5 to 30 nm. Can have a thickness of

According to the present invention, when the absorbing layer 140 is disposed in the middle of the resonant layers 130a and 130b, high-order resonance higher than the third-order resonance, for example, by suppressing the fifth-order resonance, is emitted by the emission of the fifth-order resonance frequency light. The problem of color purity degradation caused can be solved. As described above, in order to implement a color filter using a high-order resonance rather than a first-order resonance, the thickness of the resonant layers 130a and 130b must be thicker than the first-order resonance, in this case, a short wavelength region within a visible light range. In other orders of magnitude higher than the third-order resonance, for example, the fifth-order resonance may be generated, and as a result, the color purity may be lowered by mixing light of the third-order resonance frequency and light of the fifth-order resonance frequency. have. However, according to the present invention, when the absorbing layer 140 is disposed in the middle of the resonant layers 130a and 130b, it is possible to solve the problem of color purity deterioration due to the occurrence of the fifth resonant.

The structural color filter 100 according to an embodiment of the present invention may further include an anti-reflection layer 150.

The anti-reflection layer 150 may be the second reflective layer 120b through which external light is incident. The anti-reflection layer 150 may be formed of a high refractive index transparent material. For example, the anti-reflection layer 150 may be formed of one material selected from zinc sulfide (ZnS), zinc selenide (ZnSe), titanium oxide (TiO ₂ ), and tantalum oxide (Ta ₂ O ₅ ). . The thickness and refractive index of the anti-reflection layer 150 may be appropriately adjusted according to the wavelength of light emitted by the structural color filter 100, respectively.

According to the structural color filter 100 of the present invention, since it emits light of a specific wavelength by using a single tertiary resonance rather than the primary resonance, it can emit high purity light having a narrow half width. In addition, since the absorber layer is disposed in the middle of the resonant layer, high-order resonance other than the third-order resonance can be suppressed, thereby resolving the problem that the color purity is lowered by emitting light at the other higher-order resonance frequency.

2A and 2B have a layered structure of “anti-reflection layer (ZnS) / reflection layer (Ag) / resonance layer (ZnS) / reflection layer (Ag)”, and the thickness of the resonant layer is set so that a third resonance occurs at a wavelength of 630 nm Irradiance profile at the third resonance simulated for the transmissive structural color filter according to the comparative example (if the third resonance occurs at the wavelength of 630 nm, the fifth resonance occurs at the wavelength of 450 nm) and the irradiance at the fifth resonance 3A and 3B are graphs showing each of the ounce profiles, and FIGS. 3A and 3B are examples of a structure having the same structure as the color filter of the comparative example, except that a 10 nm thick germanium (Ge) absorbing layer is inserted in the middle of the resonant layer (ZnS). These are graphs showing the irradiance profile at the 3rd resonance and the irradiance profile at the 5th resonance, respectively, for the transmissive structural color filter.

2A and 2B, it can be seen that in the case of the structural color filter according to the comparative example, strong irradiance is formed inside the resonance layer not only for the third resonance but also for the fifth resonance.

On the other hand, referring to FIGS. 3A and 3B, in the case of the structural color filter according to the embodiment, strong irradiance is formed inside the resonant layer for the third resonance, but strong irradiance inside the resonant layer for the fifth resonance. It can be confirmed that the su is not formed.

In summary, it can be seen that in the case where the absorber layer is disposed in the center of the resonant layer according to an embodiment of the present invention, the fifth resonant resonance can be suppressed.

In addition, in the structural color filter according to the embodiment, since the irradiance for the third resonance is not high at the position where the absorption layer is disposed, it is found that even if the absorption layer is disposed in the center of the resonance layer, the emission efficiency of 630 nm wavelength light hardly decreases. You can.

4 is a red, green and blue transmissive structural color filter according to a comparative example having a stacked structure of “anti-reflection layer (ZnS) / reflection layer (Ag) / resonance layer (ZnS) / reflection layer (Ag) / substrate (glass)” 5 shows a simulated transmission spectrum for the fields, and FIG. 5 is a red color according to an embodiment having the same structure as the color filter according to the comparative example, except that a germanium (Ge) absorbing layer is inserted in the middle of the resonant layer (ZnS). , It is a simulated transmission spectrum for green and blue transmissive structural color filters.

Referring to FIG. 4, in the case of the red structural color filter according to the comparative example in which the thickness of the resonant layer is relatively thick, it can be seen that the fifth resonance occurs at a wavelength of 450 nm, which causes the color to be close to magenta rather than red. It has been shown to emit light.

Referring to FIG. 5, in the case of the red structure color filter according to the embodiment, it can be confirmed that the fifth resonance at 450 nm wavelength does not occur due to the insertion of the Ge absorption layer in the middle of the resonance layer. On the other hand, although the Ge absorbing layer is inserted, it can be seen that the red, green and blue transmissive structural color filters according to the embodiment exhibit similar transmission efficiency to the red, green and blue transmissive structural color filter according to the comparative example.

On the other hand, the red, green, and blue transmissive structural color filters according to the embodiment and the red, green, and blue transmissive structural color filters according to the comparative example all use a third resonance, so that a very narrow half-width of about 50 nm is emitted. Appeared to release. In addition, although the thickness of each Ag reflective layer was designed to be 30 nm, the red, green, and blue transmissive structural color filters according to the comparative example showed a transmission efficiency close to about 70%, and the red, green, and It was also found that the blue transmissive structural color filters showed high transmission efficiency of 65% or more.

6 is a color space coordinate obtained by calculating transmission spectra of red, green, and blue transmissive structural color filters according to the embodiment of FIG. 5 in a CIE chromaticity diagram.

Referring to FIG. 6, blue, green, and red color coordinates are (0.187, 0.149), (0.318, 0.586), and (0.578, 0.346). Based on this, the structural color filter according to the present invention has a very improved color purity. It can be seen that can be achieved.

7 and 8 are graphs showing the light transmission efficiency at the third resonant wavelength according to the thickness of the absorption layer in the transmissive red structure color filter.

7 and 8, it can be seen that as the thickness of the absorption layer increases, transmittance at the third resonant wavelength decreases and the third resonant wavelength shifts to the right. Specifically, it can be seen that the transmittance of about 4 to 5% is decreased whenever the thickness of the Ge or Ti absorbing layer is increased by 5 nm. In addition, it can be seen that as the thickness of the absorbing layer increases, the light transmittance at the 5th resonance wavelength decreases.

Summarizing the above, it can be seen that it is necessary to set the thickness of the absorbing layer in consideration of the suppression of the 5th resonance, the transmittance of the light at the 3rd resonance wavelength, and the change in the resonance wavelength. In the structural color filter according to the present invention, the absorption layer may have a thickness of about 5 to 30 nm, preferably about 10 to 20 nm.

9A to 9C show cross-sectional views, measurement transmission spectra, and sample pictures of a structural color filter manufactured according to an embodiment, respectively. In FIG. 9A, the numbers in parentheses indicate the thickness of the corresponding layer, and the unit is nm.

9A to 9C, it can be seen that red, blue, and green structural color filters all have a narrow half-width and exhibit high transmittance of 60% or more.

10A to 10C are graphs showing a change in resonance frequency according to a change in incident angle of TM polarized light for blue, green, and red structural color filters having the structure shown in FIG. 9A, and FIGS. 11A to 11C are 9A are graphs showing changes in resonance frequency according to a change in incident angle of unpolarized light for blue, green, and red structural color filters having the structure shown in FIG. 9A.

10A to 10C and FIGS. 11A to 11C, it can be seen that the resonance frequency hardly changes even when the incident angle of the incident light increases to 75 °, not only for the TM polarized light but also for the unpolarized light. This is because the material ZnS of the resonant layer has a high refractive index (n = 2.32 @ 60nm) in the visible light band, so the angle of refraction inside the resonant layer is not relatively large even if the incident angle of light changes.

12 are graphs showing a transmission spectrum of a transmissive red structural color filter according to the material of the absorption layer.

Referring to FIG. 12, when an absorber layer is formed of a material having high absorbance in a visible light band such as Ti, Ni, Ge, Cr, or W, the fifth-order resonance is effectively suppressed, and high light transmittance at the third-order resonance wavelength It can be confirmed that can be achieved.

13 is a graph showing the transmission spectrum of the transmissive blue, green and red structural color color filters formed on the flexible substrate, and FIG. 14 are pictures of the structural color color filters, and FIGS. 15A to 15C and FIGS. 16A and 16B are The structural color filters are graphs showing changes in transmittance and tertiary resonance wavelength according to changes in the bending curvature radius, and FIG. 17 is a graph showing changes in transmittance according to the number of repetitions of the bending test.

13, 14, 15A to 15C, 16A and 16B, and 17, even if the bending curvature radius changes, the transmittance at the third and third resonant wavelengths hardly changes, even when the bending curvature radius changes. It can be seen that the durability is maintained until more than 3000 repetition tests.

18A is a reflective yellow structure color filter, “ZnS (45 nm) /, according to a comparative example having a stacked structure of“ ZnS (35 nm) / Ag (45 nm) / ZnS (140 nm) / Ag (150 nm) ” Reflective magenta structure color filter and “ZnS (55nm) / Ag (45nm) / ZnS (230nm)” according to a comparative example having a stacked structure of Ag (45nm) / ZnS (180nm) / Ag (150nm) ” / Ag (150nm) "shows a reflection spectrum of a reflective cyan color filter according to a comparative example having a stacked structure, and FIG. 18B shows“ ZnS (35nm) / Ag (45nm) / ZnS (70nm) / Ge (5nm) / ZnS (70nm) / Ag (150nm) ”reflective yellow color filter,“ ZnS (45nm) / Ag (45nm) / ZnS (90nm) ” / Ge (5nm) / ZnS (90nm) / Ag (150nm) ”reflective type magenta structure color filter and“ ZnS (55nm) / Ag (45nm) / ZnS (115nm) according to an embodiment having a stacked structure ) / Ge (10nm) / ZnS (115nm) / Ag (150nm) ”Reflective Spectrum of Reflective Cyan Structure Color Filter according to Example It represents.

18A and 18B, when the thickness of the lower Ag layer is designed to be thick, the light of the resonant wavelength is absorbed by the lower metal layer, and cyan, which is a complementary color of red, green, and blue, respectively ( Cyan), magenta, and yellow (yellow) color filters can be confirmed to be implemented, and when the absorption layer is inserted in the center of the light absorbing layer, it can be seen that the fifth resonance is suppressed.

FIG. 19 shows the change of the third resonant wavelength according to the change in the incident angle of TM and TE polarized light in the reflective yellow, magenta, and cyan color filters according to the embodiment of FIG. 18B. These are graphs.

Referring to FIG. 19, it can be seen that for both the TM polarized light and the TE polarized light, even though the incident angle of the light is changed, the change in the third resonant wavelength is not large.

Although described above with reference to the preferred embodiment of the present invention, those skilled in the art may variously modify and change the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that you can.

100: structural color color filter 110: substrate
120a, 120b: reflective layers 130a, 130b: resonant layers
140: absorption layer 150: anti-reflection layer

Claims (15)

A first reflective layer;
A second reflective layer facing the first reflective layer;
A first resonance layer disposed between the first reflective layer and the second reflective layer;
A second resonant layer disposed between the first resonant layer and the second reflective layer; And
And an absorption layer disposed between the first resonance layer and the second resonance layer,
The absorbent layer is a single formed of one or more materials selected from the group consisting of germanium (Ge), silicon (Si), titanium (Ti), titanium nitride (TiN), nickel (Ni), tungsten (W) and chromium (Cr). It has a layer structure or a multi-layer stacked structure,
The absorption layer has a thickness of 5 to 30 nm, characterized in that the structural color filter. According to claim 1,
Each of the first reflective layer and the second reflective layer independently includes a metal thin film selected from the group consisting of silver (Ag), aluminum (Al), and gold (Au). According to claim 1,
One surface of the first resonant layer is in contact with one surface of the first reflective layer to form an interface, one surface of the second resonant layer is in contact with one surface of the second reflective layer to form an interface, structural color Color filter. According to claim 1,
Each of the first and second resonant layers is independently selected from a group consisting of zinc sulfide (ZnS), zinc selenide (ZnSe), titanium oxide (TiO ₂ ), and tantalum oxide (Ta ₂ O ₅ ). Characterized in that the structure color filter, characterized in that formed. According to claim 4,
The first resonance layer and the second resonance layer are formed of the same material as each other,
The thickness of the first resonant layer is characterized in that the same as the thickness of the second resonant layer, structural color filter. According to claim 4,
The first resonance layer and the second resonance layer are formed of the same material as each other,
The absorbing layer is arranged to maintain the third-order resonance of the irradiance and weaken the fifth-order resonance of the color filter. The method according to claim 5 or 6,
Structure color filter, characterized in that the first resonant layer and the second resonant layer operates as a single resonant layer. According to claim 1,
The structural color color filter is characterized in that it emits light of a third resonant wavelength among the light incident from the outside, the structural color color filter. According to claim 1,
A structure color filter, further comprising an anti-reflection layer disposed on an upper portion of the reflective layer disposed in a direction in which external light is incident among the first and second reflective layers. The method of claim 9,
The anti-reflection layer is formed of one material selected from the group consisting of zinc sulfide (ZnS), zinc selenide (ZnSe), titanium oxide (TiO2), and tantalum oxide (Ta2O5). According to claim 1,
The structural color filter is a structural color filter, characterized in that the transmission type color filter for selectively transmitting light corresponding to the third resonant wavelength of the external light. According to claim 1,
The structural color filter is a reflective color filter, which is a reflective color filter that selectively reflects light corresponding to a third resonant wavelength among external light. The method of claim 12,
Structural color filter, characterized in that the reflective layer disposed below the first and second reflective layers based on the direction in which the external light is incident is thicker than the remaining reflective layers. According to claim 1,
A color filter having a structure color, further comprising a substrate disposed under the first reflective layer and supporting the substrate. The method of claim 14,
The substrate is formed of glass, metal, semiconductor, ceramic or polymer material, characterized in that the structural color filter.

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