Combination structure, optical filter, image sensor, camera module, and electronic device

Abstract

Disclosed are a combination structure, an optical filter, an image sensor, a camera module, and an electronic device including the combination structure, the optical filter, the image sensor, and the camera module. The combination structure includes: a nanostructure array including a plurality of nanostructures having a size smaller than a near-infrared wavelength, which are repeatedly arranged; and a light-absorbing portion adjacent to the nanostructure array and including a near-infrared absorbing material configured to absorb light in at least a portion of a near-infrared wavelength region.

Description

Technical Field

[0001] The combined structure, optical filter, image sensor, camera module, and electronic devices are disclosed. Background Technology

[0002] Electronic devices such as mobile phones, digital cameras, portable video cameras, or cameras, including image sensors that store images as electrical signals, have been used.

[0003] These electronic devices may include optical filters to reduce or prevent optical distortion caused by light in regions other than the visible wavelength range. Summary of the Invention

[0004] The example implementation provides a combined structure that can achieve desired optical performance for light outside the visible wavelength region with a thin thickness.

[0005] Some example implementations provide an optical filter that includes this combined structure.

[0006] Some example implementations provide an image sensor that includes the combined structure and / or the optical filter.

[0007] Some example implementations provide a camera module that includes the combined structure, the optical filter, and / or the image sensor.

[0008] Some example implementations provide an electronic device that includes the combined structure, the optical filter, the image sensor, and / or the camera module.

[0009] According to some example embodiments, a combined structure includes: a nanostructure array comprising a plurality of nanostructures having dimensions smaller than the near-infrared wavelength arranged in a repeating manner; and a light-absorbing portion adjacent to the nanostructure array and comprising a near-infrared absorbing material configured to absorb light in at least a portion of the near-infrared wavelength region.

[0010] The light-absorbing portion can be disposed on at least one of the lower surface, upper surface and side surface of the plurality of nanostructures.

[0011] The multiple nanostructures and light-absorbing components can be in contact with each other.

[0012] Near-infrared wavelengths can be in the range of greater than about 700 nm and less than or equal to about 1200 nm.

[0013] Near-infrared wavelengths can range from approximately 890 nm to approximately 990 nm.

[0014] The width of the nanostructure can be from about 100 nm to about 500 nm, and the thickness of the nanostructure can be from about 50 nm to about 500 nm.

[0015] Each of the plurality of nanostructures may include a high refractive index material having a refractive index greater than or equal to about 2.4 at 940 nm.

[0016] Each of the plurality of nanostructures may include titanium oxide, silicon, aluminum, III-V semiconductor compounds, or combinations thereof.

[0017] Near-infrared absorbing materials can be configured to absorb light in at least a portion of a wavelength region greater than about 700 nm and less than or equal to 1200 nm.

[0018] The maximum absorption wavelength of near-infrared absorbing materials can be in the range of approximately 890 nm to approximately 990 nm.

[0019] The refractive index of the light-absorbing portion can be lower than that of the nanostructure.

[0020] The refractive index of the light-absorbing portion at 940 nm can be less than or equal to about 1.8.

[0021] Near-infrared absorbing materials may include quantum dots, quinone metal complexes, polymethyl compounds, anthocyanin compounds, phthalocyanine compounds, terpinenine compounds, naphthalene phthalocyanine compounds, imine compounds, diimine compounds, triarylmethane compounds, dipyrrole methylene compounds, anthraquinone compounds, diquinone compounds, naphthoquinone compounds, squartzium compounds, naphthalene-benzene compounds, perylene compounds, pyranium compounds, squartzium compounds, thiaranium compounds, diketopyrrolopyrrole compounds, boron dipyrrole methylene compounds, nickel-dithiol complexes, ketoneonium compounds, their derivatives, or combinations thereof.

[0022] The spectrum of the combined structure can have a maximum absorption wavelength in the wavelength region greater than about 700 nm and less than or equal to 1200 nm, and the light absorption ratio at the maximum absorption wavelength can be greater than about 50%.

[0023] The maximum absorption wavelength can be in the range of approximately 890 nm to approximately 990 nm.

[0024] The spectrum of this combined structure can have a minimum transmission wavelength in the wavelength region greater than about 700 nm and less than or equal to 1200 nm, and the transmittance at the minimum transmission wavelength can be less than or equal to about 35%.

[0025] The minimum transmission wavelength can be in the range of approximately 890 nm to approximately 990 nm.

[0026] The combined structure may also include a substrate layer, the refractive index of which may be lower than that of the nanostructure.

[0027] The thickness of this composite structure can be less than or equal to about 1 μm.

[0028] According to some example implementations, an optical filter including the combined structure is provided.

[0029] According to some example embodiments, an image sensor includes: a semiconductor substrate including a plurality of photodiodes; and an optical filter disposed on the semiconductor substrate and configured to block light in at least a portion of the near-infrared wavelength region, wherein the optical filter includes the combined structure.

[0030] The image sensor may also include a color filter disposed on the semiconductor substrate and on or below the optical filter.

[0031] The image sensor may also include a dual bandpass filter configured to transmit a portion of the near-infrared wavelength region and all visible wavelength regions.

[0032] According to some example implementations, a camera module including the optical filter or the image sensor is provided.

[0033] According to some example embodiments, an electronic device includes the combined structure, the optical filter, the image sensor, or the camera module.

[0034] It is possible to achieve the desired optical performance for light outside the visible wavelength region with a thin thickness. Attached Figure Description

[0035] Figure 1 This is a schematic diagram illustrating an example of a combined structure according to some exemplary embodiments.

[0036] Figure 2 yes Figure 1 A cross-sectional view of the combined structure.

[0037] Figure 3 These are simulated images illustrating the absorption principle of a combined structure according to some example embodiments.

[0038] Figure 4 This is a schematic diagram illustrating an example of a combined structure according to some exemplary embodiments.

[0039] Figure 5 yes Figure 4 A cross-sectional view of the combined structure.

[0040] Figure 6 These are simulated images illustrating the absorption principle of a combined structure according to some example embodiments.

[0041] Figure 7 This is a schematic diagram illustrating an example of a combined structure according to some exemplary embodiments.

[0042] Figure 8 yes Figure 7 A cross-sectional view of the combined structure.

[0043] Figure 9 This is a schematic diagram illustrating an example of a combined structure according to some exemplary embodiments.

[0044] Figure 10 yes Figure 9 A cross-sectional view of the combined structure.

[0045] Figure 11 This is a schematic diagram illustrating an example of a camera module according to some exemplary embodiments.

[0046] Figure 12 This is a schematic diagram illustrating another example of a camera module according to some exemplary implementations.

[0047] Figure 13 This is a cross-sectional view illustrating an example of an image sensor according to some exemplary embodiments.

[0048] Figure 14 This is a cross-sectional view illustrating another example of an image sensor according to some exemplary embodiments.

[0049] Figure 15 This is a cross-sectional view illustrating another example of an image sensor according to some exemplary embodiments.

[0050] Figure 16 This is a cross-sectional view illustrating another example of an image sensor according to some exemplary embodiments.

[0051] Figure 17 It is based on the spectrum of the structure in Example 1.

[0052] Figure 18 Based on the spectrum of the structure of Comparative Example 1,

[0053] Figure 19 Based on the spectrum of the structure of Comparative Example 2,

[0054] Figure 20 It is based on the spectrum of the structure in Example 3.

[0055] Figure 21 Based on the spectrum of the structure of Comparative Example 3,

[0056] Figure 22 Based on the spectrum of the structure of Comparative Example 4,

[0057] Figure 23 It is based on the spectrum of the structure in Example 4.

[0058] Figure 24Based on the spectrum of the structure of Comparative Example 5, and

[0059] Figure 25 It is based on the spectrum of the structure of Comparative Example 6. Detailed Implementation

[0060] In the following description, exemplary embodiments will be detailed so that those skilled in the art will understand them. However, this disclosure may be embodied in many different forms and is not to be construed as limited to the exemplary embodiments set forth herein.

[0061] In the accompanying drawings, the thickness of layers, films, panels, regions, etc., is exaggerated for clarity. Throughout the specification, the same reference numerals denote the same elements. It will be understood that when an element such as a layer, film, region, or substrate is referred to as "on" another element, the element may be directly on said other element, or an intervening element may be present. In contrast, when an element is referred to as "directly on" another element, no intervening element is present.

[0062] In the following description, the combined structures according to some exemplary embodiments will be described with reference to the accompanying drawings.

[0063] Figure 1 This is a schematic diagram illustrating an example of a combined structure according to some exemplary embodiments. Figure 2 yes Figure 1 A cross-sectional view of the combined structure.

[0064] According to some example embodiments, the combined structure 10 includes a nanostructure array 11, a light-absorbing portion 12, and a substrate layer 13.

[0065] The nanostructure array 11 can be a structure with optical properties, referred to as a metamaterial or metastructure. The nanostructure array 11 can include multiple nanostructures 11a arranged repeatedly or periodically, and the multiple nanostructures 11a can be arranged repeatedly or periodically along rows and / or columns. The multiple nanostructures 11a can be arranged regularly or randomly. The multiple nanostructures 11a can be separated from each other or connected to each other.

[0066] The nanostructure 11a can be a three-dimensional structure with a width (w) and a thickness (t), such as a cuboid shape, a hexahedron shape, a cylinder shape, or a disk shape, but is not limited thereto. The cross-sectional shape of the nanostructure 11a can be, for example, a rectangle or a square.

[0067] Multiple nanostructures 11a can be arranged in a period (p) and / or a gap (g), wherein the period (p) can be the distance between the centers of adjacent nanostructures 11a, and the gap (g) can be the distance between the facing surfaces of adjacent nanostructures 11a.

[0068] The nanostructure array 11 and / or nanostructure 11a can be configured to reflect or absorb light of a certain wavelength and thus exhibit optical properties, for example, by controlling the shape, geometry, size, and / or orientation of the nanostructure 11a and / or the arrangement of the nanostructure array 11. For example, the size of the nanostructure 11a can be a subwavelength smaller than the wavelength of the light to be reflected or absorbed. Here, the size of the nanostructure 11a can be width, thickness, gaps, and / or periodicity, and when the nanostructure 11a has a cylindrical or disk-shaped shape, the width can be a diameter. For example, the size of the nanostructure 11a can be both width and thickness.

[0069] For example, the nanostructure array 11 can be configured to reflect or absorb light of wavelengths belonging to the near-infrared wavelength region, wherein the size of the nanostructure 11a can be smaller than the wavelength belonging to the near-infrared wavelength region. Here, the near-infrared wavelength region can be greater than about 700 nm and less than or equal to about 1200 nm, for example, about 750 nm to about 1100 nm, about 750 nm to about 1000 nm, about 800 nm to about 1000 nm, about 850 nm to about 990 nm, about 870 nm to about 990 nm, or about 890 nm to about 990 nm.

[0070] When the terms “about” or “substantially” are used in conjunction with numerical values ​​in this specification, it means that the relevant numerical value includes a tolerance of ±10% around the stated value. When a range is specified, the range includes all values ​​within that range, such as increments of 0.1%.

[0071] For example, the width (w) of the nanostructure 11a can be from a few nanometers to hundreds of nanometers, such as about 100 nm to about 800 nm, about 100 nm to about 500 nm, about 200 nm to about 500 nm, or about 300 nm to about 500 nm.

[0072] For example, the thickness (t) of the nanostructure 11a can be from a few nanometers to hundreds of nanometers, such as about 50 nm to about 800 nm, about 50 nm to about 700 nm, about 50 nm to about 600 nm, about 50 nm to about 500 nm, about 100 nm to about 500 nm, about 200 nm to about 500 nm, or about 250 nm to about 500 nm.

[0073] For example, the period (p) of the nanostructure 11a can be from a few nanometers to hundreds of nanometers, such as about 200 nm to about 800 nm, about 200 nm to about 700 nm, about 200 nm to about 600 nm, or about 200 nm to about 500 nm.

[0074] For example, the gap (g) of the nanostructure 11a can be from tens of nanometers to hundreds of nanometers, such as about 50 nm to about 500 nm, about 50 nm to about 400 nm, about 70 nm to about 400 nm, about 70 nm to about 300 nm, or about 80 nm to about 250 nm.

[0075] For example, the nanostructure array 11 can be configured to reflect light of wavelengths belonging to the near-infrared wavelength region, and can have reflectance ratios in the wavelength region from about 700 nm to about 1100 nm, for example, greater than or equal to about 80%, greater than or equal to about 82%, greater than or equal to about 85%, greater than or equal to about 88%, greater than or equal to about 90%, greater than or equal to about 92%, greater than or equal to about 95%, greater than or equal to about 97%, greater than or equal to about 99%, or about 100%. For example, the nanostructure array 11 can not be configured to substantially absorb light of wavelengths belonging to the near-infrared wavelength region, and can have absorption ratios in the wavelength region from about 700 nm to about 1100 nm, for example, less than or equal to about 5%, less than or equal to about 3%, less than or equal to about 2%, less than or equal to about 1%, less than or equal to about 0.5%, or about 0%.

[0076] The nanostructure 11a may include a high-refractive-index material having a high refractive index. The refractive index may have a wavelength distribution, and the nanostructure 11a may include a high-refractive-index material having, for example, a refractive index of about 2.0 or greater than or equal to about 2.3, about 2.4 or greater than or equal to about 2.5, about 3.0 or greater than or equal to about 3.5, or about 4.0 or greater than or equal to about 4.0 at about 900 nm to about 1000 nm (e.g., 940 nm). For example, the nanostructure 11a may have the following refractive indices: about 2.0 to about 5.0, about 2.3 to about 5.0, about 2.4 to about 5.0, about 2.5 to about 5.0, about 3.0 to about 5.0, about 2.0 to about 4.0, about 2.3 to about 4.0, about 2.4 to about 4.0, about 2.5 to about 4.0, about 3.0 to about 4.0, or about 2.0 to about 3.0. For example, nanostructure 11a may include an insulator, conductor, semiconductor or combination thereof having the said refractive index, such as oxide, nitride, sulfide, metal, semiconductor, semiconductor compound or combination thereof, such as titanium oxide, zinc oxide, indium oxide, zirconium oxide, silicon, aluminum, group III-V semiconductor compound or combination thereof, but is not limited thereto.

[0077] The light-absorbing portion 12 is a region configured to absorb light of a certain wavelength. The light-absorbing portion 12 may be disposed adjacent to the nanostructure array 11, and may, for example, be in contact with the nanostructure array 11. The light-absorbing portion 12 may be a light-absorbing layer below the plurality of nanostructures 11a, and may be in contact with the lower surface of the plurality of nanostructures 11a.

[0078] The light-absorbing portion 12 includes a light-absorbing material configured to absorb light of a certain wavelength. This light-absorbing material can be one or more light-absorbing materials, and can be, for example, an organic material, an inorganic material, an organic / inorganic material, or a combination thereof.

[0079] For example, the light-absorbing portion 12 may include a near-infrared absorbing material configured to absorb light in at least a portion of the near-infrared wavelength region. The near-infrared absorbing material may be configured to absorb light in at least a portion of the wavelength region greater than about 700 nm and less than or equal to 1200 nm, and the maximum absorption wavelength (λ) of the near-infrared absorbing material... max,A It can be, for example, about 750nm to about 1100nm, about 750nm to about 1000nm, about 800nm ​​to about 1000nm, about 850nm to about 990nm, about 870nm to about 990nm, or about 890nm to about 990nm.

[0080] The near-infrared absorbing material can be one or more near-infrared absorbing materials, and is not particularly limited, as long as it can selectively absorb light in the near-infrared wavelength region. The near-infrared absorbing material can be an organic material, an inorganic material, an organic / inorganic material, and / or a combination thereof.

[0081] Near-infrared absorbing materials may include, for example, quantum dots, quinone metal complexes, polymethyl compounds, anthocyanin compounds, phthalocyanine compounds, terpinenine compounds, naphthalene phthalocyanine compounds, imine compounds, diimine compounds, triarylmethane compounds, dipyrrole methylene compounds, anthraquinone compounds, diquinone compounds, naphthoquinone compounds, squaronium compounds, rylene compounds, perylene compounds, pyranonium compounds, squaraine compounds, thiaranonium compounds, diketopyrrolopyrrole compounds, boron-dipyrrole methylene compounds, nickel-dithiol complexes, croconium compounds, their derivatives, or combinations thereof, but are not limited thereto.

[0082] For example, the light-absorbing portion 12 comprising near-infrared absorbing material may have a refractive index in the near-infrared wavelength region that is less than or equal to about 2.0 or less than or equal to about 1.8 (e.g., in the range of about 1.1 to about 2.0 or about 1.1 to about 1.8), and its refractive index in the wavelength region of about 900 nm to about 1000 nm (e.g., 940 nm) may, for example, be less than or equal to about 2.0 or less than or equal to about 1.8, for example, in the range of about 1.1 to about 2.0 or about 1.1 to about 1.8. For example, the light-absorbing portion 12 comprising near-infrared absorbing material may have an extinction coefficient in the near-infrared wavelength region that is in the range of about 0.01 to about 0.5, for example, in the wavelength region of about 900 nm to about 1000 nm (e.g., about 940 nm) that is in the range of about 0.01 to about 0.5.

[0083] The light-absorbing portion 12 may be formed from a composition including the aforementioned near-infrared absorbing material, and the light-absorbing portion 12 may be, for example, a cured product of the composition.

[0084] In addition to the aforementioned near-infrared absorbing material, the composition may also include a binder. The binder may be an organic binder, an inorganic binder, an organic / inorganic binder, or a combination thereof, and is not particularly limited, as long as it is a material capable of mixing with, dispersing, or binding the near-infrared absorbing material. The binder may be a curable binder, such as a thermosetting binder, a photocurable binder, or a combination thereof.

[0085] The binder may be, for example, (meth)propylene binder, methylcellulose, ethylcellulose, hydroxypropyl methylcellulose (HPMC), hydroxypropyl cellulose (HPC), xanthan gum, polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), cyclic olefin polymer (COP), carboxymethyl cellulose, hydroxyethyl cellulose, silicone, organic-inorganic hybrid materials, copolymers thereof, or combinations thereof, but is not limited thereto.

[0086] For example, the near-infrared absorbing material may be included in amounts of about 0.01 to about 50 parts by weight, about 0.01 to about 30 parts by weight, about 0.01 to about 20 parts by weight, about 0.01 to about 15 parts by weight, or about 0.01 to about 10 parts by weight based on 100 parts by weight of the adhesive.

[0087] In addition to the aforementioned near-infrared absorbing material and binder, the composition may optionally include a solvent.

[0088] The composition can be coated and dried on substrate layer 13, which will be described later, and optionally cured. Coating can be, for example, spin coating, slot coating, bar coating, doctor blade coating, stencil coating, and / or inkjet coating. Drying can be performed, for example, by natural drying, hot air drying, and / or heat treatment at a temperature higher than the boiling point of the aforementioned solvent. Curing can be thermosetting, photocuring, or a combination thereof.

[0089] The light-absorbing portion 12 may have a thickness ranging from about 1 nm to about 1000 nm, for example, about 10 nm to about 1000 nm, about 10 nm to about 700 nm, about 10 nm to about 500 nm, or about 10 nm to about 300 nm.

[0090] The substrate layer 13 is disposed below the nanostructure array 11 and the light-absorbing portion 12, and supports the nanostructure array 11 and the light-absorbing portion 12. The substrate layer 13 may be a transparent substrate layer, and has, for example, a transmittance of greater than or equal to about 85% or greater than or equal to about 90% in the wavelength region of about 400 nm to about 1000 nm.

[0091] The substrate layer 13 may have a lower refractive index than that of the nanostructure 11a, for example, a refractive index less than or equal to about 1.7 in the range of about 900 nm to about 1000 nm (e.g., about 940 nm), such as a refractive index in the range of about 1.4 to about 1.7. The substrate layer 13 may include, for example, organic materials, inorganic materials, organic / inorganic materials or combinations thereof, such as oxides, nitrides, sulfides, fluorides, polymers or combinations thereof, such as glass, silicon oxide, aluminum oxide, magnesium fluoride, polystyrene, polymethyl methacrylate, polycarbonate or combinations thereof, but is not limited thereto.

[0092] The composite structure 10 may have the following thicknesses: about 10 μm, less than or equal to about 5 μm, less than or equal to about 3 μm, less than or equal to about 2 μm, less than or equal to about 1 μm, less than or equal to about 900 nm, less than or equal to about 800 nm, less than or equal to about 700 nm, less than or equal to about 600 nm, or less than or equal to about 500 nm. For example, the thickness of the composite structure 10 may be in the following ranges: about 100 nm to about 10 μm, about 100 nm to about 5 μm, about 100 nm to about 3 μm, about 100 nm to about 2 μm, about 100 nm to about 1 μm, about 100 nm to about 900 nm, about 100 nm to about 800 nm, about 100 nm to about 700 nm, about 100 nm to about 600 nm, or about 100 nm to about 500 nm.

[0093] By combining the nanostructure array 11 and the light-absorbing portion 12, the combined structure 10 can exhibit high light absorption characteristics with a thin thickness. This is likely due to the unique optical properties of the nanostructure array 11, referred to as a metamaterial or metastructure, and the fact that the nanostructure array 11 and / or nanostructure 11a can confine incident light of a certain wavelength. Furthermore, the adjacent light-absorbing portion 12 can be configured to absorb the incident light confined within the nanostructure array 11 and / or nanostructure 11a multiple times, thus exhibiting a high light absorption effect. The absorbed light dose through multiple absorptions can be significantly higher than the absorbed light dose through a single absorption in the light-absorbing portion 12 of a planar structure without the nanostructure array 11.

[0094] Figure 3 This is a simulated image illustrating the absorption principle of a combined structure according to some example embodiments.

[0095] Reference Figure 3 Incident light from the top of the nanostructure 11a with subwavelength dimensions can be confined inside the nanostructure 11a, and the confined light inside the nanostructure 11a can flow into the light absorption portion 12 via an evanescent wave and be absorbed multiple times therein. Therefore, the combined structure can exhibit high light absorption characteristics.

[0096] For example, the nanostructure array 11 can be designed to reflect or absorb light with wavelengths in the near-infrared wavelength region, and the light-absorbing portion 12 can include a near-infrared absorbing material configured to absorb light in at least a portion of the near-infrared wavelength region. Thus, the combined structure 10 can be effectively configured to transmit light in the visible wavelength region and effectively absorb light in the near-infrared wavelength region.

[0097] Therefore, the spectrum of the combined structure 10 can have a maximum absorption wavelength (λ) in the wavelength region greater than about 700 nm and less than or equal to about 1200 nm. max,A ) and minimum transmission wavelength (λ) min,T For example, it has the maximum absorption wavelength (λ) in the following range. max,A ) and minimum transmission wavelength (λ) min,T The wavelengths are approximately 750 nm to approximately 1100 nm, approximately 750 nm to approximately 1000 nm, approximately 800 nm to approximately 1000 nm, approximately 850 nm to approximately 990 nm, approximately 870 nm to approximately 990 nm, or approximately 890 nm to approximately 990 nm. The combined structure 10 can achieve absorption at the maximum wavelength (λ). max,A At the minimum transmission wavelength (λ), it has a light absorption ratio greater than or equal to about 50%, for example greater than or equal to about 55%, greater than or equal to about 60%, greater than or equal to about 65%, or greater than or equal to about 70%. The combined structure 10 has a light absorption ratio greater than or equal to about 50%, for example greater than or equal to about 55%, greater than or equal to about 60%, greater than or equal to about 65%, or greater than or equal to about 70%. min,TThe transmittance at a certain point can be less than or equal to about 35%, for example, less than or equal to about 32%, less than or equal to about 30%, less than or equal to about 28%, less than or equal to about 25%, less than or equal to about 22%, less than or equal to about 20%, less than or equal to about 18%, less than or equal to about 15%, less than or equal to about 10%, or less than or equal to about 5%.

[0098] The following will describe the combined structures according to some example implementations.

[0099] Figure 4 This is a schematic diagram illustrating an example of a combined structure according to some exemplary embodiments. Figure 5 yes Figure 4 A cross-sectional view of the combined structure.

[0100] According to some example embodiments, as in the aforementioned embodiments, the same combined structure 10a includes a nanostructure array 11 containing a plurality of nanostructures 11a, a light-absorbing portion 12, and a substrate layer 13.

[0101] However, in the combined structure 10a according to some exemplary embodiments, unlike the aforementioned embodiments, the nanostructure array 11 and the light-absorbing portion 12 are disposed in the same layer. For example, the light-absorbing portion 12 may be disposed on the side of the plurality of nanostructures 11a, and the light-absorbing portion 12 may be in contact with the side surface of the nanostructures 11a.

[0102] Furthermore, unlike the aforementioned embodiments, the combined structure 10 according to some example embodiments may also include a protective layer 14 on the nanostructure array 11 and the light-absorbing portion 12. Figure 4 In this diagram, the protective layer 14 is not shown to show the nanostructure array 11 and the light-absorbing portion 12 beneath it. The protective layer 14 may comprise, but is not limited to, organic materials, inorganic materials, organic / inorganic materials, or combinations thereof, such as oxides, nitrides, fluorides, polymers, or combinations thereof, such as glass, silicon oxides, magnesium fluorides, polystyrene, polymethyl methacrylate, polycarbonate, or combinations thereof. The protective layer 14 may be omitted as needed.

[0103] Figure 6 This is a simulated image illustrating the absorption principle of a combined structure according to some example embodiments.

[0104] Reference Figure 6 Incident light from the top of the nanostructure 11a with subwavelength dimensions can be confined within the nanostructure 11a, and the confined light in the nanostructure 11a can flow through an evanescent wave into the light-absorbing portion 12 at the side and be absorbed multiple times therein. Therefore, the combined structure can exhibit high light absorption characteristics.

[0105] The following describes a combination structure based on some example implementations.

[0106] Figure 7 This is a schematic diagram illustrating an example of a combined structure according to some exemplary embodiments. Figure 8 yes Figure 7 A cross-sectional view of the combined structure.

[0107] According to some exemplary embodiments, as in the aforementioned embodiments, the combined structure 10b includes a nanostructure array 11 comprising a plurality of nanostructures 11a, a light-absorbing portion 12, a substrate layer 13, and optionally includes a protective layer 14. Figure 7 In order to show the nanostructure array 11 and the light-absorbing portion 12 beneath the protective layer 14, the protective layer 14 is not shown.

[0108] However, unlike the aforementioned embodiments, the combined structure 10b according to some example embodiments may include light-absorbing portions 12 disposed below the nanostructure array 11 and in the same layer as the nanostructure array 11. For example, the light-absorbing portions 12 may be disposed on the sides and below the plurality of nanostructures 11a, and the light-absorbing portions 12 may contact the side surface and the bottom surface of the nanostructure 11a respectively on the sides and below the nanostructure 11a.

[0109] The following describes a combination structure based on some example implementations.

[0110] Figure 9 This is a schematic diagram illustrating an example of a combined structure according to some exemplary embodiments. Figure 10 yes Figure 9 A cross-sectional view of the combined structure.

[0111] According to some example embodiments, as in the aforementioned embodiments, the combined structure 10c includes a nanostructure array 11 containing a plurality of nanostructures 11a, a light-absorbing portion 12, and a substrate layer 13.

[0112] However, unlike the aforementioned embodiments, the combined structure 10c according to some example embodiments may include light-absorbing portions 12 on the top and sides of the nanostructure array 11. For example, the light-absorbing portions 12 may contact the upper and side surfaces of the nanostructure 11a, respectively, on the nanostructure 11a and on the side of the nanostructure 11a.

[0113] By increasing light absorption at the desired wavelength, the combined structure 10 / 10a / 10b / 10c can exhibit high light absorption characteristics with a thin thickness, thereby realizing a thin-film optical filter. For example, the combined structure 10 / 10a / 10b / 10c, configured to selectively absorb light in the near-infrared wavelength region, can effectively transmit light in the visible wavelength region and effectively absorb light in the near-infrared wavelength region, and thus can be effectively applied as an optical filter configured to block light in the near-infrared wavelength region in a light-sensing sensor (such as an image sensor). Furthermore, as described above, the combined structure 10 / 10a / 10b / 10c can exhibit sufficient light absorption characteristics with a thin thickness, and therefore can be integrated into a sensor (such as an image sensor) to realize an internal optical filter.

[0114] The combined structure 10 / 10a / 10b / 10c can be used as an optical filter in all applications requiring the filtering of light within a specific wavelength range, and can be effectively used as a near-infrared cutoff filter configured to filter light in the near-infrared wavelength range. Optical filters can be usefully applied to electronic devices, including, for example, image sensors and camera modules. These electronic devices can be, but are not limited to, digital cameras, portable camcorders, surveillance cameras (such as CCTV), vehicle cameras, medical cameras, mobile phones with built-in or external cameras, computers with built-in or external cameras, and laptop computers with built-in or external cameras.

[0115] The following will describe examples of camera modules provided with the aforementioned combined structures 10 / 10a / 10b / 10c.

[0116] Figure 11 This is a schematic diagram illustrating an example of a camera module according to some exemplary implementations.

[0117] Reference Figure 11 The camera module 20 includes a lens barrel 21, a housing 22, an optical filter 10A, and an image sensor 23.

[0118] The lens barrel 21 includes at least one lens for imaging an object, and the lens can be positioned along the optical axis. Here, the optical axis can be the direction perpendicular to the lens barrel 21. The lens barrel 21 is built into and combined with the housing 22. The lens barrel 21 can move along the optical axis inside the housing 22 for autofocus.

[0119] The housing 22 supports and houses the lens barrel 21 and is open in the optical axis direction. Therefore, incident light from one surface of the housing 22 can pass through the lens barrel 21 and the optical filter 10A to reach the image sensor 23.

[0120] The housing 22 may be equipped with an actuator for moving the lens barrel 21 in the optical axis direction. The actuator may include a voice coil motor (VCM) comprising a magnet and a coil. However, various methods other than actuators may be employed, such as mechanical drive systems or piezoelectric drive systems using piezoelectric devices.

[0121] The optical filter 10A may include the same combination structure 10 / 10a / 10b / 10c as described above.

[0122] Image sensor 23 can collect images of objects, thus storing them as data, and the stored data can be displayed as images through a display medium.

[0123] Image sensor 23 can be mounted in and electrically connected to a substrate (not shown). The substrate can be, for example, a printed circuit board (PCB) or electrically connected to a printed circuit board, and the printed circuit board can be, for example, a flexible printed circuit board (FPCB).

[0124] Image sensor 23 collects light passing through lens barrel 21 and optical filter 10A and generates video signal, and may be a complementary metal-oxide-semiconductor (CMOS) image sensor and / or charge-coupled device (CCD) image sensor.

[0125] Figure 12 This is a schematic diagram illustrating another example of a camera module according to some example implementations.

[0126] Reference Figure 12 As in the aforementioned embodiments, the camera module 20a according to some example embodiments includes a lens barrel 21, a housing 22, an optical filter 10A, and an image sensor 23.

[0127] However, unlike the aforementioned embodiments, in the camera module 20a according to some example embodiments, the optical filter 10A and the image sensor 23 can be in contact with each other. For example, the optical filter 10A and the image sensor 23 can be provided as an integrated image sensor 23A.

[0128] In the following description, an example of an image sensor integrating an optical filter will be described with reference to the accompanying drawings. A CMOS image sensor is described as an example of an image sensor.

[0129] Figure 13 This is a cross-sectional view illustrating an example of an image sensor according to some exemplary implementations.

[0130] An integrated image sensor 23A according to some example embodiments includes an image sensor 23 and an optical filter 10A. The image sensor 23 includes a semiconductor substrate 110, a lower insulating layer 60, a color filter layer 70, and an upper insulating layer 80.

[0131] Semiconductor substrate 110 may be a silicon substrate and is integrated with photosensitive devices 50a, 50b, and 50c and a transmission transistor (not shown). Photosensitive devices 50a, 50b, and 50c may be photodiodes. For example, photosensitive device 50a may be a blue photosensitive device 50a configured to sense light in the blue wavelength region passing through a blue filter 70a (described later), photosensitive device 50b may be a green photosensitive device 50b configured to sense light in the green wavelength region passing through a green filter 70b (described later), and photosensitive device 50c may be a red photosensitive device 50c configured to sense light in the red wavelength region passing through a red filter 70c (described later). Photosensitive devices 50a, 50b, and 50c and the transmission transistor may be integrated in each pixel. Photosensitive devices 50a, 50b, and 50c sense light, and the sensed information may be transmitted by the transmission transistor.

[0132] Metal lines (not shown) and pads (not shown) are formed on the semiconductor substrate 110. To reduce signal delay, the metal lines and pads may be made of metals with low resistivity, such as aluminum (Al), copper (Cu), silver (Ag), and / or alloys thereof, but are not limited thereto. However, the structure is not limited to this, and the metal lines and pads may be disposed below the photosensitive devices 50a, 50b, and 50c.

[0133] The lower insulating layer 60 is formed on the metal lines and pads. The lower insulating layer 60 may be made of inorganic insulating materials (such as silicon oxide and / or silicon nitride) or low dielectric constant (low K) materials (such as SiC, SiCOH, SiCO and SiOF).

[0134] A color filter layer 70 is formed on the lower insulating layer 60. The color filter layer 70 includes a blue filter 70a formed in the blue pixels, a green filter 70b formed in the green pixels, and a red filter 70c formed in the red pixels. However, this disclosure is not limited thereto; for example, at least one of the blue filter 70a, green filter 70b, and red filter 70c may be replaced by a yellow filter, a cyan filter, and / or a magenta filter.

[0135] An upper insulating layer 80 is formed on the color filter layer 70. The upper insulating layer 80 can provide a flat surface by reducing the stepped portions formed by the color filter layer 70. The upper insulating layer 80 can be made of inorganic insulating materials (such as silicon oxide and / or silicon nitride) or organic insulating materials. The upper insulating layer 80 can be omitted if necessary.

[0136] An optical filter 10A is formed on the upper insulating layer 80. As described above, the optical filter 10A can be a combined structure 10 / 10a / 10b / 10c comprising a nanostructure array 11 containing multiple nanostructures 11a, a light-absorbing portion 12, and a substrate layer 13, and can, for example, block light in wavelength regions other than the visible wavelength region (such as the near-infrared wavelength region). When the upper insulating layer 80 is the same as the substrate layer 13 of the combined structure 10 / 10a / 10b / 10c, either the upper insulating layer 80 or the substrate layer 13 can be omitted. The specific description of the combined structure 10 / 10a / 10b / 10c is the same as described above.

[0137] A focusing lens (not shown) may also be formed on the optical filter 10A. However, this disclosure is not limited thereto, and the optical filter 10A may be disposed on the focusing lens. The focusing lens can control the direction of the incident light and concentrate the light in a region. The focusing lens may have, for example, a cylindrical or hemispherical shape, but is not limited thereto.

[0138] A dual bandpass filter (not shown) may be disposed on the focusing lens. The dual bandpass filter may be configured to selectively transmit light in at least two wavelength regions of the incident light, and may be configured, for example, to selectively transmit light in the visible wavelength region and in the near-infrared wavelength region.

[0139] As described above, the optical filter 10A can be configured to effectively transmit light in the visible wavelength region and to effectively absorb and block light in other regions (such as the near-infrared region) besides the visible wavelength region, thus transmitting pure light in the visible wavelength region to the image sensor. Therefore, crosstalk is reduced or prevented when the signal generated by the light in the visible wavelength region crosses and mixes with another signal generated by the light in the non-visible wavelength region, especially the near-infrared wavelength region.

[0140] Specifically, the optical filter 10A can have a thickness of less than or equal to about 10 μm, less than or equal to about 5 μm, less than or equal to about 3 μm, less than or equal to about 2 μm, or less than or equal to about 1 μm. Thus, the optical filter 10A and the image sensor 23 can be implemented as an integrated image sensor 23A. Therefore, it is possible to achieve a thin image sensor, camera module, and electronic device equipped with the image sensor and camera module.

[0141] Figure 14 This is a cross-sectional view showing another example of an image sensor according to some example implementations.

[0142] According to some example embodiments, as in the aforementioned embodiments, the integrated image sensor 23B includes an image sensor 23 and an optical filter 10A. The image sensor 23 includes a semiconductor substrate 110, a lower insulating layer 60, and a color filter layer 70. The semiconductor substrate 110 is integrated with photosensitive devices 50a, 50b, and 50c.

[0143] However, according to some exemplary embodiments, in the integrated image sensor 23B, unlike the aforementioned embodiments, the optical filter 10A is disposed below the color filter layer 70. In the drawings, the optical filter 10A is shown as an example having a structure in which the optical filter 10A is disposed between the lower insulating layer 60 and the color filter layer 70. However, this disclosure is not limited thereto, and the optical filter 10A may be disposed between the semiconductor substrate 110 and the lower insulating layer 60.

[0144] Figure 15 This is a cross-sectional view showing another example of an image sensor according to some example implementations.

[0145] According to some example embodiments, as in the aforementioned embodiments, the integrated image sensor 23C includes an image sensor 23 and an optical filter 10A. The image sensor 23 includes a semiconductor substrate 110, a lower insulating layer 60, a color filter layer 70, and an upper insulating layer 80. The semiconductor substrate 110 is integrated with photosensitive devices 50a, 50b, and 50c.

[0146] However, according to some example embodiments, the integrated image sensor 23C may include a photosensitive element 50d for sensing light belonging to the infrared wavelength region, which is additionally integrated into the semiconductor substrate 110. The color filter layer 70 may include a transparent filter or a white filter (not shown) at a location corresponding to the photosensitive element 50d, or may simply have empty space without a specific filter.

[0147] Optical filter 10A may be placed on or below blue filter 70a, green filter 70b and red filter 70c, but not on or below transparent filter or white filter.

[0148] Dual bandpass filters can be configured, for example, to selectively transmit light in the visible wavelength region and in the near-infrared wavelength region.

[0149] For example, the photosensitive element 50d can be used as an auxiliary device to improve the sensitivity of image sensors in low-light environments.

[0150] For example, the photosensitive device 50d can be used as an infrared sensor configured to sense light in the near-infrared wavelength region. The infrared sensor can extend the dynamic range by specifically dividing black-and-white contrast in stages, thereby improving visible light image quality and enhancing the ability to sense long-range information images. The infrared sensor can be, for example, a biometric sensor, such as an iris sensor, depth sensor, fingerprint sensor, or vascular distribution sensor, but is not limited to these.

[0151] Figure 16 This is a cross-sectional view showing another example of an image sensor according to some example implementations.

[0152] According to some example embodiments, as in the aforementioned embodiments, the integrated image sensor 23D includes an image sensor 23 and an optical filter 10A. The image sensor 23 includes a semiconductor substrate 110, a lower insulating layer 60, and a color filter layer 70. The semiconductor substrate 110 is integrated with photosensitive devices 50a, 50b, 50c, and 50d.

[0153] However, according to some example embodiments, in the integrated image sensor 23D, the optical filter 10A is disposed below the color filter layer 70. The optical filter 10A may have a structure in which the optical filter 10A is disposed between the lower insulating layer 60 and the color filter layer 70. However, this disclosure is not limited thereto, and the optical filter 10A may be disposed between the semiconductor substrate 110 and the lower insulating layer 60.

[0154] In the following description, exemplary embodiments are illustrated with reference to examples in more detail. However, these examples are exemplary, and the scope of this disclosure is not limited thereto.

[0155] Fabrication and performance evaluation of near-infrared absorption films

[0156] 0.1g of near-infrared absorbing compound (Epolight) TM 1178), 1 g of a cyclic olefin polymer (poly[[octahydro-5-(methoxycarbonyl)-5-methyl-4,7-methylene-1H-indene-1,3-diyl]-1,2-ethylenediyl], CAS No. 123322-60-1, Sigma-Aldrich Ltd.) and 25 g of chloroform were mixed to prepare a composition, and the composition was spin-coated on a SiO2 substrate (3000 rpm, 20 seconds) to form a near-infrared absorbing film of about 800 nm thickness.

[0157] Inspect the performance of the obtained near-infrared absorption film.

[0158] The transmittance and absorbance of the film were measured using a UV-VIS-NIR spectrophotometer (Shimadzu Solid Spec-3700 DUV), and the film thickness was measured using an Alpha-Step surface profiler (D-500 Stylus Profiler, KLA). The transmittance and film thickness were used to obtain the extinction coefficient according to the following formula.

[0159] [Relational Formula]

[0160] T(λ)=exp(-α(λ)d)=exp(-4π / λ×k(λ)d)

[0161] In this relationship, T(λ) is the transmittance that depends on the wavelength, λ is the wavelength (in nm), k(λ) is the extinction coefficient that depends on the wavelength, and d is the film thickness (in nm).

[0162] The refractive index and extinction coefficient were obtained from the changes in polarization characteristics using an ellipsometer (JA Woollam). Here, the extinction coefficient obtained from ellipsometric technique is consistent with the extinction coefficient obtained from Equation 1.

[0163] As a result, the average transmittance was 94.5% in the visible wavelength region from 430 nm to about 680 nm, and the average transmittance was 29.8% in the near-infrared wavelength region from 890 nm to about 990 nm. The minimum transmission wavelength (λ) min,T The minimum transmission wavelength (λ) is 960 nm. min,T The transmittance at 900 nm to 1000 nm is 27.9%, the average refractive index (n) is 1.5 (at 900 nm to 1000 nm), and the average absorbance (k) is 0.11 (at 900 nm to 1000 nm).

[0164] Design and evaluation of composite structures

[0165] Based on the performance of near-infrared absorption films, optical simulations of combined structures, including nanostructure arrays and light-absorbing components, were performed using FDTD (Finite Difference Time Domain, Lumerical) software.

[0166] Example 1

[0167] The structure consists of a SiO2 substrate layer, a light-absorbing layer (thickness: 200 nm), and a TiO2 nanostructure array stacked from the bottom up. The light-absorbing layer is based on the performance of the aforementioned near-infrared absorption film.

[0168] Regarding the TiO2 nanostructure array, a periodic pattern of TiO2 nanostructures (refractive index: 2.5, at 940 nm) was set.

[0169] —Shape: Cuboid

[0170] —Cross-section shape: Square

[0171] —Width (w): 350nm

[0172] —Thickness (t): 425nm

[0173] —Period (p): 600nm

[0174] —Gap (g): 250nm

[0175] Comparative Example 1

[0176] Except for setting a stacked structure of SiO2 substrate layer / TiO2 nanostructure array without a light-absorbing layer, the same structure as in Example 1 is set.

[0177] Comparative Example 2

[0178] Except for setting up a stacked structure of stacked SiO2 substrate layer / light-absorbing layer (thickness: 200nm) without TiO2 nanostructure array, the same structure as in Example 1 is set up.

[0179] Evaluate

[0180] The optical performance of the structures based on Example 1, Comparative Example 1, and Comparative Example 2 was evaluated.

[0181] The results are shown in Table 1 and Figures 17 to 19 As shown in the image.

[0182] Figure 17 It is based on the spectrum of the structure in Example 1. Figure 18 Based on the spectrum of the structure of Comparative Example 1, Figure 19 It is based on the spectrum of the structure of Comparative Example 2.

[0183] Table 1

[0184] Example 1 Comparative Example 1 Comparative Example 2 Light absorption ratio (at 937 nm) (%) 71 0 22 Transmittance (at 937 nm) (%) 5 <1 75 Reflectance (at 937 nm) (%) 24 >99 3

[0185] Refer to Table 1 and Figures 17 to 19 Compared to the structures according to Comparative Examples 1 and 2, the structure according to Example 1 exhibits very high light absorption characteristics due to the complementary combination of the nanostructure array and the light-absorbing layer. The structure of Example 1 exhibits a light absorption ratio of 71%, which is significantly higher than the combined light absorption ratio of 22% of the structures of Comparative Examples 1 and 2. This is because the new optical phenomenon is not generated by a simple combination of two materials but by the complementary combination of a nanostructure array called a superstructure and the light-absorbing layer.

[0186] Design and Evaluation of Composite Structures II

[0187] Except for changing the thickness of the TiO2 nanostructure to 275 nm in terms of the physical properties of the near-infrared absorption film, the same structure as the example above was set up, and the optical simulation of the combined structure including the nanostructure array and the light absorption part was performed using FDTD (Finite Difference Time Domain, Lumerical) software.

[0188] As shown in Example 1, when the TiO2 nanostructure array has a thickness of 400 nm or more, a high aspect ratio etching technique is required when forming the TiO2 nanostructure array. Therefore, the optical performance of the TiO2 nanostructure array with a thickness of 275 nm and without the need for a high aspect ratio etching technique is evaluated.

[0189] Example 2

[0190] The structure is constructed by stacking a SiO2 substrate layer, a light-absorbing layer (thickness: 200 nm), and a TiO2 nanostructure array (thickness: 275 nm) from the bottom up. The light-absorbing layer is based on the performance of the aforementioned near-infrared absorption film.

[0191] The TiO2 nanostructure array was configured with a periodic pattern of the following TiO2 nanostructures.

[0192] —Shape: Cuboid (or cube)

[0193] —Cross-section shape: Square

[0194] —Width (w): 350nm

[0195] —Thickness (t): 275nm

[0196] —Period (p): 600nm

[0197] —Gap (g): 250nm

[0198] Comparative Example 3

[0199] Except that the stacked structure is designed to have a SiO2 substrate layer / TiO2 nanostructure array without a light-absorbing layer, the same structure as in Example 2 is set up.

[0200] Comparative Example 4

[0201] Except that the stacked structure is designed to have a SiO2 substrate layer / light-absorbing layer (thickness: 200 nm) without a TiO2 nanostructure array, the same structure as in Example 2 is set up.

[0202] Evaluate

[0203] The optical performance of the structures based on Example 2, Comparative Examples 3 and 4 was evaluated.

[0204] The results are shown in Table 2.

[0205] Table 2

[0206] Example 2 Comparative Example 3 Comparative Example 4 Light absorption ratio (at 937 nm) (%) 73 0 25 Transmittance (at 937 nm) (%) 11 <2 72 Reflectance (at 937 nm) (%) 16 >98 3 <![CDATA[λ min,T (nm)]]> 896 890 937

[0207] Referring to Table 2, compared with the structures according to Comparative Examples 3 and 4, the structure according to Example 2 exhibits very high light absorption characteristics due to the complementary combination of the nanostructure array and the light-absorbing layer.

[0208] Design and Evaluation of Composite Structures III

[0209] Except for changing the average absorbance (k) of the near-infrared absorption film to 0.08 (at 900nm-1000nm), the same structure as the example above was set up, and optical simulation of the combined structure including the nanostructure array and the light absorption part was performed using FDTD (Finite Difference Time Domain, Lumerical) software.

[0210] Example 3

[0211] A TiO2 nanostructure array and a light-absorbing portion (thickness: 275 nm) are disposed in a monolayer, wherein the side surfaces of the TiO2 nanostructure array are configured to contact the light-absorbing portion. In other words, on the SiO2 substrate layer, a side light-absorbing portion (thickness: 275 nm) with the same thickness as the TiO2 nanostructure array is configured in a stacked structure. The light-absorbing portion is based on the performance of the aforementioned near-infrared absorption film.

[0212] The TiO2 nanostructure array was configured with a periodic pattern of the following TiO2 nanostructures.

[0213] —Shape: Cuboid

[0214] —Cross-section shape: Square

[0215] —Width (w): 350nm

[0216] —Thickness (t): 275nm

[0217] —Period (p): 600nm

[0218] —Gap (g): 250nm

[0219] Evaluate

[0220] The optical performance of the structures based on Example 3, Comparative Example 3, and Comparative Example 4 was evaluated.

[0221] The results are shown in Table 3 and Figures 20 to 22 As shown in the image.

[0222] Figure 20 It is based on the spectrum of the structure in Example 3. Figure 21 Based on the spectrum of the structure of Comparative Example 3, Figure 22 It is based on the spectrum of the structure of Comparative Example 4.

[0223] Table 3

[0224] Example 3 Comparative Example 3 Comparative Example 4 <![CDATA[Light absorption ratio (at λ max,A )(%)]]> 82 0 25 <![CDATA[Transmittance (at λ min,T )(%)]]> 16 <2 72 <![CDATA[Reflectance (at λ max,A )(%)]]> 2 >98 3 <![CDATA[λ max,A 、l min,T (nm)]]> 934 890 937

[0225] Refer to Table 3 and Figures 20 to 22 Compared with the structures of Comparative Example 3 and Comparative Example 4, the structure of Example 3 exhibits very high light absorption characteristics due to the complementary combination of the nanostructure array and the light-absorbing layer.

[0226] Design and Evaluation of Composite Structures IV

[0227] Based on the performance of near-infrared absorption films, optical simulations of combined structures, including nanostructure arrays and light-absorbing components, were performed using FDTD (Finite Difference Time Domain, Lumerical) software.

[0228] Example 4

[0229] A Si nanostructure array and a light-absorbing portion (thickness: 175 nm) are disposed in a single layer, wherein the side surface of the Si nanostructure array is designed to contact the light-absorbing portion. In other words, the SiO2 substrate layer / Si nanostructure array is configured as a stacked structure having a light-absorbing portion (thickness: 175 nm) / SiO2 (thickness: 100 nm). The light-absorbing portion is based on the performance of the aforementioned near-infrared absorption film.

[0230] The Si nanostructure array was configured as a periodic pattern with the following Si nanostructures (refractive index: 4.09, at 940 nm).

[0231] —Shape: Cuboid

[0232] —Cross-section shape: Square

[0233] —Width (w): 225nm

[0234] —Thickness (t): 175nm

[0235] —Period (p): 600nm

[0236] —Gap (g): 375nm

[0237] Comparative Example 5

[0238] Except that a Si nanostructure array is formed on the entire surface of the SiO2 substrate layer without any light-absorbing portion, the structure is the same as that in Example 4.

[0239] Comparative Example 6

[0240] Except for forming a light-absorbing portion (thickness: 175 nm) on the entire surface of the SiO2 substrate layer without an array of Si nanostructures, the structure is the same as that in Example 4.

[0241] Evaluate

[0242] The optical performance of the structures based on Example 4, Comparative Examples 5 and 6 was evaluated.

[0243] The results are shown in Table 4 and Figures 23 to 25 As shown in the image.

[0244] Figure 23 It is based on the spectrum of the structure in Example 4. Figure 24 Based on the spectrum of the structure of Comparative Example 5, Figure 25 It is based on the spectrum of the structure of Comparative Example 6.

[0245] Table 4

[0246] Example 4 Comparative Example 5 Comparative Example 6 <![CDATA[Light absorption ratio (at λ max,A )(%)]]> 98 8 21 <![CDATA[Transmittance (at λ min,T )(%)]]> 1 23 76 <![CDATA[Reflectance (at λ max,A )(%)]]> 1 69 3 <![CDATA[λ max,A 、l min,T (nm)]]> 947 937 960

[0247] Refer to Table 4 and Figures 23 to 25 Compared with the structures according to Comparative Examples 5 and 6, the structure according to Example 4 exhibits very high light absorption characteristics due to the complementary combination of the nanostructure array and the light-absorbing layer.

[0248] Although this disclosure has been described in conjunction with practical exemplary embodiments as currently believed, it will be understood that the invention is not limited to the disclosed embodiments. Rather, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0249] This application claims priority and benefit to Korean Patent Application No. 10-2019-0064346, filed on May 31, 2019, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

Claims

1. A near-infrared cutoff filter comprising a combined structure, the combined structure comprising: A nanostructure array comprising a plurality of repeating nanostructures, each of which has a size smaller than the near-infrared wavelength, and The light-absorbing portion adjacent to the nanostructure array includes a near-infrared absorbing material configured to selectively absorb and block light in at least a portion of the near-infrared wavelength region and transmit light in the visible wavelength region.

2. The near-infrared cutoff filter according to claim 1, wherein the light-absorbing portion is on at least one of the lower surface, upper surface and side surface of the plurality of nanostructures.

3. The near-infrared cutoff filter according to claim 1, wherein the plurality of nanostructures and the light-absorbing portion are in contact with each other.

4. The near-infrared cutoff filter according to claim 1, wherein the near-infrared wavelength is in the range of greater than 700 nm and less than or equal to 1200 nm.

5. The near-infrared cutoff filter according to claim 4, wherein the near-infrared wavelength is in the range of 890 nm to 990 nm.

6. The near-infrared cutoff filter according to claim 1, wherein... The width of the nanostructure is 100 nm to 500 nm, and The thickness of the nanostructure is 50 nm to 500 nm.

7. The near-infrared cutoff filter of claim 1, wherein each of the plurality of nanostructures comprises a high refractive index material having a refractive index greater than or equal to 2.4 at 940 nm.

8. The near-infrared cutoff filter of claim 7, wherein each of the plurality of nanostructures comprises titanium oxide, silicon, aluminum, a group III-V semiconductor compound or a combination thereof.

9. The near-infrared cutoff filter of claim 1, wherein the near-infrared absorbing material is configured to absorb light in at least a portion of a wavelength region greater than 700 nm and less than or equal to 1200 nm.

10. The near-infrared cutoff filter according to claim 9, wherein the maximum absorption wavelength of the near-infrared absorbing material is in the range of 890 nm to 990 nm.

11. The near-infrared cutoff filter according to claim 1, wherein the refractive index of the light-absorbing portion is lower than the refractive index of the nanostructure.

12. The near-infrared cutoff filter according to claim 11, wherein the refractive index of the light-absorbing portion at 940 nm is less than or equal to 1.

8.

13. The near-infrared cutoff filter according to claim 1, wherein the near-infrared absorbing material comprises quantum dots, quinone metal complexes, polymethyl compounds, anthocyanin compounds, phthalocyanine compounds, terpinenine compounds, naphthalene phthalocyanine compounds, ammonium imide compounds, diammonium imide compounds, triarylmethane compounds, dipyrrole methylene compounds, anthraquinone compounds, diquinone compounds, naphthoquinone compounds, squartzium compounds, naphthalene-benzene compounds, perylene compounds, pyranium compounds, squartzium compounds, thiaranium compounds, diketopyrrolopyrrole compounds, boron dipyrrole methylene compounds, nickel-dithiol complexes, ketoneonium compounds, their derivatives, or combinations thereof.

14. The near-infrared cutoff filter according to claim 1, wherein the spectrum of the combined structure has a maximum absorption wavelength in the wavelength region greater than 700 nm and less than or equal to 1200 nm, and The light absorption ratio at the maximum absorption wavelength is greater than 50%.

15. The near-infrared cutoff filter according to claim 14, wherein the maximum absorption wavelength is in the range of 890 nm to 990 nm.

16. The near-infrared cutoff filter according to claim 1, wherein... The near-infrared cutoff filter has a minimum transmission wavelength in the wavelength region greater than 700 nm and less than or equal to 1200 nm. The transmittance at the minimum transmission wavelength is less than or equal to 35%.

17. The near-infrared cutoff filter of claim 16, wherein the minimum transmission wavelength is in the range of 890 nm to 990 nm.

18. The near-infrared cutoff filter according to claim 1, further comprising a substrate layer, and The refractive index of the substrate layer is lower than that of the nanostructure.

19. The near-infrared cutoff filter according to claim 1, wherein the thickness of the near-infrared cutoff filter is less than or equal to 1 μm.

20. An image sensor, comprising: A semiconductor substrate, including multiple photodiodes, and An optical filter on the semiconductor substrate, the optical filter being configured to block light in at least a portion of the near-infrared wavelength region. The optical filter described herein includes the near-infrared cutoff filter according to claim 1.

21. The image sensor of claim 20, further comprising a color filter, the color filter being on the semiconductor substrate and on or below the optical filter.

22. The image sensor of claim 20, further comprising a dual bandpass filter configured to transmit a portion of the near-infrared wavelength region and all visible wavelength regions.

23. A camera module comprising the near-infrared cutoff filter according to claim 1.

24. A camera module comprising the image sensor of claim 20.

25. An electronic device comprising the near-infrared cutoff filter according to claim 1.

26. An electronic device comprising the camera module according to claim 23.

27. An electronic device comprising an image sensor according to claim 20.

Images