Light sensor

Abstract

One embodiment of the present invention comprises: a silicon substrate; a light-blocking layer disposed on an upper surface of the silicon substrate; and a plurality of silicon nanowires formed to protrude from the upper surface of the silicon substrate and penetrate the light-blocking layer, wherein the silicon nanowires have a diameter (D) of 40 nm or less, thereby enabling selective detection of light in the ultraviolet wavelength range.

Description

light sensor

[0001] The present invention relates to an optical sensor. More specifically, the present invention relates to an optical sensor comprising silicon nanowires.

[0002] As we enter the full-fledged information age, the field of display devices that visually display electrical information signals is rapidly developing, and research is ongoing to develop performances such as thinning, weight reduction, and low power consumption for various display devices.

[0003] Meanwhile, light sensors are being placed in display devices to compensate for the brightness of these display devices, and in particular, research is being actively conducted on silicon light sensors that have excellent light absorption capabilities and a wide response range.

[0004] However, the silicon optical sensor above has a problem in that it cannot selectively sense only specific wavelengths by responding to all light having energy higher than the band gap, and the sensor performance is deteriorated because not all incident light is absorbed.

[0005] Accordingly, research is actively being conducted on silicon optical sensors that can selectively sense light of a specific wavelength and easily achieve excellent light absorption rates.

[0006] Embodiments of the present invention provide an optical sensor that selectively detects ultraviolet rays and has excellent quantum efficiency.

[0007] One embodiment of the present invention provides an optical sensor comprising: a silicon substrate; a light-blocking layer disposed on an upper surface of the silicon substrate; and a plurality of silicon nanowires formed to protrude from the upper surface of the silicon substrate and penetrating the light-blocking layer, wherein the diameter (D) of the silicon nanowires is 40 nm or less.

[0008] In the present embodiment, the plurality of silicon nanowires may further include a first metal oxide layer disposed on each surface and in direct contact with the surface of the silicon nanowires.

[0009] In this embodiment, the first metal oxide layer can completely cover the surface of the silicon nanowire.

[0010] In this embodiment, the thickness of the first metal oxide layer may be greater than 0 nm and less than or equal to 100 nm.

[0011] In the present embodiment, the first metal oxide layer may include aluminum (Al) oxide, indium (In) oxide, zirconium (Zr) oxide, molybdenum (Mo) oxide, titanium (Ti) oxide, tungsten (Wo) oxide, tin (Sn) oxide, silver (Ag) oxide, iron (Fe) oxide, or any combination thereof.

[0012] In the present embodiment, a second metal oxide layer may be further included, which is disposed between the upper surface of the silicon substrate and the light-blocking layer and extends from the first metal oxide layer.

[0013] In this embodiment, the diameter of the silicon nanowire may be 10 nm to 40 nm.

[0014] In this embodiment, the length (L) of the silicon nanowire may be 100 nm to 10,000 nm.

[0015] In the present embodiment, the distance (P) from the center of one of the plurality of silicon nanowires to the center of an adjacent silicon nanowire may be 10 nm to 5,000 nm.

[0016] In this embodiment, the light-blocking layer may include a reflective layer or a light-absorbing layer.

[0017] In this embodiment, the reflectivity of the reflective layer may be 30% or more.

[0018] In this embodiment, the reflective layer may include aluminum (Al), silver (Ag), tin (Sn), chromium (Cr), molybdenum (Mo), copper (Cu), titanium (Ti), tungsten (W), or any combination thereof.

[0019] In this embodiment, the light absorbing layer may include a material having a band gap of 3.1 eV or less.

[0020] In this embodiment, the absorbance of the light absorbing layer may be 10% or more.

[0021] In the present embodiment, the device may further include a first electrode disposed on the upper surface of the silicon substrate; and a second electrode disposed on the lower surface of the silicon substrate.

[0022] In this embodiment, the first electrode and the second electrode may independently include aluminum (Al), silver (Ag), gold (Au), copper (Cu), or any combination thereof.

[0023] The optical sensor according to the present embodiments can effectively suppress light absorption by the silicon substrate by including a light-blocking layer disposed on the silicon substrate. Accordingly, the proportion of light absorption by the silicon nanowires among the total light absorption by the optical sensor can be increased, and light absorption by the silicon substrate can be reduced. Accordingly, light having a wavelength that can resonate with the silicon nanowires can be selectively detected.

[0024] In addition, the optical sensor according to the present embodiments can selectively detect ultraviolet rays because the diameter (D) of the silicon nanowire satisfies 40 nm or less.

[0025] The scope of the present invention is not limited by these effects.

[0026] FIG. 1 is a plan view schematically illustrating an optical sensor according to one embodiment of the present invention.

[0027] Figure 2 is a graph showing the light absorption ratio of silicon nanowires according to diameter.

[0028] FIGS. 3 to 5 are graphs showing the light absorption rate of the silicon nanowire and the entire light sensor according to the wavelength of the light sensor according to embodiments.

[0029] Figure 6 is a graph showing the light absorption rate of the silicon nanowire and the entire light sensor according to the wavelength of the light sensor according to a comparative example.

[0030] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. In describing the present invention, detailed descriptions of related known technologies will be omitted if they are deemed to obscure the gist of the present invention.

[0031] Terms such as "first" and "second" may be used to describe various components, but the components should not be limited by these terms. These terms are used solely to distinguish one component from another.

[0032] The terminology used in this application is solely for the purpose of describing specific embodiments and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. Furthermore, in each drawing, components are exaggerated, omitted, or schematically depicted for convenience and clarity of explanation, and the sizes of each component do not entirely reflect their actual sizes.

[0033] In the description of each component, when it is described as being formed on or under, on and under include both those formed directly or through the intervention of other components, and the standards for on and under are explained based on the drawings.

[0034] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In describing with reference to the attached drawings, identical or corresponding components are assigned the same drawing numbers, and redundant descriptions thereof will be omitted.

[0035] FIG. 1 is a plan view schematically illustrating an optical sensor according to one embodiment of the present invention.

[0036] Referring to FIG. 1, an optical sensor (100) according to one embodiment of the present invention may include a silicon substrate (110); a light-blocking layer (130) disposed on an upper surface (A) of the silicon substrate (110); a plurality of silicon nanowires (120) formed to protrude from the upper surface (A) of the silicon substrate (110) and penetrating the light-blocking layer (130); and a first metal oxide layer (142) disposed on the surfaces of the plurality of silicon nanowires. The diameter (D) of the silicon nanowires may be 40 nm or less.

[0037] For example, when the optical sensor (100) absorbs light irradiated onto the optical sensor (100), carriers (e.g., electrons and holes) may be formed within the optical sensor (100). The optical sensor (100) may sense light by detecting an electrical signal generated by the carriers formed when the irradiated light is absorbed.

[0038] For example, the silicon substrate (110) absorbs light regardless of wavelength, but the silicon nanowire (120) resonates with a specific wavelength depending on the diameter (D) of the silicon nanowire (120), and can selectively absorb light of a specific wavelength.

[0039] For example, the light blocking layer (130) included in the optical sensor (100) can suppress light absorption by the silicon substrate (110). On the other hand, the silicon nanowires (120) are formed by penetrating the light blocking layer (130), and thus can absorb light of a specific wavelength without being affected by the light blocking layer (130). Accordingly, the proportion of the total light absorbed by the optical sensor (100) of the present invention that is absorbed by the silicon nanowires (120) can increase, and the proportion that is absorbed by the silicon substrate (110) can decrease.

[0040] For example, the optical sensor (100) of the present invention includes a light blocking layer (130), so that noise signals generated when the silicon substrate (110) absorbs light can be minimized. Accordingly, light of a specific wavelength can be selectively absorbed through the silicon nanowire (120), so that detection can be made easier according to the wavelength of the light.

[0041] For example, the optical sensor (100) of the present invention can more easily detect light belonging to the ultraviolet wavelength range (100 nm to 400 nm) by satisfying the diameter (D) of the silicon nanowire of 40 nm or less.

[0042] According to one embodiment, the optical sensor (100) is disposed on each of the surfaces of the plurality of silicon nanowires (120) and may further include a first metal oxide layer (141) in direct contact with the surfaces of the silicon nanowires (120).

[0043] For example, the first metal oxide layer (141) may be disposed on the surface of the silicon nanowire (120) to form a junction with the silicon nanowire. For example, the first metal oxide layer (141) may be in direct contact with the silicon nanowire (120) and may form a field-induced junction on the surface of the silicon nanowire (120). The field-induced junction formed on the surface of the silicon nanowire (120) may absorb light irradiated to the optical sensor (100) to form carriers (e.g., electrons and holes). The optical sensor (100) of the present invention may detect light through an electrical signal generated from the carrier.

[0044] In addition, the field-induced junction formed by the first metal oxide layer (141) can significantly suppress recombination, unlike the case where the silicon nanowire (120) and the silicon substrate (110) are doped with impurities. For example, when the silicon nanowire (120) and the silicon substrate (110) are doped with impurities, the impurities may penetrate into the silicon lattice in the silicon nanowire (120) and take the place of silicon atoms, thereby rapidly increasing Auger recombination or SRH (Shockley-Read-Hall) recombination, which may reduce quantum efficiency. On the other hand, the non-doped junction formation (field-induced junction) by the metal oxide layer (140) forms an electrically negative charge layer on the surface of the silicon nanowire (120) and the silicon substrate (110), thereby repelling electrons near the surface of the silicon nanowire (120) and the silicon substrate (110), thereby forming a junction, and thus impurities do not penetrate the lattice, so that Auger recombination or SRH (Shockley-Read-Hall) recombination can be reduced. In addition, the metal oxide layer (140) simultaneously performs the role of surface passivation, so that dangling bonds on the silicon surface can be reduced, while Auger recombination or SRH (Shockley-Read-Hall) recombination can be significantly reduced compared to the existing doping method. Accordingly, the optical sensor (100) including the metal oxide layer (140) can have improved quantum efficiency.

[0045] According to one embodiment, the silicon nanowire (120) may be undoped. For example, the silicon nanowire (120) and the silicon substrate (110) may be undoped. For example, the term "undoped" may mean that the silicon nanowire (120) and the silicon substrate (110) do not contain impurities having an N-type conductivity type or impurities having a P-type conductivity type.

[0046] According to one embodiment, the first metal oxide layer (141) can completely cover the surface of the silicon nanowire (120). In this case, as a field-induced junction is formed over the entire surface of the silicon nanowire (120), the quantum efficiency of the optical sensor (100) of the present invention can be further improved.

[0047] According to one embodiment, the thickness of the first metal oxide layer (141) may be greater than 0 nm and less than or equal to 100 nm. For example, the thickness of the first metal oxide layer (141) may be from 1 nm to 100 nm.

[0048] According to one embodiment, the first metal oxide layer (141) may include aluminum (Al) oxide, indium (In) oxide, zirconium (Zr) oxide, molybdenum (Mo) oxide, titanium (Ti) oxide, tungsten (Wo) oxide, tin (Sn) oxide, silver (Ag) oxide, iron (Fe) oxide, or any combination thereof.

[0049] According to one embodiment, the first metal oxide layer (141) may include Al2O3, In2O3, ZrO, MoO2, TiO2, WO3, SnO2, Ag2O, Fe2O3, or any combination thereof. For example, the first metal oxide layer may include Al2O3.

[0050] According to one embodiment, the light sensor (100) is disposed between the upper surface (A) of the silicon substrate (110) and the light blocking layer (130), and may further include a second metal oxide layer (142) extending from the first metal oxide layer (141).

[0051] For example, the second metal oxide layer (142) connects a plurality of first metal oxide layers (141) respectively disposed on the surfaces of a plurality of silicon nanowires (120), and can cover at least a portion of the upper surface (A) of the silicon substrate (110).

[0052] According to one embodiment, the second metal oxide layer (142) may be in direct contact with the upper surface of the silicon substrate (110). For example, the second metal oxide layer (142) may be in direct contact with the upper surface of the silicon substrate (110) to form a field-induced junction on the upper surface (A) of the silicon substrate (110).

[0053] For example, the second metal oxide layer (142) is disposed between the upper surface (A) of the silicon substrate (110) and the light-blocking layer (130), and can prevent the silicon substrate (110) and the light-blocking layer (130) from making direct contact. Accordingly, a short circuit phenomenon caused by contact between the metal included in the light-blocking layer (130) and the silicon substrate (110), which will be described later, can be prevented.

[0054] According to one embodiment, the second metal oxide layer (142) can completely cover the upper surface (A) of the silicon substrate (110). In this case, a short circuit phenomenon caused by contact between the metal included in the light-blocking layer (130) described later and the silicon substrate (110) can be more effectively prevented.

[0055] According to one embodiment, the thickness of the second metal oxide layer (142) may be the same as the thickness of the first metal oxide layer (141). For example, the thickness of the second metal oxide layer (142) may be greater than 0 and less than or equal to 100 nm, or 1 to 100 nm.

[0056] According to one embodiment, the second metal oxide layer (142) may include the same composition as the first metal oxide layer (141). For example,

[0057] For example, the second metal oxide layer (142) may include aluminum (Al) oxide, indium (In) oxide, zirconium (Zr) oxide, molybdenum (Mo) oxide, titanium (Ti) oxide, tungsten (Wo) oxide, tin (Sn) oxide, silver (Ag) oxide, iron (Fe) oxide, or any combination thereof.

[0058] According to one embodiment, the second metal oxide layer (142) may include Al2O3, In2O3, ZrO, MoO2, TiO2, WO3, SnO2, Ag2O, Fe2O3, or any combination thereof. For example, the first metal oxide layer may include Al2O3.

[0059] According to one embodiment, the first metal oxide layer (141) may be formed on the surface of the silicon nanowire (120) through atomic layer deposition. For example, the second metal oxide layer (142) may be formed on the upper surface (A) of the silicon substrate (110) through atomic layer deposition.

[0060] According to another embodiment, the first metal oxide layer (141) and the second metal oxide layer (142) may be simultaneously formed on the surface of the silicon nanowire (120) and the upper surface (A) of the silicon substrate (110), respectively, by the atomic layer deposition method. In this case, as the first metal oxide layer (141) and the second metal oxide layer (142) are formed continuously with each other, one metal oxide layer (140) may be formed.

[0061] Fig. 2 is a graph showing the light absorption ratio of silicon nanowires according to their diameter. Referring to Fig. 2, when the diameter of the silicon nanowire is 40 nm or less, the silicon nanowire exhibits a maximum light absorption peak in a wavelength range of 400 nm or less. Accordingly, when the diameter of the silicon nanowire is 40 nm or less, light with a wavelength of 400 nm or less can be more easily detected.

[0062] According to one embodiment, the diameter of the silicon nanowire (120) may be 40 nm or less. For example, the diameter of the silicon nanowire (120) may be 1 nm to 40 nm or 10 nm to 40 nm. When the diameter of the silicon nanowire (120) satisfies the above range, the optical sensor (100) can selectively detect light in the ultraviolet wavelength range.

[0063] According to one embodiment, the silicon nanowire (120) can selectively detect light having a wavelength of 400 nm or less. For example, the silicon nanowire (120) can selectively detect light having a wavelength of 100 nm to 400 nm or light having a wavelength of 200 nm to 400 nm.

[0064] According to one embodiment, the length (L) of the silicon nanowire (120) may be 100 nm to 10,000 nm. For example, the length (L) of the silicon nanowire (120) may mean the length (L) by which the silicon nanowire (120) protrudes from the upper surface (A) of the silicon substrate (110).

[0065] For example, when the length (L) of the silicon nanowire (120) satisfies the above range, the amount of light absorbed from the silicon nanowire (120) increases, so that the resolution and efficiency of the optical sensor (100) can be improved. In particular, when detecting light in the ultraviolet region, unlike detection in the visible light region, the ultraviolet wavelength has very high n and k, so that a high absorption rate can be exhibited even at a short height compared to visible light. In addition, when the thickness of the metal oxide layer (140) and the light blocking layer (130) are taken into consideration, a minimum length must be satisfied in order for the nanowire (120) to be exposed outside the surface and effectively absorb light, and as the length of the nanowire (120) exposed outside the surface increases, the amount of light absorbed by the nanowire (120) can increase. Therefore, when the length (L) of the silicon nanowire (120) satisfies the above range, sufficient light detection performance and structural stability can be guaranteed. For example, if the length (L) of the silicon nanowire (120) exceeds the above range, it becomes difficult to form the silicon wire (120) due to an excessively high aspect ratio, and it may be difficult to ensure the stability of the silicon wire (120), such as bending, even after production.

[0066] According to one embodiment, the distance (P) from the center of one of the plurality of silicon nanowires (120) to the center of an adjacent silicon nanowire (120) may be 10 nm to 5,000 nm.

[0067] For example, when the distance (P) between the centers of adjacent silicon nanowires (120) satisfies the above range, light absorption may be enhanced and the absorption wavelength band may be broadened due to the coupling phenomenon. Accordingly, the efficiency of the optical sensor (100) may be further improved. For example, when the distance (P) between the centers of the silicon nanowires (120) exceeds the above range, the coupling phenomenon may not occur, and thus the light absorption enhancement effect due to the coupling phenomenon may not be implemented.

[0068] According to one embodiment, the light-blocking layer (130) may include a reflective layer or a light-absorbing layer. The reflective layer or the light-absorbing layer may suppress light absorption by the silicon substrate (110) by reflecting or absorbing light irradiated onto the silicon substrate (110).

[0069] According to one embodiment, the reflectivity of the reflective layer may be 30% or more. The reflective layer may include a metal having a reflectivity of 30% or more for ultraviolet rays, thereby more effectively suppressing light absorption by the silicon substrate (110).

[0070] According to one embodiment, the reflective layer may include aluminum (Al), silver (Ag), tin (Sn), chromium (Cr), molybdenum (Mo), copper (Cu), titanium (Ti), tungsten (W), or any combination thereof.

[0071] According to another embodiment, the reflective layer may have a reflectivity of 50% or more. For example, the light-blocking layer (130) may include aluminum (Al), tin (Sn), chromium (Cr), or any combination thereof.

[0072] According to one embodiment, the absorbency of the light-absorbing layer may be 50% or greater. For example, the absorbency of the light-absorbing layer for ultraviolet rays may be 50% or greater or 70% or greater.

[0073] According to one embodiment, the light absorbing layer may include a material having a band gap of 3.1 eV or less.

[0074] For example, the material having a band gap of 3.1 eV or less may include a semiconductor, an organic material, and an inorganic material having a band gap of 3.1 eV or less. For example, the material having a band gap of 3.1 eV or less may include a semiconductor having a band gap of 3.1 eV or less, such as Ge, GaAs, a-Si, or c-Si, a perovskite material having a band gap of 3.1 eV or less, an organic material having a band gap of 3.1 eV or less, and an inorganic material having a band gap of 3.1 eV or less. For example, the band gap may refer to the energy difference between a valence band and a conduction band included in a material.

[0075] For example, the material having a band gap of 3.1 eV or less may be a semiconductor having a band gap of 3.1 eV or less. For example, the material having a band gap of 3.1 eV or less may include Ge, GaAs, a-Si, or c-Si.

[0076] According to one embodiment, the light-blocking layer (130) can be selectively formed only on the silicon substrate (110) using a photoresist.

[0077] For example, after forming a metal oxide layer (140) on a silicon substrate (110) and silicon nanowires (120), a metal can be deposited to form a metal layer on the silicon substrate (110) and silicon nanowires (120). Thereafter, a photoresist is applied, but by removing the photoresist except for the photoresist applied on the silicon substrate (110), the metal layer formed on the silicon nanowires (120) is exposed, and the metal layer formed on the silicon substrate (110) can be protected by the photoresist. Thereafter, by removing the metal layer formed on the silicon nanowires (120) using an etchant, a light-blocking layer (130) can be selectively formed only on the silicon substrate (110). Thereafter, the remaining photoresist can be removed using a cleaning solution (e.g., acetone, etc.).

[0078] With reference to FIG. 1, according to one embodiment, the optical sensor (110) may further include a first electrode (151) disposed on the upper surface (A) of the silicon substrate (110); and a second electrode (152) disposed on the lower surface (B) of the silicon substrate (110).

[0079] For example, the first electrode (151) and the second electrode (152) can each receive carriers (e.g., electrons or holes) generated when light is irradiated to the light sensor (110), thereby detecting an electrical signal.

[0080] For example, the first electrode (151) can accept electrons, and the second electrode (152) can accept holes. For example, the second electrode (152) can accept electrons, and the first electrode (151) can accept holes.

[0081] According to one embodiment, the first electrode (151) and the second electrode (152) may independently include aluminum (Al), silver (Ag), gold (Au), copper (Cu), platinum (Pt), nickel (Ni), indium tin oxide (ITO), or any combination thereof.

[0082] According to one embodiment, the first electrode (151) and the second electrode (152) may include the same metal. According to another embodiment, the first electrode (151) and the second electrode (152) may include different metals.

[0083] Hereinafter, the present invention will be described in more detail through examples. These examples are intended solely to illustrate the present invention more specifically, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples.

[0084]

[0085] Example 1

[0086] A metal oxide layer containing Al2O3 was formed on a silicon substrate on which silicon nanowires were formed using atomic layer deposition. In this case, the diameter of the silicon nanowires was 40 nm.

[0087] Afterwards, a metal (aluminum Al) was deposited on the entire surface of the silicon substrate and silicon wires by physical vapor deposition (PVD) to form a metal layer. Afterwards, a photoresist (microchem, DPR-I1549) was applied on the upper surface of the silicon substrate, and the thickness of the photoresist was adjusted to 100 nm or less by plasma etching. Afterwards, the metal layer on the surface of the silicon nanowires was removed using an etchant (developer). Afterwards, the photoresist was removed using acetone, thereby forming a reflective layer containing Al and having a thickness of 50 nm.

[0088] To form electrodes, the upper electrodes were selectively formed in areas without wires on the upper portion of the substrate using photoresist and an exposure process, and the lower electrodes were deposited to cover the entire lower substrate through a deposition process, thereby manufacturing an optical sensor.

[0089]

[0090] Example 2

[0091] Compared to Example 1, a metal layer was formed by chemical vapor deposition (CVD) of Ge instead of metal (aluminum Al) over the entire surface of the silicon substrate and silicon wire. Then, a photoresist (microchem, DPR-I1549) was applied on the upper surface of the silicon substrate, and the thickness of the photoresist was adjusted to 100 nm or less by plasma etching. Then, an optical sensor was manufactured in the same manner as Example 1, except that instead of the metal etchant, germanium oxide was formed from Ge through an oxidation process, which was then dissolved in water to contain Ge and form a light-absorbing layer having a thickness of 50 nm.

[0092]

[0093] Example 3

[0094] Compared to Example 2, an optical sensor was manufactured in the same manner as Example 2, except that the thickness of the light absorbing layer was 100 nm.

[0095]

[0096] Comparative example

[0097] Compared to Example 1, an optical sensor was manufactured in the same manner as Example 1, except that a reflective layer was not formed.

[0098]

[0099] Evaluation example

[0100] The absorbance of the optical sensor according to Examples 1 to 3 and Comparative Example 1 was measured according to the wavelength. The absorbance was measured through optical simulation. The optical simulation was performed using Lumerical's finite-difference-time-domain (FDTD) program, and the optical absorption in the silicon substrate and nanowires was separately collected and recorded on a monitor by incidenting a plane wave having a wavelength range of 450 to 900 nm on the proposed device structure. Specific results are shown in FIGS. 3 to 6, respectively.

[0101] FIGS. 3 to 5 are graphs showing the light absorption rate of silicon nanowires and the entire optical sensor according to the wavelength of the optical sensor according to Examples 1 to 3, respectively, and FIG. 6 is a graph showing the light absorption rate of silicon nanowires and the entire optical sensor according to the wavelength of the optical sensor according to a comparative example.

[0102] Referring to FIGS. 3 to 5, it was confirmed that the optical sensor according to the embodiments had a significantly reduced light absorption rate for the silicon substrate, and that the light absorption rate by the silicon nanowires and the light absorption rate of the entire optical sensor were consistent in the ultraviolet wavelength range.

[0103] On the other hand, referring to Fig. 6, it was confirmed that the optical sensor according to the comparative example had a difference in the optical absorption rate of the silicon nanowire and the optical absorption rate of the entire optical sensor for the ultraviolet wavelength range.

[0104] Accordingly, the optical sensor of the present invention can selectively detect ultraviolet wavelength light without interference by a silicon substrate by including a reflective layer or a light absorption layer as a light blocking layer.

[0105]

[0106] While the above description has been made with reference to the embodiments illustrated in the drawings, these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

[0107] [Explanation of symbols]

[0108] 100: Light sensor 110: Silicon substrate

[0109] 120: Silicon nanowire 130: Light-blocking layer

[0110] 140: Metal oxide layer 141: First metal oxide layer

[0111] 142: Second metal oxide layer 150: Electrode

[0112] 151: First electrode 152: Second electrode

[0113] A: Top surface of silicon substrate B: Bottom surface of silicon substrate

Claims

1. Silicon substrate; A light-blocking layer disposed on the upper surface of the silicon substrate; and A plurality of silicon nanowires are formed by protruding from the upper surface of the silicon substrate and penetrating the light-blocking layer; An optical sensor wherein the diameter (D) of the silicon nanowire is 40 nm or less.

2. In paragraph 1, An optical sensor further comprising a first metal oxide layer disposed on each of the surfaces of the plurality of silicon nanowires and in direct contact with the surfaces of the silicon nanowires.

3. In paragraph 1, An optical sensor wherein the first metal oxide layer completely covers the surface of the silicon nanowire.

4. In paragraph 1, An optical sensor, wherein the thickness of the first metal oxide layer is greater than 0 nm and less than or equal to 100 nm.

5. In paragraph 1, An optical sensor, wherein the first metal oxide layer comprises aluminum (Al) oxide, indium (In) oxide, zirconium (Zr) oxide, molybdenum (Mo) oxide, titanium (Ti) oxide, tungsten (Wo) oxide, tin (Sn) oxide, silver (Ag) oxide, iron (Fe) oxide, or any combination thereof.

6. In paragraph 1, An optical sensor further comprising a second metal oxide layer disposed between the upper surface of the silicon substrate and the light-blocking layer and extending from the first metal oxide layer.

7. In paragraph 1, An optical sensor wherein the diameter of the silicon nanowire is 10 nm to 40 nm or less.

8. In paragraph 1, An optical sensor wherein the length (L) of the silicon nanowire is 100 nm to 10,000 nm.

9. In paragraph 1, An optical sensor, wherein the distance (P) from the center of one of the plurality of silicon nanowires to the center of an adjacent silicon nanowire is 10 nm to 5,000 nm.

10. In paragraph 1, The above light-blocking layer is a light sensor including a reflective layer or a light-absorbing layer.

11. In paragraph 10, An optical sensor having a reflectivity of the above reflective layer of 30% or more.

12. In paragraph 10, An optical sensor, wherein the reflective layer comprises aluminum (Al), silver (Ag), tin (Sn), chromium (Cr), molybdenum (Mo), copper (Cu), titanium (Ti), tungsten (W), or any combination thereof.

13. In paragraph 10, An optical sensor, wherein the absorbance of the above light absorbing layer is 50% or more.

14. In paragraph 10, An optical sensor, wherein the above light absorbing layer includes a material having a band gap of 3.1 eV or less.

15. In paragraph 1, A first electrode disposed on the upper surface of the silicon substrate; and An optical sensor further comprising a second electrode disposed on a lower surface of the silicon substrate.

16. In paragraph 15, An optical sensor, wherein the first electrode and the second electrode independently comprise aluminum (Al), silver (Ag), gold (Au), copper (Cu), platinum (Pt), nickel (Ni), indium tin oxide (ITO), or any combination thereof.

Images