KR102345744B1 - Wavelength tunable UV emission device - Google Patents

Abstract

A wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention comprises: an electron emitting device for emitting electrons; an electrode provided to be spaced apart from the electron-emitting device and supplying electrons emitted from the electron-emitting device and incident on one surface thereof to the other surface; and a plurality of ultraviolet emitting layers provided to be stacked on each other in the direction of the other surface of the electrode, having different band gaps, and emitting ultraviolet rays of different wavelengths according to their own band gaps using electrons supplied from the electrodes; characterized in that

Description

Wavelength tunable UV emission device

The present invention relates to an ultraviolet ray emitting device, and more particularly, to an ultraviolet ray emitting device capable of adjusting the wavelength of the emitted ultraviolet ray.

Ultraviolet rays (UV) are electromagnetic waves having a shorter wavelength than visible light and longer than X-rays, and typically have a wavelength of 100 nm to 400 nm. Although it is known that these ultraviolet rays are harmful when exposed to the human body, they are usefully used for various purposes in various industrial fields. For example, ultraviolet rays are used to attract insects, are used in semiconductor/display manufacturing processes such as photo lithography processes, cure processes, etc., are used for disinfection of drinking water, are used as air purifiers, It can be used for sterilization of various instruments.

On the other hand, ultraviolet rays used in various industrial fields have different wavelengths depending on their use. However, the conventional ultraviolet emitting device is simply implemented to emit only ultraviolet rays of a specific wavelength. Therefore, when using the conventional UV emitting device, there is a problem in that it is necessary to separately provide a UV emitting device having a different wavelength according to each use.

In order to solve the problems of the prior art as described above, an object of the present invention is to provide an ultraviolet emitting device capable of controlling the wavelength of emitted ultraviolet rays.

However, the problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

A wavelength-controlled ultraviolet emission device according to an embodiment of the present invention for solving the above problems, (1) an electron emission device for emitting electrons, (2) is provided to be spaced apart from the electron emission device, and the electron emission device (3) an electrode that is emitted from the device and supplies electrons incident on one surface to the other surface; It includes a plurality of ultraviolet emitting layers that emit ultraviolet rays of different wavelengths according to the band gap of the.

Each of the UV-emitting layers may have a larger band gap as it is positioned farther from the electrode.

The wavelength-controlled UV emitting device according to an embodiment of the present invention may further include a substrate provided on the other surface of the UV emitting layer having the largest band gap.

The wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention further includes a power supply having a cathode connected to the electron emitting device, and an anode connected to the electrode to supply a voltage, wherein the power supply receives the voltage supplied It may include a voltage control unit to adjust.

The voltage control unit includes a voltage control unit for determining the voltage selected by the power control unit by a user's adjustment, wherein the voltage control unit includes an index for selecting each UV emitting layer; and an index capable of selecting an interface between the respective UV-emitting layers.

The power supply unit may include a time control unit for controlling the supply time of the voltage.

The power supply unit includes an integrated management unit that comprehensively controls the voltage control unit and the time control unit, and the integrated management unit controls the voltage control unit and the time control unit to emit a voltage corresponding to each UV emitting layer. You can control time.

At least one of the plurality of UV-emitting layers may have a quantum well structure.

The electron emission device may be of a cold cathode type or a photocathode type.

The electrode may further include a light reflective layer.

The wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention may further include a gate electrode provided between the electron emitting device and the electrode.

The gate electrode may include a mesh structure having a plurality of openings.

The wavelength control UV emitting device according to an embodiment of the present invention configured as described above can be used for various purposes required for each industry because it is possible to control the wavelength of the emitted UV rays, and there is an advantage that it can be used for two or more purposes at the same time .

Since it is a simple structure that only needs to adjust the voltage in order to select an ultraviolet emitting layer that will emit ultraviolet rays from among a plurality of ultraviolet emitting layers, there is an advantage in that the manufacturing cost is low and miniaturization is possible.

1 shows a wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention.
FIG. 2 shows that the first emitting layer 3a emits UV light in a wavelength-controlled UV emitting device according to an embodiment of the present invention having two emission layers 3a and 3b.
FIG. 3 shows that the second emitting layer 3b emits UV light in the wavelength-controlled UV emitting device according to an embodiment of the present invention having two emitting layers 3a and 3b.
4 is a first emission layer (3a) and a second emission layer (3b) in the wavelength control ultraviolet emitting device according to an embodiment of the present invention having two emission layers (3a, 3b) to emit ultraviolet rays indicates.
5 shows a wavelength-controlled UV-emitting device according to an embodiment of the present invention further including a gate electrode 13 .

The above object and means of the present invention and its effects will become more apparent through the following detailed description in relation to the accompanying drawings, and accordingly, those of ordinary skill in the art to which the present invention pertains can easily understand the technical idea of the present invention. will be able to carry out In addition, in describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

In addition, the terminology used herein is for the purpose of describing the embodiments, and is not intended to limit the present invention. In the present specification, the singular form also includes the plural form as the case may be, unless otherwise specified in the phrase. As used herein, terms such as “include”, “provide”, “provide” or “have” do not exclude the presence or addition of one or more other components other than the mentioned components.

In this specification, expressions such as “or” and “at least one” may indicate one of the words listed together, or a combination of two or more. For example, “or B” and “at least one of B” may include only one of A or B, or both A and B.

In this specification, information presented such as a recited characteristic, variable, or value of a description according to an expression such as “for example” may not exactly match. In addition, the embodiments of the present invention according to various embodiments of the present invention should not be limited by effects such as variations including tolerances, measurement errors, limits of measurement accuracy, and other commonly known factors.

In this specification, when a component is referred to as 'connected' or 'connected' to another component, it may be directly connected or connected to the other component, but another component is intervening It should be understood that there may be On the other hand, when it is mentioned that a certain element is 'directly connected' or 'directly connected' to another element, it should be understood that the other element does not exist in the middle.

Unless otherwise defined, all terms used herein may be used with meanings commonly understood by those of ordinary skill in the art to which the present invention pertains. In addition, terms defined in general used dictionary are not to be interpreted ideally or excessively unless specifically defined explicitly.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

1 shows a wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention.

The wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention is a device capable of controlling the wavelength of the emitted ultraviolet ray, that is, selecting the wavelength (λ) of the emitted ultraviolet ray. As shown in FIG. 1 , the electron emitting device (1), an anode electrode (2) and an ultraviolet emitting layer (3). In this case, the electron emission device 1 and the anode electrode 2 are provided to be spaced apart from each other, and the anode electrode 2 and the ultraviolet emission layer 3 are provided to be in contact with each other.

The electron-emitting device 1 is configured to emit electrons e. At this time, the configuration of the electron-emitting device 1 is not particularly limited. However, for ease of concentration or diffusion of the electron beam and faster driving, it may be formed of a cold cathode type or a photocathode type to which a cold cathode material is applied. That is, the electron emission device 1 may include a cathode electrode 11 receiving electrons, and an emitter 12 formed to protrude on one surface of the cathode electrode 11 to emit electrons. have. Each emitter 12 may be disposed at regular intervals from each other on the other surface of the cathode electrode 11 . In this case, the materials of the cathode electrode 11 and the emitter 12 are not particularly limited. For example, the emitter 12 may be formed of any one or more of carbon nanotubes, carbon nanowires, zinc oxide nanowires, carbon nanofibers, nanographene, and microtips.

The anode electrode 2 is an anode electrode that receives electrons e emitted from the electron emission device 1 and incident on one side thereof to the other side thereof, and is provided to be spaced apart from the electron emission device 1 . At this time, the material of the anode electrode 2 is not particularly limited, but a flexible material through which electrons can easily penetrate may be more advantageous.

The ultraviolet emitting layer 3 is a configuration for emitting ultraviolet rays, and is provided in plurality. That is, each UV emitting layer 3 is provided to be stacked on each other in the direction of the other surface of the anode electrode 2 . At this time, each UV emitting layer 3 is made of a semiconductor material having a different band gap (BG), and uses electrons supplied from the anode electrode 2 to each other according to its own band gap (BG). It emits ultraviolet rays of different wavelengths (λ). At this time, the ultraviolet ray emitted from each ultraviolet emitting layer 3 has a shorter wavelength λ as the band gap BG of the ultraviolet emitting layer 3 emitting itself increases.

Specifically, the principle of emitting ultraviolet rays is as follows. That is, as the electron (e) incident on the anode electrode (2) is absorbed by the ultraviolet emission layer (3), the electron (e) in the valence band in the ultraviolet emission layer (3) is transferred to the conduction band ( excitation with a conduction band). Thereafter, the excited electrons transition to the original valence band, and at this time, the holes in the valence band and the electrons returning to the ground state combine to release residual energy. The residual energy emitted in this way has a constant wavelength according to the optical band gap of the ultraviolet emitting layer and emits ultraviolet rays. Some excited electrons are trapped in a defect state in the bandgap, and a transition to the ground state may occur on this trap. At this time, the emitted ultraviolet rays have a wavelength larger than the band gap of the original material. That is, the wavelength (λ) of the emitted ultraviolet light is inversely proportional to the band gap (BG).

At this time, each UV emitting layer 3 must be implemented so that the wavelength (λ) of the emitted UV light can be selected. That is, each ultraviolet emitting layer 3 must have a band gap BG of a certain or more, and the farther it is located from the anode electrode 2, that is, the farther it is located from the other surface of the anode electrode 2, the larger the band gap BG _a <…<BG _n ). Conversely, when the low bandgap UV emitting layer 3 is disposed farther from the anode 2, the emitted UV light is absorbed by the low bandgap material and the light efficiency is lowered.

The band gap that each UV emitter 3 should have must be 3.0 eV or more, and a material having a band gap of 3.1 eV can emit 400 nm UV light. For example, the emitted ultraviolet rays can be classified into A, B, and C, A has a range of 400 nm to 315 nm, B is 315 nm to 280 nm, and C has a range of 280 nm to 200 nm. At this time, the range of 100 nm to 200 nm is referred to as 'vacuum ultraviolet'. Each emission layer 3 may be made of a material having a band gap for emitting ultraviolet rays in any one wavelength range selected from A to C or vacuum ultraviolet rays.

The electron (e) finally arrives at a position (hereinafter, referred to as “final arrival position”) depending on the voltage applied between the electron emission device 1 and the anode electrode 2 . That is, as a larger voltage is applied, the ultraviolet emitting layer 3 disposed further from the other surface of the anode electrode 2 becomes the final arrival position of the electrons e. At this time, the UV emitting layer 3 disposed further away from the other surface of the anode 2 must have a larger band gap BG to allow UV emitting, and in the opposite case, the UV emitting efficiency is very poor.

On the other hand, the wavelength control UV emitting device according to an embodiment of the present invention may further include a substrate 4 for supporting the anode electrode 2 and the UV emitting layer (3). That is, the substrate 4 _{is provided on the other surface of the ultraviolet emitting layer 3 having the largest band gap BG n} , or may be made of a material having the largest band gap, and the band gap according to the emission wavelength and heat generation characteristics. This can be adjusted. At this time, the substrate 4 is preferably a transparent substrate so that ultraviolet rays emitted from the ultraviolet emitting layer 3 can pass therethrough, but the material is not limited thereto. That is, the ultraviolet rays emitted from the ultraviolet emission layer 3 may be output to the other surface of the substrate 4 while passing through the substrate 4 . For example, the substrate 4 may be made of a material of glass or plastic.

2 to 4 show a state in which ultraviolet rays are emitted from the wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention having two ultraviolet emitting layers 3 . That is, FIG. 2 shows that the first emitting layer 3a, FIG. 3 shows the second emitting layer 3b, and FIG. 4 shows that the first emitting layer 3a and the second emitting layer 3b emit ultraviolet light. each is indicated.

Hereinafter, with reference to FIGS. 2 to 4, the wavelength (λ) of the ultraviolet rays emitted from the wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention will be described in more detail.

The wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention further includes a power supply unit 5 to adjust the wavelength (λ) of the emitted ultraviolet rays.

The power supply unit 5 supplies a voltage between the electron emission device 1 and the anode electrode 2, but controls the magnitude of the voltage (V) supplied, the voltage (V) supply time, etc., and the cathode is the electron It is connected to the emission element (1), the anode is connected to the anode electrode (2).

The power supply unit 5 may include a voltage control unit (not shown, VC) that adjusts the supply voltage level. The voltage control unit VC adjusts the magnitude of the voltage supplied by the power supply unit 5 . The position in the ultraviolet emission layer 3 at which the electrons e emitted from the electron emission device 1 finally arrive may be controlled by the magnitude of the voltage supplied from the power supply unit 5 . Therefore, the wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention controls the voltage control unit VC of the power supply unit 5 to adjust the magnitude of the voltage supplied from the power supply unit 5 so that the electrons e are finally reached. It is possible to select a position within the UV emitting layer 3 that is to be used, that is, the UV emitting layer 3 that will emit UV light of a specific desired wavelength. At this time, as the magnitude of the voltage supplied by the power supply unit 5 increases, the final arrival position of the electrons e is further away.

The voltage controller VC may include a voltage adjusting device (not shown, VA). The voltage regulator VA is a device that determines the magnitude of the voltage supplied by the voltage controller VC, and the voltage supplied by adjusting the tap by a user or a separate control program, such as a tap changer, for example. It may be a device for adjusting the size of The voltage regulating device VA may include an index ID such as a ruler that the user can select by visually checking the desired specific UV emitting layer 3 . An index ID may be provided so that each ultraviolet emitting layer 3 is designated.

Referring to FIG. 2 , in the wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention having two ultraviolet emitting layers 3 , the power supply 5 has the final destination position of the electrons e for the first emission. _A first voltage V A sufficient to become the layer 3a may be supplied between the electron emission device 1 and the anode electrode 2 . Accordingly, the first emission layer 3a emits ultraviolet rays having a first wavelength λ _{A according to its band gap BG a .} The selection of the first emitting layer 3a can be achieved by selecting the corresponding index ID of the voltage regulator VA.

Referring to FIG. 3 , in the wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention having two ultraviolet emitting layers 3 , the power supply 5 has the final reached position of the electrons e for the second emission. _{A second voltage (V B} ) sufficient to become the layer ( 3b ) may be supplied between the electron emission device ( 1 ) and the anode electrode ( 2 ). In this case, the second voltage V _B is greater than the first voltage V _{A .} In this case, the second emission layer 3b emits ultraviolet rays having a second wavelength λ _{B according to its band gap BG b .} In this case, the second wavelength λ _B has a shorter wavelength than the first wavelength λ _{A .} Like the selection of the first emitting layer 3a, the selectivity of the second emitting layer 3b can also be achieved by selecting the corresponding index ID of the voltage regulator VA.

Referring to FIG. 4 , in the wavelength-controlled UV emitting device according to an embodiment of the present invention having two UV emitting layers 3 , the power supply 5 has the final destination position of the electrons e for the first emission. _{A third voltage (V C} ) sufficient to become an interface between the layer 3a and the second emission layer 3b may be supplied between the electron emission device 1 and the anode electrode 2 . The voltage regulating device VA may include an index ID for selecting the interface between the first emitting layer 3a and the second emitting layer 3b. _{In this case, the third voltage V C} supplied by selecting the index ID corresponding to the interface between the first emission layer 3a and the second emission layer 3b is greater than the first voltage V _{A and the second} less than the voltage V _{B .} In this case, the first emission layer 3a emits ultraviolet rays having a first wavelength λ _{A according to its band gap BG a .} At the same time, the second emission layer 3b also emits ultraviolet rays having a second wavelength λ _{B according to its band gap BG b .}

Meanwhile, the power supply unit 5 may include a time control unit (not shown, TC). The time control unit TC controls the supply time (time length, voltage supply start time, voltage supply end time, etc.) of the voltage supplied by the power supply unit 5 . The time controller TC may include a time adjusting device TA. The time adjusting device TA is a device in which the length of the voltage supply time of the time controller TC is determined by the user's adjustment. For example, the length of the voltage supply time is adjusted by adjusting the tap like a tap changer. It may be a device for adjusting, and may be a device for setting a voltage supply start time and voltage supply end time.

By the time control unit (TC), the power supply unit 5 can adjust the time for supplying the voltage, and accordingly, the wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention is a wavelength-controlled ultraviolet emitting device in which each ultraviolet emitting layer 3 emits ultraviolet rays. Time can be selected.

The power supply unit 5 may include an integrated management unit (GC). The integrated management unit GC may comprehensively control the voltage control unit VC and the time control unit TC. The integrated management unit GC simultaneously and/or sequentially controls the voltage control unit VC and the time control unit TC to control the length of time the voltage corresponding to each UV emitting layer 3 is emitted. . As described above, the integrated management unit (GC) can select the order and time at which each UV emitting layer 3 emits UV rays by controlling the length of time that the magnitude of the voltage corresponding to each UV emitting layer 3 is emitted. . That is, when looking at the ultraviolet rays, the wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention can select the ultraviolet emission time for each wavelength by the integrated management unit (GC), and at the same time select the ultraviolet emission order and time for each wavelength This is possible. For example, when three ultraviolet emitting layers 3a, 3b, and 3c are provided, the wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention adjusts the voltage level and time of the power supply 5, 1 emitting layer (3a) 10 seconds → second emitting layer (3b) 20 seconds → third emitting layer (3c) 5 seconds You can select the UV emitting layer 3 that emits UV rays in the order of 5 seconds, or in a cycle of that sequence. have. Accordingly, ultraviolet rays are emitted in the order of 10 seconds of ultraviolet rays of the first wavelength (λ _A ) → 20 seconds of ultraviolet rays of _{the second wavelength (λ B ) → 5 seconds of ultraviolet rays of the third wavelength (λ C} ), or in a cycle of that order can be

In addition, at least one of the plurality of ultraviolet emitting layers 3 may have a quantum well structure. In this case, the ultraviolet emitting layer 3 having a quantum well structure may emit ultraviolet rays with higher light efficiency. In particular, the wavelength-controlled UV emitting device according to an embodiment of the present invention does not have a high-grade UV emitting layer 3 having a quantum well structure emitting UV with high performance and a quantum well structure emitting UV with normal performance. It is possible to configure the UV emitting layer 3 of one popular type together. In this case, the wavelength-controlled ultraviolet light emitting device according to an embodiment of the present invention has the advantage of being able to select a high-grade type or a popular type of ultraviolet light emitting layer 3 according to its use.

Meanwhile, the wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention may further include a light reflective layer (not shown). In this case, the light reflective layer is a configuration for reflecting the UV light emitted from the UV emitting layer 3, and the anode electrode 2 itself may be used as a light reflecting layer, or may be provided as an additional configuration other than the anode electrode 2 . At this time, when provided as an additional configuration, the light reflective layer is a layer provided inside the anode electrode 2, a layer provided on one surface of the anode electrode 2, or the other surface of the anode electrode 2 and an ultraviolet emitting layer ( 3) may be provided between the layers, and may have a thin thickness of 100 nm or less with high ultraviolet reflection efficiency.

Accordingly, since the ultraviolet rays emitted from the ultraviolet emission layer 3 are reflected by the light reflection layer, the direction thereof can be adjusted so that it is finally output only through the transparent substrate 4 . At the same time, the optical efficiency of the final output ultraviolet ray may be improved.

5 shows a wavelength-controlled UV-emitting device according to an embodiment of the present invention further including a gate electrode 13 .

On the other hand, in the wavelength-controlled ultraviolet emission device according to an embodiment of the present invention, a voltage is applied to the gate electrode 13 and the gate electrode 13 provided between the electron emission device 1 and the anode electrode 2 . A second power supply unit 14 for applying may be further included.

The gate electrode 13 is configured to control the flow of electrons emitted from the emitter 12 according to an input voltage. The gate electrode 13 may include a mesh structure having a plurality of openings. At this time, each emitter 12 is positioned above the opening, and accordingly, the gate electrode 13 may serve to diffuse the electrons emitted from the emitter 12 so that the electrons are uniformly emitted. The gate electrode 13 is made of a conductive material, for example, a metal such as Au, Ni, Ti, Cr, indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), or IZTO ( It may be formed of a transparent conductive oxide (TCO) such as indium zinc tin oxide), a conductive polymer, or a conductive material such as graphene. The plane of the mesh structure may be formed in a circular shape.

When the gate electrode 13 is provided, there is an advantage in that it is possible to quickly, uniformly and precisely control the amount of electron emission (current), increase current stability, and easily control the amount of output light even under a low voltage condition.

The gate electrode 13 can adjust the output of the ultraviolet rays emitted in association with the anode electrode 2 differently (eg, A has a small output, B has a high output, etc.). In addition, since the gate electrode 13 is provided, the amount of current can be kept constant regardless of the distance between the anode electrode 2 and the cathode electrode 11 . That is, the gate electrode 13 may be more suitable when a short ultraviolet irradiation time is required, such as pulsed ultraviolet light generation.

In addition, as the gate electrode 13 is provided, the space between the anode electrode 2 and the cathode electrode 11 may be increased to increase the emission area and amount of emitted ultraviolet rays. That is, by the ratio of the increase in the distance between the anode electrode 2 and the cathode electrode 11, the range of the electrons e to the ultraviolet emitting layer 3 is widened to increase the emitted ultraviolet area, and at the same time, the gate By increasing the voltage applied to the electrode 13 , the amount of UV light emitted can be increased.

The wavelength control UV emitting device according to an embodiment of the present invention configured as described above can be used for various purposes required for each industry because the wavelength of the emitted UV light can be controlled, and has the advantage of being used for two or more purposes at the same time. have. For example, the wavelength-controlled ultraviolet emitting device according to an embodiment of the present invention may simultaneously perform sterilization and surface treatment functions by using ultraviolet rays of different wavelengths to be emitted.

In the detailed description of the present invention, although specific embodiments have been described, various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention is not limited to the described embodiments, and should be defined by the claims described below and equivalents to the claims.

1: electron emission element 2: anode electrode
3: UV emitting layer 4: Substrate
5: power supply 11: cathode electrode
12: emitter 14: second power supply
e: e BG: band gap
V: Voltage λ: Wavelength

Claims (12)

an electron-emitting device that emits electrons;
An electrode provided to be spaced apart from the electron-emitting device and supplying electrons emitted from the electron-emitting device and incident on one surface to the other surface;
A plurality of ultraviolet emitting layers provided to be stacked on each other in the direction of the other surface of the electrode, having different band gaps, and emitting ultraviolet rays of different wavelengths according to their band gaps using electrons supplied from the electrodes, and
A power supply having a cathode connected to the electron emission device and a cathode connected to the electrode to supply a voltage
including,
The power supply unit,
A voltage control unit for regulating the voltage supplied, and
A time control unit for controlling the supply time of the voltage
includes,
The voltage control unit
It includes a voltage regulator that determines the magnitude of the voltage to be supplied,
The voltage regulator
an index for selecting each of the UV-emitting layers; and
including an index to select the interface between each emissive layer;
The power supply is
An integrated management unit for comprehensively controlling the voltage control unit and the time control unit,
The integrated management unit
By controlling the voltage control unit and the time control unit
Wavelength-controlled ultraviolet emitting device, characterized in that for controlling the emission time of the magnitude of the voltage corresponding to each of the ultraviolet emitting layers. According to claim 1,
The wavelength-controlled UV-emitting device, characterized in that each of the UV-emitting layers has a larger band gap as it is positioned farther from the electrode. 3. The method of claim 2,
Wavelength-controlled UV-emitting device, characterized in that it further comprises a substrate provided on the other surface of the UV-emitting layer having the largest band gap. delete delete delete delete According to claim 1,
At least one of the plurality of UV-emitting layers has a quantum well structure.
Wavelength-controlled UV-emitting device. According to claim 1,
The electron-emitting device, characterized in that the cold cathode type or photocathode type
Wavelength-controlled UV-emitting device. According to claim 1,
The electrode further comprises a light reflective layer
Wavelength-controlled UV-emitting device. According to claim 1,
Further comprising a gate electrode provided between the electron emission device and the electrode
Wavelength-controlled UV-emitting device. 12. The method of claim 11,
The gate electrode is
Including a mesh structure having a plurality of openings
Wavelength-controlled UV-emitting device.

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