Electrode material selection device and method as well as electrode selection assisting device

Abstract

To suppress malfunction of an ultraviolet sensor.SOLUTION: A work function determination section 101 determines a work function of a cathode electrode of an ultraviolet sensor. The ultraviolet sensor detects an ultraviolet ray based on current generated by discharge between an anode electrode and the cathode electrode. The work function determination section 101 determines the work function of the cathode electrode based on information about an electrode material of the cathode electrode and a manufacturing condition of the cathode electrode. A selection section 102 selects, as the electrode material of the anode electrode, metal having a work function on the densest packed plane of atoms, the work function being equal to or more than a value determined by the work function determination section 101.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrode material selection device and method, and an electrode selection support device. [Background technology]

[0002] Ultraviolet sensors are used as flame detection sensors in combustion safety devices in various industrial furnaces, such as drying furnaces in painting lines for automobile bodies and parts, melting furnaces for aluminum and zinc die-casting, and heat treatment furnaces for hardening metal parts.

[0003] As shown in Fig. 6, the ultraviolet sensor includes a disk-shaped cathode electrode 503 and an anode electrode 504 sealed in a glass container 501. A plurality of through-holes 504a are formed in a mesh pattern in the anode electrode 504. The anode electrode 504 is supported by a conductive support 505, and the cathode electrode 503 is supported by a conductive support 506. A top plate 502 on the upper surface of the glass container 501 is made of glass that is transparent to ultraviolet light. A mixed gas of, for example, neon and hydrogen is sealed inside the glass container 501.

[0004] In the ultraviolet sensor, when ultraviolet light that has passed through the top plate 502 passes through the through-holes 504a of the anode electrode 504 and reaches the cathode electrode 503, electrons are emitted due to the photoelectric effect, and a current flows between the anode electrode 504 and the cathode electrode 503. After this, an electron avalanche occurs due to the enclosed gas and voltage, starting a discharge. Based on this current flowing between the anode electrode 504 and the cathode electrode 503, only ultraviolet light of a specific wavelength that has passed through the top plate 502 is detected by the ultraviolet sensor.

[0005] The photoelectric effect is a phenomenon in which electrons inside a material are excited when the material absorbs light, causing the electrons to be ejected. In this photoelectric effect, the energy required to extract one electron from the surface of the material is called the work function, and if the energy of the incident light is hν, the work function is W, and the kinetic energy of the electron ejected from the material is E, it can be expressed as E = hν - W.

[0006] The critical sensitivity wavelength of ultraviolet light to be detected by ultraviolet sensors varies depending on the field in which they are used. For example, ultraviolet sensors use tungsten as the electrode material for the cathode electrode, but there are fields in which this type of ultraviolet sensor cannot detect flames. In such fields, the electrode material of the cathode electrode is changed to expand the critical sensitivity wavelength, for example, to 260 nm to 300 nm.

[0007] When selecting a metal to be used as the electrode material for the cathode electrode of a UV sensor, it is important to select a metal that satisfies the specifications required for the cathode electrode by referring to the work function determined for each type of metal and crystal plane orientation, and the threshold sensitivity wavelength calculated from the work function (Patent Document 1). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2019-020222 [Non-patent literature]

[0009] [Non-Patent Document 1] Masao Mashimo, "Orientation of Thin Film Crystals," Surface Science, Vol. 2, No. 1, pp. 46-56, 1981. Summary of the Invention [Problem to be solved by the invention]

[0010] However, even if the electrode material of the cathode electrode is selected to meet the requirements of the field where flame detection is performed, if the electrode material of the anode electrode is not appropriately selected, the ultraviolet sensor may make a false detection.

[0011] In UV sensors, gas ions are generated by the collision of electrons emitted by the photoelectric effect. These gas ions are accelerated by the electric field and mainly collide with the cathode electrode, causing new electron emission. Some of the gas ions generated by the electron collisions remain inside the glass container, and some collide with the anode electrode. These collisions can cause sputtering at the anode electrode. Because the anode and cathode electrodes are located close to each other, metal particles from the anode electrode material generated by sputtering can adhere to the cathode electrode and partially deposit on it.

[0012] Here, we consider the work function of the cathode electrode when metal particles of the anode electrode material are deposited on the cathode electrode in the form of a thin film. If the work function of the thin film made of metal particles originating from the anode electrode deposited on the cathode electrode is smaller than the work function of the cathode electrode, the work function of the area where the thin film is formed will be smaller than the surrounding area. In other words, if a thin film is not formed, there is a possibility that the UV sensor will detect low-energy, long-wavelength light (ambient light) that would not be detected. This will result in false detection.

[0013] In other words, if an appropriate metal material is not selected for the anode electrode, the UV sensor may malfunction even if a cathode electrode is selected taking into account the work function and the limit sensitivity wavelength calculated therefrom.

[0014] The present invention has been made to solve the above problems, and has an object to suppress malfunction of the ultraviolet sensor. [Means for solving the problem]

[0015] The electrode material selection device according to the present invention includes a work function determination unit configured to determine the work function of the cathode electrode of an ultraviolet sensor that detects ultraviolet light based on a current generated by discharge between an anode electrode and a cathode electrode, and a selection unit that selects, as the electrode material for the anode electrode, a metal whose work function of the closest-packed plane of atoms is equal to or greater than the value determined by the work function determination unit.

[0016] In one example of the configuration of the electrode material selection device, the work function determination unit determines the work function of the cathode electrode based on information about the electrode material of the cathode electrode and the manufacturing conditions of the cathode electrode.

[0017] In one configuration example of the electrode material selection device, a memory unit is provided that is configured to store, for each metal, the relationship between the atomic plane of the surface in a state formed as an electrode, the processing method for forming the electrode, and the work function, and the work function determination unit determines the value of the work function of the cathode electrode by extracting it from the memory unit, and the selection unit selects a metal by extracting from the memory unit a metal whose work function of the closest-packed plane of atoms is equal to or greater than the value determined by the work function determination unit.

[0018] The electrode material selection method according to the present invention includes a first step of determining the work function of the cathode electrode of an ultraviolet sensor that detects ultraviolet rays based on a current generated by discharge between an anode electrode and a cathode electrode, and a second step of selecting, as the electrode material for the anode electrode, a metal whose work function of the closest-packed plane of atoms is equal to or greater than the value determined in the first step.

[0019] In one example of the electrode material selection method, the first step is to find the work function of the cathode electrode based on information about the electrode material of the cathode electrode and the manufacturing conditions of the cathode electrode.

[0020] In one example of the above electrode material selection method, the first step is to determine the work function value of the cathode electrode by extracting it from a memory unit that stores, for each metal, the relationship between the atomic plane of the surface in a state formed as an electrode, the processing method for forming the electrode, and the work function; and the second step is to select a metal by extracting from the memory unit a metal whose work function of the closest-packed plane of atoms is equal to or greater than the value determined in the first step.

[0021] The electrode selection support device according to the present invention supports the selection of an electrode material for an anode electrode of an ultraviolet sensor that detects ultraviolet rays based on a current generated by discharge between an anode electrode and a cathode electrode. The electrode selection support device includes: a memory unit configured to store, for each metal, the atomic planes of the surface in a state formed as an electrode, a processing method for forming the electrode, and a relationship between the work function; a reception unit configured to receive information on a first metal to be used as the material for the cathode electrode and a second metal to be used as the material for the anode electrode; a first extraction unit configured to extract from the memory a first value of the work function corresponding to each atomic plane of the first metal received by the reception unit; a second extraction unit configured to extract from the memory a second value of the work function corresponding to each atomic plane of the second metal received by the reception unit; a calculation unit configured to determine the magnitude relationship between the first value and the second value; and a presentation unit configured to present the magnitude relationship between the first value and the second value determined by the calculation unit, together with the atomic plane of the first metal corresponding to the first value and the atomic plane of the second metal corresponding to the second value. [Effects of the Invention]

[0022] As described above, according to the present invention, the work function of the cathode electrode of the UV sensor is calculated, and a metal having a work function of the closest-packed plane of atoms equal to or greater than the calculated value is used as the electrode material for the anode electrode, thereby suppressing malfunction of the UV sensor. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a diagram showing the configuration of an electrode material selection device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a flowchart illustrating a method for selecting an electrode material according to an embodiment of the present invention. [Figure 3] FIG. 3 is a configuration diagram showing the hardware configuration of the electrode material selection device according to the embodiment of the present invention. [Figure 4] FIG. 4 is a configuration diagram showing the configuration of an electrode selection support device according to an embodiment of the present invention. [Figure 5] FIG. 5 is a configuration diagram showing the hardware configuration of an electrode selection supporting device according to an embodiment of the present invention. [Figure 6] FIG. 6 is a diagram showing the configuration of the ultraviolet sensor. DETAILED DESCRIPTION OF THE INVENTION

[0024] [Electrode material selection] An electrode material selection device according to an embodiment of the present invention will be described below with reference to Fig. 1. This electrode material selection device includes a work function determination unit 101 and a selection unit .

[0025] The work function determination unit 101 determines the work function of the cathode electrode of the ultraviolet sensor. The ultraviolet sensor is a sensor that detects ultraviolet rays based on a current generated by discharge between an anode electrode and a cathode electrode. The work function determination unit 101 determines the work function of the cathode electrode based on information about the electrode material of the cathode electrode and the manufacturing conditions of the cathode electrode. For example, the work function determination unit 101 determines the work function of the cathode electrode based on information about the cathode electrode input by a user via the input unit 105. The selection unit 102 selects a metal whose work function of the closest-packed plane of atoms is equal to or greater than the value determined by the work function determination unit 101 as the electrode material for the anode electrode. The electrode material selected by the selection unit 102 is displayed, for example, on the display unit 104 so that the user can recognize it.

[0026] For example, this electrode material selection device can include a memory unit 103 that stores, for each metal, the atomic plane of the surface in a state formed as an electrode, the processing method for forming the electrode, and the relationship between the work function. The memory unit 103 stores, for example, information such as that shown in Table 1 below. As shown in Table 1, for the atomic planes, information including whether or not they are close-packed planes is stored in the memory unit 103. The work function determination unit 101 obtains the value of the work function of the cathode electrode by extracting it from the memory unit 103. Furthermore, the selection unit 102 selects metals by extracting from the memory unit 103 those metals whose work functions of the close-packed planes of atoms are equal to or greater than the value obtained by the work function determination unit 101.

[0027] [Table 1]

[0028] Next, a method for selecting an electrode material according to an embodiment of the present invention will be described with reference to FIG. 2. First, in a first step S101, the work function of the cathode electrode of a UV sensor that detects UV rays based on the current generated by discharge between an anode electrode and a cathode electrode is determined. In the first step S101, the work function of the cathode electrode is determined based on information about the electrode material of the cathode electrode and the conditions for manufacturing the cathode electrode. Next, in a second step S102, a metal whose work function of the closest-packed plane of atoms is equal to or greater than the value determined in the first step S101 is selected as the electrode material for the anode electrode.

[0029] In the first step S101, the work function of the cathode electrode is extracted from a memory unit 103, which stores the relationship between the atomic plane of the surface formed as an electrode, the processing method for forming the electrode, and the work function for each metal. In the second step S102, metals whose work functions of the closest-packed atomic planes are equal to or greater than the value obtained in the first step S101 can be selected by extracting them from the memory unit 103.

[0030] It is known that metal thin films are oriented such that the close-packed atomic plane, which minimizes surface energy, is parallel to the substrate surface (Non-Patent Document 1). For example, in a body-centered cubic metal such as tungsten, the close-packed atomic plane (110) is oriented parallel to the substrate surface. In a face-centered cubic metal such as copper, the close-packed atomic plane (111) is oriented parallel to the substrate surface. In addition, the type of metal and the work function determined by its plane orientation are known. Based on these facts, the work function of the thin film formed on the cathode electrode by the volume of metal particles originating from the anode electrode can be determined as the work function determined by the close-packed atomic plane of the metal that is the material of the anode electrode.

[0031] As mentioned above, the work function (W anode ) is the work function of the cathode electrode (W cathode), false detection occurs, whereby low-energy, long-wavelength light (ambient light) that cannot be detected by the UV sensor is detected. Therefore, by using a metal for the anode electrode whose work function of the closest-packed plane of atoms is equal to or greater than the work function of the cathode electrode, it is possible to suppress the false detection described above.

[0032] According to the above-described embodiment, for example, by inputting predetermined cathode electrode information by a user, a metal having a work function of the closest-packed plane of atoms equal to or greater than the work function of the cathode electrode is selected as the electrode material for the anode electrode. By using the selected electrode material as the anode electrode material, the above-described erroneous detection can be suppressed.

[0033] As shown in Fig. 3, the electrode material selection device according to the above-described embodiment is a computer device including a CPU (Central Processing Unit) 301, a main memory device 302, an external memory device 303, a network connection device 304, etc., and the above-described functions (electrode material selection method) can be realized by the CPU 301 operating (executing) a program loaded in the main memory device 302. The above-described program is a program for causing a computer to execute the electrode material selection method shown in the above-described embodiment. The network connection device 304 is connected to a network 305. Furthermore, the functions can be distributed among multiple computer devices.

[0034] [Electrode selection support device] Next, an electrode selection support device according to an embodiment of the present invention will be described with reference to Fig. 4. This electrode selection support device supports the selection of an electrode material for the anode electrode of an ultraviolet sensor that detects ultraviolet rays based on a current generated by discharge between an anode electrode and a cathode electrode. This electrode selection support device includes a memory unit 201, a reception unit 202, a first extraction unit 203, a second extraction unit 204, a calculation unit 205, a presentation unit 206, a display unit 207, and an input unit 208.

[0035] The storage unit 201 stores, for each metal, the relationship between the atomic plane of the surface in a state where it is formed as an anode electrode or a cathode electrode, the processing method for forming the electrode, and the work function. Information about the work function, including whether it is a close-packed plane or not, is stored in the storage unit 201. The receiving unit 202 receives information about a first metal to be used as the material for the cathode electrode and a second metal to be used as the material for the anode electrode. For example, the receiving unit 202 receives information input by a user via the input unit 105.

[0036] The first extraction unit 203 extracts from the storage unit 201 a first value of the work function corresponding to each atomic plane of the first metal received by the reception unit 202. The second extraction unit 204 extracts from the storage unit 201 a second value of the work function corresponding to each atomic plane of the second metal received by the reception unit 202. The calculation unit 205 determines the magnitude relationship between the first value and the second value. The presentation unit 206 presents the magnitude relationship between the first value and the second value obtained by the calculation unit 205, along with the atomic plane of the first metal corresponding to the first value and the atomic plane of the second metal corresponding to the second value. Information about the atomic planes, including whether they are close-packed planes, is presented. The presentation unit 206 presents the magnitude relationship by displaying it on the display unit 207.

[0037] It is known that metal thin films are oriented such that the close-packed atomic plane, which minimizes surface energy, is parallel to the substrate surface (Non-Patent Document 1). For example, in a body-centered cubic metal such as tungsten, the close-packed atomic plane (110) is oriented parallel to the substrate surface. In a face-centered cubic metal such as copper, the close-packed atomic plane (111) is oriented parallel to the substrate surface. In addition, the type of metal and the work function determined by its plane orientation are known. Based on these facts, the work function of the thin film formed on the cathode electrode by the volume of metal particles originating from the anode electrode can be determined as the work function determined by the close-packed atomic plane of the metal that is the material of the anode electrode.

[0038] As mentioned above, the work function (W anode ) is the work function of the cathode electrode (W cathode), false detection occurs, whereby low-energy, long-wavelength light (ambient light) that cannot be detected by the UV sensor is detected. Therefore, by using a metal for the anode electrode whose work function of the closest-packed plane of atoms is equal to or greater than the work function of the cathode electrode, it is possible to suppress the false detection described above.

[0039] According to the above-described embodiment, based on the presented information, the user selects a metal as the electrode material for the anode electrode, the metal having a work function of the closest-packed plane of atoms that is equal to or greater than the work function of the cathode electrode, and uses the selected electrode material as the anode electrode material, thereby suppressing the above-described erroneous detection.

[0040] As shown in Fig. 5, the electrode selection support device according to the above-described embodiment is a computer device including a CPU (Central Processing Unit) 401, a main storage device 402, an external storage device 403, a network connection device 404, etc., and the above-described functions can be realized by the CPU 401 operating (executing) a program loaded in the main storage device 402. The network connection device 404 is connected to a network 405. Furthermore, the functions can be distributed among multiple computer devices.

[0041] As described above, according to the present invention, the work function of the cathode electrode of the UV sensor is calculated, and a metal having a work function of the closest-packed plane of atoms equal to or greater than the calculated value is used as the electrode material for the anode electrode, thereby making it possible to suppress malfunction of the UV sensor.

[0042] It should be noted that the present invention is not limited to the embodiments described above, and it is clear that many modifications and combinations can be made by a person having ordinary knowledge in the art within the technical concept of the present invention. [Explanation of symbols]

[0043] 101... work function determination section, 102... selection section, 103... storage section, 104... display section, 105... input section.

Claims

1. a work function determination unit configured to determine a work function of a cathode electrode of an ultraviolet sensor that detects ultraviolet rays based on a current generated by discharge between an anode electrode and a cathode electrode; a selection unit that selects a metal having a work function of a closest-packed plane of atoms equal to or greater than the value determined by the work function determination unit as an electrode material for the anode electrode; An electrode material selection device comprising:

2. 2. The electrode material selection device according to claim 1, The work function determination unit determines the work function of the cathode electrode based on information about the electrode material of the cathode electrode and manufacturing conditions of the cathode electrode. Electrode material selection device.

3. 3. The electrode material selection device according to claim 1, a memory unit configured to store, for each metal, the atomic plane of the surface in a state formed as an electrode, a processing method for forming the electrode, and a relationship with the work function; the work function determination unit obtains a value of the work function of the cathode electrode by extracting it from the storage unit; The selection unit selects a metal by extracting from the storage unit a metal having a work function of the closest-packed plane of atoms equal to or greater than the value determined by the work function determination unit. Electrode material selection device.

4. a first step of determining a work function of a cathode electrode of an ultraviolet sensor that detects ultraviolet rays based on a current generated by discharge between an anode electrode and a cathode electrode; a second step of selecting a metal having a work function of the closest-packed plane of atoms equal to or greater than the value determined in the first step as an electrode material for the anode electrode; An electrode material selection method comprising:

5. 5. The electrode material selection method according to claim 4, The first step is to determine the work function of the cathode electrode based on information about the electrode material of the cathode electrode and the manufacturing conditions of the cathode electrode. How to select electrode materials.

6. 6. The electrode material selection method according to claim 4 or 5, The first step involves extracting and determining the value of the work function of the cathode electrode from a storage unit that stores, for each metal, the relationship between the atomic plane of the surface in a state where the cathode electrode is formed, the processing method for forming the electrode, and the work function; The second step selects metals whose work functions of the closest-packed planes of atoms are equal to or greater than the value determined in the first step by extracting them from the storage unit. How to select electrode materials.

7. 1. An electrode selection support device that supports selection of an electrode material for an anode electrode of an ultraviolet sensor that detects ultraviolet rays based on a current generated by discharge between an anode electrode and a cathode electrode, a memory unit configured to store, for each metal, the atomic plane of the surface in a state formed as an electrode, a processing method for forming the electrode, and a relationship with the work function; a receiving unit configured to receive information on a first metal to be used as a material for the cathode electrode and a second metal to be used as a material for the anode electrode; a first extraction unit that extracts, from the storage unit, a first value of the work function corresponding to each atomic plane of the first metal received by the reception unit; a second extraction unit that extracts, from the storage unit, second values ​​of the work function corresponding to each atomic plane of the second metal received by the reception unit; a calculation unit configured to determine the magnitude relationship between the first value and the second value; a presentation unit configured to present the magnitude relationship between the first value and the second value calculated by the calculation unit, together with an atomic plane of the first metal corresponding to the first value and an atomic plane of the second metal corresponding to the second value; An electrode selection support device comprising:

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