JP2011154906A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device capable of achieving low power consumption, high light-emitting efficiency, and longer lifetime, and making color-matching. <P>SOLUTION: The light-emitting device includes an airtight container 1 where a gas capable of emitting light at a plurality of wavelengths, an electron source 2 supplying electrons for exciting the gas into the airtight container 1, an anode electrode 3 oppositely arranged on the electron source 2, a phosphor layer 4 arranged at an inner surface side of the airtight container 1 and emitting the light by being excited with excited light made of light emitted at a light-emitting step of the excited gas, and a control device 5 for controlling voltage between a surface electrode 27 and a lower electrode 25 (between driving electrodes) of the electron source 2 and voltage between the anode electrode 3 and the electron source 2. The phosphor layer 4 includes a plurality of phosphors having different excited energy dependence of light intensity. The control device 5 for exciting the gas without discharging the gas by controlling voltage between the surface electrode 27 and the lower electrode 25 of the electron source 2 so as to make peak energy of an energy distribution of the electrons larger than excited energy of the gas and to make the peak energy of the energy distribution of the electrons smaller than ionized energy of the gas. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light emitting device that emits light having a wavelength longer than that of excitation light by converting the wavelength of excitation light emitted in the light emission process of a gas sealed in an airtight container with a phosphor.

  As interest in environmental problems on the earth increases, mercury-free fluorescent lamps such as rare gas fluorescent lamps that contain rare gas such as xenon gas in a light-tight airtight container without using mercury are used as light emitting devices. It is being researched and developed in various places.

  However, the rare gas fluorescent lamp is less efficient than the conventional fluorescent lamp using mercury, and in order to obtain the same luminance as the conventional fluorescent lamp, a pair of rare gas fluorescent lamps arranged in a light-transmitting hermetic container is used. There is a problem in that a higher discharge starting voltage (starting voltage) and a sustaining voltage must be applied between the discharge electrodes.

  On the other hand, a field emission type electron source is disposed separately from the pair of discharge electrodes in a light-transmitting hermetic container filled with a gas composed of a rare gas such as xenon gas, and the pair of discharge electrodes. There has been proposed a technique for reducing the discharge start voltage by driving the electron source to emit electrons before applying a voltage therebetween (see, for example, Patent Document 1), and reducing the discharge start voltage to about half. It is known that it can be done. In the light emitting device disclosed in Patent Document 1, a phosphor layer made of a phosphor that emits light by being excited by excitation light consisting of ultraviolet light generated by gas discharge is formed in an appropriate portion of the inner surface of the hermetic container. Has been.

JP 2002-150944 A

  However, in the light emitting device disclosed in Patent Document 1, it is necessary to supply electrons having an ionization energy (12.13 eV) or more of the xenon gas into the hermetic container. However, since the ionization energy of the xenon gas is larger than the excitation energy (8.44 eV) necessary for generating ultraviolet light from the xenon gas, the voltage applied between the driving electrodes of the electron source becomes larger than necessary. There is a concern that low power consumption and high luminous efficiency per unit input power are restricted, and the lifetime of the light emitting device is shortened by shortening the lifetime of the electron source. Further, in the light emitting device disclosed in Patent Document 1, damage to the electron source and the phosphor layer occurs due to collision of discharge plasma ions with the electron source and the phosphor layer, and the life of the light emitting device is shortened. There was concern that it would end up. In addition, it is also desired that color adjustment is possible in a light emitting device used as an alternative to a rare gas fluorescent lamp or the like.

  The present invention has been made in view of the above reasons, and an object of the present invention is to provide a light emitting device that can achieve low power consumption, high light emission efficiency, long life, and color matching. .

  According to the first aspect of the present invention, there is provided an airtight container in which a gas capable of emitting light at a plurality of wavelengths in the vacuum ultraviolet to visible light region is enclosed and at least a part is formed of a light-transmitting material, and electrons that excite the gas into the airtight container An electron source for supplying light, an anode electrode disposed opposite to the electron source in the hermetic container, and light emitted by excitation light including light emitted in the light emission process of the excited gas disposed on the inner surface side of the hermetic container And a control device for controlling the voltage between the driving electrode of the electron source and the voltage between the anode electrode and the electron source, and the phosphor layer has a plurality of different light intensity excitation energy dependencies. The control device sets the voltage between the driving electrodes of the electron source so that the peak energy of the electron energy distribution is larger than the excitation energy of the gas and smaller than the ionization energy of the gas. And wherein the exciting the gas without discharging the gas by Gosuru.

  According to this invention, the control device controls the voltage between the driving electrodes of the electron source so that the peak energy of the electron energy distribution is larger than the excitation energy of the gas and smaller than the ionization energy of the gas. When the gas is excited without discharging the gas, and the excitation light consisting of the light emitted in the emission process of the excited gas is wavelength-converted in the phosphor layer, so that the phosphor layer emits light by discharging the gas As compared with the above, since the voltage applied between the driving electrodes of the electron source can be reduced, low power consumption and high luminous efficiency can be achieved. Further, since the electron source and the phosphor layer are not damaged due to the ions of the discharge plasma, the lifetime can be extended. In addition, the gas sealed in the hermetic container can emit light at a plurality of wavelengths in the vacuum ultraviolet to visible light range, and the phosphor layer has a plurality of phosphors having different light intensity excitation energy dependencies. Therefore, color control is possible by changing the relative energy ratio of light emitted from the gas by changing the peak energy of the electron energy distribution by controlling the voltage between the driving electrodes of the electron source by the control device. It becomes.

  According to a second aspect of the invention, in the first aspect of the invention, the gas is a mixed gas.

  According to this invention, the design freedom of the wavelength which can be light-emitted by the gas becomes high.

  According to a third aspect of the present invention, in the second aspect of the present invention, the mixed gas comprises two kinds of rare gases.

  According to this invention, it becomes possible to emit light at a plurality of wavelengths determined by each rare gas.

  According to a fourth aspect of the present invention, in the second aspect of the present invention, the mixed gas is composed of a rare gas and a halogen gas.

  According to the present invention, it is possible to emit light at a plurality of wavelengths determined by the rare gas, the halogen gas, and the halide of the rare gas atom.

  According to a fifth aspect of the present invention, in the second aspect of the present invention, the mixed gas includes a rare gas and an inert gas excluding the rare gas.

  According to this invention, it becomes possible to emit light at a plurality of wavelengths determined by the rare gas and the inert gas.

  According to a sixth aspect of the present invention, in the first to fifth aspects of the invention, the electron source is interposed between a lower electrode, a surface electrode opposed to the lower electrode, and the lower electrode and the surface electrode. Ballistic electron surface emission electron source comprising a large number of semiconductor microcrystals and a strong electric field drift layer having a large number of insulating films formed on the surface of each semiconductor microcrystal and having a thickness smaller than the crystal grain size of the semiconductor microcrystal It is characterized by comprising.

  According to the present invention, electrons can be supplied more stably than when a Spindt-type electron source is employed as the electron source, and the voltage between the driving electrodes of the electron source and the anode electrode and the electron can be supplied. It is possible to reduce the voltage between the power source and the power consumption.

  According to the first aspect of the present invention, there are effects that low power consumption, high luminous efficiency, long life can be achieved, and color matching is possible.

It is a schematic block diagram of the light-emitting device which shows embodiment. It is principal part explanatory drawing of the electron source used for the same as the above. It is characteristic explanatory drawing same as the above. It is characteristic explanatory drawing same as the above. It is operation | movement explanatory drawing same as the above. It is characteristic explanatory drawing same as the above. It is operation | movement explanatory drawing same as the above. It is operation | movement explanatory drawing same as the above.

  As shown in FIG. 1, the light emitting device of the present embodiment includes an airtight container 1 in which a gas (e.g., xenon gas) that emits light in a vacuum ultraviolet to visible light region is enclosed, and is formed of a light transmitting material. An electron source 2 for supplying electrons that excite gas into the container 1, an anode electrode 3 made of a transparent electrode (for example, an ITO film) disposed opposite to the electron source 2 in the hermetic container 1, The voltage and anode between the phosphor layer 4 which is arranged on the inner surface side and is excited by the excitation light composed of the light emitted in the emission process of the excited gas, the surface electrode 27 and the lower electrode 25 of the electron source 2, and the anode And a control device 5 for controlling the voltage between the electrode 3 and the surface electrode 27 of the electron source 2, and light (for example, vacuum ultraviolet light) emitted in the emission process of the excited gas is a phosphor layer. 4 is converted to visible light and airtight So that the emitted through vessel 1. In the present embodiment, the surface electrode 27 and the lower electrode 25 in the electron source 2 constitute a pair of driving electrodes. In addition, the straight arrow in FIG. 1 indicates electrons emitted from the electron source 2, and the wavy arrow in FIG. 1 indicates light emitted in the emission process of the excited gas.

  The hermetic container 1 is made of a rectangular plate-like rear plate 11 made of a light-transmitting material (for example, glass) and a light-transmitting material (for example, glass) disposed to face one surface of the rear plate 11. A rectangular plate-like face plate 12 and a rectangular frame-like spacer 13 interposed between the rear plate 11 and the face plate 12, the electron source 2 is disposed on the one surface side of the rear plate 11, and the face An anode electrode 3 is formed on the surface of the plate 12 facing the electron source 2, and a phosphor layer 4 is formed on the surface of the anode electrode 3 facing the electron source 2. In addition, the shape of the airtight container 1 is not specifically limited. The material of the rear plate 11, the face plate 12, and the spacer 13 is not limited to glass, and may be, for example, a translucent ceramic. In the present embodiment, the entire hermetic container 1 is formed of a light-transmitting material, but the entire air-tight container 1 is not necessarily formed of a light-transmitting material, and at least a part of the light-transmitting material is used. It is sufficient if it is formed by.

  The electron source 2 is a ballistic electron surface-emitting device (BSD), and includes a lower electrode 25, a surface electrode 27 facing the lower electrode 25, and between the lower electrode 25 and the surface electrode 27. And a strong electric field drift layer 26 interposed therebetween. Here, the lower electrode 25 is composed of a metal film (for example, a tungsten film), and the surface electrode 27 is composed of a conductive thin film (for example, an Au film) having a thickness of about 10 to 15 nm. The materials of the lower electrode 25 and the surface electrode 27 are not particularly limited, and both are not limited to a single layer film and may be a multilayer film.

  Further, as shown in FIG. 2, the strong electric field drift layer 26 is formed at least on the surfaces of the grains 261 of columnar polycrystalline silicon grains (semiconductor crystals) 261 arranged on the surface side of the lower electrode 25. A thin silicon oxide film 262, a number of nanometer-order silicon microcrystals (semiconductor microcrystals) 263 interposed between the grains 261, and the crystal grain size of the silicon microcrystals 263 formed on the surface of each silicon microcrystal 263. Also, it is composed of a large number of silicon oxide films 264 which are insulating films having a small thickness. Here, each grain 261 extends in the thickness direction of the lower electrode 25 (that is, extends in the thickness direction of the rear plate 11).

  In order to emit electrons from the electron source 2 described above, a voltage is applied from the driving power source Vps between the surface electrode 27 and the lower electrode 25 so that the surface electrode 27 is on the high potential side with respect to the lower electrode 25. For example, electrons injected from the lower electrode 25 into the strong electric field drift layer 26 drift through the strong electric field drift layer 26 and are emitted through the surface electrode 27.

  In the electron source 2 described above, electrons can be emitted even when the voltage applied between the surface electrode 27 and the lower electrode 25 is set to a low voltage of about 10 to 20V. Note that the electron source 2 of the present embodiment has the characteristics that the electron emission characteristic is less dependent on the degree of vacuum and the popping phenomenon does not occur when electrons are emitted, so that electrons can be stably emitted with high electron emission efficiency. is doing.

The basic configuration of the above-described electron source 2 is well known, and it is considered that electron emission occurs in the following model. That is, by applying a voltage between the surface electrode 27 and the lower electrode 25 with the surface electrode 27 set to the high potential side, electrons e ⁻ are injected from the lower electrode 25 into the strong electric field drift layer 26. On the other hand, since most of the electric field applied to the strong electric field drift layer 26 is applied to the silicon oxide film 264, the injected electrons e ⁻ are accelerated by the strong electric field applied to the silicon oxide film 264, and the strong electric field drift layer 26 is applied. 2 drifts in the direction of the arrow in FIG. 2 (upward in FIG. 2) toward the surface, and the surface electrode 27 is tunneled and emitted. Therefore, in the strong electric field drift layer 26, electrons injected from the lower electrode 25 are almost scattered by the silicon microcrystal 263, are accelerated by the electric field applied to the silicon oxide film 264, and drift through the surface electrode 27. Thus, since the heat generated in the strong electric field drift layer 26 is dissipated through the grains 261, no popping phenomenon occurs during electron emission, and electrons can be stably emitted.

  In the above-mentioned strong electric field drift layer 26, the silicon oxide film 264 constitutes an insulating film, and an oxidation process is employed for forming the insulating film. However, a nitriding process or an oxynitriding process is employed instead of the oxidation process. Alternatively, when the nitridation process is adopted, the silicon oxide films 262 and 264 are both silicon nitride films, and when the oxynitride process is adopted, the silicon oxide films 262 and 264 are both silicon oxynitride. Become a film. In this embodiment, the electron source 2 is directly formed on the one surface side of the rear plate 11 made of a glass substrate. However, the lower electrode 25 of the electron source 2 is formed on the silicon substrate and the ohmic surface on the back side of the silicon substrate. It may be configured by an electrode and disposed on the one surface side of the rear plate 11.

  By the way, the control device 5 described above has a driving power source Vps for applying a voltage between the surface electrode 27 and the lower electrode 25 of the electron source 2 and a voltage between the anode electrode 3 and the surface electrode 27 of the electron source 2. And a control means 5a composed of a microcomputer for controlling each of the drive power supply Vps and the anode electrode power supply Va, and the peak energy of the electron energy distribution is The voltage between the surface electrode 27 and the lower electrode 25 of the electron source 2 is controlled so as to be larger than the excitation energy of the gas (for example, xenon gas) enclosed in the hermetic container 1 and smaller than the ionization energy of the gas. Thus, the gas is excited without discharging the gas.

  Here, in the light emitting device of the present embodiment, the control device 5 applies a voltage having a high surface electrode 27 side between the surface electrode 27 and the lower electrode 25 of the electron source 2 from the driving power source Vps. While the electrons are emitted from the electron source 2, a voltage for setting the anode electrode 3 to the high potential side is applied between the anode electrode 3 and the surface electrode 27 of the electron source 2 from the anode electrode power source Va by the control device 5. Therefore, the electrons emitted from the electron source 2 are accelerated by the electric field between the anode electrode 3 and the surface electrode 27, and gas atoms existing between the anode electrode 3 and the surface electrode 27 (for example, xenon atoms). ).

  Here, the energy obtained by the electron emitted from the electron source 2 by the electric field between the anode electrode 3 and the surface electrode 27 is the electric field strength between the anode electrode 3 and the surface electrode 27 and the average freeness of the electrons in the gas. Depending on the product of the stroke, the electric field strength depends on the voltage applied between the anode electrode 3 and the surface electrode 27 and the distance between the anode electrode 3 and the surface electrode 27, while the mean free stroke is within the hermetic vessel 1. In this embodiment, since the gas pressure is set to 5 kPa and the mean free path of electrons is short, the electrons emitted from the electron source 2 are separated from the anode electrode 3 and the surface. The energy obtained by the electric field between the electrodes 27 is smaller than the peak energy of the energy distribution of electrons emitted from the electron source 2, and the energy distribution of electrons emitted from the electron source 2 collides with the gas. Slightly from Nerugi distribution, to shift to the high-energy side. Here, in the present embodiment, when xenon gas is used as the gas, when the electron source 2 is driven so that the peak energy of the electron energy distribution is larger than the excitation energy of the xenon gas and smaller than the ionization energy of the xenon gas. The voltage applied to the surface electrode 27 between the surface electrode 27 and the lower electrode 25 of the electron source 2 with the high potential side is set to 20 V, and the peak energy of the electron energy distribution is set to about 10 eV.

  Thus, in the light emitting device of the present embodiment, the control device 5 causes the peak energy of the electron energy distribution to be larger than the excitation energy of the gas and smaller than the ionization energy of the gas. By controlling the voltage between the lower electrodes 25, the gas is excited without discharging the gas, and the excitation light composed of light emitted in the emission process of the excited gas is wavelength-converted in the phosphor layer 4. Compared with the case where the phosphor layer 4 emits light by discharging the gas, the voltage applied between the surface electrode 27 and the lower electrode 25 of the electron source 2 can be reduced and the power consumption can be reduced. High emission efficiency can be achieved, and the electron source 2 and the phosphor layer 4 are not damaged due to the ions of the discharge plasma, so that the lifetime can be extended.

  Here, in the light emitting device of the present embodiment, the distance between the electron source 2 and the anode electrode 3 is set to 1 cm, which is larger than the Paschen minimum, and gas discharge is less likely to occur. The interval between the electron source 2 and the anode electrode 3 is not limited to 1 cm.

  Further, in the light emitting device of the present embodiment, since the above-described ballistic electron surface emission type electron source is adopted as the electron source 2, it can operate stably even in gas, for example, the excitation energy of xenon gas. Electrons having an initial energy of 44 eV or more can be emitted, and the initial energy of electrons emitted from the electron source 2 is higher than when a Spindt-type electron source is employed as the electron source 2. Driving voltage (voltage between the surface electrode 27 and the lower electrode 25) and the voltage applied between the anode electrode 3 and the surface electrode 27 can be reduced, and the power consumption can be reduced.

  By the way, in the light emitting device of this embodiment, xenon gas is adopted as the gas sealed in the hermetic container 1 and the pressure of the xenon gas is set to 5 kPa. However, the gas pressure is not limited to 5 kPa. Here, the voltage applied between the anode electrode 3 and the surface electrode 27 with respect to the gas pressure in the hermetic container 1 that is changed in the range of 100 Pa to 50 kPa without providing the phosphor layer 4 in the hermetic container 1. Emission of ultraviolet light generated when a pulse voltage of 20 V is applied between the surface electrode 27 and the lower electrode 25 of the electron source 2 with the surface electrode 27 as a high potential side between the surface electrode 27 and the lower electrode 25 of the electron source 2. The results of measuring the intensity with a photomultiplier tube are shown in FIG. From FIG. 3, it was confirmed that if the gas pressure is set within the range of 2 kPa to 20 kPa, the discharge of xenon gas can be prevented and the luminous efficiency can be improved. Note that the gas pressures of 100 Pa and 1 kPa were not measured with a photomultiplier because discharge occurred.

  4 shows the result of measuring the emission intensity of ultraviolet light with a photomultiplier tube when the anode voltage is changed with the distance between the anode electrode 3 and the surface electrode 27 of the electron source 2 being 1 cm and the gas pressure being 5 kPa. Shown in Here, in the range where the anode voltage is 0 to 180 V, no discharge occurs, and the electric field strength E [V / m] between the anode electrode 3 and the surface electrode 27 of the electron source 2 and the gas pressure p [Pa]. It is understood that discharge can be prevented by setting the converted electric field strength defined by E / p in the range of 0 to 3.6 [V / mPa] using It can be seen from FIG. 4 that the emission intensity of ultraviolet light is increased by increasing the anode voltage. This is because the peak energy of the electron energy distribution shifts to the higher energy side as the anode voltage increases. However, it is assumed that this is because the probability that xenon gas is excited increases.

  Also, as shown in FIG. 5, 12.13 eV energy is required to ionize and discharge xenon atoms, whereas 8.44 eV excitation energy is required to emit ultraviolet light having a wavelength of 147 nm. In other words, emission of 172 nm, which is longer than 147 nm, can be obtained by generating an excimer (here, an xenon molecule in an excited state). In addition, the numerical value attached | subjected to the downward arrow in FIG. 5 has shown the light emission wavelength.

  Here, in this embodiment, xenon gas, which is a kind of rare gas, is used as the gas, and the pressure of the gas in the hermetic container 1 is set to 5 kPa, which is a pressure capable of generating excimer. By supplying electrons from the electron source 2 into the excimer 1, it is possible to generate excimers (excited molecules), reduce the Stokes loss in the phosphor of the phosphor layer 4, and improve the luminous efficiency. Improvements can be made.

  Further, the control device 5 in the light emitting device of the present embodiment is arranged such that the electrons are periodically supplied from the electron source 2 into the hermetic container 1 from the driving power source Vps and the surface electrode 27 and the lower portion of the electron source 2. A rectangular wave voltage is applied between the electrode 25 and the surface electrode 27 with the high potential side. Therefore, in the light emitting device of this embodiment, since the control device 5 intermittently drives the electron source 2, it is possible to reduce power consumption compared to the case where the electron source 2 is continuously driven.

  Here, without providing the phosphor layer 4 in the hermetic container 1, the pressure of the xenon gas in the hermetic container 1 is set to 5 kPa, and the surface electrode 27 is placed between the surface electrode 27 and the lower electrode 25 of the electron source 2. FIG. 6 shows the results of measuring the temporal change in the emission intensity of ultraviolet light when a pulse voltage of 20 V is applied on the potential side (“ON” in FIG. 6 indicates that the pulse voltage is applied to the electron source 2). "OFF" indicates a period during which no pulse voltage is applied to the electron source 2). FIG. 6 shows that afterglow is obtained for about 20 μsec from the stop of application of the pulse voltage to the electron source 2. In short, it can be seen that the afterglow time is about 20 μsec.

  Therefore, in the control device 5, the xenon when the off period in which the supply of electrons from the electron source 2 is stopped in one cycle of the above-described rectangular wave voltage is shifted from the on period in which electrons are supplied from the electron source 2 to the off period. It is set to be shorter than the afterglow time of the gas. Here, FIG. 7 shows off time (off period time) when the frequency and on-duty of the rectangular wave voltage are changed. In FIG. 7, the horizontal axis is frequency, the vertical axis is off time, “I” is on duty 1%, “B” is on duty 10%, “C” is on duty The case of 50% is shown.

  Therefore, in the light emitting device of the present embodiment, since the emission of ultraviolet light is continued even during the off period in which the supply of electrons from the electron source 2 is stopped, the efficiency of activation can be improved.

  In the present embodiment, as described above, the electron source 2 includes the lower electrode 25, the surface electrode 27 facing the lower electrode 25, and the strong electric field drift layer 26 interposed between the lower electrode 25 and the surface electrode 27. Therefore, if the control device 5 uses the rectangular wave voltage as an AC voltage, a forward bias voltage is applied between the surface electrode 27 and the lower electrode 25 of the electron source 2. Is applied to the airtight container 1, and a reverse bias voltage is applied between the surface electrode 27 and the lower electrode 25 to apply a strong electric field drift layer of the electron source 2 when a forward bias voltage is applied. 26, the period in which the electrons trapped in the traps in the strong electric field drift layer 26 are discharged to the lower electrode 25 outside the strong electric field drift layer 26 is repeated. It can be suppressed, thereby the life of the electron source 2.

  In the light emitting device of the present embodiment, the control device 5 is synchronized with the first rectangular wave voltage that is a rectangular wave voltage applied between the surface electrode 27 and the lower electrode 25 of the electron source 2. Is applied between the anode electrode 3 and the surface electrode 27 of the electron source 2, the power consumption can be reduced compared to the case where a constant voltage is applied between the anode electrode 3 and the electron source 2. .

  Here, the control device 5 sets the second rectangular wave voltage so that the potential of the anode electrode 3 is higher than that of the electron source 2 and is lower in the off period than in the on period. As a result, electrons can be extracted to the anode electrode 3 during the off period while reducing the power consumption of the electron source 2.

  By the way, in the light emitting device of this embodiment, xenon gas is used as a gas that can emit light at a plurality of wavelengths in the vacuum ultraviolet to visible light region, and the phosphor layer 4 has a plurality of light intensity different excitation energy dependencies. The control device 5 includes the electron source 2 so that the peak energy of the energy distribution of electrons emitted from the electron source 2 is larger than the excitation energy of the gas and smaller than the ionization energy of the gas. By controlling the voltage between the driving electrodes, the gas is excited without discharging the gas. As the phosphor, a well-known phosphor may be adopted as appropriate.

  Thus, in the light emitting device of the present embodiment, the gas sealed in the hermetic container can emit light at a plurality of wavelengths in the vacuum ultraviolet to visible light range, and the phosphor layer 4 has an excitation energy dependency of the light intensity. Since there are a plurality of different phosphors, the control device 5 controls the voltage between the driving electrodes of the electron source 2 to change the peak energy of the electron energy distribution, and the relative light of each wavelength emitted from the gas. Toning can be achieved by changing the proportion of the color. For example, if two types of phosphors having different excitation energy dependency of light intensity are provided for each of the red phosphor, the green phosphor, and the blue phosphor as the phosphors, white-color toning can be performed. .

  Here, if the gas sealed in the hermetic container 1 is a mixed gas, different gas atoms (or gas molecules) A and B are present in the hermetic container 1 (see FIG. 1) as shown in FIG. Since it exists, the design freedom of the wavelength which can be light-emitted with gas becomes high.

As such a mixed gas, for example, a mixed gas of two kinds of rare gases may be used. The two kinds of rare gases may be appropriately selected from the group of helium gas, neon gas, argon gas, krypton gas, and xenon gas. In this case, light can be emitted at a plurality of wavelengths determined by each rare gas, and is determined by the excitation level of a gas atom A (for example, xenon atom) having a relatively low excitation level as shown in FIG. 8B. wavelength lambda _a, relatively excitation level of high gas atoms B (e.g., krypton atom) wavelength lambda _B determined by the excitation level _of the possible emission, respectively.

Further, the above-mentioned mixed gas may be composed of a rare gas and an inert gas excluding the rare gas (for example, N ₂ gas, CO gas, CO ₂ gas). In this case, the rare gas and the inert gas Light can be emitted at a plurality of wavelengths determined by each. As the N ₂ gas, a forming gas (for example, a forming gas composed of 97% N ₂ and 3% H ₂ or a forming gas composed of 95% N ₂ and 3% H ₂ is used. Gas, etc.) may be used.

Further, the above mixed gas may be composed of a rare gas and a halogen gas. In this case, it is possible to emit light at a plurality of wavelengths determined by the rare gas, the halogen gas, and the halide of the rare gas atom. That is, as shown in FIG. 8C, the wavelength λ _A determined by the excitation level of the gas atom A (for example, xenon atom) having a relatively low excitation level, and the gas atom B ( For example, light can be emitted at a wavelength λ _B determined by an excitation level of iodine atoms) and a wavelength λ _AB determined by an excitation level of a halide of rare gas atoms (for example, xenon iodide). Further, the above mixed gas is not limited to the above combination, and may be, for example, a combination of halogen gases, a combination of inert gases, or a combination of a halogen gas and an inert gas. There is an advantage that it is cheaper than gas.

1 Airtight container 2 Electron source (ballistic electron surface emission type electron source)
3 Anode electrode 4 Phosphor layer 5 Control device 25 Lower electrode (drive electrode)
26 Strong electric field drift layer 27 Surface electrode (drive electrode)
263 Silicon microcrystal (semiconductor microcrystal)
H.264 silicon oxide film (insulating film)

Claims (6)

  An airtight container in which a gas that can emit light at a plurality of wavelengths in the vacuum ultraviolet to visible light region is enclosed and at least a part is formed of a light-transmitting material; an electron source that supplies electrons that excite the gas into the airtight container; An anode electrode disposed opposite to the electron source in the hermetic container, a phosphor layer disposed on the inner surface side of the hermetic container and excited by excitation light composed of light emitted in the emission process of excited gas, and an electron A control device for controlling the voltage between the source driving electrode and the voltage between the anode electrode and the electron source, the phosphor layer has a plurality of phosphors having different excitation energy dependencies of light intensity, The control device controls the voltage between the driving electrodes of the electron source so that the peak energy of the electron energy distribution is larger than the excitation energy of the gas and smaller than the ionization energy of the gas. Emitting apparatus characterized by exciting the gas without discharge.   The light emitting device according to claim 1, wherein the gas is a mixed gas.   The light-emitting device according to claim 2, wherein the mixed gas includes two kinds of rare gases.   3. The light emitting device according to claim 2, wherein the mixed gas comprises a rare gas and a halogen gas.   The light emitting device according to claim 2, wherein the mixed gas includes a rare gas and an inert gas excluding the rare gas.   The electron source is formed on the surface of a lower electrode, a surface electrode facing the lower electrode, a large number of nanometer-order semiconductor microcrystals and each semiconductor microcrystal interposed between the lower electrode and the surface electrode. 6. A ballistic electron surface emission electron source comprising a strong electric field drift layer having a number of insulating films having a thickness smaller than the crystal grain size of the crystal. The light emitting device according to item.

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