JPH10321125A - Electron emitting element and display device using this - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron emitting element having high electron emitting efficiency by imparting a film thickness not less than a specific value in an insulator layer of the electron emitting element to emit an electron by impressing an electric field between an electron supply layer and a metallic thin film electrode, and transparentizing the electron supply layer. SOLUTION: An electron emitting element is composed of an electron supply layer 12 composed of metal or a semiconductor, an insulator layer 13 and a metallic thin film electrode 15 facing to a vacuum space, which are formed in order on a transparent glass substrate 10 having a light transmissive ohmic electrode 11, and is an electron emitting element to emit an electron by impressing an electric field between the electron supply layer 12 and the metallic thin film electrode 15. The insulator layer 13 has a film thickness not less than 50 nm, and the electron supply layer 12 is transparent. When an electron is implanted in the electron supply layer 12 by impressing driving voltage Vd between the ohmic electrode 11 and the thin film electrode 15, a part of electrons is emitted in a vacuum of an external part. The emitted electron is collected to a collector electrode 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electron-emitting device and an electron-emitting display device using the same.

[0002]

2. Description of the Related Art Conventionally, an FED of a field emission display device has been used.
(field emission display) is known as a planar light emitting display with an array of cold cathode electron emission sources that does not require heating of the cathode. For example, the light emission principle of an FED using a spindt-type cold cathode is that, similar to a CRT (cathode ray tube), although the cold cathode array is different, electrons are drawn out into vacuum by a gate electrode separated from the cathode and applied to a transparent anode. The phosphor is caused to emit light by colliding with the phosphor.

However, this field emission source has a
The production process of the spindt-type cold cathode is complicated, and the number of processes is large, so that there is a problem that the production yield is low. Also,
There is also an electron-emitting device having a metal-insulation-metal (MIM) structure as a surface electron source. In the electron emission device having the MIM structure, a lower Al layer, an Al ₂ O ₃ insulator layer having a thickness of about 10 nm,
There is a structure in which an upper Au layer of about 0 nm is sequentially formed.
This is placed under the counter electrode in a vacuum and the lower Al layer and the upper
When a voltage is applied between the Au layers and an acceleration voltage is applied to the counter electrode, some of the electrons jump out of the upper Au layer and reach the counter electrode. However, the amount of emitted electrons is still insufficient to use this device as a display device. In order to improve this, the conventional Al ₂ O ₃ insulator layer is further reduced to a thickness of about several nm, and the film quality of the ultra-thin Al ₂ O ₃ insulator layer and the Al ₂ O ₃ insulator layer It is considered that it is necessary to make the interface of the upper Au layer more uniform.

For example, an attempt has been made to improve the electron emission characteristics by controlling the formation current by using an anodic oxidation method in order to make the insulator layer thinner and more uniform (Japanese Patent Laid-Open No. 7-65710). Gazette). However, M
Even in the electron emission device having the IM structure, the emission current is still 1 × 10
^-6 A / cm ² and the emission current ratio is about 1 × 10 ^-3 .

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an electron-emitting device having a high electron-emitting efficiency and an electron-emitting display device using the same. .

[0006]

According to the present invention, there is provided an electron-emitting device comprising an electron supply layer made of a metal or a semiconductor, an insulator layer formed on the electron supply layer, and a vacuum space formed on the insulator layer. An electron-emitting device comprising a metal thin film electrode facing the electron supply layer and applying an electric field between the electron supply layer and the metal thin film electrode to emit electrons, wherein the insulator layer has a thickness of 50 nm or more. The supply layer is characterized by being transparent.

In the electron-emitting device of the present invention, since the insulator layer has a large thickness, a through-hole is hardly generated, so that the production yield is improved. The emission current of the device is 1 × 10 ^-6 A / cm
Over ² × 1 ^-3 A / cm ² and emission current ratio is 1 ×
Since 10 ^-1 is obtained, when a display element is used, high luminance can be obtained, consumption of driving current and heat generation can be suppressed, and a load on a driving circuit can be reduced. Further, the insulator layer has a thickness of 50 nm.
Although having the above film thickness, since the electron supply layer is transparent,
Divergent light can be extracted from the electron supply layer side.

Further, the electron-emitting device of the present invention can be applied to a high-speed device such as a light-emitting source of a pixel valve, an electron-emitting source of an electron microscope, and a vacuum microelectronic device. It can operate as a light emitting diode or a laser diode that emits infrared, visible, or ultraviolet electromagnetic waves. Also, an electron emission display of the present invention comprises a pair of first and second substrates facing each other across a vacuum space, a plurality of electron-emitting devices provided on the inner surface of the first substrate, and an inner surface of the second substrate. An electron emission display device comprising: a collector electrode provided; and a phosphor layer formed on the collector electrode, wherein each of the electron emission elements is a metal or semiconductor formed on the first substrate side. An electron supply layer comprising: an insulator layer formed on the electron supply layer; and a metal thin film electrode formed on the insulator layer and facing the vacuum space.
The electron supply layer has a thickness of not less than 0 nm and is transparent.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the electron-emitting device includes indium tin oxide (ITO), ZnO, In ₂ O ₃ ,
An electron supply layer 12 made of metal or semiconductor, an insulator layer 13 and a metal thin film electrode 15 facing a vacuum space, which are sequentially formed on a transparent glass substrate 10 provided with a transmissive ohmic electrode 11 such as SrO; An electron-emitting device that applies an electric field between an electron supply layer and a metal thin-film electrode to emit electrons. The insulator layer 13 has a very large thickness of 50 nm or more, and the electron supply layer has a thickness of 100 nm or less.

A pair of first and second substrates 10 and 1 facing each other of the electron-emitting device are held across a vacuum space. On the inner surface of the second substrate 1, a collector electrode 2 and a phosphor layer 3 are provided. This electron-emitting device is a diode in which the thin-film electrode on the surface is set to the driving potential Vd and the ohmic electrode is set to the ground potential. When a drive voltage Vd is applied between the ohmic electrode 11 and the thin film electrode 15 to inject electrons into the electron supply layer 12, a diode current Id flows, and the insulator layer 13 has a high resistance. It depends on the insulator layer. The electrons move in the insulator layer 13 toward the metal thin film electrode 15 side. Some of the electrons that have reached the vicinity of the metal thin-film electrode tunnel through the metal thin-film electrode due to the strong electric field, and are emitted into an external vacuum. This tunnel effect causes the thin film electrode 1
Electrons e (emission current Ie) emitted from 5 are accelerated by the high acceleration voltage Vc applied to the opposing collector electrode (transparent electrode) 2 and collected at the collector electrode 2.
If the fluorescent material 3 is applied to the collector electrode 2, the corresponding visible light is diverged.

Normally, in the electron-emitting device, the stack of the ohmic electrode 11, the insulator layer 13 and the thin film electrode 15 is opaque, and the second substrate 1 provided with the collector electrode 2 and the phosphor layer 3 on the inner surface is made of a transparent material. The visible light is visually observed from the second substrate side. In this configuration, only the light transmitted through the phosphor 3 and the second substrate 1 can be used as the viewing light. Therefore, as shown in FIG. 2, on the first substrate side, indium tin oxide (IT
O), ZnO, In ₂ O ₃ , SrO, etc., as a transparent glass substrate 10 provided with a light-transmitting ohmic electrode 11, by further reducing the thickness of the electron supply layer 12 to 100 nm or less so that the second substrate 10 Visible light is visible from
The thickness of the insulator layer is 50 nm or more, preferably 100 to 4 nm.
Ohmic electrode 11, insulator layer 1
Since the entire stack of the thin film electrode 3 and the thin film electrode 15 is thin, light emitted from the phosphor layer 3 is sufficiently transmitted through the stack.

As a method of forming each layer, a sputtering method is particularly effective, but a vacuum evaporation method, a CVD (chemical v
apor deposition) method, laser ablation method, MB
E (molecular beam epitaxy) and ion beam sputtering are also effective. The sputtering method is Ar,
Gas pressure of 0.1 to 100 mTorr, preferably 0.1 to 100 mTorr, using Kr, Xe or a mixed gas thereof, or a mixed gas containing a rare gas and a predetermined material mixed with O ₂ , N ₂ , H _2, etc. ~ 20mTorr, deposition rate 0.1 ~ 100
The sputtering is performed under a sputtering condition of 0 nm / min, preferably 0.5 to 100 nm / min. The amorphous phase, particle size, and atomic ratio of the electron supply layer and the insulator layer can be controlled by appropriately changing the target and sputtering conditions of the sputtering apparatus.

As a material of the electron supply layer 12, Si is particularly effective, but germanium (Ge), silicon carbide (Si)
C), gallium arsenide (GaAs), indium phosphide (InP), cadmium selenide (CdSe), etc., Group IV, III-V, II-V
Single semiconductors such as Group I and compound semiconductors can be used. Alternatively, metals such as Al, Au, Ag, and Cu are also effective as materials for the electron supply layer, but Sc, Ti, V, Cr, Mn, Fe, Co,
Ni, Zn, Ga, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Cd, L
n, Sn, Ta, W, Re, Os, Ir, Pt, Tl, Pb, La, Ce, Pr,
Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or C can also be used. The electron supply layer can be made transparent by appropriately setting the crystal state and film thickness of these materials.

The dielectric material of the insulator layer is silicon oxide S
iOx, (x represents an atomic ratio) is particularly effective,
iO_x, LiN_x, NaO_x, KO_x, RbO_x, SsO_x,
BeO_x, MgO_x, MgN_x, CaO_x, CaN_x, Sr
O_x, BaO_x, ScO_x, YO _x, YN_x, LaO_x, La
N_x, CeO_x, PrO_x, NdO_x, SmO_x, EuO_x,
GdO_x, TbO_x, DyO_x, HoO_x, ErO_x, Tm
O_x, YbO_x, LuO_x, TbO_x, DyO_x, HoO_x,
ErO_x, TmO_x, YbO_x, LuO_x, TiO_x, Ti
N_x, ZrO_x, ZrN_x, HfO_x, HfN_x, ThO_x,
VO_x, VN_x, NbO_x, NbN_x, TaO_x, TaN_x,
CrO_x, CrN_x, MoO_x, MoN_x, WO_x, WN_x,
MnO_x, ReO_x, FeO_x, FeN_x, RuO_x, Os
O_x, CoO _x, RhO_x, IrO_x, NiO_x, PdO_x,
PtO_x, CuO_x, CuN_x, AgO _x, AuO_x, Zn
O_x, CdO_x, HgO_x, BO_x, BN_x, AlO_x, Al
N_x, GaO_x, GaN_x, InO_x, TiO_x, TiN_x,
SiN_x, GeO_x, SnO_x, PbO_x, PO_x, PN_x,
AsO_x, SbO_x, SeO_x, TeO_xSuch as metal oxides
Alternatively, metal nitride may be used.

Further, LiAlO_Two, Li_TwoSiO_Three, Li_Two
TiO_Three, Na_TwoAl_{twenty two}O₃₄, NaFeO_Two, Na_FourSiO
_Four, K_TwoSiO_Three, K_TwoTiO_Three, K_TwoWO_Four, Rb_TwoCr
O_Four, CS_TwoCrO_Four, MgAl_TwoO_Four, MgFe_TwoO_Four, M
gTiO_Three, CaTiO_Three, CaWO_Four, CaZrO_Three, S
rFe₁₂O₁₉, SrTiO_Three, SrZrO_Three, BaA_l2O
_Four, BaFe₁₂O₁₉, BaTiO_Three, Y_ThreeAl_FiveO₁₂, Y_Three
Fe_FiveO₁₂, LaFeO_Three, La_ThreeFe_FiveO₁₂, La_TwoTi_Two
O₇, CeSnO_Four, CeTiO_Four, Sm_ThreeFe_FiveO₁₂, E
uFeO_Three, Eu_ThreeFe_FiveO₁₂, GdFeO_Three, Gd_ThreeFe_Five
O₁₂, DyFeO_Three, Dy_ThreeFe_FiveO₁₂, HoFeO_Three, H
o_ThreeFe_FiveO₁₂, ErFeO_Three, Er_ThreeFe_FiveO ₁₂, Tm_ThreeF
e_FiveO₁₂, LuFeO_Three, Lu_ThreeFe_FiveO₁₂, NiTi
O_Three, Al_TwoTiO_Three, FeTiO_Three, BaZrO_Three, Li
ZrO_Three, MgZrO_Three, HfTiO_Four, NH_FourVO_Three, A
gVO_Three, LiVO_Three, BaNb_TwoO₆, NaNbO_Three, S
rNb_TwoO₆, KTaO_Three, NaTaO_Three, SrTa_TwoO₆,
CuCr_TwoO_Four, Ag_TwoCrO_Four, BaCrO_Four, K_TwoMoO
_Four, Na_TwoMoO_Four, NiMoO_Four, BaWO_Four, Na_TwoWO
_Four, SrWO_Four, MnCr_TwoO_Four, MnFe_TwoO_Four, MnTi
O_Three, MnWO_Four, CoFe_TwoO_Four, NnFe_TwoO_Four, FeW
O_Four, CoMoO_Four, CoTiO_Three, CoWO_Four, NiFe
_TwoO_Four, NiWO_Four, CuFe_TwoO_Four, CuMoO_Four, CuT
iO_Three, CuWO_Four, Ag_TwoMoO_Four, Ag_TwoWO_Four, ZnA
l_TwoO_Four, ZnMoO_Four, ZnWO_Four, CdSnO_Three, Cd
TiO_Three, CdMoO_Four, CdWO_Four, NaAlO_Two, Mg
Al_TwoO_Four, SrAl_TwoO_Four, Gd_ThreeGa_FiveO₁₂, InFeO
_Three, MgIn_TwoO_Four, Al_TwoTiO_Five, FeTiO_Three, MgT
iO_Three, Na_TwoSiO_Three, CaSiO_Three, ZrSiO_Four, K_Two
GeO_Three, Li_TwoGeO_Three, Na_TwoGeO_Three, Bi_TwoSn
_ThreeO₉, MgSnO_Three, SrSnO_Three, PbSiO_Three, Pb
MoO_Four, PbTiO_Three, SnO_Two-Sb_TwoO_Three, CuSe
O_Four, Na_TwoSeO_Three, ZnSeO_Three, K_TwoTeO_Three, K_TwoT
eO_Four, Na_TwoTeO_Three, Na_TwoTeO_FourMetal complex acids such as
Compound, FeS, Al_TwoS_ThreeOf sulfur, MgS, ZnS, etc.
Material, LiF, MgF_Two, SmF_ThreeSuch as fluoride, HgC
1, FeCl_Two, CrCl_ThreeChloride, such as AgBr, C
uBr, MnBr_TwoSuch as bromide, Pbl_Two, CuI, F
eI_TwoSuch as iodide or metal such as SiAlON
Even oxynitride is effective as a dielectric material for the insulator layer.
You.

Further, carbon such as diamond, fullerene (C _2n ), or Al as a dielectric material of the insulator layer.
_{4 C 3, B 4 C,} CaC 2, Cr 3 C 2, Mo 2 C, MoC, NbC, SiC, TaC, T
Metal carbides such as iC, VC, W ₂ C, WC, and ZrC are also effective.
Incidentally, Fullerene (C _2n) are include C ₃₂ -C ₉₆₀ spherical cage molecules represented by C ₆₀ consisting solely of carbon atoms, In the above formula, O _x, x of N _x the atomic ratio Represent. same as below.

The material of the metal thin film electrode on the electron emission side is P
Metals such as t, Au, W, Ru, Ir are effective, but Al, Sc,
Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Y, Zr, Nb,
Mo, Tc, Rh, Pd, Ag, Cd, Ln, Sn, Ta, Re, Os, Tl, Pb,
La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, T
m, Yb, Lu can also be used. The material of the element substrate 10 may be ceramics such as Al ₂ O ₃ , Si ₃ N ₄ , quartz in addition to glass. (Example) Specifically, an electron-emitting device was manufactured and its characteristics were examined.

[0018] The ITO ohmic electrode on the electrode surface of the glass substrate to a thickness of 300nm by sputtering, a few each film thickness by sputtering electron supply layer and the SiO _x insulation layer of a silicon (Si) nm~10
It was formed in order of 0 nm and several nm to 500 nm. Many such Si substrates were prepared. Finally, a 10 nm-thick Pt thin film electrode was sputter-deposited on the surface of the amorphous SiO _x layer of each substrate to form a number of element substrates.

On the other hand, when an ITO collector electrode is formed on the inner surface of a transparent glass substrate, or on each collector electrode,
A transparent substrate was prepared in which phosphor layers composed of phosphors corresponding to R, G, and B were formed by a conventional method. The device substrate and the transparent substrate are held in parallel by a spacer at a distance of 10 mm so that the thin film electrode and the collector electrode face each other, and a gap is formed at a vacuum of 10 ⁻⁷ Torr or 10 ⁻⁵ Pa. Produced.

Thereafter, for each of the obtained devices,
The diode current Id and emission current Ie corresponding to the thickness of the iO _x layer were measured. 3 and 4 show the relationship between the emission current Ie and the electron emission efficiency (Ie / Id) at each film thickness with respect to the SiO _x layer film thickness when Vd is applied to the manufactured electron-emitting device at 0 to 200 V. Is shown. As is clear from FIGS. 3 and 4, a sufficient emission current and electron emission efficiency were obtained even at a film thickness of 50 nm, and
A maximum emission current of 1 × 10 ⁻³ A / cm ² and a maximum electron emission efficiency of about ¹ × 10 ⁻¹ were obtained with the device of 00 nm.

From these results, it is found that by applying an electric field of 200 V or less, the emission current of 1 × 10 ⁻⁶ A / cm ² or more,
It has been found that an electron emission efficiency of 10 ⁻³ or more can be obtained from a device having a SiO _x dielectric layer having a thickness of 50 nm or more, preferably 100 to 400 nm. Further, in the state of applying the accelerating voltage of approximately 4kV between the collector electrode and the thin film electrode coated with phosphor, uniform fluorescent pattern corresponding to the shape of the thin-film electrode by SiO _x layer thickness 50nm or more elements are observed Was. This indicates that the electron emission from the amorphous SiO _x layer is uniform and highly linear, and can operate as a light emitting diode or a laser diode that emits infrared or visible light or ultraviolet electromagnetic waves as an electron emitting diode. It indicates that there is.

When the surface of the insulator layer formed by sputtering was observed by SEM, it was found that the insulator layer was characterized by being composed of agglomerates of about 20 nm. It is considered that a peculiar phenomenon that a tunnel current flows while having a film thickness of 50 nm or more is caused by this feature. That is, as shown in FIG. 6, SiO ₂ is originally an insulator, but a large number of low-potential bands appear due to crystal defects or impurities which are likely to be generated in or near the agglomerates. It is presumed that electrons tunnel one after another through the band with a low potential, and as a result, tunnel even a film thickness of 50 nm or more.

FIG. 5 shows an electron emission display device according to the embodiment.
The embodiment comprises a pair of a transparent substrate 1 and an element substrate 10, and the substrates face each other with a vacuum space 4 interposed therebetween. In the illustrated electron-emitting display device, for example, indium tin oxide (so-called IT) is provided on the transparent front plate 1, which is the display surface, that is, on the inner surface of the transparent substrate (the surface facing the back plate 10).
O), a plurality of transparent collector electrodes 2 made of tin oxide (SnO), zinc oxide (ZnO) or the like are formed in parallel with each other. Further, collector electrode 2 may be formed integrally. The group of transparent collector electrodes for capturing emitted electrons is a set of three in accordance with red, green, and blue R, G, and B color signals in order to form a color display panel, and a voltage is applied to each of them. . Therefore, on the three collector electrodes 2, the phosphor layers 3 R, 3 G, 3 B made of the phosphors corresponding to R, G, B face the vacuum space 4.
Each is formed.

On the other hand, an insulator layer 18 is provided on the back plate 10 made of glass or the like facing the front plate with the vacuum space 4 interposed therebetween, that is, on the inner surface of the element substrate (the surface facing the front plate 1).
A plurality of ohmic electrodes 11 extending in parallel with each other are formed. This insulator layer 18
The substrate 1 is made of an insulator such as SiO ₂ , SiN _x , Al ₂ O ₃ , and AlN.
It functions to prevent adverse effects on the device from 0 (elution of impurities such as alkali components and unevenness of the substrate surface). A plurality of electron-emitting devices S are formed on the ohmic electrode, electrically connect adjacent metal thin-film electrodes, and extend on a part thereof so as to extend perpendicularly to the ohmic electrode and extend in parallel with each other. Bus electrode 16 is provided. The electron-emitting device S includes an electron supply layer 12, an insulator layer 13, and a metal thin-film electrode 15 formed in this order on an ohmic electrode. The metal thin film electrode 15 faces the vacuum space 4. In order to divide the surface of the metal thin film electrode 15 into a plurality of electron emission regions, an insulating protective layer 17 having an opening is formed. The insulating protective layer 17 covers the bus electrode 16 to prevent unnecessary short circuit.

The material of the ohmic electrode 11 is A
Materials such as u, Pt, Al, and W, which are generally used for wiring of ICs, have a uniform thickness to supply substantially the same current to each element. The material of the electron supply layer 12 is, for example, silicon (Si). However, the electron supply layer of the present invention is not limited to silicon, but may be other semiconductors or metals, such as amorphous,
Either polycrystal or single crystal may be used.

The material of the thin film electrode 15 is a material having a small work function φ from the principle of electron emission. In order to increase the electron emission efficiency, the material of the thin film electrode 15 is preferably a metal of Group I or Group II of the periodic table, for example, Mg, Ba, Ca,
Cs, Rb, Li, Sr and the like are effective, and further, alloys thereof may be used. The material of the thin-film electrode 15 is preferably a metal having high conductivity and being chemically stable in terms of ultra-thinness. For example, a simple substance of Au, Pt, Lu, Ag, Cu, or an alloy thereof is desirable. It is also effective to coat or dope these metals with a metal having a low work function.

The material of the bus electrode 16 is Au, P
What is generally used for IC wiring, such as t and Al, may be used.
An appropriate thickness is 0.1 to 50 μm, which is sufficient to supply substantially the same potential to each element. Further, as a driving method of the display device, a simple matrix method or an active matrix method can be applied.

In the above embodiment, Si and S
Although iO _x is dispersed in the insulator layer, the insulator layer may be composed of a multilayer in which Si layers and SiO _x layers are alternately stacked.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an electron-emitting device according to the present invention.

FIG. 2 is a schematic sectional view of an electron-emitting device according to the present invention.

FIG. 3 is a graph showing the dependence of the electron emission current on the thickness of the insulator layer in the electron emission display device according to the present invention.

FIG. 4 is a graph showing the dependence of electron emission efficiency on the thickness of an insulator layer in an electron emission display device according to the present invention.

FIG. 5 is a schematic perspective view showing an electron emission display device according to an embodiment of the present invention.

FIG. 6 is an operation explanatory diagram illustrating the operation of the electron-emitting device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Collector electrode 3R, 3G, 3B phosphor layer 4 Vacuum space 10 Element substrate 11 Ohmic electrode 12 Electron supply layer 13 Insulator layer 15 Metal thin film electrode 16 Bus electrode 17 Insulation protection layer 18 Insulator layer

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shingo Iwasaki 6-1-1, Fujimi, Tsurugashima-shi, Saitama Pioneer Research Institute (72) Inventor Kiyohide Ogasawara 6-1-1, Fujimi, Tsurugashima-shi, Saitama Inside Pioneer Research Institute (72) Inventor Hiroshi Ito 6-1-1 Fujimi, Tsurugashima-shi, Saitama Prefecture Pioneer Research Institute

Claims (3)

[Claims] 1. An electron supply layer comprising a metal or a semiconductor, an insulator layer formed on the electron supply layer, and a metal thin film electrode formed on the insulator layer and facing a vacuum space,
An electron-emitting device that applies an electric field between the electron supply layer and the metal thin-film electrode to emit electrons, wherein the insulator layer has a thickness of 50 nm or more, and the electron supply layer is transparent. Characteristic electron-emitting device. A pair of first and second substrates opposed to each other across a vacuum space, a plurality of electron-emitting devices provided on an inner surface of the first substrate, and a collector electrode provided on an inner surface of the second substrate. And a phosphor layer formed on the collector electrode, wherein each of the electron-emitting devices is an electron supply layer made of metal or semiconductor formed on the first substrate side, An insulator layer formed on the electron supply layer and a metal thin film electrode formed on the insulator layer and facing the vacuum space, wherein the insulator layer has a thickness of 50 nm or more and is transparent. An electron emission display device, characterized in that: 3. The first substrate is transparent and the first substrate is transparent.
3. The electron emission display according to claim 2, further comprising a transparent electrode formed between the substrate and the electron supply layer.