JP3119513B2 - Avalanche light emitting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a short wavelength light emitting device.

[0002]

2. Description of the Related Art A light emitting device currently used is a material that directly emits light (e.g., mainly GaAs, Al, etc.) that easily emits light when electrons in a conduction band and holes in a valence band recombine. , In, P, Sb, etc.).

FIG. 7 shows the structure (a) and operation principle (b) of a light emitting diode having a double hetero structure.

[0004] FIG. 7 (a), sandwiched in GaAs layer 602 of p-type, double P-type Ga _{1 over} x Al _x As layer 601 and the n-type Ga _{1 over} y Al _y As layer 603 It has a hetero structure.

[0005] Metal electrodes 604 serving as the ohmic contact is used as the electrode of a P-type Ga _{1 over} x Al _x As layer 601, an ohmic contact is an electrode of the n-type Ga _{1 over} y Al _y As layer 603 A metal electrode 605 is used.

The operation of this light emitting diode is shown in FIG.
As shown in FIG. 5, electrons injected from the n-type Ga _1-y Al _y As layer 603 through a forward-biased pn junction are p-type Ga
The holes recombine with holes in the As layer 602 and emit light at a wavelength (0.89 μm) corresponding to the energy difference between the bands of GaAs.

On the other hand, the injected electrons cannot diffuse into the p-type Ga _1-x Al _x As layer 601 due to the barrier of the hetero junction, and emit light only in the p-type GaAs layer 602. Will be.

The emitted light is extracted outside without being absorbed because the energy difference between the bands of the GaAlAs layer is large.

FIG. 8 shows the structure (a) and the operating principle (b) of a semiconductor laser having a double hetero structure.

FIG. 8A shows an n-type Ga _{1 -x} Al _x As layer 7.
01, p-type (or n-type) GaAs layer 702, p-type G
a _{1 over} x Al _x Ga _{1 over} grown three layers of As layer 703 x A
A parallel reflecting mirror surface is formed at a portion 706 by cleaving both ends of a cut piece from the l _x As wafer. G
an aAs layer 702 is an active layer that causes laser oscillation;
A hetero pn junction is formed between the p-type Ga _1-x Al _x As layer 701 and the p-type GaAs layer, and a hetero-isolation is formed between the p-type GaAs layer 702 and the p-type Ga _1-x Al _x As layer 703. Joining. The metal electrodes 704 and 705 are n-type G
a _{1 -x} Al _x As layer 701 and p-type Ga _{1 -x} Al _x As
Ohmic contact with layer 703.

The operation of this semiconductor laser is shown in FIG.
As shown in FIG. 2, electrons injected from the n-type Ga _1-x Al _x As layer 701 through the forward-biased pn junction are p-type Ga _-x Al _x As layers.
As layer 702 produces a laser oscillation while recombine with holes injected from the p-type Ga _{1 over} x Al _x As layer 703.
(Literature: Ai Hayashi, M. Hazanis, F. K. Reinhardt, "GaAs-Al _x Ga
_1-x As double hetero-injection laser "(I. Hayashi, MBPanish,
and FKReinhart, "GaAs-Al _x Ga _1-x As double heterost
ructure injection lazers "), J. Appl. Phys., vol. 42, n
o.4, p.1929, see Apr. 1971)

[0012]

However, with the above-described structure, light having a practical luminance level has been successfully achieved up to a part of the wavelength range of infrared light to visible light (red and green) and commercialized. However, as for light emission in the wavelength region of visible light from blue to ultraviolet light, there is only a research report on light emission at an experimental level, and light emission at a practical luminance level is extremely difficult.

In order to emit light of a practical luminance level in the wavelength range of visible light from blue to ultraviolet light, it is necessary to satisfy the following four conditions.

(1) A material having a band gap of 2.6 eV or more is required.

(2) Use a direct transition material in which the injected carriers are efficiently converted into light.

(3) Carriers (electrons,
A pn junction capable of injecting holes efficiently is required.

(4) Ohmic contact metal electrodes are required as terminal electrodes of the pn junction element.

In the wavelength region of visible light from blue to ultraviolet light, zinc sulfide ZnS (3.7 eV), zinc selenide Zn
Se (2.7 eV) or the like satisfies the conditions (1) and (2) and is promising as a material for a light emitting element. However, since the material used for such blue light emission is an ionic crystal, it is difficult to produce a high-concentration p-type crystal.
As a result, an ohmic contact metal electrode cannot be formed on the semiconductor layer of the mold, and the conditions (3) and (4) are not satisfied.

The present invention pays attention to such a problem of the conventional light emitting device, and a sufficient light emission luminance can be obtained by a pn junction using a low-concentration p-type material, and an ohmic contact metal electrode is used as a terminal electrode of the element. It is an object of the present invention to provide a light emitting device that does not require a light emitting device.

[0020]

According to the present invention, there is provided a first semiconductor region having an electron conduction (N) type and a low impurity concentration, a second semiconductor region having a hole conduction (P) type and a low impurity concentration, and a first semiconductor region having a low impurity concentration. And a third semiconductor region of intrinsic conduction (i) type having a smaller band gap energy Eg3 than the second semiconductor region to form a PiN junction, and the first semiconductor region and the first metal form a PiN junction. 1 rectifying contact (a metal semiconductor contact where φM1> χ1 is established between the electron affinity 電子 1 of the first semiconductor and the work function φM1 of the first metal) is formed, and the second semiconductor region and the second metal And the second rectifying contact (electron affinity χ2 and band gap energy Eg of the second semiconductor)
Between the work function φM2 of the second metal and φM2 <｛χ2 +
This is an avalanche light-emitting device in which (Eg / q) 金属 is formed and avalanche-carrier multiplication caused by a reverse bias voltage applied to the PiN junction determines luminous efficiency.

[0021]

According to the present invention, an avalanche carrier enhancement caused by a high reverse bias voltage applied to a pn junction is realized in order to realize equivalently sufficient carrier injection conditions even with a pn junction manufactured using a low-concentration p-type material. The present invention provides a light emitting device that uses a rectifying contact-type metal electrode that generates a sufficient number of carriers and that forms a Schottky barrier for a majority carrier of a semiconductor as a terminal electrode of an element. Therefore, high-concentration p-type material is not required, and luminous efficiency is improved by using a crystal with few impurities as a luminescent material. Ohmic contact, which is difficult to realize, is not required. Also in the region, a light-emitting element that is easy to manufacture and has high efficiency can be realized.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1A, 1B and 1C show a first embodiment of the present invention.

As shown in FIGS. 1A and 1B, the device structure of this embodiment has an intrinsic conduction (i) type ZnSe layer 101 with a band gap energy Egi of 2.7 eV. , Pg type Zn with EgP and EgN of 3.8 eV
_{This is a} double hetero structure PiN junction composed of a _1-x Cd _x S layer 103 and an N-type Zn _1-x Cd _x S layer 102.

As a terminal electrode of the N-type Zn _{1 -x} Cd _x S layer 102, a metal electrode 1 forming a Schottky barrier is used.
The use of 04 forms a barrier to electrons. At this time, the electron affinity of the Zn _{1 -x} Cd _x S layer 102 is reduced by χ.
If the work function of the metal electrode 104 is φM1, then φM1
> Χ1 holds.

As a terminal electrode of the P-type Zn _{1 -x} Cd _x S layer 103, a metal electrode 1 forming a Schottky barrier is used.
By using 05, a barrier to holes is formed. At this time, if the electron affinity and band gap energy of the Zn _{1 -x} Cd _x S layer 103 are χ2 and EgP, respectively, and the work function of the metal electrode 105 is MM2,
φM2 <{2+ (EgP / q)} holds.

The operation of the light emitting device will be described below.

When a reverse bias is applied to the PiN junction as shown in FIG. 1 (c), for example, electrons are accelerated by the electric field as shown by reference numeral 110, and the electrons are accelerated as shown by reference numeral 110 or more. When the kinetic energy is obtained, a part of the energy is given to electrons in the valence band,
As indicated by reference numeral 112, ionization is performed. As a result, an electron-hole pair is generated, and at the same time, the first electron tries to reach thermal equilibrium and reaches the bottom of the conduction band as indicated by reference numeral 111. There will be two electrons and one hole that can be heated by the electric field. These are again about 1.5 x Eg
When they get a kinetic energy of P (or about 1.5 x EgN), each creates more electron-hole pairs, and this process is repeated many times like an avalanche.

Many electrons and holes thus generated are confined in the ZnSe layer 101 having a small band gap energy, and the wavelength (0.46 μm) of blue light corresponding to the energy difference between the bands of ZnSe upon recombination. Emits light.

FIG. 1A shows a case where laser oscillation is performed.
It can be realized by forming the part 106 to be a reflecting mirror by cleavage or the like.

As described above, according to the present embodiment, even if only a low-concentration p-type semiconductor can be manufactured, and even if a terminal electrode of ohmic contact cannot be formed, avalanche multiplication under reverse bias is used. Sufficient carriers can be generated in the light emitting region, and short wavelength light emitting diodes and lasers
A diode can be realized.

The avalanche light emitting device 150 is shown in FIG.
It is also possible to form an avalanche light emitting device for an area using the multiplexers 160 and 170 for selecting horizontal and vertical, the selecting switches 161 and 171 for horizontal and vertical, and the power supply P as shown in FIG.

FIGS. 3A, 3B and 3C show a second embodiment of the present invention.

As shown in FIGS. 3A and 3B, the device structure has an electron conduction (n) type ZnSe layer 201 with a band gap energy Egi of 2.7 eV and
EgP and EgN are PnN junction of a double heterostructure consisting of Zn _{1 over} x Cd _x S layer 203 and the N-type Zn _{1 over} x Cd _x S layer 202 of P-type at 3.8 eV.

As a terminal electrode of the N-type Zn _{1 -x} Cd _x S layer 202, a metal electrode 2 forming a Schottky barrier is used.
The use of 04 forms a barrier to electrons. At this time, the electron affinity of the Zn _1-x Cd _x S layer 202 is reduced by χ.
If the work function of the metal electrode 204 is φM1, then φM1
> Χ1 holds.

As the terminal electrode of the P-type Zn _{1 -x} Cd _x S layer 203, a metal electrode 2 forming a Schottky barrier is used.
By using 05, a barrier to holes is formed. At this time, if the electron affinity and band gap energy of the Zn _{1 -x} Cd _x S layer 203 are χ2 and EgP, respectively, and the work function of the metal electrode 205 is MM2,
M2 <{2+ (EgP / q)} holds.

The operation of the light emitting device is as follows.

When a reverse bias is applied to the PnN junction as shown in FIG. 3C, for example, when electrons are accelerated by an electric field and a kinetic energy equal to or more than 1.5 × EgP is obtained, the kinetic energy is increased. Some of the energy is given to electrons in the valence band, causing ionization into the conduction band. As a result, electron-hole pairs are generated, and at the same time, the first electron tries to reach thermal equilibrium and reaches the bottom of the conduction band. There will be two electrons and one hole that can be heated by the electric field.
These are again about 1.5 x EgP (or about 1.5 x EgN)
When each kinetic energy is obtained, each further creates an electron-hole pair, and this process is repeated many times like an avalanche.

Many electrons and holes thus generated are confined in the ZnSe layer 201 having a small band gap energy, and the wavelength (0.46 μm) of blue light corresponding to the energy difference between the bands of ZnSe upon recombination. Emits light.

FIG. 3A shows a case where laser oscillation is performed.
It can be realized by forming the portion 206 to be a reflecting mirror by cleavage or the like.

As described above, according to this embodiment, even if only a low-concentration p-type semiconductor can be manufactured, or if an intrinsically conductive semiconductor cannot be manufactured, a terminal electrode for ohmic contact cannot be formed. Also, if avalanche multiplication under reverse bias is used, sufficient carriers can be generated in the light emitting region, and a short wavelength light emitting diode or laser diode can be realized.

FIGS. 4A, 4B and 4C show a third embodiment of the present invention.

As shown in FIGS. 4A and 4B, the device structure has a band gap energy Egi of 2.7 eV.
With the intrinsic conduction (i) type ZnSe layer 301 interposed therebetween, EgP and EgN are 3.8 eV and P type Zn _1−x Cd _x
A PiN junction of a double heterostructure consisting of S layer 303 and the N-type Zn _{1 over} x Cd _x S layer 302.

As a terminal electrode on the side of the N-type Zn _{1 -x} Cd _x S layer 302, a metal electrode 3 with an insulator layer 307 interposed therebetween
04 is formed.

As a terminal electrode on the side of the P-type Zn _{1 -x} Cd _x S layer 303, a metal electrode 3 with an insulator layer 308 interposed therebetween is used.
05 is formed.

The operation of the light emitting device is as follows.

When a reverse bias is applied to the PiN junction as shown in FIG. 4 (c), for example, when electrons are accelerated by an electric field and a kinetic energy equal to or more than 1.5 × EgP is obtained, Some of the energy is given to electrons in the valence band, causing ionization into the conduction band. As a result, electron-hole pairs are generated, and at the same time, the first electron tries to reach thermal equilibrium and reaches the bottom of the conduction band. There will be two electrons and one hole that can be heated by the electric field.
These are again about 1.5 x EgP (or about 1.5 x EgN)
When each kinetic energy is obtained, each further creates an electron-hole pair, and this process is repeated many times like an avalanche.

Many electrons and holes thus generated are confined in the ZnSe layer 301 having a small band gap energy, and the wavelength (0.46 μm) of blue light corresponding to the energy difference between the bands of ZnSe upon recombination. Emits light.

When laser oscillation is performed, FIG.
It can be realized by forming the portion 306 to be a reflecting mirror by cleavage as shown in FIG.

As described above, according to this embodiment, even if only a low-concentration p-type semiconductor can be manufactured, the avalanche multiplication under the reverse bias can be used without concern for the contact state between the terminal electrode and the semiconductor. If sufficient carriers can be generated in the light emitting region, a short wavelength light emitting diode or laser diode can be realized.

FIGS. 5A, 5B and 5C show a fourth embodiment of the present invention.

As shown in FIGS. 5A and 5B, the device structure has a band gap energy Egi of 3.8 eV and an intrinsic conduction (i) type ZnS layer 401 sandwiched therebetween.
gP and EgN of 2.7 eV and a double heterostructure pI composed of a p-type ZnSe layer 403 and an n-type ZnSe layer 402
It is an n-junction.

As a terminal electrode of the n-type ZnSe layer 402, an electron barrier is formed by using a metal electrode 404 forming a Schottky barrier. At this time, if the electron affinity of the ZnSe layer 402 is χ1 and the work function of the metal electrode 404 is MM1, then MM1> χ1 holds.

As a terminal electrode of the p-type ZnSe layer 403, a barrier against holes is formed by using a metal electrode 405 forming a Schottky barrier. At this time, if the electron affinity and band gap energy of the ZnSe layer 403 are χ2 and EgP, respectively, and the work function of the metal electrode 405 is MM2, then MM2 <｛χ2 +
(EgP / q)｝ holds.

The operation of the light emitting device is as follows.

When a reverse bias is applied to the pIn junction as shown in FIG. 5 (c), for example, electrons are accelerated by an electric field as shown by reference numeral 410, and are equal to or more than 1.5 × EgP. When the kinetic energy is obtained, a part of the energy is given to electrons in the valence band, and ionized as shown by reference numeral 412 in the conduction band. As a result, an electron-hole pair is generated, and at the same time, the first electron tries to reach thermal equilibrium and reaches the bottom of the conduction band as indicated by reference numeral 411.
There will be two electrons and one hole that can be heated by the electric field. These are again about 1.5 x EgP
(Or about 1.5 x EgN), each creates more electron-hole pairs, and this process is repeated many times, like an avalanche.

Out of the large number of electrons and holes thus generated, the electrons are Zn having a large band gap energy.
Holes gather near the boundary between the S layer 401 and the p-type ZnSe layer 403, and holes are formed in Zn having a large band gap energy.
It gathers near the boundary between the S layer 401 and the n-type ZnSe layer 402.

At this time, if the thickness of the ZnS layer 401 is slightly less than twice the thickness required for the tunnel effect, 4 in FIG.
The wavelength of blue light (0.46 μm) corresponding to the energy difference between the bands of ZnSe when electrons and holes tunnel and recombine in the ZnS layer 401 as in 20 and 430.
Emits light.

When laser oscillation is performed, FIG.
It can be realized by forming a portion 406 to be a reflecting mirror by cleavage or the like.

As described above, according to this embodiment, even if only a low-concentration p-type semiconductor can be manufactured, or if a terminal electrode for ohmic contact cannot be formed, avalanche carrier multiplication under reverse bias is used. In addition, even if the band gap energy of the semiconductor layer that emits light is larger than a desired value, sufficient carriers can be generated in the light emitting region by using the tunnel effect, so that a short wavelength light emitting diode or laser diode can be used. realizable.

FIGS. 6A, 6B and 6C show a fifth embodiment of the present invention.

As shown in FIGS. 6 (a) and 6 (b), the element structure has an insulator layer 501 (indicated by Ψ) sandwiched between E layers.
pΨ of a double hetero structure composed of a p-type ZnSe layer 503 and an n-type ZnSe layer 502 with gP and EgN of 2.7 eV.
It is an n-junction.

As a terminal electrode of the n-type ZnSe layer 502, a barrier against electrons is formed by using a metal electrode 504 forming a Schottky barrier. At this time, if the electron affinity of the ZnSe layer 502 is χ1 and the work function of the metal electrode 504 is MM1, then MM1> χ1 holds.

As a terminal electrode of the p-type ZnSe layer 503, a barrier against holes is formed by using a metal electrode 505 forming a Schottky barrier. At this time, if the electron affinity and band gap energy of the ZnSe layer 503 are χ2 and EgP, respectively, and the work function of the metal electrode 505 is MM2, then φM2 <｛χ2 +
(EgP / q)｝ holds.

The operation of the light emitting device is as follows.

When a reverse bias is applied to the pΨn junction as shown in FIG. 6C, for example, when electrons are accelerated by an electric field to obtain a kinetic energy equal to or more than 1.5 × EgP, Some of the energy is given to electrons in the valence band, causing ionization into the conduction band. As a result, electron-hole pairs are generated, and at the same time, the first electron tries to reach thermal equilibrium and reaches the bottom of the conduction band. There will be two electrons and one hole that can be heated by the electric field.
These are again about 1.5 x EgP (or about 1.5 x EgN)
When each kinetic energy is obtained, each creates an additional electron-hole pair, and this process is repeated many times like an avalanche.

Out of the large number of electrons and holes thus generated, the electrons are the insulator layer 501 and the p-type ZnSe layer 50.
3 and the holes are formed between the insulator layers 501 and n.
Gather near the boundary of the ZnSe layer 502.

At this time, if the thickness of the insulator layer 501 is slightly less than twice the thickness required for the tunnel effect, 5 in FIG.
The wavelength of blue light (0.46 μm) corresponding to the energy difference between the bands of ZnSe when electrons and holes tunnel and recombine in the insulator layer 501 as in 20 and 530.
Emits light.

FIG. 6A shows a case where laser oscillation is performed.
As described above, this can be realized by forming the portion 506 to be a reflecting mirror by cleavage or the like.

As described above, according to this embodiment, even if only a low-concentration p-type semiconductor can be manufactured, and if a terminal electrode for ohmic contact cannot be formed, avalanche carrier multiplication under reverse bias is used. Further, even if an insulator layer is used in the light emitting portion, a sufficient carrier can be generated in the light emitting region by using the tunnel effect, so that a short wavelength light emitting diode or laser diode can be realized.

[0071]

As described above, according to the present invention, even when light emission of a practical luminance level is realized in the wavelength range of visible light from blue to ultraviolet light, a forward bias is applied to the pn junction to inject carriers. It does not require high-concentration p-type semiconductors or ohmic contact terminal electrode metals that are difficult to manufacture like conventional light emitting diodes and laser diodes that emit light in a state, and uses avalanche carrier multiplication under reverse bias to provide sufficient carriers Can be generated in the light emitting region, so that it is easy to realize in terms of manufacturing, and the practical effect brought about by the present invention is extremely large.

[Brief description of the drawings]

FIG. 1 is a structure and energy band diagram of a first embodiment of the present invention.

FIG. 2 is an energy band diagram of the first embodiment of the present invention.

FIG. 3 is a structure and energy band diagram of a second embodiment of the present invention.

FIG. 4 is a structure and energy band diagram of a third embodiment of the present invention.

FIG. 5 is a structure and energy band diagram of a fourth embodiment of the present invention.

FIG. 6 is a structure and energy band diagram of a fifth embodiment of the present invention.

FIG. 7 is a structure and energy band diagram of a conventional light emitting diode.

FIG. 8 is a structure and energy band diagram of a conventional laser diode.

[Explanation of symbols]

101, 201, 301, 401 Third semiconductor region (light-emitting region) 501 Insulator region (light-emitting region) 102, 202, 302, 402, 502 First semiconductor region 103, 203, 303, 403, 503 Second Semiconductor region 307, 308 Insulator region 104, 204, 304, 404, 504 First metal electrode 105, 205, 305, 405, 505 Second metal electrode 106, 206, 306, 406, 506 Reflecting mirror surface (laser oscillation 420, 430, 520, 530 Carrier tunnel penetration

Claims (6)

(57) [Claims] 1. An electron conductive (N) type low impurity concentration first
Semiconductor region and hole-conducting (P) type low impurity concentration second
And a third semiconductor region of intrinsic conduction (i) type having a smaller band gap energy Eg3 than the first and second semiconductor regions, forming a PiN junction, and forming the first semiconductor region. The first in the region and the first metal
(A metal-semiconductor contact where φM1> χ1 is satisfied between the electron affinity χ1 of the first semiconductor and the work function φM1 of the first metal) is formed, and the second semiconductor region and the second metal And the second rectifying contact (electron affinity of the second semiconductor χ
2 and a band gap energy Eg and a metal semiconductor contact satisfying φM2 <{2+ (Eg / q)} are formed between the work function φM2 of the second metal and the reverse voltage applied to the PiN junction. An avalanche light emitting device characterized in that avalanche carrier multiplication caused by a bias voltage determines light emission efficiency. 2. An electron-conducting (N) type first impurity having a low impurity concentration.
Semiconductor region and hole-conducting (P) type low impurity concentration second
A PnN junction is formed by the semiconductor region of (a) and a third semiconductor region having a hole conduction (n) type and a low impurity concentration having a band gap energy Eg3 smaller than that of the first and second semiconductor regions; The first semiconductor region and the first semiconductor region;
A first rectifying contact (a metal-semiconductor contact in which φM1> χ1 is established between the electron affinity χ1 of the first semiconductor and the work function φM1 of the first metal) with the second semiconductor; A second rectifying contact between the region and the second metal (φM2 <φ2 between the electron affinity ギ ャ ッ プ 2 and band gap energy Eg2 of the second semiconductor and the work function φM2 of the second metal).
+ (Eg2 / q)｝ is formed, and avalanche carrier multiplication caused by a reverse bias voltage applied to the PnN junction determines light emission efficiency. 3. An electron conductive (n) first impurity having a low impurity concentration.
Semiconductor region with a hole-conducting (p) type and low impurity concentration second
A pn junction is formed with the first semiconductor region, a first insulator layer (Ψ1) is formed between the first semiconductor region and the first metal, and the second semiconductor region and the second metal are formed. And a second insulator layer (Ψ2) is formed between the avalanche and the avalanche voltage generated by the reverse bias voltage applied to the {2pn} 1 junction.
An avalanche light-emitting device characterized in that carrier multiplication determines luminous efficiency. 4. An electron-conducting (n) type first impurity having a low impurity concentration.
Semiconductor region with a hole-conducting (p) type and low impurity concentration second
And a third semiconductor region of intrinsic conduction (I) type having a larger band gap energy Eg3 than those of the first and second semiconductor regions, thereby forming a pIn junction, and forming the third semiconductor region. The thickness of the region is thinner than twice the thickness at which the tunnel injection of carriers is established, and the first semiconductor region and the first metal make a first rectifying contact (electron affinity of the first semiconductor). A metal semiconductor contact that satisfies φM1> 成立 1 is formed between χ1 and the work function φM1 of the first metal, and a second rectifying contact (second rectification contact) between the second semiconductor region and the second metal is formed. A metal-semiconductor contact where φM2 <{2+ (Eg / q)} is formed between the electron affinity {2 and band gap energy Eg of the semiconductor and the work function φM2 of the second metal, and the pIn junction is formed. The arc generated by the applied reverse bias voltage Avalanche light-emitting device increase tranches carrier times is characterized by determining the emission efficiency. 5. An electron conductive (n) type first impurity having a low impurity concentration.
Semiconductor region with a hole-conducting (p) type and low impurity concentration second
And an insulator region (represented by Ψ) having a larger band gap energy Eg3 than the first and second semiconductor regions, and a pΨn junction is formed. And a first rectifying contact between the first semiconductor region and the first metal (the electron affinity χ1 of the first semiconductor and the first metal). Between the work function φM1
1> χ1 is formed, and a second rectifying contact (second contact) between the second semiconductor region and the second metal is formed.
Between the electron affinity χ2 and the band gap energy Eg of the semiconductor and the work function φM2 of the second metal.
An avalanche light-emitting device characterized in that an avalanche-carrier multiplication caused by a reverse bias voltage applied to the pΨn junction determines luminous efficiency. . 6. An electron-conducting (N) type first impurity having a low impurity concentration.
Semiconductor region and hole-conducting (P) type low impurity concentration second
And a third intrinsic semiconductor region of intrinsic conductivity (i) having a band gap energy Eg3 smaller than that of the first and second semiconductor regions.
An iN junction light-emitting pixel portion is two-dimensionally arranged, and a first rectifying contact with the first semiconductor region (φM1> χ1 between the electron affinity χ1 of the first semiconductor and the work function φM1 of the first metal). The first metal forming the metal-semiconductor contact that satisfies the following conditions is used as a row selection line of the light-emitting pixel portion, and a second rectifying contact (electron affinity of the second semiconductor χ2 and band The second metal forming a metal semiconductor contact that satisfies φM2 <{2+ (Eg / q)} between the gap energy Eg and the work function φM2 of the second metal is selected as a column of the light emitting pixel unit. A two-dimensional avalanche light emitting device, comprising: a line and a row and column multiplexer for selecting the row and column selection line.