JPH10270799A - Light emitting element - Google Patents

Abstract

(57) [Problem] To provide a light emitting element capable of changing an emission wavelength with a sufficient width without changing element characteristics other than the emission wavelength. SOLUTION: The light emitting element has an n-type clad layer 6, a light emitting layer 7
And a light emitting portion composed of a p-type cladding layer 8 and a light excitation n
And a wavelength conversion unit including the i-p-i laminated light emitting layer 4. The light-excited nip-i-p laminated light emitting layer 4 is formed by alternately laminating p-type GaN layers and n-type GaN layers in a plurality of periods. When a voltage is applied between the light emitting unit driving electrode 9 and the common electrode 10, the light emitting layer 7 emits light. Light emitted from the light-emitting layer 7 is absorbed by the photo-excited nip-pi laminated light-emitting layer 4, and light-emitting recombination is performed. When a voltage is applied between the common electrode 10 and the wavelength variable electrode 11, an external electric field is applied to the photoexcited nipi laminated light emitting layer 4. The energy of light generated by radiative recombination changes depending on the magnitude or presence or absence of an external electric field.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In a light emitting device such as a semiconductor laser device or a light emitting diode, the emission wavelength is basically unique to the device, and the wavelength varies with a change in temperature. As a method of intentionally changing the emission wavelength, there are a method of changing the element temperature, and a method of changing the emission wavelength by changing a transition probability between a plurality of quantum levels in a light emitting layer using a quantum well. is there.

[0003]

However, when the emission wavelength is changed by a method of changing the device temperature or a method of changing the transition probability between quantum levels, the device characteristics other than the emission wavelength change. There is. When the emission wavelength is changed by such a method, the width of the change in the emission wavelength is small.

An object of the present invention is to provide a light emitting device capable of changing an emission wavelength with a sufficient width without changing device characteristics other than the emission wavelength.

[0005]

A light-emitting device according to a first aspect of the present invention includes a light-emitting portion that emits light of a predetermined wavelength, a light-emitting portion that absorbs light generated by the light-emitting portion, and absorbs the absorbed light. A wavelength converter for converting the light into a light having a wavelength based on the magnitude or presence or absence of the external electric field and emitting the light.

In the light emitting device according to the present invention, light generated by the light emitting section is absorbed by the wavelength converting section, and the light is converted into light having a wavelength based on the magnitude or presence or absence of the external electric field by the wavelength converting section. It is emitted outside.

Thus, the wavelength of the emitted light can be changed depending on the magnitude or presence or absence of the external electric field. Therefore, the wavelength of light can be changed with a sufficient width without changing the element characteristics other than the wavelength of light.

In particular, the wavelength conversion section may be formed by alternately stacking a plurality of n-type layers and a plurality of p-type layers. Also,
The wavelength conversion unit may emit light by recombination of electrons and holes excited by light from the light emitting unit.

In this case, an internal electric field consisting of peaks and valleys is formed in the energy band of the wavelength converter. Electron-hole pairs are generated in the conduction band and the valence band by absorption of light from the light emitting portion. These electrons and holes are spatially separated by moving to the valley of the conduction band and the valley of the conduction band by the internal electric field, respectively, and at the same time, after losing energy, radiatively recombine.

The energy of light generated by the recombination changes depending on the magnitude or presence or absence of an external electric field. Therefore,
The emission wavelength can be changed depending on the magnitude or presence or absence of the external electric field.

[0011] The light emitting element may further include an electrode for applying an external electric field to the wavelength conversion section. In this case, an external electric field can be applied to the wavelength conversion unit by applying a voltage to the electrode, and the wavelength of light emitted from the wavelength conversion unit can be changed depending on the magnitude of the voltage or the presence or absence of the application of the voltage. it can.

[0012] The light emitting section may be composed of a light emitting diode. Alternatively, the light emitting section may be composed of a semiconductor laser element.

Further, the wavelength converter may have an optical resonator structure. In that case, laser light is emitted from the wavelength conversion unit. The light emitting unit and the wavelength conversion unit may be provided in the optical resonator. In this case, a laser beam is generated from the light emitting unit,
The wavelength converted laser light is emitted from the wavelength converter. It is preferable that the light emitting unit and the wavelength conversion unit are formed on the same substrate.

[0014] An electronic apparatus according to a second aspect of the invention includes the light emitting device according to the first aspect of the invention. Thus, the emission wavelength can be changed with a sufficient width without changing other element characteristics.

[0015]

FIG. 1 is a schematic sectional view of a light emitting device according to a first embodiment of the present invention. In the light emitting device of this embodiment, the light emitting section is formed of a light emitting diode.

In FIG. 1, a substrate 1 made of Al ₂ O ₃
A contact layer 2 made of p-type or n-type GaN,
2000 mm thick Al _x Ga ₁ -xN (0 <x ≦ 1) semi-insulating layer 3, photo-excited nip-pi-stacked light emitting layer 4 and 2000 mm thick Al _x Ga ₁ -xN ( 0 <x ≦ 1)
Are formed in order. Light excitation n-
The ipi laminated light emitting layer 4 is a p-type GaN having a layer thickness of 300 °.
Layer (acceptor concentration: 10 ¹⁹ cm ^-3 ) and 300 nm thick n
Type GaN layer (donor concentration 10 ¹⁹ cm ⁻³ )
It is periodically laminated.

On the semi-insulating layer 5, an n-type Al _x Ga ₁ -xN
An n-type cladding layer 6 made of, a light emitting layer 7 made of GaN, and a p _- type cladding layer 8 made of p _- type Al _x Ga ₁ -xN are formed in this order.

Part of the region from the p-type cladding layer 8 to a predetermined depth of the contact layer 2 is removed, and an electrode forming region 12 is formed on the contact layer 2. Further, a part of the region from the p-type cladding layer 8 to a predetermined depth of the n-type cladding layer 6 is removed, and an electrode formation region 13 is formed on the n-type cladding layer 6. The light emitting portion driving electrode 9 is formed on the p-type cladding layer 8, and the electrode forming region 13 of the n-type cladding layer 6 is formed.
The common electrode 10 is formed thereon, and the wavelength variable electrode 11 is formed on the electrode forming region 12 of the contact layer 2.

In the light emitting device of this embodiment, the light emitting diode composed of the n-type clad layer 6, the light-emitting layer 7, and the p-type clad layer 8 serves as a light-emitting portion, and the light-excited nip-i-p laminated light-emitting layer 4 converts the wavelength. Department.

In the light emitting device shown in FIG.
When a voltage is applied between the light emitting layer 7 and the common electrode 10, the light emitting layer 7 emits light. When a voltage is applied between the common electrode 10 and the wavelength variable electrode 11, an external electric field is applied to the photoexcited nipi laminated light emitting layer 4.

FIG. 2 shows the photo-excitation n- in the light emitting device of FIG.
FIG. 4 is a diagram showing a partial structure of an ipi laminated light emitting layer 4 and an energy band structure in a state where no electric field is applied.

As shown in FIG. 2, photoexcitation nipi
The stacked light emitting layer 4 is formed by alternately stacking n-type GaN layers 4a and p-type GaN layers 4b. When no electric field is applied, the level of the positively ionized impurity is localized below the valley 201 of the conduction band, and the level of the negatively ionized impurity is localized above the peak 202 of the valence band. I do. Note that n-type GaN
When the impurity concentration of the layer 4a and the p-type GaN layer 4b is high, the bending of the band becomes large, and the valley 201 of the conduction band and the valley 20 of the valence band even when no electric field is applied.
2 has a carrier.

FIG. 3 shows a photo-excited nip-pi laminated light emitting layer 4.
FIG. 4 is an energy band structure diagram when the photoexcited nipi laminated light emitting layer 4 is photoexcited by light emission from the light emitting layer 7 in a state where no electric field is applied.

Light emission from the light emitting layer 7 is photoexcited nip
-I Absorbed by the laminated light emitting layer 4 to become an electron e-hole h pair (excitation light absorption). These electrons e and holes h are spatially separated by the internal electric field, and the electrons e
1 and the holes h move to the peak 202 of the valence band and at the same time lose energy, and then perform radiative recombination.

In this case, the energy of the incident light is
And the bandgap energy of GaN, which is the material of the photo-excited ni-p-i laminated light emitting layer 4, the incident light is efficiently absorbed by the photo-excited ni-pi-laminated light-emitting layer 4 and n-type Al n-type cladding layer 6 made of _x Ga _1-x n
And is not absorbed by the semi-insulating layer 5 made of Al _x Ga ₁ -xN. Here, the light emission from the light emitting layer 7 is caused by the light excitation ni
The reason why the material is not absorbed by the n-type cladding layer 6 and the semi-insulating layer 5 before reaching the -pi laminated light emitting layer 4 is that the band gap energy of the material forming the n-type cladding layer 6 and the semi-insulating layer 5 is This is because it is larger than the energy of light from the light emitting layer 7.

The energy of light generated by the radiative recombination is smaller than the band gap energy of GaN.
Broad with a peak around 650nm wavelength
Red light emission occurs. Therefore, the light generated by the light-emitting recombination is not absorbed except by the light-emitting portion driving electrode 9, the common electrode 10, and the wavelength variable electrode 11, and is efficiently extracted to the outside.

FIG. 4 is a photo-excited nip-pi laminated light emitting layer 4
FIG. 4 is an energy band structure diagram when the light-excited nip-pi laminated light-emitting layer 4 is photo-excited by light emission from the light-emitting layer 7 in a state where an electric field is applied. Here, the common electrode 1
With respect to 0, a voltage of 30 V is applied to the wavelength variable electrode 11.

Light emission from the light emitting layer 7 is photoexcited nip
-I Absorbed by the laminated light emitting layer 4 to become an electron e-hole h pair (excitation light absorption). These electrons e and holes h are spatially separated by an internal electric field, and simultaneously lose energy and then undergo radiative recombination.

In this case, as in the case where no electric field is applied to the photo-excited nip-i-pi laminated light emitting layer 4, the energy of the incident light is reduced by the light-emitting layer 7 and the photo-excited nip-light.
Since the energy band gap energy of GaN, which is the material of the i-stacked light emitting layer 4, is equal to that of GaN, the incident light is n-
It is efficiently absorbed by the ipi laminated light emitting layer 4 and n-type Al
n-type cladding layer made of _x Ga _1-x N 6 and Al _x G
It is not absorbed by the semi-insulating layer 5 made of a _{1 -xN} . Here, the reason that the light emitted from the light emitting layer 7 is not absorbed by the n-type cladding layer 6 or the semi-insulating layer 5 before reaching the photoexcited nip-pi laminated light-emitting layer 4 is also explained. This is because the band gap energy of the material forming the semi-insulating layer 5 is larger than the energy of light from the light emitting layer 7.

Although the energy of light generated by the radiative recombination is smaller than the band gap energy of GaN, it becomes larger than that in the case where no electric field is applied to the photoexcited nip-pi laminated light emitting layer 4. Broad blue light emission having a peak near a wavelength of 470 nm occurs.

As described above, the wavelength of light generated by recombination in the photo-excited nip-pi-stacked light emitting layer 4 can be changed depending on whether or not a voltage is applied to the wavelength variable electrode 11. Further, by changing the magnitude of the voltage applied to the wavelength tunable electrode 11, the wavelength of light generated by recombination in the photoexcited nipi laminated light emitting layer 4 can be arbitrarily and continuously changed. Can be done.

In place of the n-type cladding layer 6, a p-type A
l _x Ga a p-type cladding layer used consisting of _1-x N, made of n-type Al _x Ga _1-x N in place of the p-type cladding layer 8 n
A mold cladding layer may be used.

FIGS. 5 and 6 are sectional views showing the steps of a method for manufacturing a light emitting device according to the second embodiment of the present invention. In the light emitting device of this embodiment, the light emitting portion is formed of a stripe type laser device.

First, as shown in FIG._TwoO
_ThreeN-type Al on a substrate 21 made of _xGa_1-xFrom N
N-type cladding layer 22, luminescent layer 23 made of GaN, and
And p-type Al_xGa_1-xN-type p-type cladding layer 24
Form in order.

Next, as shown in FIG. 5B, a partial region from the p-type cladding layer 24 to the predetermined depth of the n-type cladding layer 22 is subjected to RIE (reactive ion etching) using a chlorine-based gas. ). Thereby, the n-type cladding layer 22 is exposed.

Next, as shown in FIG. 5C, on the p-type cladding layer 24 and on the exposed n-type cladding layer 22,
A high-resistance layer 25 made of GaN, a photo-excited nip-p-i laminated light-emitting layer 26, a high-resistance layer 27 made of GaN, and p-type GaN (acceptor concentration 1 × 10 ¹⁹ cm ⁻³ ) or n-type GaN (donor concentration The contact layer 28 of 1 × 10 ¹⁹ cm ⁻³ ) is formed by MBE (molecular beam epitaxial growth).
In order.

The conditions for forming the photo-excited ni-pi laminated light emitting layer 26 are as follows: a growth temperature is 780 ° C., a vapor pressure of Ga as a solid source is 5 × 10 ⁻⁸ Torr, N Pressure of 1 × 10 ^-4 T
orr. The temperature of the Mg injection cell was set to 170 ° C.
And the temperature of the Si injection cell is set to 1000 ° C.

Thereafter, as shown in FIG.
The contact layer 28, the high-resistance layer 27, and the photo-excited nip-p-i except for the region on the end face side of the n-type clad layer 22 by the method.
The laminated light emitting layer 26 and the high resistance layer 25 are removed. Thereby, the light emitting unit 30 and the wavelength conversion unit 31 separated from each other by the separation groove 29 are formed. Width L1 of separation groove 29
Is, for example, 10 μm. Both end faces 32 and 33 of the wavelength conversion unit 31 are mirror-processed to form a Fabry-Perot resonator (optical resonator).

Finally, as shown in FIG. 6E, a light emitting portion driving electrode 34 made of Au is formed on the p-type cladding layer 24, and Ti is formed on the n-type cladding layer 22 in the separation groove 35.
Is formed, and a wavelength variable electrode 36 made of Au is formed on the contact layer 28.

In the light emitting device of this embodiment, the light emitting portion 30 is a stripe type laser device comprising the n-type cladding layer 22, the light emitting layer 23 and the p-type cladding layer 24, and the light excitation ni-pi of the resonator structure. The laminated light emitting layer 4 is a wavelength conversion unit 31
Becomes

In the light emitting device shown in FIG.
When a voltage is applied between the light emitting layer 2 and the common electrode 35, the light emitting layer 2
3 emits light. Thereby, laser light is emitted from both end surfaces of the light emitting layer 23. When a voltage is applied between the common electrode 35 and the wavelength variable electrode 36, the light excitation nip
-I An external electric field is applied to the laminated light emitting layer 26. As a result, both end faces 32 of the photo-excited ni-pi stacked light emitting layer 4 are formed.
A wavelength-variable laser beam is emitted from 33.

The n-type cladding layer 22 and the p-type cladding layer 24 are replaced with a p-type cladding layer and an n-type cladding layer, respectively.
A mold cladding layer may be provided. Further, instead of the p-type contact layer 28, an n-type contact layer may be provided.

FIG. 7 is a schematic sectional view of a light emitting device according to a third embodiment of the present invention. In the light emitting device of this embodiment,
The photo-excited nip-i-p laminated light emitting layer has a laser device structure.

On a substrate 41 made of Al ₂ O ₃ , an n-type A
l _x Ga _1-x n-type cladding layer 42 N consisting emitting layer 43 and the p-type consisting of GaN Al _x Ga _1-x N composed of p-type cladding layer 44 are sequentially formed.

On the p-type cladding layer 44, a high-resistance semiconductor multilayer mirror 45, a photo-excited nipi laminated light emitting layer 4
6 and a dielectric multilayer mirror 47 are formed in this order. The high-resistance semiconductor multilayer mirror 45 is made of, for example, AlGa.
An N layer and a GaN layer are alternately stacked. Further, the photo-excited ni-p-i laminated light emitting layer 46 is formed by a p-type GaN layer
GaN layers are alternately stacked.

Dielectric multilayer mirror 47, photo-excited ni-
Part of the p-i laminated light emitting layer 46 and the high resistance semiconductor multilayer mirror 45 are partially removed, exposing the p-type cladding layer 44. Further, a partial region from the dielectric multilayer mirror 47 to a predetermined depth of the n-type cladding layer 42 is removed, and n
The mold cladding layer 42 is exposed. A wavelength variable electrode 48 is formed on the dielectric multilayer mirror 47, a common electrode 49 is formed on the p-type cladding layer 44, and the n-type cladding layer 4 is formed.
2, a light emitting unit driving electrode 50 is formed.

In the light emitting device of this embodiment, a light emitting diode comprising an n-type cladding layer 42, a light-emitting layer 43 and a p-type cladding layer 44 serves as a light-emitting portion. In addition, a vertical resonator is formed by the high-resistance semiconductor multilayer mirror 45 and the dielectric multilayer mirror 47, and the photo-excited nipi laminated light emitting layer 4 is formed.
6 is a wavelength converter.

In the semiconductor device shown in FIG. 7, when a voltage is applied between the light emitting portion driving electrode 50 and the common electrode 49, the light emitting layer 43 emits light. Further, when a voltage is applied between the common electrode 49 and the wavelength variable electrode 48, photoexcitation nipi is performed.
An external electric field is applied to the laminated light emitting layer 46. This allows
Variable wavelength laser light 5 from the upper and lower surfaces of the light emitting element
1,52 are emitted.

Note that a semiconductor multilayer mirror may be used in place of the dielectric multilayer mirror 47.

FIG. 8 is a schematic sectional view of a light emitting device according to a fourth embodiment of the present invention. In the light emitting device of this embodiment,
The photo-excited nip-i-p laminated light emitting layer has a laser device structure.

In FIG. 8, a substrate 6 made of Al ₂ O ₃
1, an n _- type cladding layer 62 made of n _- type Al _x Ga ₁ -xN, a light emitting layer 63 made of GaN, and a p-type Al _x Ga
_A p-type cladding layer 64 made of _1-xN is formed in order.

On the p-type cladding layer 64, a high-resistance semiconductor layer 65, a photo-excited nip-laminated light emitting layer 66, and a dielectric multilayer mirror 67 are sequentially formed. On the lower surface of the substrate 61, a dielectric multilayer mirror 68 is formed.

Dielectric multilayer mirror 67, photo-excited ni-
Part of the p-i stacked light emitting layer 66 and the high resistance semiconductor layer 65 are partially removed, exposing the p-type cladding layer 64.
In addition, the dielectric multi-layer mirror 67 transfers the n-type clad layer 62
Is removed to a predetermined depth to expose the n-type cladding layer 62. A variable wavelength electrode 69 is formed on the dielectric multilayer mirror 67, a common electrode 70 is formed on the p-type cladding layer 64, and a light emitting unit driving electrode 71 is formed on the n-type cladding layer 62.

In the light emitting device of this embodiment, a light emitting diode comprising an n-type cladding layer 62, a light-emitting layer 63 and a p-type cladding layer 64 serves as a light-emitting portion. Further, the dielectric multilayer mirror 68 and the dielectric multilayer mirror 67 constitute a vertical resonator, and the light-excited nip-pi laminated light emitting layer 66 becomes a wavelength converter.

In the semiconductor laser device of FIG. 8, when a voltage is applied between the light emitting portion driving electrode 71 and the common electrode 70,
The light emitting section 63 emits light. When a voltage is applied between the common electrode 70 and the wavelength variable electrode 69, the light excitation ni-
An external electric field is applied to the pi stacked light emitting layer 66. As a result, the wavelength-variable laser light is emitted from the upper surface and the lower surface of the light emitting element.

It should be noted that a semiconductor multilayer mirror may be used instead of the dielectric multilayer mirrors 67 and 68.

FIG. 9 is a schematic sectional view of a light emitting device according to a fifth embodiment of the present invention. In the light emitting device of this embodiment,
The photo-excited nip-i-p laminated light emitting layer has a laser device structure.

On a substrate 81 made of Al ₂ O ₃ , an n-type A
l _x Ga _1-x n-type cladding layer 82 N consisting emitting layer 83 and p-type consisting of GaN Al _x Ga _1-x N composed of p-type cladding layer 84 are sequentially formed. On the p-type cladding layer 84, a high resistance layer 85, a photo-excited nip-i-pi laminated light emitting layer 86, and a high resistance layer 87 are formed in this order.

The high resistance layer 87, the photoexcited nipi laminated light emitting layer 86 and a part of the high resistance layer 85 are removed,
The p-type cladding layer 84 is exposed. The high resistance layer 8
7 to a predetermined depth of the n-type cladding layer 82 are removed, and the n-type cladding layer 82 is exposed.

A wavelength variable electrode 88 is formed on the high resistance layer 87, a common electrode 89 is formed on the p-type cladding layer 84, and a light emitting unit driving electrode 90 is formed on the n-type cladding layer 82. .

Resonance surfaces are formed on both end faces 91 and 92 of the photo-excited nip-i-pi laminated light emitting layer 86 by mirror processing.

In the light emitting device of this embodiment, a light emitting diode comprising an n-type cladding layer 82, a light-emitting layer 83 and a p-type cladding layer 84 serves as a light-emitting portion. In addition, the light-excited nipi laminated light-emitting layer 86 having a resonator structure serves as a wavelength converter.

In the semiconductor laser device of FIG. 9, when a voltage is applied between the light emitting portion driving electrode 90 and the common electrode 89,
The light emitting layer 83 emits light. When a voltage is applied between the common electrode 89 and the wavelength variable electrode 88, the light excitation ni-
An external electric field is applied to the pi stacked light emitting layer 86. Thereby, both end faces 9 of the photoexcited nipi laminated light emitting layer 86 are formed.
The wavelength-variable laser light is emitted from 1,92.

FIG. 10 is a schematic sectional view of a light emitting device according to a sixth embodiment of the present invention. In the light emitting device of this embodiment, the light emitting section is formed of a surface emitting laser device.

On a substrate 101 made of Al ₂ O ₃ , a semiconductor multilayer mirror 102, an n-type cladding layer 103, a light emitting layer 104 and a p-type cladding layer 105 are formed in this order. On the p-type cladding layer 105, a high-resistance semiconductor multilayer mirror 106, a photo-excited nip-p-i stacked light emitting layer 107
And a dielectric multilayer mirror 108 are formed in this order.

Part of the dielectric multilayer mirror 108 from the mirror 108 to a predetermined depth of the p-type cladding layer 105 is removed, and the p-type cladding layer 105 is exposed. Further, a part of the region from the dielectric multilayer mirror 108 to a predetermined depth of the n-type cladding layer 103 is removed, so that the n-type cladding layer 103 is exposed.

A wavelength variable electrode 109 is formed on the dielectric multilayer mirror 108, a common electrode 110 is formed on the p-type cladding layer 105, and a light emitting unit driving electrode 111 is formed on the n-type cladding layer 103. ing.

In the light emitting device of this embodiment, a vertical resonator is constituted by the semiconductor multilayer mirror 102 and the high resistance semiconductor multilayer mirror 106, and the high resistance semiconductor multilayer mirror 1
06 and the dielectric multilayer mirror 108 constitute a vertical resonator. In this case, the surface emitting laser device including the p-type cladding layer 103, the light-emitting layer 104, and the n-type cladding layer 105 serves as a light-emitting portion, and is provided with an optically pumped n-type laser having a vertical cavity structure.
The ipi laminated light emitting layer 107 serves as a wavelength converter.

In the semiconductor laser device of FIG. 10, when a voltage is applied between the light emitting unit driving electrode 111 and the common electrode 110, a laser beam is emitted from the light emitting unit 104 in the vertical direction. When a voltage is applied between the common electrode 110 and the wavelength variable electrode 109, an external electric field is applied to the photoexcited nipi laminated light emitting layer 107. As a result, the wavelength-variable laser light is emitted from the upper surface and the lower surface of the light emitting element.

Note that a semiconductor multilayer mirror may be used instead of the dielectric multilayer mirror 108.

FIG. 11 is a schematic sectional view of a light emitting device according to a seventh embodiment of the present invention. In the light emitting device of this embodiment, the light emitting section is formed of a surface emitting laser device.

On a substrate 121 made of Al ₂ O ₃ , an n-type cladding layer 122, a light-emitting layer 123, and a p-type cladding layer 124 are sequentially formed. On the p-type cladding layer 124, a high-resistance semiconductor multilayer mirror 125, an optically pumped ni
-Pi laminated light emitting layer 126 and dielectric multilayer mirror 1
27 are formed in order.

A part of the region from the dielectric multilayer mirror 127 to a predetermined depth of the p-type cladding layer 124 is removed, and the p-type cladding layer 124 is exposed. Further, a part of the region from the dielectric multilayer mirror 127 to a predetermined depth of the n-type cladding layer 122 is removed, so that the n-type cladding layer 122 is exposed. On the other hand, on the lower surface of the substrate 121, a dielectric multilayer mirror 128 is formed.

A wavelength tunable electrode 129 is formed on the dielectric multilayer mirror 127, a common electrode 130 is formed on the p-type cladding layer 124, and a light emitting unit driving electrode 131 is formed on the n-type cladding layer 122. ing.

In the light emitting device of this embodiment, a vertical resonator is constituted by the dielectric multilayer mirror 128 and the high resistance semiconductor multilayer mirror 125, and the high resistance semiconductor multilayer mirror 1
25 and the dielectric multilayer mirror 127 constitute a vertical resonator. In this case, a surface-emitting laser device including the n-type cladding layer 122, the light-emitting layer 123, and the p-type cladding layer 124 serves as a light-emitting portion, and the light-excitation n-
The ipi laminated light emitting layer 126 serves as a wavelength converter.

In the semiconductor laser device shown in FIG. 11, when a voltage is applied between the light emitting unit driving electrode 131 and the common electrode 130, laser light is emitted from the light emitting unit 123 in the vertical direction. When a voltage is applied between the common electrode 130 and the wavelength variable electrode 129, an external electric field is applied to the photoexcited nipi laminated light emitting layer 126. As a result, the wavelength-variable laser light is emitted from the upper surface and the lower surface of the light emitting element.

The dielectric multilayer mirrors 127 and 128
Instead, a semiconductor multilayer mirror may be used.

FIG. 12 is a schematic sectional view of a light emitting device according to the eighth embodiment of the present invention. In the light emitting device of this embodiment, the light emitting section is formed of a surface emitting laser device.

On a substrate 141 made of Al ₂ O ₃ , a semiconductor multilayer mirror 142, an n-type cladding layer 143, a light emitting layer 144 and a p-type cladding layer 145 are formed in this order. On the p-type cladding layer 145, a high-resistance semiconductor multilayer mirror 146, a photo-excited nip-i-p laminated light emitting layer 147
And a high resistance layer 148 are formed in this order.

From the high resistance layer 148 to the p-type cladding layer 145
Of the p-type cladding layer 145 is partially exposed to a predetermined depth. Further, a part of the region from the high resistance layer 148 to a predetermined depth of the n-type cladding layer 143 is removed, and the n-type cladding layer 143 is exposed.

The wavelength variable electrode 149 is formed on the high resistance layer 148.
Is formed, and the common electrode 150 is formed on the p-type cladding layer 145.
Is formed, and a light-emitting portion driving electrode 151 is formed on the n-type cladding layer 143. A resonator surface is formed on both end surfaces 152 and 153 of the photoexcited nip-i-p laminated light emitting layer 147 by mirror processing.

In the light emitting device of this embodiment, the semiconductor multilayer mirror 142 and the high-resistance semiconductor multilayer mirror 146 constitute a vertical resonator. In this case, the n-type cladding layer 14
3. A surface emitting laser device including the light emitting layer 144 and the p-type cladding layer 145 becomes a light emitting unit. In addition, the light-excited nipi laminated light-emitting layer 147 having a vertical resonator structure serves as a wavelength converter.

In the light emitting device shown in FIG. 12, when a voltage is applied between the light emitting unit driving electrode 151 and the common electrode 150, a laser beam is emitted from the light emitting unit 144 in the vertical direction. Further, when a voltage is applied between the common electrode 150 and the wavelength variable electrode 149, the photoexcited nipi laminated light emitting layer 14
7, an external electric field is applied. Thereby, the light excitation ni
The wavelength-variable laser light is emitted from both end surfaces 152 and 153 of the -pi laminated light emitting layer 147.

In the first to eighth embodiments, not only the emission wavelength can be simply changed, but also a light emission having a pseudo arbitrary spectrum shape (white, gold, (A color obtained by mixing colors such as brown and pink) can be generated by one light emitting element.

Further, the light emission intensity of the light emitting section may be modulated by synchronizing the voltage for wavelength conversion with the modulation.

The light-emitting device of the present invention is a full-color display, a pilot lamp, an indicator, a light source for photochemical reaction, a light source for an analytical instrument, a light source for a color sensor, a light source for a banknote discriminator, a color sample, a light source for optical communication, a medical device, and an optical computer. , Signals, lighting, and various other electronic devices.

In the above embodiment, the n-type layer and the p-type layer are alternately laminated to form the photo-excited nipi laminated light-emitting layer. A non-dove i-layer may be inserted between them.

As the material of the light emitting device of the present invention, various direct transition semiconductors can be used.
InN, InP, AlAs, GaAs, InAs, Al
Sb, GaSb, InSb, GaPAs, AlGaN,
AlInN, AlNAs, AlNSb and their mixed crystals (GaInN, AlGaInN, AlGaNAs, G
aNAs, GaInNAs, AlInP, GaInP,
AlGaInP, InPAs, AlGaPAs, AlI
nPAs, GaInPAs, GaInAs, AlInA
s, AlGaAs, AlGaInAs, GaInAsS
b, AlInAsSb, AlGaAsSb, AlGaI
nAsSb, GaInSb, AlInSb, AlGaS
b, AlGaInSb, GaInNAsSb, AlIn
NAsSb, AlGaNAsSb, AlGaInNSA
sSb, GaInNSb, AlInNSb, AlGaN
Sb, AlGaInNSb, etc.), BeS, BeSe, B
eTe, MgS, MgSe, MgTe, ZnO, Zn
S, ZnSe, ZnTe, CdS, CdSe, CdT
e, HgS, HgSe, HgTe and mixed crystals thereof (BeMgS, BeMgSe, BeMgTe, BeZn
S, BeZnSe, BeZnTe, BeCdS, BeC
dSe, BeCdTe, BeHgS, BeHgSe, B
eHgTe, MgZnS, MgZnSe, MgZnT
e, MgCdS, MgCdSe, MgCdTe, MgH
gS, MgHgSe, MgHgTe, ZnCdO, Zn
CdS, ZnCdSe, ZnCdTe, ZnHgO, Z
nHgS, ZnHgSe, ZnHgTe, CdHgS,
CdHgSe, CdHgTe, BeMgZnS, BeM
gZnSe, BeMgZeTe, BeMgCdS, Be
MgCdSe, BeMgCdTe, BeMgHgS, B
eMgHgSe, BeMgHgTe, BeSSe, Be
SeTe, BeSTe, MgSSe, MgSeTe, M
gSTe, ZnOS, ZnSSe, ZnSeTe, Zn
STe, ZnOSe, ZnOTe, CdSSe, CdS
eTe, CdSTe, HgSSe, HgSeTe, Hg
STe, etc.) can be used.

However, the material is selected such that the bandgap energy of the material constituting the wavelength conversion section is substantially equal to or less than the energy of light generated from the light emitting section.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a light emitting device according to a first embodiment of the present invention.

FIG. 2 shows photoexcitation nipi in the light emitting device of FIG.
It is a figure which shows the structure of a part of laminated light emitting layer, and the energy band structure in the state where an electric field is not applied.

FIG. 3 shows a photo-excited n-p-i layer formed by applying light emission from a light-emitting layer in a state where no electric field is applied to the laminated layer.
It is an energy band structure diagram at the time of photoexcitation of an ipi laminated light emitting layer.

FIG. 4 shows a photo-excited nip by light emission from the light-emitting nip layer in a state where an electric field is applied to the luminescent layer.
FIG. 3 is an energy band structure diagram when the i-layer light emitting layer is photoexcited.

FIG. 5 is a process sectional view illustrating a method for manufacturing a light emitting device according to a second embodiment of the present invention.

FIG. 6 is a process sectional view illustrating the method for manufacturing the light emitting device in the second embodiment of the present invention.

FIG. 7 is a schematic sectional view of a light emitting device according to a third embodiment of the present invention.

FIG. 8 is a schematic sectional view of a light emitting device according to a fourth embodiment of the present invention.

FIG. 9 is a schematic sectional view of a light emitting device according to a fifth embodiment of the present invention.

FIG. 10 is a schematic sectional view of a light emitting device according to a sixth embodiment of the present invention.

FIG. 11 is a schematic sectional view of a light emitting device according to a seventh embodiment of the present invention.

FIG. 12 is a schematic sectional view of a light emitting device according to an eighth embodiment of the present invention.

[Explanation of symbols]

4,26,46,66,86,107,126,147
Light-excited ni-pi laminated light-emitting layers 7, 23, 43, 63, 83, 104, 123 Light-emitting layers 9, 34, 50, 71, 90, 111, 131 Light-emitting portion driving electrodes 10, 35, 49, 70, 89, 110, 130 Common electrode 11, 36, 48, 69, 88, 109, 129 Wavelength variable electrode

Claims (9)

[Claims] 1. A light emitting section for generating light of a predetermined wavelength, absorbing light generated by the light emitting section, converting the absorbed light into light of a wavelength based on the magnitude or presence or absence of an external electric field, and emitting the light. A light emitting device comprising: 2. The light emitting device according to claim 1, wherein the wavelength conversion section is formed by alternately stacking a plurality of n-type layers and a plurality of p-type layers. 3. The light emitting device according to claim 1, wherein the wavelength conversion unit emits light by recombination of electrons and holes excited by light from the light emitting unit. 4. The apparatus according to claim 1, further comprising an electrode for applying an external electric field to said wavelength conversion unit.
The light emitting device according to any one of the above. 5. The light-emitting device according to claim 1, wherein the light-emitting unit includes a light-emitting diode. 6. The light emitting device according to claim 1, wherein said light emitting unit is formed of a semiconductor laser device. 7. The light emitting device according to claim 1, wherein said wavelength converter has an optical resonator structure. 8. The light emitting device according to claim 1, wherein said light emitting section and said wavelength converting section are provided in an optical resonator. 9. An electronic device comprising the light emitting device according to claim 1.