JP3536976B2 - Light emitting element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a light emitting device and a method for manufacturing the same.

[0002]

BACKGROUND OF THE INVENTION _{(Al x Ga 1-x)} y In 1-y P
(However, 0 ≦ x, y ≦ 1 and x + y = 1)
A light-emitting element in which a light-emitting layer is formed of AlGaInP mixed crystal or AlGaInP) has a thin A
The 1GaInP active layer is composed of an n-type AlGaInP cladding layer having a larger band gap and a p-type AlGaIn
By employing a double hetero structure sandwiched between the P cladding layer and the P cladding layer, a high-luminance element can be realized. However, as a result of many years of progress in the material and structure of the light emitting layer portion, the photoelectric conversion efficiency in the light emitting layer portion is gradually approaching the theoretical limit. Therefore, when an element with higher luminance is to be obtained, the light extraction efficiency from the element is extremely important.

[0003] As a method for improving the light extraction efficiency,
A method has been proposed in which a light-transmitting semiconductor layer having a lower refractive index than a cladding layer made of AlGaInP mixed crystal is formed as a light extraction layer in contact with a light-emitting layer portion. This alleviates the phenomenon that the light that is about to leak from the light emitting layer portion returns to the inside due to the total reflection on the surface of the light emitting layer portion, and the light extraction efficiency can be improved. Conventionally, such a light extraction layer has good translucency with respect to green to red wavelengths (approximately 550 nm to 650 nm) emitted from the light-emitting layer portion of the AlGaInP mixed crystal, and thus has a good light transmission property.
Compound semiconductors such as As mixed crystals have been used.

[0004]

The AlGaAs mixed crystal is
Since it is lattice-matched with the AlGaInP mixed crystal, it is possible to perform consistent growth in a growth furnace, but in the above-mentioned emission wavelength band, the refractive index is 3.3 to 3.4 (for example, emission wavelength 600 nm).
, About 3.4), the critical angle of total reflection becomes small, and it is difficult to greatly improve the light extraction efficiency.

[0005] Here, the critical angle θc of total reflection is as follows: when light is extracted in the air, the refractive index of the compound semiconductor constituting the light extraction layer is n ₁ , and the refractive index of the air is n ₂ , θc = Sin ⁻¹ (n ₂ / n ₁ )}. The refractive index of air is approximately the refractive index of vacuum (=
Since it can be regarded as equal to 1), by using this, it can be expressed as θc = Sin ⁻¹ (1 / n ₁ ) ‥‥.

In the case of an AlGaAs mixed crystal having a refractive index n ₁ = 3.4, the critical angle θc of total reflection is 17 °. In this case, as shown in FIG. 8, the critical angle of total reflection θc = 17 °
Only light that reaches the interface within an angle smaller than that, that is, at an angle close to perpendicular to the interface, is emitted into the air (FIG. 8A). Then, light reaching the interface at an angle larger than θc = 17 ° is totally reflected, reflected inside the crystal and absorbed (FIG. 8B).

Further, in order to sufficiently secure the light transmittance in the above-mentioned wavelength band, the AlAs mixed crystal ratio must be considerably increased. However, a high AlAs mixed crystal AlG
Since an aAs mixed crystal is very easily oxidized, when an AlGaInP-based light emitting device using an AlGaAs light extraction layer having a high AlAs mixed crystal ratio is used by conducting and emitting light outdoors, an AlGaAs
There is a problem in that the luminescence of the light extraction layer is caused to cause deterioration of light emission luminance and further damage.

On the other hand, since GaP does not contain Al, there is no possibility of adversely affecting the life characteristics. However, the refractive index is slightly smaller than that of the AlGaAs mixed crystal (for example, about 3.35 at an emission wavelength of 600 nm), and does not have the effect of suppressing total reflection so as to greatly improve the light extraction efficiency.

According to the present invention, there is provided a light emitting device in which the light extraction efficiency is greatly improved by using a light transmitting compound semiconductor layer having a smaller refractive index than that of a conventional GaP or AlGaAs mixed crystal as a light extraction layer. And a method of manufacturing the same.

[0010]

Means for Solving the Problems and Actions / Effects In order to solve the above-mentioned problems, the light emitting device of the present invention comprises (Al)
_x Ga _1-x ) _y In _1-y P (where 0 ≦ x, y ≦ 1
And x + y = 1) having, as a light emitting layer portion, a double hetero structure in which a first conductivity type clad layer, an active layer, and a second conductivity type clad layer composed of a mixed crystal are laminated, and A light extraction layer made of a compound semiconductor having a refractive index of 3.2 or less for light in a wavelength band of 550 nm or more and 650 nm or less is formed on at least one side.

A green-red emission wavelength band (550 nm or more and 65 nm or more) from the emission layer portion having the double heterostructure layer.
0 nm or less) for conventional GaP or AlGaAs.
By forming a light extraction layer made of a light-transmitting compound semiconductor having a refractive index smaller than that of the mixed crystal, specifically, a refractive index of 3.2 or less, it is possible to obtain a more complete structure than when using a GaP or AlGaAs mixed crystal. The critical angle of reflection can be increased, and the light extraction efficiency of the light emitting element can be greatly improved. The compound semiconductor constituting the light extraction layer is specifically ZnS
e, ZnS, ZnTe, and CdS.

Table 1 shows the refractive index of each compound semiconductor of ZnSe, ZnS, ZnTe and CdS, and the value of the critical angle θc calculated by the formula in comparison with the values of GaP and AlGaAs mixed crystals. However, in the table, values without parentheses are measured values using a single crystal sample to which no dopant is added, and values with parentheses are calculated values obtained by interpolation from the measured values. The refractive index of the above four compounds is 3.2 or less in all wavelength ranges of 550 nm to 650 nm, and the critical angle θc is, for example, about 8 to 50% as compared with the value of GaP. It can also be seen that is also improved. That is, in the light emitting device of the present invention, the loss due to total reflection is less likely to occur due to the increase in the critical angle, and GaP or AlGa is used as the light extraction layer.
The light extraction efficiency can be increased as compared with the case where the As mixed crystal is used. In addition, since none of the compounds positively contains Al, the life characteristics of the light emitting element are good.

[0013]

[Table 1]

The refractive index of the compound semiconductor single crystal slightly varies depending on the amount of dopant added. However, the range of the amount of addition usually employed to function as a light extraction layer also serving as a current diffusion layer (for example, 1 × 10 4 ¹⁷ atoms / cm ³ ~
At 5 × 10 ¹⁸ atoms / cm ³ ), the fluctuation range is 5 based on the refractive index when no dopant is added.
%. Therefore, at least ZnSe, ZnS,
For the four kinds of ZnTe and CdS, 550 to 650
2. In the wavelength band of nm, regardless of the amount of dopant added.
The value is still 2 or less.

Next, as the compound semiconductor forming the light extraction layer, a compound semiconductor having a band gap energy larger than the photon energy corresponding to the emission wavelength from the light emission layer portion is used to reduce the light absorption in the light extraction layer. It is desirable in order to suppress and improve the light extraction efficiency. From the viewpoint of the absolute value of the band gap energy, it is desirable to select a compound semiconductor having the band gap energy of 2.2 eV or more. This makes it difficult for the light extraction layer to absorb light in the green-red wavelength band (550 nm or more and 650 nm or less) from the light emitting layer portion having the double hetero structure, thereby reducing the luminous efficiency due to the absorption. The decrease can be effectively suppressed. The band gap energy values of ZnSe, ZnS, ZnTe, and CdS described above are as shown in Table 1, and all are in the range of 2.2 eV to 3.6 eV. However,
When the light extraction layer is made of ZnTe, the transmittance of ZnTe to light in the vicinity of 550 nm to 560 nm is low, so that the emission wavelength of Al is 570 nm to 650 nm.
More preferably, the present invention is applied to a light emitting element having a light emitting layer portion composed of a GaInP mixed crystal. 570 nm or more 65
The transmittance of ZnTe for light in a wavelength band of 0 nm or less is almost 100%. In this case, the mixed crystal ratio (the values of x and y described above) of the AlGaInP mixed crystal is appropriately adjusted so that the emission wavelength is 570 nm or more and 650 nm or less.

In addition, since these compound semiconductors have good conductivity, the electrode terminals can be wire-bonded through a light extraction layer made of the compound semiconductor to conduct electricity. That is, GaP or Al is used as the light extraction layer.
Wire bonding can be performed in the same process as that of a conventional light emitting diode element using a GaAs mixed crystal, and there is also an advantage that the production can be performed by using the existing production line without changing it.

The light extraction layer is made of ZnSe, ZnS, ZnTe.
When the light emitting device of the present invention is composed of a compound semiconductor composed of any one of CdS and CdS, the light emitting device of the present invention can be manufactured by the following method for manufacturing a light emitting device of the present invention. That is, the _{method, (Al x Ga 1-x} ) y In 1-y P
(However, 0 ≦ x, y ≦ 1 and x + y = 1) On the compound semiconductor single crystal substrate lattice-matched with the mixed crystal, (Al _x Ga
_1-x ) _y In _1-y P (where 0 ≦ x, y ≦ 1 and x
+ Y = 1) a first conductivity type clad layer composed of a mixed crystal,
The main surface of the double hetero structure in which the active layer and the second conductivity type clad layer are stacked and the main surface of a single crystal substrate made of any of ZnSe, ZnS, ZnTe and CdS are joined.

The above-mentioned compound semiconductors forming the light extraction layer are all AlGaIn forming a double hetero structure.
Since the P mixed crystal is a lattice mismatched system, the AlGaInP
Epitaxial growth cannot be performed directly on the mixed crystal. Therefore, it is effective to form a device by joining the main surface of a single crystal substrate made of such a compound semiconductor to the main surface of a double hetero structure.

[0019]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a conceptual diagram showing a light emitting device 100 according to one embodiment of the present invention. In the light emitting device 100, the first light extraction layer 10 and the first electrode 14 are formed in this order on the first main surface 17 side of the light emitting layer portion 24. The second light extraction layer 13 and the second electrode 15 are formed in this order on the second main surface 18 side of the light emitting layer portion 24. The first electrode 14 is formed so as to cover only a part of the surface of the first light extraction layer 10. The second electrode 15 is formed so as to cover only a part of the surface of the second light extraction layer 13.

The light emitting layer portion 24 is made of AlGaInP mixed crystal, and the first conductivity type cladding layer 6 located on the first electrode 14 side, the second conductivity type cladding layer 4 located on the second electrode 15 side, And a double heterostructure comprising an active layer 5 located between the first conductivity type cladding layer 6 and the second conductivity type cladding layer 4. Specifically, the active layer 5 made of a non-doped AlGaInP mixed crystal is formed by p-type AlGaInP.
InP cladding layer 6 and n-type AlGaInP cladding layer 4
It is a structure sandwiched between. The AlGaInP mixed crystal is a direct transition type semiconductor having a large band gap, and has an energy barrier caused by a band gap difference between the cladding layers 6 and 4 formed on both sides of the active layer 5.
Since the injected holes and electrons are confined in the narrow active layer 5 and efficiently recombine, very high luminous efficiency can be realized. Further, by adjusting the composition of the active layer 5, it is possible to realize a wide range of emission wavelengths from green to red (emission wavelength of 550 nm to 650 nm). In the light emitting device 100 of FIG. 1, the p-type AlGaInP cladding layer 6 is disposed on the first electrode 14 side, and the n-type AlGaInP cladding layer 4 is disposed on the second electrode 15 side. Therefore, the current supply polarity is positive on the first electrode 14 side.

Next, the first and second light extraction layers 10, 13
Is a translucent compound semiconductor having a refractive index of 3.2 or less for visible light in a wavelength band of 550 nm or more and 650 nm or less, specifically, ZnSe, ZnS, ZnTe, and CdS.
As a single crystal layer. Among these, the first light extraction layer 10 contains impurities such as nitrogen (N) in an amount of 1 × 10 ¹⁸ atoms / cm ^{3 to} 5 × 10 ¹⁸ atoms.
By doping at a high concentration of about ms / cm ³ , the conductivity becomes p-type, and the second light extraction layer 13 contains impurities such as aluminum (Al) at 1 × 10 ¹⁸ atoms / cm ^3.
by doping a high concentration of cm ^{3, ~5 × 10 1 8 atoms / cm} 3, conductivity is n-type.

The refractive index of the AlGaInP mixed crystal varies depending on the mixed crystal ratio, but is about 3.3 to 3.8. On the other hand, as shown in Table 1, the refractive index of the compound semiconductor single crystal constituting the light extraction layers 10 and 13 is clearly smaller than that of the AlGaInP mixed crystal constituting the light emitting layer section 2.3.
It has a value in the range of not less than 3.2 and not more than 3.2. As a result, the light extraction layers 10 and 13 are connected to the surrounding atmosphere forming medium (for example, air) where the light emitting element 100 is arranged, and are connected to each other.
By being interposed between the cladding layers 6 and 4 made of 1GaInP mixed crystal and having an intermediate refractive index between them, the loss due to the total reflection of the light L from the light emitting layer portion 24 is reduced, and the light extraction efficiency is reduced. Play a role to improve. In the present embodiment, the light extraction layers 10 and 13 are configured as ZnTe single crystal layers.

The compound semiconductors constituting the light extraction layers 10 and 13 have high conductivity, and apply a current flowing through the electrodes 14 and 15 covering only a part of the surface to the light emitting layer portion 24. It also plays the role of a current spreading layer that spreads current so as to be uniform in the in-plane direction.

The first electrode 14 and the second electrode 15 are
For example, it can be configured as a layer made of Au or an Au alloy. As shown in FIG. 2, between the electrodes 14 and 15 and the light extraction layers 10 and 13, a thin film of a highly doped compound semiconductor (for example, GaAs) is used in order to reduce the contact resistance.
Layers: hereinafter referred to as contact layers) 14a and 15a can also be formed. However, the light extraction layers 10, 13
Of ZnSe, ZnS, ZnTe or CdS
Has good ohmic bonding with Au or an Au alloy, and as shown in FIG.
It is also possible to form it directly in contact with 0,13. For example, in a conventional light emitting device in which the light extraction layer is made of GaP or AlGaAs mixed crystal, inserting the above contact layer between the light emitting layer and an electrode made of Au or an Au alloy reduces the operating voltage. Indispensable for lowering, Zn
When Se, ZnS, ZnTe or CdS is used,
There is an advantage that the contact layer can be omitted.

In the light emitting device 100 of FIG. 1, the following numerical values can be exemplified as examples of the thickness of each layer:
First light extraction layer (p-type ZnTe layer) 10 = 300 μm,
p-type AlGaInP cladding layer 6 = 1 μm, AlGaI
nP active layer 5 = 0.6 μm, n-type AlGaInP cladding layer 4 = 1 μm, second light extraction layer (n-type ZnTe layer) 1
3 = 300 μm.

Hereinafter, a method for manufacturing the light emitting device 100 of FIG. 1 will be described. First, as shown in FIG.
On a first main surface 1a of a GaAs single crystal substrate 1 which is a compound semiconductor single crystal substrate lattice-matched with a GaInP mixed crystal, an n-type GaAs buffer layer 2 of, for example, 0.5 μm and a release layer 3 of an n-type AlAs layer are formed. For example, a 0.5 μm epitaxial growth is performed. Next, as the light emitting layer portion 24, 1
A μm n-type AlGaInP cladding layer 4, a 0.6 μm AlGaInP active layer (non-doped) 5, and a 1 μm p-type AlGaInP cladding layer 6 are epitaxially grown in this order. Thereafter, an etch stop layer 7 made of a p-type GaAs layer is further formed to a thickness of, for example, 5 nm,
The cap layer 8 made of an nP layer is epitaxially grown, for example, by 0.3 μm. The cap layer 8 is formed to prevent the incorporation of hydrogen into the grown epicapital layer to inactivate the dopant. The epitaxial growth of each of these layers is performed by metalorganic vapor phase epitaxial growth (Metalorg
anic Vapor Phase Epitaxy (MOVPE) method.

After the above growth, as shown in FIG.
The cap layer 8 is peeled off with hydrochloric acid, and sulfuric acid / hydrogen peroxide solution (H ₂ SO ₄ / H ₂ O ₂ / H) is used as an etchant.
_The etch stop layer 7 is peeled off by, for example, etching at 50 ° C. for 2 seconds using 2O). Hereinafter, the laminated body after the completion of this processing is referred to as a DH wafer 9 with a substrate.

Next, the first main surface of the p-type ZnTe single crystal substrate, which is a single crystal substrate for forming a light extraction layer, is
Surface treatment with H aqueous solution. Thereafter, the p-type ZnTe single crystal substrate is bonded to the first main surface 17 of the DH wafer 9 with a substrate, pressed, and heat-treated under predetermined conditions (for example, at 300 ° C. for 5 minutes in a nitrogen atmosphere). ,
A p-type ZnTe single crystal substrate is bonded to the surface of the p-type AlGaInP cladding layer 6 to form a first light extraction layer 10. The surface treatment with the NaOH aqueous solution has the effect of increasing the sticking force when sticking a p-type ZnTe single crystal substrate. Hereinafter, the laminate in this state is referred to as ZnTe /
This is referred to as DH wafer 11.

Then, the substrate-attached ZnTe / DH wafer 11 is immersed in an etching solution composed of, for example, a 10% aqueous solution of hydrofluoric acid, and the AlAs peeling layer 3 is selectively etched as shown in FIG. The n-type GaAs single crystal substrate 1 is peeled off from the stacked body of the light emitting layer portion 24 and the first light extraction layer 10 bonded thereto. Hereinafter, the laminated body in a state where this processing is performed is referred to as a ZnTe / DH wafer 12.

Next, an n-type ZnTe single crystal substrate, which is another single crystal substrate for forming a light extraction layer, is similarly surface-treated with the above-described NaOH aqueous solution to form a ZnTe / DH wafer 12.
4A, and pressed and heat-treated under the same conditions as shown in FIG.
The type ZnTe single crystal substrate is joined to the surface of the n-type AlGaInP cladding layer 4 to form the second light extraction layer 13.

The laminated wafer obtained as described above is formed by forming a first electrode 14 on the first light extraction layer 10 side and a second electrode 15 on the second light extraction layer 13 side, and dicing. After that, the semiconductor chip is fixed to a support, the lead wires 14b and 15b are wire-bonded as shown in FIG. 1, and furthermore, resin sealing (not shown) is performed to obtain the light emitting element 100.

As in the light emitting device 50 shown in FIG. 5, the light extraction layer 10 may be joined to only one side of the light emitting layer portion 24 having a double hetero structure layer. In this case, n
The type GaAs substrate 1 is used as an element substrate, and a second electrode 15 is formed on the second main surface side. Further, as in a light emitting element 51 shown in FIG. 6, an n-type GaAs substrate 1 and a light emitting layer 2
For example, a semiconductor multilayer film disclosed in Japanese Patent Application Laid-Open No. 7-66455 or a metal layer made of Au or an Au alloy can be inserted as the reflection layer 16. Thereby, in addition to the light L leaking directly from the light emitting layer portion 24 to the light extraction layer side, the light L ′ reflected by the reflection layer 16
Is added, so that the light extraction efficiency can be increased. In order to further reduce the total reflection loss, Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent Publication No. 90893, the interface between the light emitting layer portion and the light extraction layer may be curved in a convex shape in the light extraction direction.

In the embodiment described above, the light extraction layer is
The light extraction layer was composed of any one of ZnSe, ZnS, ZnTe, and CdS, as shown in FIG.
It can also be formed as a laminate of a plurality of layers of different types of compound semiconductors. As for the difference in the refractive index between the light extraction layer and the surrounding medium (air, etc.), the smaller the difference, the greater the critical angle of total reflection on the surface of the light extraction layer, and the higher the light extraction efficiency from the light extraction layer. . When the light extraction layer is formed of a single compound semiconductor, this tendency increases as the refractive index of the compound semiconductor used decreases. However, if the refractive index of the compound semiconductor is too small, the refractive index difference between the light emitting layer portion and the light extraction layer becomes large, and total reflection at the interface between the two may become a problem. Therefore, as shown in FIG. 7, by arranging the layers forming the light extraction layer such that the refractive index becomes smaller as the layer located on the surface side of the light extraction layer, the light emitting layer portion, the light extraction layer, and the light The relative refractive index difference between each layer constituting the extraction layer and each interface between the light extraction layer and the surrounding atmosphere can be reduced, and total reflection can be made more difficult. FIG. 7A shows ZnTe
On the layer 21, a ZnSe layer 22 having a smaller refractive index
FIG. 2B is an example of a light extraction layer having a three-layer structure in which a CdS layer 23 having a smaller refractive index is stacked.

[Brief description of the drawings]

FIG. 1 is a schematic view illustrating an example of a light-emitting element of the present invention in a stacked structure.

FIG. 2 is a schematic view showing a modification in which a contact layer is inserted between an electrode and a light extraction layer.

FIG. 3 is a schematic view showing a manufacturing process of the light emitting device of FIG.

FIG. 4 is a schematic view following FIG. 3;

FIG. 5 is a schematic view showing an example of an element structure in which a light extraction layer is formed only on a first main surface of a light emitting layer portion.

FIG. 6 is a schematic view showing an example of an element structure in which a reflection layer is inserted on the second main surface side of the light extraction layer in FIG.

FIG. 7 is a schematic view showing some examples in which a light extraction layer is formed in a plurality of layers.

FIG. 8 is a diagram illustrating how the relationship between the incident angle of light from the light emitting layer and the critical angle θc affects the intensity of emitted light.

[Explanation of symbols]

Reference Signs List 1 n-type GaAs single crystal substrate (single-crystal substrate for growth) 4 n-type AlGaInP cladding layer (second conductivity type cladding layer) 5 AlGaInP active layer 6 p-type AlGaInP cladding layer (first conductivity type cladding layer) 10 first Light extraction layer 13 Second light extraction layer 14 First electrode 15 Second electrode 50, 51, 100 Light emitting element

Continuation of the front page (56) References JP-A-7-38148 (JP, A) JP-A-4-361572 (JP, A) JP-A-9-74221 (JP, A) JP-A-6-296040 (JP) JP-A-5-275740 (JP, A) JP-A-9-162500 (JP, A) JP-A-11-8440 (JP, A) JP-A-56-42388 (JP, A) 61-96780 (JP, A) JP 2001-15805 (JP, A) JP 2001-44495 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 33/00 H01L 21 / 60

Claims (10)

(57) [Claims] 1. Each of (Al _x Ga _1-x ) _y In _1-y
P (where 0 ≦ x, y ≦ 1 and x + y = 1) a double hetero structure in which a first conductivity type clad layer, an active layer, and a second conductivity type clad layer composed of a mixed crystal are laminated is used as a light emitting layer. And 550 on at least one side of the light emitting layer portion.
A light extraction layer made of a compound semiconductor having a refractive index of 3.2 or less for light in a wavelength band of not less than 650 nm and
Assume that multiple layers of different compound semiconductor types are stacked
Are formed Te, layers constituting the light extraction layer, light
The closer to the extraction layer surface, the lower the refractive index
A light emitting device characterized by being arranged as follows . 2. The light emitting device according to claim 1, wherein the compound semiconductor forming the light extraction layer has a band gap energy larger than a photon energy corresponding to an emission wavelength from the light emitting layer. 3. The light emitting device according to claim 2, wherein a band gap energy of the compound semiconductor constituting the light extraction layer is 2.2 eV or more. 4. A compound semiconductor constituting the light extraction layer
One light-emitting element according to any one of claims 1 to 3, characterized in that a ZnSe. 5. A compound semiconductor constituting the light extraction layer
One light-emitting element according to any one of claims 1 to 3, characterized in that a ZnS. 6. A compound semiconductor constituting the light extraction layer
One light-emitting element according to any one of claims 1 to 3, characterized in that a ZnTe. 7. A compound semiconductor constituting the light extraction layer
One light-emitting element according to any one of claims 1 to 3, characterized in that it is CdS. 8. At least an outermost layer portion of the light extraction layer
Is any of ZnSe, ZnS, ZnTe and CdS
The electrode is in direct contact with the surface of the outermost layer portion
The light emitting device according to claim 1 , wherein the light emitting device is formed. 9. Each of (Al _x Ga _1-x ) _y In _1-y
P (however, 0 ≦ x, y ≦ 1 and x + y = 1)
First conductivity type clad layer to be formed, active layer and second conductivity type
The double hetero structure where the cladding layer is laminated
Having an emission wavelength of 570 nm or more and 650 nm or less.
The mixed crystal ratios x and y are adjusted so that
570 nm or more and 650 nm or less on at least one side of the part
The refractive index for light in the wavelength band of 2.9 or more and 3.2 or less
Light - emitting element you <br/> characterized in that the light extraction layer is ZnTe is formed. 10. A first main surface side of said light emitting layer portion,
A light extraction layer is formed, and a second main surface side of the light emitting layer portion is
The second light extraction layer is formed.
9, wherein the light-emitting element.