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• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/80—Constructional details
  • H10H20/81—Bodies
  • H10H20/811—Bodies having quantum effect structures or superlattices, e.g. tunnel junctions
  • H10H20/812—Bodies having quantum effect structures or superlattices, e.g. tunnel junctions within the light-emitting regions, e.g. having quantum confinement structures
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/01—Manufacture or treatment
  • H10H20/011—Manufacture or treatment of bodies, e.g. forming semiconductor layers
  • H10H20/013—Manufacture or treatment of bodies, e.g. forming semiconductor layers having light-emitting regions comprising only Group III-V materials
  • H10H20/0137—Manufacture or treatment of bodies, e.g. forming semiconductor layers having light-emitting regions comprising only Group III-V materials the light-emitting regions comprising nitride materials
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/80—Constructional details
  • H10H20/81—Bodies
  • H10H20/822—Materials of the light-emitting regions
  • H10H20/824—Materials of the light-emitting regions comprising only Group III-V materials, e.g. GaP
  • H10H20/825—Materials of the light-emitting regions comprising only Group III-V materials, e.g. GaP containing nitrogen, e.g. GaN
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/80—Constructional details
  • H10H20/81—Bodies
  • H10H20/813—Bodies having a plurality of light-emitting regions, e.g. multi-junction LEDs or light-emitting devices having photoluminescent regions within the bodies
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/80—Constructional details
  • H10H20/81—Bodies
  • H10H20/817—Bodies characterised by the crystal structures or orientations, e.g. polycrystalline, amorphous or porous
  • H10H20/818—Bodies characterised by the crystal structures or orientations, e.g. polycrystalline, amorphous or porous within the light-emitting regions

Definitions

• LEDs or LEDs as well as luminous emitting devices based on such LEDs (screens, projectors, image walls, etc.).
• the invention is advantageously applied to LEDs emitting in the range of wavelengths corresponding to the green and / or red color, that is to say in the wavelength range between about 500 nm and 700 nm.
• LEDs emitting in the wavelength range corresponding to the green color are mainly manufactured with I nGaN quantum wells comprising a large indium composition, i.e., greater than about 25%, by compared to gallium.
• I nGaN quantum wells comprising a large indium composition, i.e., greater than about 25%, by compared to gallium.
• Such LEDs are for example described in documents US 2013/0028281 A1 and "Approaches for high interna quantum efficiency green InGa N light-emitting diodes with large overlap quantum wells" by H. Zhao et al., Optics Express, Vol. 19, Issue S4, pp.
• One of the problems of these LEDs is that an alloy demixing occurs in such quantum wells of I nGaN, which does not make it possible to obtain good radiative efficiencies within such quantum wells. because of the defects caused by this demixing alloy.
• Another problem of these LEDs is related to the strong constraint that exists between the GaN of the barrier layers (between which are the quantum wells) and the I nGaN quantum wells, this constraint resulting from the difference in mesh ratios between these two materials and causing the formation of defects, for example dislocations, in quantum wells. This constraint also tends to favor the demixing of InGaN from quantum wells.
• FIG. 1 represents the rate of radiative recombinations, in logarithmic scale and per cm 3 .
• an LED comprising a quantum well formed of an InN layer of thickness equal to 2 monolayers and disposed between two GaN barrier layers each of thickness equal to about 10 nm.
• the rate of radiative recombinations in the InN layer is of the same order of magnitude as that in the GaN barrier layer on the n side of the LED, and is relatively low (from order of 10 21 recombinations cm 3 s 1 ) due to the very low density of states in the InN layer.
• FIG. 2 represents the rate of radiative recombinations, in logarithmic scale and per cm 3 . s, obtained in a quantum well formed of a layer of InN of thickness equal to 2 monolayers and disposed between two barrier layers of lno, 2Gao, sN each of thickness equal to about 10 nm.
• the level of radiative recombinations in the InN layer is here also of the same order of magnitude as that in the InGaN barrier layer lying n-side of the LED, and is relatively low (of the order of 10 21 recombinations. cm 3. 1 s) because of the very low density of states in the InN layer.
• Document US 2011/0204328 A1 discloses a symmetrical quantum well comprising a core layer of InN disposed between two InGaN barrier layers. As previously, the very low density of states in the InN layer does not allow a satisfactory radiative recombination rate to obtain sufficient emission in the desired wavelength range.
• An object of the present invention is to propose a light-emitting diode making it possible to obtain a better rate of radiative recombinations and thus to have a better emission efficiency, especially in the wavelength range corresponding to the green or red color, while avoiding the problems of defects and demixing alloy in the active zone of the light emitting diode.
• the present invention proposes a light-emitting diode comprising at least one n- doped lnx n Ga (ix n ) N layer and a p- doped lnx p Ga (ix P ) N layer together forming a pn junction of the diode. and an active region disposed between the n layer lnx Ga (ix n) N n-doped and the p layer lnx Ga (ix P) N p-doped and in which radiative recombination are apt to occur, the area active compound comprising at least:
• the separation layer disposed between the first InN layer and the second InN layer and such that the first InN layer is disposed between the separation layer and the doped N- lnx Ga (ix n ) N layer.
• the separation layer comprising lnxbGa (i-xb) N and a thickness less than or equal to about 3 nm;
• a layer of lnxiGa (i-xi) N disposed between the n- doped n- lnx Ga (ix n ) N layer and the first InN layer;
• the charge carriers can easily pass from one layer of InN to the other.
• the second layer of InN on the p-side of the diode forms a reservoir of holes, these holes easily passing through the first InN layer which is on the n side of the diode.
• Substantially equivalent concentrations of electrons and holes are obtained in the first InN layer, which makes it possible to have a very high rate of radiative recombinations in this first InN layer, and therefore a better emission efficiency of the InN layer.
• electroluminescent diode than those of the prior art.
• a light emission in the range of wavelengths corresponding to the green or red color is well obtained.
• this excellent emission efficiency is obtained without using InGaN high indium concentration, which avoids the problems of alloy demixing and defects in the active zone of the light emitting diode.
• the thickness less than or equal to 3 nm of the layer separating the two layers of InN thus makes it possible to obtain an asymmetrical tunneling effect, that is to say that the electrons are trapped in the first layer of InN (that on the side of the n -doped lnx n Ga (i-xn) N layer while the holes can pass from the second InN layer (the one on the side of the lnx p Ga layer (ix P ) N doped p) to the first layer of InN.
• the second layer of InN forms a reservoir of holes and the first layer of InN forms the emitting layer of the diode.
• Thicknesses ei n Nio6 and emNios can be between
• the indium Xb composition may be greater than or equal to about 0.15.
• the thickness of said one or each of the first InN layer and the second InN layer may be less than or equal to 2 monolayers.
• the emNioe and emNios thicknesses can be such that emNioe ⁇ emNios. This configuration makes it possible to accentuate the roles of emissive layer and reservoir of holes respectively filled by the first layer of InN and the second layer of InN.
• the indium compositions XI and X2 may be such that XI X X2.
• the indium compositions Xn, Xp, XI and X2 may be such that Xn ⁇ X1 ⁇ X2 ⁇ Xp, which makes it possible to homogenize the distribution of the electrons in the different layers of the active zone.
• the thickness of the n- doped lnx n Ga (ix n ) N layer and / or the thickness of the p -doped lnx p Ga (i-xp) N layer may be between approximately 20 nm and 10 ⁇ . and / or the thickness of the LnxiGa (i-xi) N layer and / or the thickness of the lnx 2 Ga (i-x2) N layer may be between about 1 nm and 200 nm.
• the light emitting diode may further include a first metal electrode disposed against the n-layer lnx Ga (ix n) N n-doped and a second metal electrode disposed against the rinx p Ga layer (ix P) N p-doped.
• the active area of the light emitting diode may have a number of InN layers greater than 2, each of the InN layers being separated from the or each of the adjacent InN layers by a separation layer comprising InGaN or GaN and thickness less than or equal to about 3 nm.
• the light-emitting diode may comprise a plurality of active regions arranged between the n- doped n-doped lnx n Ga (ix n ) n layer and the p- doped lnx p Ga (ix p ) n layer and in which radiative recombinations are able to occur. .
• the light-emitting diode may furthermore comprise, between the n -doped lnx n Ga (i-xn) N layer and the active zone, an n-doped InGaN buffer layer, the n-doped InGaN of the buffer layer comprising an energy bandgap of less than or equal to about 97% of the p- banded p-type ( p ) N-banded bandwidth energy.
• the invention also relates to a method for producing a light-emitting diode as described above, wherein the layers of the light-emitting diode are planar layers grown one above the other, or in which the layers of the light-emitting diode are grown in the form of radial or axial nanowires.
• the invention also relates to a light emitting device comprising at least one light emitting diode as described above.
• FIGS. 1 and 2 represent radiative recombination rates obtained in electroluminescent diodes of the prior art
• FIG. 3 schematically shows a light emitting diode, object of the present invention, according to a particular embodiment
• FIG. 4 represents the rate of radiative recombinations obtained in the active zone of a light-emitting diode, object of the present invention, according to a first exemplary embodiment
• FIG. 5 represents the concentrations of electrons and holes obtained in the active zone of the light-emitting diode, object of the present invention, according to the first embodiment
• FIG. 6 represents the radiative recombination rate obtained in a light-emitting diode, object of the present invention, according to a second exemplary embodiment
• FIGS. 7A and 7B show diagrammatically light-emitting diodes, objects of the present invention, produced in the form of nanowires. Identical, similar or equivalent parts of the different figures described below bear the same numerical references so as to facilitate the passage from one figure to another.
• FIG. 3 schematically represents a light-emitting diode 100, or LED 100, according to a particular embodiment.
• X represents the indium composition of the material, that is to say the proportion of indium relative to the total amount of indium and gallium in the lnxGa material (ix) N.
• LED 100 has a pn junction formed by an n -doped lnx n Ga (i-xn) N layer 102 (also referred to as lnx n Ga (ix n ) Nn), with a donor concentration equal to about 3.10 18 donors / cm 3 , and a p- doped lnx p Ga (ix P ) N layer 104 (also called lnx p Ga (ix P ) Np) with an acceptor concentration equal to about 2.10 19 acceptors / cm 3 .
• These two doped layers 102 and 104 for example, each have a thickness (dimension along the Z axis shown in FIG. 3) of between approximately 20 nm and 10 ⁇ .
• a first metal electrode 101 is disposed against the lnx n Ga layer (i-xn) Nn 102 and forms a cathode of the LED 100
• a second metal electrode 103 is disposed against the lnx p Ga layer (ix P ) Np 104 and forms an anode of the LED 100.
• the lnx n Ga (ix n ) Nn 102 layer can have a donor concentration of between about 10 17 and 10 20 donors / cm 3
• the lnx layer of p Ga (ix P) Np 104 may have an acceptor concentration of between about 10 15 and 10 20 acceptors / cm 3.
• the LED 100 comprises, between the doped layers 102 and 104, an active zone 105 in which radiative recombinations occur resulting in a
• the active zone 105 comprises in particular a first layer of I nN 106 which is located on the side of the layer of lnx n Ga (ix n ) Nn 102, and a second layer of InN 108.
• the two layers of InN 106 and 108 are separated from each other by a thin separating layer 110 comprising lnxbGa on the side of the layer of lnx p Ga (ix P ) Np 104. (i-xb) N.
• the first InN layer 106 is separated from the n ⁇ n Ga layer (ix n ) Nn 102 by a layer of l nxiGa (i-xi) N 112, and the second layer of I nN 108 is separated from the layer of lnx p Ga (ix P ) Np 104 by a layer
• All the layers of the active zone 105 of the LED 100 (that is to say the layers 106, 108, 110, 112 and 114 in the example of Figure 3) comprise unintentionally doped materials (concentration of residual donors n n id equal to about 10 17 cm 3 , or between about 10 16 and 10 20 donors / cm 3 ).
• each of the indium compositions XI, X2 and Xb may be between 0 and 0.25 (when one of these indium compositions has a value of zero, the material associated with this composition is then GaN). .
• the indium compositions XI and X2 are such that 0.05 XI XI 0,0 0.08 and 0.12 X X ⁇ 0.2, and the indium composition X b is such that 0.05 X X b 0 0 2.
• the indium compositions Xn, XI, X2 and Xp respectively of the layers 102, 112, 114 and 104 are advantageously such that Xn ⁇ XI ⁇ X2 ⁇ Xp, which makes it possible to homogenize the distribution of the electrons in the layers of the active zone 105 of the LED 100.
• the thicknesses (dimensions along the Z axis shown in FIG. 3) of the InN layers 106 and 108, respectively called ei n Nio6 and einNios, are such that einNio6 e einNios.
• Each of these thicknesses ei n Nio6 and einNios is between 1 monolayer and 3 monolayers (1 Monolayer of InN corresponding to a thickness equal to about 0.25 nm), and preferably between 1 monolayer and 2 monolayers.
• Xb> 0.15 when one or both of the two thicknesses ei n Nio6 and einNios is between 2 monolayers and 3 monolayers, it is for example possible to have Xb> 0.15.
• Xb ⁇ 0.15 the thickness of this or each of these layers is preferably chosen less than or equal to about 2 monolayers.
• the thickness of the separation layer 110 is less than or equal to about 3 nm, and advantageously less than or equal to at about 2 nm.
• the two InN layers 106 and 108 are part of the same active zone of the LED 100 and work together to produce a light emission from this active zone 105 of the LED 100.
• the thicknesses of the layers 112 and 114 are between about 1 nm and 200 nm.
• a first exemplary embodiment of the diode 100 is described below.
• the n 102 doped layer has a thickness of about 500 nm and comprises GaN-n with a donor concentration of about
• the p-doped layer 104 has a thickness of about 500 nm and comprises GaN-p with an acceptor concentration of about
• the layers 112 and 114 each have a thickness of approximately 5 nm and comprise non-intentionally doped GaN (GaN-nest) of residual donor concentration n n id equal to about 10 17 cm 3.
• the InN layers 106 and 108 each have a thickness equal to about 2 monolayers and comprise ⁇ -nid.
• the separation layer 110 has a thickness equal to about 1 nm and comprises
• FIG. 4 represents the rate of radiative recombinations obtained in the different layers of the active zone 105 of the LED 100 according to the first embodiment described above.
• the references of the different layers of the LED 100 are recalled in FIG. 4, the vertical lines represented in FIG. 4 symbolizing the interfaces between the layers of the LED 100. It is seen in this figure that a maximum rate of radiative recombinations of about 24 recombinations.
• cm 3 . 1 is obtained in the first layer of InN 106 located on the GaN-n 102 layer side, which is much higher than the rate of about 10 21 recombinations.
• cm 3 . s 1 obtained with a quantum well formed of a single layer of InN disposed between two barrier layers of InGaN or GaN as previously described in connection with FIGS. 1 and 2.
• FIG. 5 represents the concentrations of electrons (represented by cross referenced 120) and holes (represented by diamonds referenced 122), per cm 3 , obtained in the different layers of the active zone 105 of LED 100 according to the first example embodiment described above.
• This figure clearly shows that in the first InN layer 106, on the side of the n 102 doped layer, the electron and hole concentrations are substantially equivalent, which makes it possible to have a high rate of radiative recombinations in this first layer.
• This good radiative efficiency in the first layer of InN 106 located on the side of the n 102 doped layer is obtained in particular by virtue of the use of the thin separation layer 110 between the two layers of InN. 106, 108 because the second layer of InN 108 then forms, vis-à-vis the first layer of InN 106, a reservoir of holes from which these holes migrate in the first layer of InN 106.
• a second exemplary embodiment of the LED 100 is described below.
• the n 102 doped layer has a thickness of about 500 nm and comprises GaN-n with a donor concentration of about
• the p-doped layer 104 has a thickness of about 500 nm and comprises GaN-p with an acceptor concentration of about
• the layers 112 and 114 each have a thickness of about 2 nm and comprise unintentionally doped 1n, 2Gao, 8N (lno, 2Gao, sN-nid) residual donor concentration n n id equal to about 10 17 cm 3 .
• the two layers InN 106 and 108 both contain ⁇ -nid. In this second exemplary embodiment, the two InN layers 106 and 108, on the other hand, have different thicknesses.
• the first InN layer 106 located on the side of the n-doped layer 102 has a thickness equal to about 1 monolayer and the second InN layer 108 located on the p-doped layer side 104 has a thickness equal to about 3 monolayers.
• the separation layer 110 has a thickness of about 2 nm and comprises lno, 2Gao, 8N-nest. The rate of radiative recombinations obtained in LED 100 according to this second exemplary embodiment is shown in FIG. 6.
• This dissymmetry between the thicknesses of the InN layers 106 and 108 makes it possible to promote the light emission produced by the thinnest InN layer (here the first InN layer 106 being on the side of the n 102 doped layer). Because this small thickness makes it possible to have better control of the light emission produced by the first layer of InN 106.
• the greater thickness of the second layer of InN 108 makes it possible to accentuate the role reservoir, or capture, holes filled by this layer, and therefore to increase the rate of recombination occurring in the first layer of InN 106.
• the active zone 105 of the LED 100 may comprise more than two InN-nest layers, each of these InN layers being in this case separated from the or each of the layers. adjacent InNs by a thin layer of separation similar to the layer 110 and comprising InGaN (the proportion of InGaN indium of each of these thin separating layers which may or may not be similar to a layer of other) or GaN.
• the LED 100 comprises, between the doped layers 102 and 104, several active zones, for example similar to the active zone 105 previously described. , arranged one above the other, and each comprising at least two layers of InN separated from each other by a thin separation layer similar to the separation layer 110 described above.
• the LED then forms a LED with multiple quantum wells.
• an InGaN-n buffer layer comprising a band energy. of less than or equal to about 97% of the band gap energy of the p- channel (ix P ) Np of the layer 104.
• Such a buffer layer creates, by its bandgap energy less than or equal to about 97% of the bandgap energy of the p-doped layer 104, that is to say such that the gap of this buffer layer is at least 3% less than the gap of the p-doped layer 104 (Egtampon ⁇ 0 , 97 Egio 4 ), an asymmetry in the structure of the LED 100, and more particularly an asymmetry in the pn junction of the LED 100. This asymmetry facilitates the circulation of the holes in the LED 100 and makes it possible to obtain a more homogeneous distribution. carriers (electrons and holes) in the active zone 105 of the LED 100.
• This buffer layer comprises InGaN with advantageously an indium composition greater than or equal to 2.5% relative to to the value of Xp, that is to say of the indium composition of the semiconductor of the p-doped layer 104.
• the buffer layer and the n-doped layer 102 may comprise a semiconductor of identical composition and / or doping.
• the indium composition of the semiconductor of the n-doped layer 102 may be similar to the indium composition of the semiconductor of the buffer layer, and / or the concentration of donors in the semiconductor of the n-doped layer. 102 may be similar to the donor concentration in the n-doped semiconductor of the buffer layer.
• the indium composition of the semiconductor of the buffer layer may vary along the thickness of the buffer layer, thereby forming a gradient in the indium composition along the thickness of the buffer layer. It is also possible to make a superlattice (ln, Ga) N / lnGaN for the buffer layer. It is also possible for the LED 100 to comprise an electron-blocking layer, for example based on AIGaN, placed between the layer 114 and the p-doped layer 104. Such an electron-blocking layer makes it possible to prevent the passing electrons to the p-doped layer 104. Such an electron-blocking layer also makes it possible to decrease the DROOP, ie the fall in the internal quantum efficiency when the current density in the LED increases, this fall being partially due to the escape of electrons from the active zone 105 when the current increases.
• Such an LED 100 operates regardless of the orientation of the structure, whether in the plane c (under the presence of a strong internal electric field), the plane M, semi-polar, etc.
• the LED 100 may be in the form of a planar diode as shown in FIG. 3, that is to say in the form of a stack of layers formed on a substrate (the substrate not being represented on Figure 3), the main faces of the different layers being arranged parallel to the plane of the substrate (parallel to the plane (X, Y)).
• a first layer of GaN of thickness equal to about 2 ⁇ on a sapphire substrate for example by MOCVD ("MetalOrganic Chemical Vapor Deposition" in English) at a temperature of about 1000 ° C. vs.
• MOCVD MetalOrganic Chemical Vapor Deposition
• This growth is completed by forming the layer 102 of GaN-n doped with silicon at 3.10 18 donors / cm 3 , with a thickness of about 500 nm.
• the temperature is then lowered to about 830 ° C to grow about 10 nm of unintentionally doped 10n, osGao, 95N, forming layer 112.
• the temperature is then lowered to about 600 ° C to grow 3 monolayers of InN unintentionally doped, forming the first layer of InN 106.
• the temperature is raised to about 720 ° C to grow 1 nm of lno, 2Gao, sN unintentionally doped, forming the separation layer 110.
• the temperature is lowered from again at about 600 ° C to grow 2 unintentionally doped InN monolayers, forming the second layer
• the temperature is raised to about 750 ° C to grow 10 nm of unintentionally doped 11n, 12Gao, 88N, forming layer 114.
• the temperature is lowered to about 730 ° C to grow 500nm. 1n, isGao, 82N doped with magnesium, forming the layer 104.
• the second metal electrode 103 is then made in the form of a Ni / Au layer on the p-doped layer 104, and the first metal electrode 101 is finally performed in the form of a Ti / Au layer on the n 102 doped layer (after separation of the n 102 doped layer with the first GaN layer of thickness equal to about 2 ⁇ ).
• the LED 100 may be in the form of nanowires.
• FIG. 7A represents such an LED 100 made in the form of axial nanowires, these nanowires comprising a stack formed of the first electrode 101, a semiconductor substrate 124 (for example gallium) of n-type, nucleating layer 126 for the growth of the nanowires, the n-doped layer 102, the active zone 105, the p-doped layer 104, and the second electrode 103.
• An insulating material 128 may surround at least a portion of these nanowires which extend parallel to the Z axis.
• FIG. 7B represents an LED 100 made in the form of radial nanowires, these nanowires comprising a stack formed of the first electrode 101, the semiconductor substrate 124, the nucleation layer 126 and the n 102 doped layer. insulating portions 128 partially surround the n-doped layer 102 and the nucleation layer 126.
• the active zone 105 (formed at least of the layers 106, 108, 110, 112 and 114) is formed such that it surrounds at least a portion of the nd-doped layer 102.
• the p-doped layer 104 is made such that it surrounds the active zone 105.
• the second electrode 103 is made by covering the p-doped layer 104.
• the structure of these nanowires can be reversed, with in this case a semiconductor substrate 124, for example gallium nitride, of the p-type on which is realized the p-doped layer 104, then the other elements of the LED 100 in the reverse order of that described in FIGS. 7A and 7B.
• a semiconductor substrate 124 for example gallium nitride
• diode 100 in the form of radial nanowires is described below.
• Silicon doped GaN nanowires with a donor concentration equal to about 3 ⁇ 10 18 donors / cm 3 are grown on a sapphire substrate, for example by MOCVD at a temperature of about 1050 ° C., also forming a layer of silica.
• the temperature is then lowered to about 600 ° C to grow a shell of thickness equal to about 3 monolayers of unintentionally doped InN, forming the first layer of InN 106.
• the temperature is rising to about 720 ° C to grow a shell of thickness equal to about 1 nm of lno, 2Gao, sN unintentionally doped, forming the separation layer 110.
• the temperature is lowered again cal at about 600 ° C to grow a shell of thickness equal to about 2 monolayers of unintentionally doped InN, forming the second layer of InN 108.
• the temperature is raised to about 750 ° C to grow a shell of a thickness equal to about 10 nm of lno, i2Gao, 88N unintentionally doped, forming the layer 114.
• the active area 105 here forms a stack of shells on each other.
• the temperature is lowered to about 720 ° C to grow a shell of thickness about 500 nm magnesium-doped 1n, isGao, 82N forming the p-doped layer 104.
• the second metal electrode 103 is then made under the shape of a Ni / Au layer on the nm shell, isGao, Mg doped 82N, and the first metal electrode 101 is then formed as a Ti / Au layer on the Si doped GaN layer. between the GaN nanowires (n-doped Si layer 102 previously described).
• the electrode 103 Ni / Au which is also deposited between the wires, is etched by fluorinated reactive ionic etching for nickel and by Kl etching for gold. According to this embodiment, n-doped nanowires connected by a continuous 2D layer of n-doped GaN are obtained.
• the various characteristics (thicknesses, doping, etc.) previously exposed for the planar type LED 100 may be similar for the LED 100 made in the form of nanowires.
• the temperatures indicated above for the realization of the LED 100 in planar form or nanowires vary according to the MOCVD device used. In addition, in the case of a nanowire structure, the temperatures can vary depending on the diameters, lengths and density of the nanowires.

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