Optoelectronic device with transition zones

Abstract

Title: Optoelectronic device with transition zones The invention relates to an optoelectronic device comprising a first LED (100) forming a first active structure and comprising first nanowires (101) having first diameters φ1 such that 0.9.φ10 < φ1 < 1.1.φ10 with φ10 a target value of the first diameters, said first nanowires (101) being arranged according to at least a first lattice with pitch p1, said first LED being configured to emit a first light beam having mainly a first wavelength λ1, and a first transition zone (1000) bordering at least partially said first LED (100), said first transition zone (1000) comprising a plurality of first transition nanowires (1001), the device being characterized in that the first transition nanowires (1001) have first transition diameters and / or a first transition lattice pitch varying progressively with respect to the first LED (100). Figure for the abstract: Fig. 3.

Description

Title of the invention: Optoelectronic device with transition zones technical field

[0001] The present invention relates in particular to the field of microelectronics and optoelectronics technologies. Its particularly advantageous, but not limiting, application lies in LED (Light-Emitting Diode) display systems. PRINCIPAL OF THE TECHNOLOGY

[0002] A display screen generally comprises a plurality of pixels arranged on a so-called basal plane and emitting independently of one another. Each color pixel generally comprises at least three emission and / or light conversion components, also called sub-pixels. These sub-pixels each emit a light flux substantially in a single color (typically red, green, and blue). The color of a pixel perceived by an observer results from the superposition of the different light fluxes emitted by the sub-pixels.

[0003] Typically, an LED or micro-LED emits the luminous flux associated with a sub-pixel. An LED may, in particular, comprise a plurality of active nanowires arranged in a periodic photonic crystal and emitting said luminous flux at the desired wavelength. This photonic crystal is characterized, in particular, by the diameter of the nanowires and the pitch between the nanowires.

[0004] Figure 4a illustrates a classic arrangement of subpixels within a pixel. While practical, this type of arrangement does not offer optimal performance. Therefore, there is a need to improve the performance of self-emissive nanowire-based pixels. SUMMARY

[0005] To achieve this objective, according to one embodiment, an optoelectronic device is provided comprising at least: - a first LED extending mainly in a plane defined by a first direction and a second direction, said first LED comprising a plurality of first nanowires having first diameters having a value substantially equal to a first target value q>i0 and arranged in Ni fd” rows oriented along the second direction, said first rows, said first rows being separated by first distances taken along the first direction having a value substantially equal to a first target distance piOjX, said first LED being configured to emit a first beam of light having primarily a first wavelength and - a first transition zone extending mainly in the plane and at least partially bordering said first LED, said first transition zone comprising a plurality of first transition nanowires having first transition diameters and organized in Nt^x, rows oriented along the second direction, called first transition rows and indexed according to a numbering from 1 to Nt^x,! moving away from the first LED along the first direction, the first rows being indexed according to a numbering from 1 to Ni along the first direction moving closer to the first transition zone, the device being characterized in that the first transition zone comprises a first sub-transition zone formed by the first Nsous tranS,i transition rows, with 2 < Nsous tranSji < Ntrans,x,i, bordering the first LED, first sub-transition zone in which: - the first transition nanowires are such that: i. the value of the first transition diameters of the first transition nanowires of the first transition row no. 1 varies in a proportion less than 5% of the first target value q>i0, and ii. the value of the first transition diameter of each first transition nanowire of any first transition row n°i, i being between 2 and Nsous_tranS,i, varies in a proportion between 3% and 13% of the value of the first transition diameter of the first transition nanowire of the first transition row n°i-1 being closest to it, and / or - the first transition nanowires are such that: i. The first row n°NLEDjXji and the first transition row n°l are separated along the first direction x by a first interface distance dinterfacejb. The first interface distance dinterface>i and the distance along the first direction between the first transition row n°1 and the first transition row n°2 vary in a proportion between 2% and 4% of the distance along the first direction between the first row n°Ni .fd , il and the first row n°Ni pd ki and the first interface distance dinterfaceCe, respectively. ii. The distance along the first direction between any first transition row n°i and the first transition row n°i+l varies in a proportion between 2% and 4% of the distance along the first direction between the first transition row n°i-1 and the first transition row n°i, i being between 2 and

[0006] The optoelectronic device can also be described as comprising at least: - a first LED comprising a plurality of first nanowires having first diameters with a value substantially equal to a first target diameter value q>i0 and arranged in rows oriented along a second direction, called first rows, and separated by first distances taken along a first direction having a value substantially equal to a first target distance value piOjX, said first LED being configured to emit a first light beam having mainly a first wavelength XI, and - a first transition zone bordering at least partially said first LED, and comprising a plurality of first transition nanowires having first transition diameters and arranged in rows oriented along the second direction, called first transition rows, and separated by first transition distances along the first direction, said first LED and said first transition zone being separated, between a first row and an adjacent first transition row, by a first interface distance along the first direction, the device being characterized in that, moving away from the first LED along the first direction: - the value of the first transition diameters of the first transition row adjacent to the first LED varies by less than 5% of the first target diameter value, and the value of the first transition diameters varies from one adjacent row to the next, between two adjacent first transition rows, by a proportion between 3% and 13%, and / or - the value of the first interface distance is between 2% and 4% of the first target distance value, the value of the distance between the first transition row adjacent to the first LED and the first transition row adjacent to it is between 2% and 4% of the first interface distance, and the value of the first transition distances varies from one to the next, between two first adjacent transition rows, in a proportion between 2% and 4%.

[0007] A key challenge of these technologies concerns the transition zones between adjacent sub-pixels. Indeed, the sub-pixels constituting current display screens are typically placed side by side, whereas a sub-pixel exhibits very Often, the nanowire diameter and inter-nanowire pitch differ from those of the neighboring subpixel. Only abrupt 1000' transition zones separate the subpixels, as shown in [Fig. 4a]. The same is true at the higher level, between pixels. The presence of these abrupt 1000' transition zones has the disadvantage of breaking the lattice symmetry and, consequently, creating detrimental edge effects during nanowire growth. These edge effects also prevent the achievement of an otherwise advantageous optical cavity effect at the subpixel level.

[0008] The presence of a transition zone makes it possible to avoid any break in symmetry and to reduce the phenomenon of edge effects.

[0009] According to an advantageous possibility, transition nanowires also make it possible to extend the gamut of a set of subpixels, that is, the set of colors that it can render. The spectrum of colors that can be emitted by a pixel is typically limited to the set of colors within the triangle defined by the native colors emitted by three subpixels constituting said pixel on the chromaticity diagram of the CIE (International Commission on Illumination) XYZ color system, typically red (C1), green (C2), and blue (C3), as shown in [Fig. 6a]. The colors within this triangle, called gamut 4, are actually obtained by linear combinations of the three native colors emitted by the three subpixels of the pixel. Only a limited range of chromaticities can thus be obtained. The present invention proposes a solution for extending this range.

[0010] Thus, in this perspective, it is predicted that the first transition nanowires will have an active region configured to emit a first transition light beam having mainly a first transition wavelength distinct from the first wavelength XL BRIEF DESCRIPTION OF FIGURES

[0011] The aims, objects, features and advantages of the invention will become clearer from the detailed description of an embodiment thereof, which is illustrated by the following accompanying drawings in which:

[0012] [Fig.1] Fig.1 represents a top view of the device according to an embodiment of the invention, comprising an LED and a transition zone.

[0013] [Fig.2] Fig.2 represents a top view of the device according to an embodiment of the invention, comprising two LEDs separated by a transition zone.

[0014] [Fig.3] Fig.3 represents a cross-section of the device according to an embodiment of the invention, comprising two LEDs separated by a transition zone.

[0015] [Fig.4a] Fig.4a represents a four-LED device with abrupt transition zones between the LEDs, according to the prior art.

[0016] [Fig. 4b] [Fig. 4b] represents a four-LED device according to a mode of rea In the implementation of the invention, this device presents progressive transition zones between the LEDs.

[0017] [Fig.5] Fig.5 represents a device according to the invention with three LEDs separated by progressive transition zones.

[0018] [Fig.6a] The [Fig.6a] represents the chromaticity diagram of a pixel commonly used in current display screens.

[0019] [Fig.6b] Fig.6b represents the chromaticity diagram of a pixel that can be obtained using the device that is the subject of the invention.

[0020] [Fig.7] Fig.7 represents a three-LED device according to an embodiment of the invention, this device having active progressive transition zones between the LEDs as well as an intermediate region emitting white light.

[0021] [Fig.8] Fig.8 represents a device according to the invention with two LEDs separated by a progressive transition zone.

[0022] The drawings are given by way of example and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate understanding of the invention and are not necessarily to scale with practical applications. In particular, the dimensions of each of the elements are not representative of reality. DETAILED DESCRIPTION

[0023] Before proceeding with a detailed review of embodiments of the invention, optional features that may be used in combination or alternatively are listed below:

[0024] According to one embodiment, the first transition diameters of the first transition nanowires of the same first transition row are equal.

[0025] According to one embodiment: - the value of the first transition diameters of the first transition nanowires of the first transition rows shows a strictly increasing or strictly decreasing evolution over at least three successive first transition rows when moving away from the first LED, and / or - the distance between two successive first transition rows when moving away from the first LED shows a strictly increasing or strictly decreasing evolution over at least three successive first transition rows when moving away from the first LED.

[0026] According to one embodiment: - the value of the first transition diameters of the first transition nanowires of the first transition rows shows a linear evolution over at least three successive first transition rows as you move away of the first LED, and / or - the distance between two successive first transition rows when moving away from the first LED shows a linear evolution over at least three successive first transition rows when moving away from the first LED.

[0027] According to one embodiment, the first nanowires and the first transition nanowires are further arranged in rows along the first direction.

[0028] According to one embodiment the first direction and the second direction are orthogonal.

[0029] According to one embodiment, the first transition subzone extends over at least three rows, preferably at least five rows, of first transition nanowires.

[0030] According to one embodiment the first sub-transition zone has a surface Siooo and the first LED has a surface Sioo such that Sioo / 5 < Siooo < Sioo / 2.

[0031] According to one embodiment, the first nanowires on the one hand and the first transition nanowires on the other hand are powered by separate electrical contacts.

[0032] According to one embodiment, the device further comprises: - a second LED extending mainly in the plane, said second LED comprising a plurality of second nanowires having second diameters having a value substantially equal to a second target diameter q>20 and arranged in Ni m rows oriented along the second direction, said second rows, and indexed according to a numbering from 1 to N, fd x ? moving away from the first transition zone along the first direction, said second rows being separated by first distances taken along the first direction having a value substantially equal to a second target distance p2o.x- said second LED being configured to emit a second light beam having mainly a second wavelength X2, the said first and second LEDs being separated at least by the first transition zone.

[0033] According to an embodiment N^^pN^^ and: - the value of the first transition diameters of the first transition nanowires of the first transition row varies in proportion less than 5% of the second target diameter <p2o, et / ou - the second row n°1 and the first transition row noNsous trans,ibeing separated along the first direction by a second interface distance d interface, 2? - the distance along the first direction between the first transition row n°Nsous_tranS,i and the first transition row n°Nsous_tranS,il vary in a proportion between 2% and 4% of the second interface distance d interface, 2*

[0034] According to one embodiment, the first transition zone comprises a second sub-transition zone formed by the first transition rows n°Nsous_trans,2 to N trans.x.1, with Nsous trans,i < Nsous_trans,2 <NtranS,x,i, deuxième sous-zone de transition dans laquelle : - the first transition nanowires are such that: i. The value of the first transition diameters of the first transition nanowires of the first transition row n°1^^,1 varies in a proportion less than 5% of the second target diameter q>20, and ii. The value of the first transition diameters of the first transition nanowire of any first transition row n°i, i being between Nsous-trans,2 and Ntrans.xi-l varies in a proportion between 3% and 13% of the value of the first transition diameters of the first transition nanowires of the first transition row n°i+l, and / or - the first transition nanowires are such that: i. the second row n°1 and the first transition row n°Ntrans.x.1 being separated along the first direction x by a second interface distance dinterface>2, the distance along the first direction (x) between the first transition row n°Ntrans,x,i and the first transition row n°Ntrans.x,il and the second interface distance dinterface 2 vary in a proportion between 2% and 4% of the second interface distance dinterface 2 and the distance along the first direction (x) between the second row n°1 and the second row n°2 respectively, ii. The distance along the first direction between any first transition row n°i and the first transition row n°i-1 varies in a proportion between 2% and 4% of the distance along the first direction between the first transition row n°i and the first transition row n°i+l, i being between Ntrans>x>i-1 and Nsous tranS,2 +1.

[0035] According to one embodiment: - the value of the first transition diameters of the first transition nanowires of the first transition rows shows a strictly increasing or strictly decreasing evolution over at least the first three successive transition rows moving away from the second LED, and / or - the distance between two first successive transition rows in moving away from the first LED exhibits a strictly increasing or strictly decreasing evolution over at least three successive first transition rows when moving away from the second LED.

[0036] According to one embodiment: - the value of the first transition diameters of the first transition nanowires of the first transition rows shows a linear evolution over at least three successive first transition rows when moving away from the second LED, and / or - the distance between two successive first transition rows when moving away from the first LED shows a linear evolution over at least three successive first transition rows when moving away from the second LED.

[0037] According to one embodiment, the second rows are spaced along the first direction x by a distance called second pitch p2.

[0038] According to an embodiment Nsous tranSji < Nsous tranSj2 and wherein: - the distance between the first transition rows noNsous tranSji at n°Nseuii,i, with Nso^-t^^Nseuii,!^ 2 is constant and / or, - the first transition diameters of the first transition nanowires of the first transition rows n°Nsous trans>i to n°Nseuii,i, with Nsous_trans>i <Nseuiiji< NsoustranSj2Sont constants, thus forming a sub-zone known as the first threshold sub-zone.

[0039] According to one embodiment at least a portion of the first transition nanowires comprise an active region configured to emit a first transition light beam.

[0040] According to one embodiment, the first transition light beam mainly has a first transition wavelength with Xi and ,i

[0041] According to one embodiment: - the first nanowires are organized into Ni pn yi rows oriented along the first direction, called first secondary rows, indexed according to a numbering from 1 to Ni pn yi and separated by first secondary distances taken along the second direction having a value substantially equal to a first target secondary distance pi0>y, and - the second nanowires are organized into Ni pn,^ rows oriented along the first direction, called secondary second rows and indexed according to a numbering from 1 to Ni pny2 and separated by second distances se secondary distances taken along the second direction having a value substantially equal to a second secondary target distance p2o,y.

[0042] According to one embodiment, the device further comprises: - a third LED extending mainly in the plane, said third LED comprising a plurality of third nanowires having third diameters having a value substantially equal to a target third diameter q>30 and arranged in Ni pd, ^rows oriented along the second direction, called third rows and in NLED y 3rows oriented along the first direction, called secondary third rows, said third LED being configured to emit a third light beam having mainly a third wavelength X3, - a second transition zone extending mainly in the plane and at least partially bordering said second LED and said third LED, said second transition zone comprising a plurality of second transition nanowires having second transition diameters and arranged in Ntrans,y,2 rows oriented along the first direction, called secondary second transition rows and indexed according to a numbering from 1 to Ntrans.yi approaching the second LED along the second direction, - a third transition zone extending mainly in the plane and bordering at least in part said third LED and said first LED, said third transition zone comprising a plurality of third transition nanowires having third transition diameters and organized into Ntrans,y,3 rows oriented along the first direction, called secondary third transition rows and indexed according to a numbering from 1 to Ntra^^ approaching the first LED along the second direction, said second and third LEDs being separated by the second transition zone, said third and first LEDs being separated by the third transition zone, wherein the second nanowires of the second transition zone are such that: i. The value of the second transition diameters of the second transition nanowires of the second transition row #1 varies in a proportion less than 5% of the third target diameter q>30, and ii. The value of the second transition diameter of each second transition nanowire of any second secondary transition row n°i, i being between 2 and Nu-ans, varies in a proportion between 3% and 13% of the value of the second transition diameter of the second transition nanowire of the second secondary transition row n°i-1 being the largest close, and iii. The value of the second transition diameters of the second transition nanowires of the second transition row noNtranSjy,2 varies by less than 5% of the target second diameter <p2o, and / or i. the second secondary row n° 1 and the second secondary transition row n°Ntransjyj2 being separated along the second direction (y) by a third interface distance dinterface 3, the third interface distance dinterface,3 and the distance along the second direction (y) between the second secondary transition row noNtrans>yj2 and the second secondary transition row n°Ntrans^^-l vary in a proportion between 2% and 4% of the distance along the second direction (y) between the second secondary transition row noNtrans>yj2 and the second secondary transition row n°Ntrans,y,2-1 and the third interface distance dinterface,3 respectively, ii. The distance along the second direction between any second secondary transition row n°i and the second secondary transition row n°i+l varies in a proportion between 2% and 4% of the distance along the second direction between the second secondary transition row n°il and the second secondary transition row n°i, i being between 2 and N trans,y,2” 1 »Ct iii. the third secondary row n° Ni i and the second secondary transition row n°l being separated along the second direction by a fourth interface distance dinterface>4, the fourth interface distance dinterface>4 and the distance along the second direction between the second secondary transition row n°2 and the second secondary transition row n°1 vary in a proportion between 2% and 4% of the distance along the second direction between the third secondary row noNLED y 3 and the third secondary row n° NLED y 3-l and the fourth interface distance dinterface4 respectively, and in which the third nanowires of the third transition zone are such that: i. the value of the third transition diameters of the third transition nanowires of the third transition row #1 varies in a proportion less than 5% of the target third diameter q>30, and ii. The value of the third transition diameter of each third transition nanowire of any third secondary transition row n°i, i being between 2 and Nn-ans,y,3, varies in a proportion between 3% and 13% of the value of the third transition diameter of the third transition nanowire of the third secondary transition row n°i-1 being the most close, and iii. the value of the third transition diameters of the third transition nanowires of the third transition row noNtranSjy>3 varies in a proportion less than 5% of the first target diameter q>i0, and / or i. the first secondary row no. 1 and the third secondary transition row no. Ntrans.y.3 being separated along the second direction by a sixth interface distance dinterface6, the sixth interface distance dinterface6 and the distance along the second direction between the third secondary transition row noNtrans>yj3 and the third secondary transition row no. N^ns^-l vary in a proportion between 2% and 4% of the distance along the second direction between the third secondary transition row noNtransjy>3 and the third secondary transition row no. N^ns^-l and the sixth interface distance dinterface,3 respectively, ii. The distance along the second direction between any third secondary transition row n°i and the third secondary transition row n°i+1 varies in a proportion between 2% and 4% of the distance along the second direction between the third secondary transition row n°i-1 and the third secondary transition row n°i, i being between 2 and N trans,y,3” 1 iii. the third secondary row n° NLED y>3 and the third secondary transition row n°1 being separated along the second direction by a fifth interface distance dinterfacej5, and the fifth interface distance dinterface5 and the distance along the second direction between the third secondary transition row n°2 and the third secondary transition row n°1 vary in a proportion between 2% and 4% of the distance along the second direction between the third secondary row n°NLED>y 3 and the third secondary row n° NiEny 3-1 and the fourth interface distance dinterfacej4 respectively.

[0043] According to one embodiment, the device further comprises an intermediate region bordered by the first transition zone, the second transition zone, the third transition zone and the third LED, said intermediate region comprising a plurality of intermediate nanowires having a diameter distribution such that the set of said intermediate nanowires emit at a plurality of wavelengths distributed over the whole of the visible spectrum.

[0044] A wire or nanowire is understood to be a 3D structure elongated in the longitudinal direction. The longitudinal dimension of the 3D structure, along z in the figures, is greater, and preferably much greater, than the transverse dimensions of the structure. 3D, in the xy plane in the figures. The longitudinal dimension is, for example, at least five times, and preferably at least ten times, greater than the transverse dimensions.

[0045] The diameter refers to the largest transverse dimension of the nanowire. In the present invention, the 3D structures do not necessarily have a circular cross-section. In particular, in the case of GaN-based 3D structures, this cross-section may be hexagonal. The diameter then corresponds to the distance between two opposite vertices of the hexagonal section. Alternatively, the diameter may correspond to an average diameter calculated from the diameter of a circle inscribed in the polygon of the cross-section and the diameter of a circumcircle of this polygon.

[0046] 3D structures may also have a hexagonal or polygonal cross-section.

[0047] In this patent application, the terms "light-emitting diode", "LED" or simply "diode" are used synonymously. An "LED" may also be understood to mean a "micro-LED".

[0048] In the following, the following abbreviations relating to a material M may be used:

[0049] Mi refers to the intrinsic or unintentionally doped material M, according to the terminology usually used in the field of microelectronics for the suffix -i.

[0050] Mn refers to the material M doped N, N+ or N++, according to the terminology usually used in the field of microelectronics for the suffix -n.

[0051] Mp refers to the material M doped with P, P+ or P++, according to the terminology usually used in the field of microelectronics for the suffix -p.

[0052] A substrate, layer, or device "based on" a material M is understood to mean a substrate, layer, or device comprising only that material M or that material M and optionally other materials, for example, alloying elements, impurities, or dopant elements. Thus, a 3D structure based on gallium nitride (GaN) may, for example, comprise gallium nitride (GaN or GaN-i) or doped gallium nitride (GaN-p, GaN-n). An active region based on gallium-indium nitride (InGaN) may, for example, comprise gallium-aluminum nitride (AlGaN) or gallium nitride with varying aluminum and indium content (GalnAIN). In the context of the present invention, the material M is generally crystalline.

[0053] A coordinate system, preferably orthonormal, comprising the x, y, z axes is shown in the attached figures.

[0054] The terms "approximately," "about," and "in the order of" mean, when referring to a value, "within 10%" of that value, or, when referring to an angular orientation, "within 10°" of that orientation. Thus, a direction substantially normal to a plane means a direction having an angle of 90 + 10° with respect to the plane.

[0055] A "light beam exhibiting predominantly a wavelength X" is defined as a beam whose peak spectral wavelength is at wavelength X. The beam spectrum typically follows a Gaussian distribution. The peak of the spectrum is then understood as the maximum value of the Gaussian distribution.

[0056] The term "light beam emitted mainly along a direction d" means a beam whose maximum luminous intensity is located in the axis defining the direction d.

[0057] To determine the geometry of the 3D structures and the compositions of the different elements (wire, active region, collar for example) of these 3D structures, one can carry out analyses of Scanning Electron Microscopy (SEM) or Transmission Electron Microscopy (TEM or TEM for the English acronym for "Transmission Electron Microscopy") or even Scanning Transmission Electron Microscopy (STEM) (English acronym for "Scanning Transmission Electron Microscopy").

[0058] TEM or STEM are particularly well suited to the observation and identification of quantum wells – whose thickness is generally on the order of a few nanometers – in the active region. Various techniques, listed below in a non-exhaustive manner, can be implemented: dark-field and bright-field imaging, weak beam imaging, and high-angle annular dark field (HAADF) diffraction.

[0059] The chemical compositions of the different elements can be determined using the well-known EDX or X-EDS method, an acronym for "energy dispersive x-ray spectroscopy" which means "energy dispersive analysis of X-ray photons".

[0060] This method is well suited for analyzing the composition of small optoelectronic devices such as 3D LEDs. It can be implemented on metallurgical sections within a Scanning Electron Microscope (SEM) or on thin sections within a Transmission Electron Microscope (TEM).

[0061] The optical properties of the different elements, and in particular the main emission wavelengths of the axial 3D LEDs based on GaN and / or the active regions based on InGaN, can be determined by spectroscopy.

[0062] Cathodoluminescence (CL) and photoluminescence (PL) spectroscopies are well suited to optically characterize the 3D structures described in the present invention.

[0063] The techniques mentioned above make it possible in particular to determine whether an optoelectronic device with an axial 3D wire structure includes InGaN-based quantum wells formed at the top of a GaN-based wire, and a masking layer indicative of an implementation of a MOVPE-type deposition.

[0064] It should be noted that in the chromaticity diagrams shown in Figures 6a and 6b, the coordinates correspond to the trichromatic x and y coordinates typically defined by the standards of the CIE XYZ colorimetric system.

[0065] As illustrated in [Fig. 3], the optoelectronic device 1 of the invention typically comprises a substrate 2 extending along the xy plane shown in Figures 1 to 5. The substrate has a top face 20 also extending along the first and second directions. The substrate 2 may be in the form of a stack comprising, along the z direction, a support 21, a surface layer called a nucleation layer 22, and a masking layer 23.

[0066] The support 21 can be made of sapphire to limit lattice parameter mismatch with GaN, or of silicon to reduce costs and address technological compatibility issues. In the latter case, it can be in the form of a wafer with a diameter of 200 mm or 300 mm. It serves, in particular, as a support for 3D structures.

[0067] The nucleation layer 22 is, for example, based on AIN. It can alternatively be based on other metal nitrides, for example GaN or AlGaN. It can be formed on the silicon support 21 by epitaxy, preferably by metal-organic vapor phase epitaxy (MOVPE). In a known manner, one or more intermediate buffer layers can be arranged between the nucleation layer 22 and the support 21. According to one example, the nucleation layer 22 has a thickness of between 1 nm and 10 pm. Preferably, it has a thickness on the order of a few hundred nanometers, for example about 100 nm or 200 nm, to a few microns, for example on the order of 2 pm. It can also have a thickness of less than 100 nm. Such a thickness helps to limit the appearance of structural defects in the nucleation layer 22.In particular, the growth of this nucleation layer 22 can be pseudomorphic, meaning that the epitaxial constraints (related in particular to the difference in lattice parameters between Si and AlN, GaN or AlGaN) can be elastically relaxed during growth. The crystalline quality of this nucleation layer 22 can thus be optimized.

[0068] The masking layer 23 is preferably made of a dielectric material, for example silicon nitride Si3N4. It can be deposited by chemical vapor deposition (CVD) onto the nucleation layer 22. It partially masks the nucleation layer 22 and includes or Preferably circular openings exposing areas of the nucleation layer 22. These openings typically have different dimensions, for example different diameters, depending on the areas considered, in particular the areas corresponding to the first LED and / or the first transition zone and / or the second LED and / or the second transition zone etc. The openings can be distributed regularly within each zone, for example in the form of an ordered network. Different pitches d, i.e., the distance separating the centers of two adjacent apertures 120, can be defined according to these zones. These apertures can be created, for example, by UV or DUV lithography (acronym for Deep UV), by electron beam lithography, or by NIL (acronym for Nanoinprint lithography). Such a masking layer 23 allows localized growth of a 3D structure, such as a nanowire, from the nucleation layer 22 and at each aperture. The lower part of the 3D structure then rests on the nucleation layer of the substrate 2 via its base.

[0069] The optoelectronic device 1 further comprises a first LED 100 disposed on the upper face 20 of the substrate 2 and also extending in the xy plane. This first LED 100 typically comprises at least one active nanowire 101. Such a nanowire 101 advantageously extends from the optional nucleation layer 22 and through an opening in the optional masking layer 23 of the substrate 2. The first LED 100 advantageously comprises a plurality of first active nanowires 101, as shown in Figures 1 to 5.

[0070] The first nanowires 101 have initial diameters with a value substantially equal to a target value called the first target diameter q>i0. It is understood that, due to inaccuracies arising from the manufacturing processes, it is difficult for all the first nanowires 101 to have a diameter equal to the first target diameter q>i0. Therefore, for each first nanowire, a first real diameter, denoted cpi.n, is defined, where n indexes the first nanowires and thus varies from 1 to Ni, Ni being the number of first nanowires 101. This first real diameter is preferably such that 0.9.q>i0 < <Pi,n < 1,l.q>io. Variations in the nanowire diameter value due to manufacturing variations can indeed be estimated at approximately 10% of the target value.

[0071] A first active nanowire 101 comprises an active region 102 and is typically electrically connected. This active region 102 is the site of radiative recombinations of electron-hole pairs, resulting in light radiation with a principal wavelength. The active region 102 typically comprises a plurality of quantum wells, for example, formed by emissive layers based on GaN, InN, InGaN, AlGaN, AIN, AlInGaN, GaP, AlGaP, AlInGap, AlGaAs, GaAs, InGaAs, AlIlAs, or a combination of several of these materials.

[0072] The set of the first 101 active nanowires of the first 100 LED form of preferably a photonic crystal that can be described by several parameters, including: - the emission wavelength, - the lack of network coverage, - the fill rate, also called the openness rate or density, generally between 10 and 90%, - the type of mesh (hexagonal, square...), - the refractive index of the material filling the spaces between the nanowires 101, commonly called "filler", preferably between 1 and 1.7, and - the dimensions of the nanowires.

[0073] A crystal is typically characterized by the ratio between the lattice pitch, commonly referred to by the English term "pitch", and the emission wavelength.

[0074] As illustrated in [Fig. 8], the first nanowires 101 are advantageously arranged in rows oriented along a first direction and / or a second direction. These rows are called first rows and first secondary rows, respectively. In the figures, the first direction and the second direction correspond respectively to the x and y directions of the orthonormal coordinate system. Thus, in the figures, the first and second directions are normal. However, it is possible that they are not. The first and first secondary rows are respectively 111 and 1111. They are also identified using an indexing system ranging from 1 to 111 and from 1 to 1111, respectively.

[0075] The set of these rows and therefore of the first nanowires 101 advantageously forms a regular two-dimensional network. It can, for example, be a monoclinic network, an orthorhombic network, a tetragonal network or even a hexagonal network.

[0076] The first rows are advantageously separated by first distances measured along the first direction having a value substantially equal to a first target distance piOjX. It is understood that, due to inaccuracies arising from the manufacturing processes, the distance between two adjacent first rows may vary around the first target distance piOjX. Variations in the value of the distance between two adjacent first rows due to manufacturing uncertainties can be estimated at approximately 10% of the target value.

[0077] The first LED 100 typically comprises a layer based on a transparent conductive oxide, commonly referred to as TCO (Transparent Conductive Oxide), the thickness of which is preferably between 100 and 300 nm. The nanowires can be arranged, along the longitudinal direction, between a layer The mirror is based on a metallic material, typically Ai, and the TCO layer. This arrangement of nanowires between the mirror layer and the TCO layer potentially allows the creation of a Fabry-Perot cavity in the longitudinal direction.

[0078] The first LED 100 is advantageously sized to have dimensions on the order of those of a sub-pixel of a display device.

[0079] The first LED 100 is configured to emit a first light beam 110. Advantageously, the first light beam 110 is configured to be emitted primarily in a direction normal to the substrate 2, i.e., extending parallel to the z-axis shown in Figures 1 to 5, referred to as the longitudinal direction. The light beam 110, however, comprises a multitude of rays propagating in as many emission directions. The emission is, for example, omnidirectional. In another embodiment, the beam rays are typically emitted according to a Lambertian or orthotropic profile, i.e., the luminance of the LED 100 is angularly uniform, but the emitted light intensity depends on the emission direction. The beam intensity typically varies according to Lambert's law:

[0080] [Math.l] I = / cos(0)

[0081] with I the luminous intensity along an emission direction, Io the luminous intensity at the source, and 0 the angle of the emission direction with respect to the normal to the source surface, here the longitudinal direction. It is understood that any other emission profile is conceivable and that the first LED 100 is not limited to a Lambertian source.

[0082] The device 1 further includes a first transition zone 1000 bordering at least in part the first LED 100.

[0083] The first transition zone 1000 comprises a plurality of first transition nanowires 1001 extending in the transverse direction from the upper face 20 of the substrate 2.

[0084] The first 1001 transition nanowires can be active or passive depending on their intended use. A "passive nanowire" is defined as a nanowire that does not emit light. A passive nanowire is typically similar to an active nanowire but is not electrically connected.

[0085] The first transition nanowires 1001 preferably form a photonic crystal extending over the substrate 2. The parameters for describing this photonic crystal are the same as those describing the photonic crystal formed by the active nanowires 102 (no lattice, mesh type, filling rate...), with the exception of the emission length which is not defined here when the first transition nanowires are passive.

[0086] The first 1001 transition nanowires are advantageously arranged according to Rows oriented along the first x direction and / or the second y direction. These rows are called first transition rows and first secondary transition rows and number Ntrans.x.iCt Ntrans>yire respectively. They are also identified using an index ranging from 1 to Ni prwien moving away from the first LED 100 and from 1 to NLEDyire respectively.

[0087] Advantageously, the set of first transition nanowires 1001 forms a regular two-dimensional network, preferably of the same type as the set of first nanowires 101. This allows the fabrication of the first LED 100 and the first transition zone 1000 to be optimized, which is advantageously done simultaneously.

[0088] A transition sub-zone 1100 is expected to border the first LED 100 and be formed by the first Nsous_trans_i transition rows, with Nsous_trans_i being between 2 and Nsous_i. The first transition nanowires 1001 of the first transition sub-zone 1100 are characterized by diameters, referred to as first transition diameters, and / or distances between consecutive first transition rows that vary with distance from the first LED 100. This characteristic prevents an abrupt change in diameter and / or distance between nanowires at the edge of the first LED. This avoids edge effects that could impair the efficiency of the first LED 100.

[0089] The variations in the value of the first transition diameters of the first transition nanowires 1001 or in the value of the distance between two consecutive rows of first transition nanowires when moving away from the first LED 100 is indeed fundamental.

[0090] These variations within the first transition sub-zone 1100 can follow different progression laws as they move away from the first LED 100. The variations in diameter and the variations relative to the distance between two consecutive first transition rows can follow similar or distinct progression laws. These variations can, for example, be monotonic or even strictly monotonic, that is, increasing or decreasing, or even strictly increasing or strictly decreasing. The variation of these parameters can also be linear. Furthermore, it is not excluded that one of the two parameters may exhibit an increasing and then decreasing evolution as one moves away from the first LED, or vice versa.The diameter and / or the distance between two consecutive rows can indeed increase in some regions of the first transition sub-zone 1100 and decrease in other regions of the first transition sub-zone 1100, depending on the intended applications. Advantageously, it is predicted that the first transition nanowires 1001 constituting the first transition rows immediately bordering the first LED 100 will have first transition diameters varying monotonically over several rows, for example, 3 to 5 rows. Similarly, it is predicted that... The distance between two consecutive first transition rows varies monotonically over several first transition rows immediately bordering the first LED, for example, 3 to 5 rows. The "first transition rows immediately bordering the first LED" are defined as the first transition rows encountered when moving away from the first LED 100 along the first x-direction. In other words, these are the first transition nanowires 1001 exhibiting the smallest x-distance to the LED 100, or the lowest indexing.

[0091] Regardless of the law governing the variations in the diameters of the first transition nanowires and the distances between the first transition rows within the first transition sub-region 1100, to avoid any abrupt transition in the first transition diameter and / or the distance between two consecutive rows when moving away from the first LED 100, these variations are expected to be bounded. In particular, it is expected that, when moving away from the first LED 100, the diameter of the transition nanowires 1001 in two consecutive rows can only increase or decrease by 3 to 13% of the preceding row. The spacing between two consecutive rows when moving away from the first LED 100 can only increase or decrease by 2 to 4% compared to the preceding spacing.

[0092] It is also provided, in order to avoid any abrupt transition between the first LED 100 and the first transition zone 1000, that the first transition nanowires 1001 immediately bordering the first LED 100 have a diameter close to the target diameter of the first nanowires 101 of the first LED 100. Their diameter typically varies in a proportion of less than 5% of q>i0.

[0093] Similarly, any abrupt transition in the distance between nanowires at the interface between the first LED 100 and the first transition zone 1000 is prevented. To this end, a first interface distance dinterface i is defined, separating the first row bordering the first transition zone 1000 (first row NLEDjXji) and the first transition row bordering the first LED 100 (first transition row Nl). The value of the first interface distance dinterface,i and that of the distance along the first direction x between the first transition row N1 and the first transition row N2 vary in a proportion between 2% and 4% of the distance along the first direction x between the first row NLED>1 and the first row NLEDj and the first interface distance dinterface,1, respectively.

[0094] It is also conceivable that the first transition zone 1000 comprises a subzone bordering the first transition subzone, called the threshold subzone, in which at least one of the two parameters among the diameter of the first transition nanowires 1001 and the distance between the first neighboring transition rows remains constant while moving away from the first LED 100.

[0095] The power supply to an array of active nanowires is typically carried out in parallel. The active nanowires of the same array are in fact conventionally connected in parallel to an upper electrode and a lower electrode arranged under the substrate 2 from which said active nanowires extend.

[0096] In the context of the invention, it is advantageously provided that the first nanowires 101 of the first LED 100 and the first transition nanowires 1001 of the first transition zone 1000 are powered separately by distinct electrodes. Such separation makes it possible, in particular, to control which nanowires are powered and consequently which zones emit. This feature is particularly advantageous in the application of the present invention relating to the gamut extension of the device described below. However, it is not excluded that the first nanowires 101 of the first LED 100 and the first transition nanowires 1001 of the first transition zone 1000 may be powered simultaneously by the same electrode.

[0097] According to an advantageous embodiment illustrated in [Fig.2], the optoelectronic device 1 comprises a second LED 200 disposed on the upper face of the substrate 2 and adjacent to the first LED 100. The two LEDs 100, 200, can be considered as two adjacent sub-pixels of a display screen.

[0098] The second LED 200 is configured to emit a second light beam 210, which, like the first light beam 110, is advantageously configured to be emitted primarily in the transverse direction. The second light beam 210 is, for example, omnidirectional and typically has a Lambertian profile.

[0099] The second light source 200 comprises at least one second active nanowire 201 extending from the upper face 20 of the substrate 2, and preferably a plurality of second active nanowires 201. The second active nanowires 201 preferably form a photonic crystal that can be described in the same way as the photonic crystal formed by the first active nanowires 101. The second nanowires 201 are advantageously arranged in rows oriented along a first direction and / or a second direction. These rows are called second rows and secondary second rows, respectively. The second rows and secondary second rows are respectively of number N1 and N2. They are further identified using an indexing system ranging from 1 to N1 as one moves away from the first transition zone and from 1 to N2, respectively.The second rows are advantageously separated by second distances taken along the first direction, having a value substantially equal to a second target distance p20jX. It is understood that, due to inaccuracies arising from manufacturing processes, the distance between two adjacent second rows may vary around the second target distance p20jX. Variations in the value of the distance between two... Second rows of adjacent items due to manufacturing variations can be estimated at approximately 10% of the target value.

[0100] As for the first nanowires 101, for each second nanowire 201 a second real diameter denoted 92>n is defined, n indexing the second nanowires and therefore varying from 1 to N2, N2 being the number of first nanowires 101. This first real diameter is preferably such that 0,9.920 < 92,n < 1,1.920,920, being a second target diameter.

[0101] The transition zone 1000 separates the first LED 100 and the second LED 200. Several configurations for the transition zone are possible. For example, it is possible to include the following within the transition zone, separating the first 100 LED and the second 200 LED: - the first 1100 transition sub-zone as described previously, bordering the first LED 100, - possibly a second 1200 transition sub-zone bordering the second 200 LED, - possibly a threshold sub-zone as described above and separating the first transition sub-zone 1100 and the second transition sub-zone 1200. The characteristics of the first transition subzone 1100 apply mutatis mutandis to the second transition subzone 1200.

[0102] Advantageously, the first transition diameters and / or the distances between first neighboring transition rows vary progressively: - from the target value of the first diameters, 910, of the first nanowires 101 of the first LED 100, to the target value of the second diameters, 920, of the second nanowires 201 of the second LED 200, the values ​​910 and 920 being taken by the diameters of the transition nanowires 1001 of the first transition rows n°1 and N11, respectively, and / or - from the first target distance, piOjX, to the second target distance, p20jX, the values ​​pi0,x and p20jX being respectively taken between the first transition row n°1 and the first transition row n°2 on the one hand and the first transition row n°NtranSjXji-l and the first transition row n°1^^,1 on the other hand, respectively.

[0103] Fig. 2 illustrates, for example, the case where the diameter of the transition nanowires 1001 varies from 910 to 920 when traversing the transition zone 1000 from the first LED 100 to the second LED 200.

[0104] Fig. 3 illustrates in particular the case where the distance between two successive first transition rows varies from pi0,x to p2o,x when traversing the transition zone 1000 from the first LED 100 to the second LED 200.

[0105] This continuous or even monotonic preference variation forms a smooth transition between the first and second LEDs 100, 200. This avoids symmetry breaks between the different nanowire networks forming the first and second LEDs 100, 200. Edge effects are thus advantageously limited or eliminated.

[0106] Preferably, this variation of the first transition diameters and / or of the distances between neighboring first transition rows is linear.

[0107] The embodiments described above, in which the device 1 comprises a transition zone and respectively one and two LEDs, can be extended to devices comprising a greater number of LEDs and transition zones. A device with three LEDs 100, 200, 300 and two transition zones 1000, 2000 separating respectively the first and second LEDs 100, 200 on the one hand and the second and a third LED 200, 300 on the other hand, is illustrated for example in [Fig. 5]. According to one possibility, the device includes three LEDs 100, 200, 300 and three transition zones 1000, 2000, 3000, the first transition zone 1000 separating the first and second LEDs 100, 200, the second transition zone 2000 separating the second and third LEDs and the third transition zone 3000 separating the third and first LEDs.This embodiment allows in particular the creation of RGB pixels consisting of three sub-pixels R, G, B, corresponding to the three LEDs 100, 200, 300, emitting respectively in red (R designating "red"), green (G designating "green") and blue (B designating "blue").

[0108] It is also conceivable that the device 1 comprises four LEDs 100, 200, 300, 400 separated by four transition zones 1000, 2000, 3000, 4000 as shown in [Fig.4b].

[0109] The characteristics of the first and second LEDs 100, 200 described above apply mutatis mutandis to the third and fourth LEDs 300, 400. As illustrated in [Fig. 4b], the latter typically comprise third nanowires 301 and fourth nanowires 401 respectively, having a third target diameter q>30 and a fourth target diameter q>30, respectively. <p40et ordonnés en rangées orientées selon la deuxième direction. ces sont typiquement elles-mêmes espacées première direction par une troisième distance cible p30jx et quatrième p40jx, respectivement.

[0110] The characteristics of the first transition zone 1000 described above apply mutatis mutandis to the three transition zones 2000, 3000, 4000.

[0111] According to an advantageous embodiment of the present invention, at least a portion of the nanowires in the transition zone(s) are active nanowires and are used to extend the range of colors that can be rendered by the device 1.

[0112] The figures, and in particular figures 6a, 6b and 7, illustrate this embodiment applied to a device with four LEDs emitting three native colors (C1, C2 and C3), but it is understood that this principle can be applied to any device comprising more than two LEDs.

[0113] The colors usually emitted by the subpixels of a single pixel are red (C1 on the chromaticity diagram shown in [Fig. 6a]), green (C2 on the chromaticity diagram), and blue (C3 on the chromaticity diagram). However, other colors can be rendered from such a pixel. All the colors within gamut 4, defined by the colors emitted by the three subpixels on the chromaticity diagram of the CIE XYZ color system, can be obtained by linear combinations of the three native colors. For example, by turning off the subpixel emitting in the blue range and by linear combination of the red and green beams, it is possible to make the color perceived by an observer yellow. However, not all the hues of the spectrum locus, that is, the set of pure colors perceptible by human vision, are included in gamut 4 characterizing the hues that can be generated by the pixel.However, some hues located outside of gamut 4 might be necessary to accurately render an image. Transition zones can be advantageously used to achieve these hues in spectrum locus 3 that are outside gamut 4.

[0114] Indeed, the parameters characterizing all the transition nanowires of a transition zone separating two LEDs can be configured so that this zone emits a beam whose wavelength is outside the gamut 4. Among these parameters is in particular the diameter of each of the transition nanowires.

[0115] For example, it is conceivable that, over several consecutive rows, the transition nanowires 1001 are all configured to emit a beam at the same wavelength, called the transition wavelength, distinct from the wavelengths emitted by the adjacent LEDs. The wavelength of the overall beam obtained by the superposition of the beams emitted by each of these transition nanowires 1001 is then also of

[0116] According to another embodiment, the overall beam at the wavelength outside gamut 4 is generated by an array of 1001 transition nanowires. This is made possible by an averaging effect of the individual beams generated by each of the 1001 transition nanowires involved. These 1001 transition nanowires can also have progressively varying parameters (pitch, diameters), as described above.

[0117] In all cases, the transition wavelength is chosen so as to be advantageous in the context of image display.

[0118] As mentioned previously, the first nanowires 101 of the first LED 100 and the first transition nanowires 1001 of the first transition zone 1000 are advantageously electrically powered independently of each other, by separate electrodes. This allows only the first 1001 transition nanowires to be powered. Device 1 can then emit only the color corresponding to this transition zone. The ability to isolate this color can be particularly advantageous for rendering certain images.

[0119] According to an advantageous embodiment, the first set of transition nanowires of a threshold subzone as described above and separating a first LED 100 and a second LED 200 are configured to emit a wavelength distinct from Xi and X2.

[0120] According to a particularly advantageous embodiment shown in [Fig. 7], the device 1 comprises an intermediate region 500 including a plurality of intermediate nanowires 501 configured so that the intermediate region emits a beam of white light. This embodiment is particularly suited to devices 1 comprising three or four LEDs separated in pairs by transition zones. As shown in [Fig. 7], the intermediate region 500 is, in this example, bordered by the first, second, and third transition zones 1000, 2000, 3000, as well as the third LED 300. The intermediate nanowires 501 have, in particular, a variety of diameters enabling them to emit at a plurality of wavelengths distributed substantially over the entire visible spectrum. The intermediate region 500 thus advantageously generates, by an averaging effect, a substantially white beam of light.The diameters of the intermediate 501 nanowires immediately bordering each of the 1000, 2000, and 3000 transition zones are also chosen to avoid any abrupt transitions, similar to the transition zone described previously. It should be noted that the sizing of the nanowire array in the intermediate 500 region (pitch, diameter) must take into account the current injected into each intermediate nanowire. The light power emitted by these intermediate 501 nanowires depends on this current, and even at a constant current, it is not equal from one nanowire to another when they emit at different wavelengths. The sizing of the intermediate 501 nanowires must therefore be done accordingly: obtaining white light depends on the number of intermediate 501 nanowires emitting at each wavelength and the power emitted by each of them.Typically, the intermediate region 500 is powered by a single electrode: the injected current is then identical for each of the intermediate nanowires 501. However, it is conceivable that several electrodes could be used to power different sets of intermediate nanowires 501. This allows for more precise adjustment of the sizing of the intermediate nanowires 501 and facilitates the production of white light.

[0121] It is understood that this embodiment applies to any device according to the invention comprising a number of LEDs greater than three.

[0122] Through the different embodiments described above, it is clear that the invention offers an effective solution to the problems due to edge effects around the pixels and sub-pixels of display screens, as well as to the current limitations of the gamut of these same screens.

[0123] The invention is not, however, limited to the embodiments described above.

[0124] In particular, the number, shape and arrangement of each element of the device can be adapted according to display requirements.

Claims

1. Claims Optoelectronic device (1) comprising at least: - a first LED (100) extending mainly in a plane (xy) defined by a first direction (x) and a second direction (y), said first LED (100) comprising a plurality of first nanowires (101) having first diameters having a value substantially equal to a first target diameter q>i0 and organized in Ni fd » rows oriented along the second direction (y), called first rows, said first rows being separated by first distances taken along the first direction (x) having a value substantially equal to a first target distance p io,x, said first LED (100) being configured to emit a first light beam having mainly a first wavelength and - a first transition zone (1000) extending mainly in the plane (xy) and at least partly bordering said first LED (100), said first transition zone (1000) comprising a plurality of first transition nanowires (1001) having first transition diameters and organized in Nt^x, rows oriented in the second direction (y), called first transition rows and indexed according to a numbering from 1 to N^sai moving away from the first LED (100) in the first direction (x), the first rows being indexed according to a numbering from 1 to Ni fd , 1 in the first direction (x) moving closer to the first transition zone (1000), the device being characterized in that the first transition zone (1000) comprises a first transition sub-zone (1100) formed by the Nsub-trans, first transition rows, with 2 < N,„u, N^ns, x,b bordering the first LED (100), first transition sub-zone (1100) in which: - the first transition nanowires (1001) are such that: i. the value of the first transition diameters of the first transition nanowires (1001) of the first transition row No. 1 varies in a proportion less than 5% of the first target diameter q>i0, and the value of the first transition diameter of each first transition nanowire (1001) of any first transition row no. i, i being between 2 and N under trans.i, varies in a proportion between 3% and 13% of the value of the first transition diameter of the first transition nanowire (1001) of the first transition row no. i being closest to it, and / or the first transition nanowires (1001) are such that: the first row n°NLEDjX>i and the first row of transition No. 1 being separated along the first direction x by a first interface distance d interface,!, the first interface distance d interface i and the distance along the first direction (x) between the first row of transition No. 1 and the first row of transition No. 2 vary in a proportion between 2% and 4% of the distance along the first direction (x) between the first row No. N i.Er> x il and the first row No. NLEDjX>i and the first interface distance d interface,iréspectivement, the distance along the first direction (x) between any first transition row no. i and first transition row no. i+l varies in a proportion between 2% and 4% of the distance in the first direction (x) between first transition row no. il and first transition row no. i, i being between 2 and

2.

3. Optoelectronic device (1) according to the preceding claim in in which the first transition diameters of the first transition nanowires (1001) of the same first transition row are equal. Optoelectronic device (1) according to any one of the preceding claims in which: - the value of the first transition diameters of the first transition nanowires (1001) of the first transition rows has a strictly increasing or strictly decreasing evolution over at least three successive first transition rows moving away from the first LED (100), and / or - the distance between two successive first transition rows moving away from the first LED (100) has a strictly increasing or strictly decreasing evolution over at least three successive first transition rows moving away from the first LED (100).

4. Optoelectronic device (1) according to the preceding claim wherein: - the value of the first transition diameters of the first transition nanowires (1001) of the first transition rows has a linear evolution over at least three successive first transition rows moving away from the first LED (100), and / or - the distance between two successive first transition rows moving away from the first LED (100) has a linear evolution over at least three successive first transition rows moving away from the first LED (100).

5. Optoelectronic device (1) according to the preceding claim wherein the first nanowires (101) and the first transition nanowires (1001) are further organized in rows along the first direction (x).

6. An optoelectronic device (1) according to any preceding claim wherein the first direction (x) and the second direction (y) are orthogonal.

7. Optoelectronic device (1) according to any one of the preceding claims wherein the first transition sub-zone (1100) extends over at least three rows, preferably at least five rows, of first transition nanowires (1001).

8. Optoelectronic device (1) according to any one of the preceding claims in which the first transition sub-zone (1100) has a surface Siooo and the first LED (100) has a surface Sjqo such that Sioo / 5 < Siooo< Sioo / 2.

9. Optoelectronic device (1) according to any one of the preceding claims in which the first nanowires (101) on the one hand and the first transition nanowires (1001) on the other hand are powered by separate electrical contacts.

10. Optoelectronic device (1) according to any one of the preceding claims further comprising: - a second LED (200) extending mainly in the plane (xy), said second LED (200) comprising a plurality of second nanowires (201) having second diameters having a value substantially equal to a second target diameter q>20 and organized in NLED,x,2 rows oriented in the second direction (y), called second rows, and indexed according to a numbering from 1 to Ni mx ? moving away from the first transition zone (1000) in the first direction (x), said second rows being separated by first distances taken in the first direction (x) having a value substantially equal to a second target distance p2o,x.said second LED (200) being configured to emit a second light beam having mainly a second wavelength X2, said first and second LEDs (100, 200) being separated at least by the first transition zone (1000).

11. Optoelectronic device (1) according to the preceding claim in which and in which: - the value of the first transition diameters of the first transition nanowires (1001) of the first transition row n°Nsous_trans, varies in a proportion less than 5% of the second target diameter q>20, and / or - the second row n° 1 and the first transition row n°N sous irailx.i being separated in the first direction (x) by a second interface distance dinterface>2, - the distance in the first direction (x) between the first

12. transition row noNsous_trans>i and the first transition row noNsous_trans>it varies in a proportion between 2% and 4% of the second interface distance dinterface,2- Optoelectronic device (1) according to claim 10 wherein the first transition zone (1000) comprises a second transition sub-zone (1200) formed by the first transition rows n°N sub-trans^to Ntr^i, with Nsous^.i< Nsous_tranSj2 <ntrans>Xji, second sub-zone (1200) of transition in which: - the first transition nanowires (1001) are such that: i. the value of the first transition diameters of the first transition nanowires (1001) of the first transition row n°NtranSjXji varies in a proportion less than 5% of the second target diameter <p2o, et ii. the value of the first transition diameters of the first transition nanowires (1001) of any first transition row no. i, i being between Ns^n-ans, 2 and Ntrans^j-1 varies in a proportion between 3% and 13% of the value of the first transition diameters of the first transition nanowires (1001) of the first transition row no. i+l, and / or - the first transition nanowires (1001) are such that: i. the second row No. 1 and the first transition row No. NtranSjXji being separated along the first direction x by a second interface distance d interface,2, the distance along the first direction (x) between the first transition row No. NtranSjXji and the first transition row No. NtranSjXji-l and the second interface distance dinterface2 vary in a proportion of between 2% and 4% of the second interface distance dinterface2 and of the distance along the first direction (x) between the second row No. 1 and the second row No. 2 res respectively, ii. the distance in the first direction (x) between any first transition row no. i and the first transition row no. 11 varies in a proportion between 2% and 4% of the distance in the first direction (x) between the first transition row no. i and the first transition row no. i+1, i being between Na-a^11 and Nsous tranS,2+1-

13. Optoelectronic device (1) according to the preceding claim in which: - the value of the first transition diameters of the first transition nanowires (1001) of the first transition rows exhibits a strictly increasing or strictly decreasing evolution over at least three successive first transition rows moving away from the second LED (200), and / or - the distance between two first successive transition rows moving away from the first LED (100) has a strictly increasing or strictly decreasing evolution over at least three first successive transition rows moving away from the second LED (200).

14. Optoelectronic device (1) according to the preceding claim in which: - the value of the first transition diameters of the first transition nanowires (1001) of the first transition rows exhibits a linear evolution over at least three successive first transition rows moving away from the second LED (200), and / or - the distance between two successive first transition rows moving away from the first LED (100) has a linear evolution over at least three successive first transition rows moving away from the second LED (200).

15. Optoelectronic device (1) according to any one of claims 11 to 14 in which Nsous tranS,i < Nsous tranS,2 and in which: - the distance between the first transition rows n°N under trans,ian Nseuni, with N,„lh i <N,eui| |< Nsous_trans,2est constante et / ou, - les premiers diamètres de transition des premiers nanofils de transition (1001) des premières rangées de transition n°N sous trans,i a n Nseuni, avec N,„lh |l..,l|V|<N,eui| |< Nsous.^ans,2$orit constants, formant ainsi une sous-zone dite première sous-zone seuil.

16. An optoelectronic device (1) according to any preceding claim wherein at least a portion of the first transition nanowires (1001) comprise an active region (1002) configured to emit a first transition light beam.

17. Optoelectronic device (1) according to the preceding claim wherein the first transition light beam mainly has a first transition wavelength with 14 Xl and XtransJ X2.

18. Optoelectronic device (1) according to any one of claims 10 to 17 wherein: - the first nanowires (101) are organized in Ni .pnyj rows oriented along the first direction (x), called first secondary rows, indexed according to a numbering from 1 to N LED.yi and separated by first secondary distances taken along the second direction (y) having a value substantially equal to a first target secondary distance pi0>y, and - the second nanowires (201) are organized in NLED>y>2 rows oriented along the first direction (x), called second secondary rows and indexed according to a numbering from 1 to N, ed y 7 and separated by second secondary distances taken along the second direction (y) having a value substantially equal to a second target secondary distance p20>y.

19. Optoelectronic device (1) according to the preceding claim further comprising: - a third LED (300) extending mainly in the (xy) plane, said third LED (300) comprising a plurality of third nanowires (301) having third diameters having a value substantially equal to a third target diameter q>30 and organized in Ni pd, 3 rows oriented in the second direction (y), called third rows and in N, fd y 3 rows oriented in the first direction (x), called third secondary rows, said third LED (300) being configured to emit a third light beam having mainly a third wavelength X3, - a second transition zone (2000) extending mainly in the (xy) plane and at least partly bordering said second LED (200) and said third LED (300), said second transition zone (2000) comprising a plurality of second transition nanowires (2001) having second transition diameters and organized in Nuans,y,2 rows oriented along the first direction (x), called second secondary transition rows and indexed according to a numbering from 1 to Nu-ans,y,2 approaching the second LED (200) along the second direction (y), - a third transition zone (3000) extending mainly in the plane (xy) and at least partly bordering said third LED (300) and said first LED (100), said third transition zone (3000) comprising a plurality of third transition nanowires (3001) having third transition diameters and organized in NuanS,y,3 rows oriented in the first direction (x), called third secondary transition rows and indexed according to a numbering from 1 to ^„^3 when approaching the first LED (100) in the second direction (y), said second and third LEDs (200, 300) being separated by the second transition zone (2000), said third and first LEDs (300, 100) being separated by the third transition zone (3000), wherein the second nanowires of the second transition zone (2000) are such that: i. the value of the second transition diameters of the second transition nanowires (2001) of the second transition row No. 1 varies in a proportion less than 5% of the third target diameter q>30, and ii. the value of the second transition diameter of each second transition nanowire (2001) of any second secondary transition row no. i, i being between 2 and N tranS,y,2, varies in a proportion between 3% and 13% of the value of the second transition diameter of the second transition nanowire (2001) of the second secondary transition row no. i-1 closest to it, and iii. the value of the second transition diameters of the second transition nanowires (2001) of the second transition row noNtranSjy>2 varies in a proportion less than 5% of the second target diameter q>20, and / or i. the second secondary row No. 1 and the second secondary transition row noNtrans>yj2 being separated in the second direction (y) by a third interface distance dinterface3, the third interface distance dinterface 3 and the distance in the second direction (y) between the second secondary transition row noNtrans>yj2 and the second secondary transition row No. Ntrans^^-l vary in a proportion of between 2% and 4% of the distance in the second direction (y) between the second secondary transition row noNtrans>yj2 and the second secondary transition row noNtranSjy>2-1 and the third interface distance dinterface,3 respectively, ii. the distance in the second direction (y) between any second secondary transition row no. i and the second secondary transition row no. i+l varies in a proportion between 2% and 4% of the distance in the second direction (y) between the second secondary transition row no. i-1 and the second secondary transition row no. i, i being between 2 and N^ns^-l^t iii. the third secondary row noNLED y 3 and the second secondary transition row no. 1 being separated in the second direction (y) by a fourth interface distance dinterfacej4, the fourth interface distance dinterfaCe,4 and the distance in the second direction (y) between the second secondary transition row No. 2 and the second secondary transition row No. 1 vary in a proportion between 2% and 4% of the distance in the second direction (y) between the third secondary row No. Ni pn y ^ and the third secondary row No. NLED,y,3-l and the fourth interface distance dinterfaCe,4 respectively, and wherein the third nanowires of the third transition zone (3000) are such that: i. the value of the third transition diameters of the third transition nanowires (3001) of the third transition row No. 1 varies in a proportion less than 5% of the third target diameter q>30, and ii. the value of the third transition diameter of each third transition nanowire (3001) of any third secondary transition row no. i, i being between 2 and N tranS,y,3, varies in a proportion between 3% and 13% of the value of the third transition diameter of the third transition nanowire (3001) of the third secondary transition row no. i-1 closest to it, and iii. the value of the third transition diameters of the third transition nanowires (3001) of the third transition row noNtranSjy>3 varies in a proportion less than 5% of the first target diameter q>i0, and / or i. the first secondary row No. 1 and the third secondary transition row noNtranSjy>3 being separated along the second direction (y) by a sixth interface distance d interfaœ,6, the sixth interface distance dinterface 6 and the distance along the second direction (y) between the third secondary transition row noNtrans>yj3 and the third secondary transition row No. 1 vary in a proportion of between 2% and 4% of the distance along the second

20. direction (y) between the third secondary transition row n°NtranSjyj3 and the third secondary transition row n° N trans,y,3-l and the sixth interface distance dinterfaCe,3 respectively, ii. the distance in the second direction (y) between any third secondary transition row no. i and the third secondary transition row no. i+l varies in a proportion between 2% and 4% of the distance in the second direction (y) between the third secondary transition row no. i-1 and the third secondary transition row no. i, i being between 2 and N^ns^sl^t iii. the third secondary row noNLED y 3 and the third secondary transition row no. 1 being separated in the second direction (y) by a fifth interface distance dinterfacej5, the fifth interface distance dinterfacej5 and the distance in the second direction (y) between the third secondary transition row no. 2 and the third secondary transition row no. 1 vary in a proportion between 2% and 4% of the distance in the second direction (y) between the third secondary row no. Ni Fr>.y.3 and the third secondary row no. Ni ed y 3-1 and the fourth interface distance dinterfaCe,4 respectively. Optoelectronic device (1) according to the preceding claim further comprising an intermediate region (500) bordered by the first transition zone (1000), the second transition zone (2000), the third transition zone (3000) and the third LED (300), said intermediate region comprising a plurality of intermediate nanowires (501) having a diameter distribution such that all of said intermediate nanowires (501) emit at a plurality of wavelengths distributed across the entire visible spectrum.< / ntrans>

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