Method for manufacturing an optoelectronic device

Abstract

Method for manufacturing an optoelectronic device. This description relates to an organic light-emitting diode (100) comprising an emissive layer (150), emitting at a first wavelength, disposed between an electron injection layer (132) and a hole injection layer (131), at least one of the electron injection layer (132) or the hole injection layer (131) being a layer of a first inorganic perovskite material. It also relates to an OLED display or a micro-OLED display comprising such OLEDs, as well as their fabrication methods. A top electrode (122) and / or spectral conversion elements (161, 162) can be formed by PLD on the layers described above. Figure for the abstract: Fig. 2

Description

Title of the invention: Method for manufacturing an optoelectronic device. Technical field.

[0001] This description relates generally to the field of organic optoelectronic devices, particularly display, lighting, or signaling devices. The invention relates more particularly to organic light-emitting diode (OLED) devices such as displays or microdisplays. Prior art

[0002] An OLED is formed from a stack of organic semiconductor layers comprising at least one emissive (electroluminescent) layer, arranged between a hole-carrying layer and an electron-carrying layer. The stack is located between two electrodes, most often metallic. A hole-injection layer and an electron-injection layer allow, when a potential difference is applied between the electrodes, the injection of electrons and holes into the organic stack. The holes and electrons are then transmitted and recombine radiatively in the emissive layer.

[0003] To form colour screens, different colour conversion elements, typically quantum dots (also called quantum dots or QDs for 'quantum dots') are used to convert, for example, the blue light emitted by the OLED into green light and red light.

[0004] In the case of top emission, the emitted photons pass through the upper electrode (the cathode) which must be both conductive and transparent (or made of a material thin enough to be transparent).

[0005] However, the organic stack of the OLED is sensitive not only to atmospheric oxygen and humidity but also to temperature. Thus, an encapsulation layer is generally used to protect it from the environment.

[0006] In addition, the upper electrode must be deposited at a low temperature so as not to damage the underlying organic stack, which often reduces the quality of the deposited material and therefore the performance of the final device. Summary of the invention

[0007] There is a need for a manufacturing process for a device that overcomes the drawbacks of the prior art and allows, in particular, for good performance.

[0008] This goal is achieved by an organic light-emitting diode comprising an emissive layer, emitting at a first wavelength, arranged between a layer electron injection and a hole injection layer, at least one of the electron injection layer or hole injection layer being a layer in a first inorganic perovskite material.

[0009] According to a particular embodiment, the other of the electron injection layer or the hole injection layer is a layer in a second inorganic perovskite material.

[0010] According to a particular embodiment, the organic light-emitting diode comprises a substrate covered successively by: - ​​a first electrode, - the hole injection layer, - a hole transport layer, - the emitting layer, - an electron transport layer, - the electron injection layer, firstly in inorganic perovskite material, - a second electrode in transparent conductive oxide, for example in indium tin oxide.

[0011] According to a particular embodiment, a first additional layer, for example in oxide, in particular in tungsten oxide, is in contact with the first layer of inorganic perovskite material so as to form a bilayer and / or a second additional layer, for example in oxide, in particular in tungsten oxide, is in contact with the second layer of inorganic perovskite material so as to form another bilayer.

[0012] This goal is also achieved by an optoelectronic device, for example, an OLED microdisplay or an OLED display, comprising successively: - a substrate, - the first structured electrodes arranged on the substrate, delimiting blue pixels, red pixels and green pixels, - a layer of hole injection covering the first electrodes, - a layer for transporting holes, - an emitting layer, emitting at a first wavelength, - an electron transport layer, - an electron injection layer, - a spectral conversion element positioned directly above one of the first electrodes defining the red pixel, absorbing at the first wavelength and emitting at a second wavelength longer than the first wavelength, and an additional spectral conversion element positioned directly above one of the first electrodes defining the green pixel, absorbing at the first wavelength and emitting at a third wavelength longer than the first wavelength, at least one of the electron injection layer or hole injection layer being a layer of a first inorganic perovskite material and, preferably, the other of the electron injection layer or hole injection layer being a layer of a second inorganic perovskite material.

[0013] According to a particular embodiment, the first inorganic perovskite material layer is the electron injection layer, the device further comprising a second electrode in a transparent conductive oxide, for example in indium tin oxide, the second electrode covering the spectral conversion element and the additional spectral conversion element, or the second electrode being disposed between, on the one hand, the electron injection layer and, on the other hand, the spectral conversion element and the additional spectral conversion element.

[0014] According to a particular embodiment, the spectral conversion element is in a third inorganic perovskite material and the additional spectral conversion element is in a fourth inorganic perovskite material.

[0015] This goal is also achieved by a method of manufacturing an organic light-emitting diode comprising an emissive layer, emitting at a first wavelength, disposed between an electron injection layer and a hole injection layer, the method comprising a step in which at least one of the electron injection layer or the hole injection layer is formed by depositing a first inorganic perovskite material by PLD.

[0016] According to a particular embodiment, the other of the electron injection layer or of the hole injection layer is formed by depositing a second inorganic perovskite material, preferably by PLD.

[0017] According to a particular embodiment, a top electrode made of a transparent conductive oxide, for example in indium tin oxide, is deposited by PLD on the stack comprising the emissive layer, the electron injection layer and the hole injection layer.

[0018] This goal is also achieved by a method of manufacturing an optoelectronic device, comprising the implementation of the method of manufacturing an OLED as described above, to manufacture several OLEDs on a substrate, and in which spectral conversion elements in perovskite material are deposited on the OLEDs by PLD. Brief description of the drawings

[0019] These features and advantages, as well as others, will be described in detail in the following description of particular embodiments, given by way of non-limiting example, in relation to the accompanying figures, among which:

[0020] Figures [Fig. 1A] and [Fig. 1B] schematically and in cross-section represent a light-emitting diode according to different particular embodiments of the invention,

[0021] Figures [Fig. 2], [Fig. 3] and [Fig. 4] schematically and in cross-section represent different optoelectronic devices according to different particular embodiments of the invention,

[0022] [Fig.5A], [Fig.5B], [Fig.5C] and [Fig.5D] schematically represent different stages of a first part of a manufacturing process for an optoelectronic device, according to a particular embodiment of the invention;

[0023] [Fig.6A] and [Fig.6B] schematically represent different stages of a second part of a manufacturing process for an optoelectronic device, according to a particular embodiment of the invention;

[0024] [Fig.7A] and [Fig.7B] schematically represent different stages of a second part of a manufacturing process for an optoelectronic device, according to another particular embodiment of the invention.

[0025] The different elements are not necessarily represented at a uniform scale to make the figures more legible. Description of the implementation methods

[0026] The same elements have been designated by the same reference numerals in the different figures. In particular, the structural and / or functional elements common to the different embodiments may have the same reference numerals and may have identical structural, dimensional and material properties.

[0027] For the sake of clarity, only the steps and elements useful for understanding the described embodiments have been represented and are detailed.

[0028] Unless otherwise specified, when referring to two elements connected together, this means directly connected without intermediate elements other than conductors, and when referring to two elements connected (in English "coupled") together, this means that these two elements can be connected or linked through one or more other elements.

[0029] In the following description, when reference is made to absolute position qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative position qualifiers, such as the terms "above", "below", "superior", "inferior", etc., or to orientation qualifiers, such as the terms "horizontal", "vertical", etc., reference is made, unless otherwise specified, to the orientation of the figures.

[0030] Unless otherwise specified, the expressions "approximately", "about", "significantly", and "in the order of" mean at 10%, preferably at 5%.

[0031] A perovskite material is defined as a material of formula ABX3, where A represents a cation or a mixture of metallic cations preferably selected from Cs, Rb, K, and Na; B a metallic cation preferably selected from Pb, Sn, and Ge; and X a halogen preferably selected from Cl, Br, and I. The perovskite materials described are inorganic perovskite materials. They have, for example, the following formula: - for injection layers: CsPbCl3et - for conversion elements: CsPbBr3 or CsPbI2Br.

[0032] By transparency, it is understood that the structure or element in question has a transmittance greater than or equal to 70%, preferably greater than or equal to 80%, and even more preferably greater than or equal to 90%. Transmittance represents the intensity of light passing through the element or structure across the visible spectrum. It can be measured by UV-Vis-IR spectrometry. The transmittance of the visible spectrum corresponds to the transmittance for wavelengths between 350 and 800 nm.

[0033] Spectral conversion elements are elements that convert at least part of the excitation light they receive into emitted light of a longer wavelength. By way of illustration, they can be adapted to absorb blue light, i.e., light with a wavelength between approximately 440nm and 490nm, and to emit in the green, i.e., at a wavelength between approximately 495nm and 560nm, or even in the red, i.e., at a wavelength between 600nm and 650nm.

[0034] By between X and Y, we mean that the bounds X and Y are included.

[0035] By bilayer, we mean an element comprising two layers arranged one on top of the other the other and in direct contact. In other words, there is no intermediate layer between the two layers of the bilayer.

[0036] We will first describe an organic light-emitting diode (OLED) with reference to [Fig.1A] and [Fig.1B].

[0037] The OLED may be a so-called bottom emission OLED. Preferably, the OLED is a so-called top emission OLED.

[0038] The top-emitting OLED comprises successively from a substrate 110 ([Fig.1A] and [Fig.1B]): - a first electrode (or lower electrode) 121, - possibly a buffer layer (not shown), - the hole injection layer 131 (P-type layer) covering the first electrode 121, - a layer of hole transport 141, - an electroluminescent layer 150 (or emissive layer), emitting at a first wavelength, - an electron transport layer 142, - an electron injection layer 132 (N-type layer), - a second electrode (or top electrode) 122.

[0039] Such a structure is a top-emitting structure. The invention can also be applied to a so-called inverted top-emitting structure, in which case the position of the electron injection / transport layers and the hole injection / transport layers are reversed.

[0040] At least one electron injection layer 132 or hole injection layer 131 is a layer made of a first inorganic perovskite material. The other of the electron injection layer 132 or hole injection layer 131 may be a layer made of a second inorganic perovskite material. Such layers exhibit good performance and very good long-term stability.

[0041] The first inorganic perovskite material and the second inorganic perovskite material are chosen so as to permit an electrical function which allows electrons or holes to pass through.

[0042] The first inorganic perovskite material and the second inorganic perovskite material are, for example, CsPbCl3. They may be perovskite materials doped with elements, particularly metallic elements, acting as charge carriers. For example, their doping level is greater than 10¹⁶ cm³.

[0043] According to a particular embodiment, when the electron injection layer 132 is made of perovskite material, it can perform both the role of injection and spectral conversion.

[0044] The thickness of the layer in first inorganic perovskite material and / or the thickness of the layer in second inorganic perovskite material are, for example, less than 20 pm, and in particular between 50 nm and 2 pm, preferably between 100 nm and 1 pm.

[0045] If one of the injection layers is not made of perovskite material, it may be made of organic or polymer material, doped or undoped, semiconductor or conductive.

[0046] The electron or hole injection function can be managed entirely by the first perovskite material layer or the second perovskite material layer ([Fig.1A]).

[0047] Alternatively, the perovskite material layers can be used in combination with additional layers in the form of a bilayer. The materials of the additional layers are different from the materials of the perovskite layers. The additional layers are made of a material that provides an electrical function and allows current to pass through. electrons or holes. For example, the additional shells are oxide shells, notably tungsten oxide WO3.

[0048] For example, [Fig.1B] represents an electron injection layer 132 in a first inorganic perovskite material used in association with a first additional layer 134. The hole injection layer 131 in a second inorganic perovskite material is used in association with a second additional layer 133.

[0049] The additional layers are preferably arranged between the injection layers 131, 132 and the organic stack or between the injection layers 131, 132 and the electrodes 121, 122.

[0050] In the various attached figures, the transport and injection functions (of holes or electrons) are carried out by separate layers.

[0051] According to an alternative embodiment, not shown, the hole transport or electron transport function can be performed by the hole injection or electron injection layer. The OLED then comprises the following stack: a hole injection layer, an electroluminescent layer properly speaking, emitting at a first wavelength, and an electron injection layer.

[0052] According to a particular embodiment not shown, the device may also include an electron carrier blocking layer on the side of the hole injection / transport layers and / or a hole carrier blocking layer on the side of the electron injection / transport layers.

[0053] The substrate 110 is, for example, a glass or silicon substrate. For example, it is a TFT substrate. In particular, a TFT glass substrate will be chosen.

[0054] The first electrodes 121 are, for example, made of indium tin oxide (or ITO for "indium tin oxide"), Al, or an AlCu or TiN alloy. The first electrodes 121 may be opaque and may be relatively thick (several hundred nanometers, or even a few micrometers). The first electrodes are anodes.

[0055] The buffer layer is, for example, made of TiN. It can have a thickness of around 10 nm.

[0056] The electroluminescent layer 150 exhibits, for example, an emission centered at the wavelength of 550 nm. It is an organic layer, for example a doped or undoped polymer material.

[0057] The hole transport layer (HTL) 141 and the electron transport layer (ETL) 142 are made of an organic material, such as a polymer material, doped or undoped, semiconductor or conductive. These materials are known per se and will not be described in detail here.

[0058] The electroluminescent layer 150 and the electron transport layers 142 or hole transport layers 141 form an organic stack.

[0059] The second electrode 122 can be metallic. The second electrode 122 is, for example, made of Ag and has a thickness of, for example, 10 nm. The chosen thickness is sufficiently small so that the electrode 122 is substantially transparent.

[0060] Preferably, the electron injection layer 132 is made of perovskite material. This allows for a wider choice of materials for the upper electrode 122. It is, for example, made of a transparent conductive oxide, for example ITO.

[0061] The second electrode 122 is the cathode.

[0062] Such OLEDs are particularly interesting for the manufacture of optoelectronic devices, such as OLED displays, especially direct-view OLED displays, which can range in size from that of a watch face to that of a television screen, or such as OLED microdisplays. In the first case, the support / control circuit board is a glass plate with TFTs; in the second, it is a silicon CMOS circuit. Color microdisplays comprise pixels made up of blue, green, and red sub-pixels (RGB pixels). In the following description, these sub-pixels will be referred to simply as pixels for the sake of brevity. The pixels form the emitting part of the system. Each pixel can comprise an OLED as described above.

[0063] The optoelectronic device co-integrates organic pixels adapted to emit light in different wavelength ranges: for example blue pixels emitting blue light (i.e. wavelength between 450 and 490 nm), green pixels emitting green light (i.e. wavelength between 490 and 570 nm) and red pixels emitting red light (i.e. wavelength between 600 and 700 nm).

[0064] Figures 2 to 4 represent 1000 emission optoelectronic devices comprising three pixels B, R and G. In practice, the display device may comprise a plurality of identical or similar B pixels, a plurality of identical or similar R pixels, and a plurality of identical or similar G pixels, the pixels of each type B, R and G being able to be regularly distributed over substantially the entire surface of the device, for example according to a matrix arrangement.

[0065] The device is a top emission device.

[0066] The device 1000 shown in the figures is a monolithic device. However, the individual pixels B, R and G could be manufactured individually.

[0067] More particularly, the device 1000, for example, a micro OLED display or an OLED display, comprising OLEDs as described above. More particularly, the device 1000 comprises successively (Figures 2, 3 and 4): - a substrate 110, - first structured electrodes 121 (or lower electrodes) arranged on the substrate, delimiting blue pixels, red pixels and green pixels, - possibly, a buffer layer (not shown), - a layer of hole injection 131 covering the first electrodes 121, - a layer of hole transport 141, - an emissive layer 150, emitting at a first wavelength, - an electron transport layer 142, - an electron injection layer 132, - a spectral conversion element 161 arranged directly above one of the first electrodes delimiting the red pixel, absorbing at the first wavelength and emitting at a second wavelength greater than the first wavelength and an additional spectral conversion element 162 arranged directly above one of the first electrodes delimiting the green pixel, absorbing at the first wavelength and emitting at a third wavelength greater than the first wavelength.

[0068] Device 1000 further comprises: - a second electrode (or upper electrode) 122 common to the three pixels B, R, G, and - an encapsulation layer 170.

[0069] According to a first embodiment, for example shown in [Fig.2], the device 1000 comprises from the electron injection layer 132: - the second electrode 122, - the encapsulation layer 170, - the spectral conversion elements 161, 162.

[0070] According to a second embodiment, for example represented in [Fig.3], the device 1000 comprises from the electron injection layer 132: - the spectral conversion elements 161, 162, - the second electrode 122, - the encapsulation layer 170.

[0071] As previously stated, at least one of the hole injection layer 132 or the hole injection layer 131 of the OLED is a layer made of a first inorganic perovskite material and, optionally, the other of the electron injection layer 132 or the hole injection layer 131 is a layer made of a second inorganic perovskite material. One of the injection layers 131, 132 or both injection layers 131, 132 may be used in the form of a bilayer as previously described.

[0072] As previously stated, when the electron injection layer 132 is made of perovskite material, it can perform both the role of injection and spectral conversion.

[0073] Preferably, at least the electron injection layer 132 is the first layer made of inorganic perovskite material. It is thus possible to use, not only, A wider choice of deposition techniques for forming the top electrode 122 and / or the spectral conversion elements 161, 162, as well as a wider choice of materials. The perovskite material layer protects the underlying organic material layers during the formation of the overlying layers.

[0074] Preferably, the spectral conversion element 161 is a third inorganic perovskite material and / or the additional spectral conversion element 162 is a fourth inorganic perovskite material. For example, the spectral conversion element 161 for converting blue light to red light is CsPbI2Br. The spectral conversion element 162 for converting blue light to green light is CsPbBr3.

[0075] The use of perovskite converters 161, 162 makes it possible to obtain thinner converters (typically less than 500 nm thick), more stable and with a longer lifespan compared to the use of QD. The efficiency is thus improved, the emitted lights at different wavelengths are more intense and it is possible to achieve color saturation.

[0076] Alternatively, one or both of the spectral conversion elements 161, 162 may be in a composite material comprising quantum dots (QDs) dispersed, for example, in a resin.

[0077] The spectral conversion elements 161, 162 locally cover the underlying layer. They can be separated from each other by an element such as a refractive index liquid or by a gap.

[0078] The device 1000 obtained exhibits better stability.

[0079] According to a particular embodiment, for example shown in [Fig. 4], color filters 180 cover the spectral conversion elements 161, 162. Color filters are optical elements that transmit certain wavelengths while absorbing other wavelengths. For example, a red filter allows red light to pass through and filters or blocks light of other colors (blue and green, for example). For the red pixel, a red filter is placed on the spectral conversion element 161, and for the green pixel, a green filter is placed on the additional spectral conversion element 162.

[0080] The 180 colour filters are preferably made of an organic material.

[0081] The encapsulation layer 170 is made of an insulating material, for example silica or silicon nitride. It can also be made of alumina or titanium oxide. It can have a thickness of between 5 and 25 nm, preferably between 5 and 10 nm. A multilayer encapsulation structure is also possible. For example, a SiO2 / TiO2 multilayer is possible.

[0082] The device also includes a control circuit (not shown) allowing the OLEDs to be individually controlled to display images.

[0083] We will now describe in more detail the manufacturing process of a device 1000 as previously described by referring to figures 5A to 5F, 6A and 6B as well as 7A and 7B.

[0084] The manufacturing process comprises at least the following steps which: - to form the first electrodes 121 on a substrate 110, each first electrode 12 delimiting a pixel ([Fig.5A]), - possibly apply a buffer layer, - deposit a layer of hole injection 131, so as to cover the substrate 110 and the first electrodes 121 ([Fig.5B]), - to form an electroluminescent organic stack by successively depositing a hole transport layer 141, an electroluminescent layer 150 and an electron transport layer 142 ([Fig.5C]), - deposit an electron injection layer 132 ([Fig.5D]).

[0085] The OLEDs (apart from the upper electrode 122) are thus formed on the substrate 110.

[0086] According to a first embodiment shown in Figures 6A and 6B, the process further comprises the following subsequent steps: - deposit a conductive layer by PLD to form the second electrode 122, then deposit an encapsulation layer 170 ([Fig.6A]), - form spectral conversion elements 161, 162 in inorganic perovskite material opposite some of the first electrodes, preferably by PLD ([Fig.6B]), - possibly place separation elements 190 between the conversion elements 161, 162, - preferably, place color filters 180 on spectral conversion elements 161, 162.

[0087] According to a second embodiment shown in Figures 7A and 7B, the process further comprises the following subsequent steps: - to form spectral conversion elements 161, 162 in inorganic perovskite material opposite some of the first electrodes, by PLD ([Fig.7A]), - preferably, to deposit color filters 180 on the spectral conversion elements 161, 162, - possibly place separation elements 190 between the conversion elements 161, 162, - deposit a conductive layer, preferably by PLD, to form the upper electrode 122 and then deposit an encapsulation layer 170 ([Fig.7B]).

[0088] In these two embodiments, the injection layer(s) 131, 132 are preferably deposited by pulsed laser ablation (PLD for 'pulsed laser deposition'). The PLD is a physical vapor deposition (PVD) technique that involves forming a plasma plume from a target material using a pulsed laser. The plasma plume has a composition very close to that of the target (stoichiometric transfer of species). When the plume comes into contact with the structure onto which the perovskite layer is to be deposited, it triggers nucleation of the layer under vacuum and in a controlled atmosphere. The structure can then be moved within the deposition chamber to ensure uniform coating.

[0089] If one of the injection layers 131, 132 is made of an organic material, it can be deposited by other techniques, in particular by liquid means.

[0090] The first electrodes 121 are formed by applying a mask with openings corresponding to the positions of the electrodes 121 to be deposited to the substrate 110, and then depositing the electrodes through this mask. They can be deposited, for example, by physical vapor deposition (PVD). They can be deposited by a conventional chemical vapor deposition (CVD) technique. It is also possible to deposit a layer of metal and then structure it by lithography / etching to form the first electrodes 121.

[0091] The buffer layer can be deposited for example by PLD, PVD, PECVD (“Plasma-Enhanced Chemical Vapor Deposition”) or ALD (“Atomic Layer Deposition”).

[0092] The organic stack is then deposited. It can be formed by PVD or liquid phase deposition.

[0093] The second electrode 122 can be deposited by PLD onto the perovskite electron injection layer 132. PLD deposition makes it possible to obtain good quality layers at low temperatures (typically from room temperature (20 to 25 °C) to 70-80 °C). The PLD-deposited electrode can be made of ITO. The ITO electrode thus obtained is both transparent and conductive. Such properties are obtained at low temperatures, whereas for sputter-deposited electrodes, an additional annealing step would be necessary, which would be prohibitive for OLEDs.

[0094] The encapsulation layer 170 can be deposited by ALD or PVD. For example, a silicon oxide layer can be deposited by PVD. A TiO2 layer can be formed by atomic layer deposition (ALD). An alumina layer can be deposited by ALD.

[0095] The conversion elements 161, 162 can be deposited by PLD when they are made of perovskite material. When they are made of hybrid (or composite) material, they can be deposited by liquid deposition, evaporation, PVD, CVD or by a hybrid process.

[0096] With such a process, the device is simpler to manufacture.

[0097] The different characteristics presented for the OLED are found for the device and the different characteristics for the manufacturing process are found for the device or for the OLED and vice versa.

[0098] Various embodiments and variations have been described. A person skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will become apparent to a person skilled in the art.

[0099] Finally, the practical implementation of the embodiments and variants described is within the reach of a person skilled in the art, based on the functional indications given above.

Claims

Demands

1. Organic light-emitting diode (100) comprising an emissive layer (150), emitting at a first wavelength, disposed between an electron injection layer (132) and a hole injection layer (131), at least one of the electron injection layer (132) or of the hole injection layer (131) being a layer in a first inorganic perovskite material.

2. Diode according to claim 1, wherein the other of the electron injection layer (132) or hole injection layer (131) is a layer in a second inorganic perovskite material.

3. Diode according to any one of the preceding claims, wherein a substrate (110) is successively covered by: - ​​a first electrode (121), - the hole injection layer (131), - a hole transport layer (141), - the emissive layer (150), - an electron transport layer (142), - the electron injection layer (132), made of a first inorganic perovskite material, - a second electrode (122) made of a transparent conductive oxide, for example in indium tin oxide.

4. Diode according to any one of the preceding claims, wherein a first additional layer (133), for example of oxide, in particular of tungsten oxide, is in contact with the first layer of inorganic perovskite material so as to form a bilayer and / or wherein a second additional layer (134), for example of oxide, in particular of tungsten oxide, is in contact with the second layer of inorganic perovskite material so as to form another bilayer.

5. An optoelectronic device (1000) with organic light-emitting diodes, for example, an OLED microdisplay or an OLED display, comprising successively: - a substrate (110), - first structured electrodes (121) arranged on the substrate (110), delimiting blue pixels, red pixels and green pixels, - a layer of hole injection (131) covering the first electrodes (121), - a hole transport layer (141), - an emitting layer (150), emitting at a first wavelength, - an electron transport layer (142), - an electron injection layer (132), - a spectral conversion element (161) positioned above one of the first electrodes (121) defining the red pixel, absorbing at the first wavelength and emitting at a second wavelength longer than the first, and an additional spectral conversion element (162) positioned above one of the first electrodes (121) defining the green pixel, absorbing at the first wavelength and emitting at a third wavelength longer than the first, at least one of the electron injection layer (132) or the hole injection layer (131) being a layer of a first inorganic perovskite material and, preferably, the other of the electron injection layer (132) or the hole injection layer (131) being a layer in a second inorganic perovskite material.

6. Device according to claim 5, wherein the first layer of inorganic perovskite material is the electron injection layer (132), the device further comprising a second electrode (122) of conductive transparent oxide, for example indium tin oxide, the second electrode (122) covering the spectral conversion element (161) and the additional spectral conversion element (162), or the second electrode (122) being disposed between, on the one hand, the electron injection layer (132) and, on the other hand, the spectral conversion element (161) and the additional spectral conversion element (162).

7. Device according to any one of claims 5 and 6, wherein the spectral conversion element (161) is in a third inorganic perovskite material and the additional spectral conversion element (162) is in a fourth inorganic perovskite material.

8. A method for manufacturing an organic light-emitting diode (100) comprising an emissive layer (150), emitting at a first wavelength, disposed between an electron injection layer (132) and a hole injection layer (131), the method comprising a step in which at least one of the electron injection layer (132) or the hole injection layer (131) is formed by depositing a first inorganic perovskite material by PLD.

9. A method according to claim 8, wherein the other of the electron injection layer (132) or hole injection layer (131) is formed by depositing a second inorganic perovskite material, preferably by PLD.

10. A method according to any one of claims 8 and 9, wherein a top electrode (122) made of a transparent conductive oxide, for example in indium tin oxide, is deposited by PLD on the stack comprising the emissive layer (150), the electron injection layer (132) and the hole injection layer (131).

11. A method for manufacturing an optoelectronic device (1000), comprising implementing the method for manufacturing an OLED according to any one of claims 7 to 9 for manufacturing several OLEDs on a substrate (110), and wherein spectral conversion elements (161, 162) made of perovskite material are deposited on the OLEDs by PLD.

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