Light-transmitting multilayer structures for optoelectronic devices

Abstract

A light-transmitting multilayer structure for an optoelectronic (OP) device comprises: a substrate (11); an electrode structure (13); and a barrier structure (12) disposed between the substrate (11) and the electrode structure (13). The multilayer structure can be prepared to be deformable, such as a flexible foil, and can be used in various OP devices, such as perovskite or organic photovoltaic (PV) devices or organic light-emitting diodes (OLEDs).

Description

Technical Field

[0001] The present invention relates to a light-transmitting electrode multilayer structure for an optoelectronic (OP) device. The multilayer structure can be prepared as a deformable (e.g., a flexible foil) and can be used as one of the electrodes next to the photosensitive material of the optoelectronic device in various optoelectronic devices (e.g., perovskite or organic photovoltaic (PV) devices or organic light-emitting diodes (OLEDs)), preferably as a front electrode. Background Art

[0002] From the patent literature thin foil-like multilayer structures are known for use in various optoelectronic devices.

[0003] International patent application WO2018139945 describes a semi-transparent photovoltaic foil, consisting of a plastic foil substrate, a conductive layer and a barrier layer arranged between the conductive layer and the plastic substrate. The barrier layer is made of a material selected from silicon oxide, aluminum oxide, titanium oxide, silicon oxynitride, silicon nitride, organic silicon compound, zirconium oxide, hafnium oxide, chromium oxide and paraxylene, wherein the barrier layer can be a single layer or a multilayer structure. The conductive layer includes at least two sublayers: an oxide layer (such as AZO, IZO, FTO, ZTO, ITO, GZO, GIO, IO:H, CdO or TiOx) and a metal layer, which is composed of at least one metal selected from Al, Ti, Ni, Cr, Au, Mg, Ta, Ge, Ag, Cu, Zr, Pt and W. Since the barrier layer is located between the plastic foil substrate and the conductive layer, the water vapor permeability (WVTR) of the plastic foil is 10 per day. -3 -10 -6 g / m 2 , and exhibits stable barrier properties, including high hydrophobicity and resistance to UV radiation. The foil's conductive layer can replace a single, thicker conductive ITO (indium tin oxide).

[0004] In addition, US patent application US20140054578 describes a multilayer electronic device consisting mainly of an organic polymer layer and an electrode located on the polymer layer. The electrode consists of a thin metal layer, a moisture and gas barrier layer called a first barrier layer, an anti-reflective coating and a capping layer made of oxidized or unoxidized metal. The over-barrier layer is used to protect the thin metal layer when depositing subsequent layers in an oxidizing or nitriding atmosphere. The multilayer structure of the electronic device may involve a structure such as ZnO / Ag / Ti / TiO x , so that one metal layer (Ag) is adjacent to another metal layer (Ti). In this device structure, the constituent barrier layers of the electrode layers have alternating low and high refractive indices, thereby providing an interference filter in the electrode structure. Therefore, the barrier layer participates in the anti-reflection effect of the thin metal layer of the electrode.

[0005] Patent application EP2871681 describes a back contact substrate for photovoltaic cells, which has a carrier substrate and an electrode coating. The electrode layer of the substrate includes an aluminum-based metal film with a thickness of 80-300 nm, an ohmic contact film (such as molybdenum or tungsten-based) that can form contact when sulfided or selenized, and a selenide barrier layer with a thickness of 20-50 nm between the metal layer and the ohmic contact film. However, this design does not propose another possibility for the arrangement of the layers. In addition, the barrier layer can only effectively control the migration of sodium.

[0006] Furthermore, patent application EP2720276 describes a solar cell substrate consisting of a multilayer metal diffusion barrier layer that prevents metal diffusion. The metal diffusion barrier layer is made of the following materials: chromium, nickel, titanium and metal oxides. By selecting the materials, the layer can inhibit the diffusion of impurities: Na and Fe. The diffusion barrier layer is located between the lower substrate and the lower electrode of the solar cell substrate. This structure has the effect of preventing the diffusion of the substrate; see paragraph 0043. 0043: "(...) Due to the interference formed by the metal layer and the oxide layer, the multilayer diffusion barrier layer plays a role in blocking the diffusion of impurities (such as Na and Fe) at the interface formed between different types of materials (...)". In this scheme, the metal layer is directly applied to the substrate, while the oxide metal layer is only arranged between the two metals (inside the multilayer diffusion barrier layer) to effectively inhibit the penetration of Na and Fe.

[0007] Light transmittance is an important factor in the function of multilayer optoelectronic (OP) devices. Therefore, highly transparent anti-reflection coatings are often used in the multilayer structure of OP devices to reduce Fresnel reflection losses, thereby increasing the amount of light passing through the OP device layer structure. This can improve the efficiency of the device. Anti-reflection coatings are usually applied on transparent substrates, and can also be applied to external coatings deposited on the outside of the device. Anti-reflection coatings can be made of materials such as glass or plastic. Therefore, anti-reflection coatings can effectively reduce surface reflection losses over a wide range of light wavelengths and incident angles. Typically, anti-reflection coatings adopt a multilayer design, including an alternating stacking structure of high refractive index and low refractive index material layers. In addition, in the optoelectronic device structure, reflection losses can also be reduced by the appropriate arrangement of materials and their thicknesses.

[0008] Essentially, the refractive index (n) is defined as a dimensionless number that describes the speed of light propagation in a material. It is defined as n = c / v, where c is the speed of light in a vacuum and v is the phase velocity of light in a given (considered) medium (material). For example, silicon dioxide (SiO 2 ) is used in the production of anti-reflective coatings due to its low refractive index, good durability and strong environmental resistance.

[0009] Furthermore, T. Flaim et al., in their scientific publication "High Refractive Index Polymer Coatings for Optoelectronics Applications" published in the February 2004 issue of the Proceedings of SPIE - The International S℃iety for Optical Engineering, describe a high refractive index polymer coating for optoelectronic applications such as flat panel displays, imaging sensors, photonic circuits, and light emitting diodes. The polymer coating material has a refractive index ranging from 1.6 to 1.9 and is applied to the light emitting or sensing portion of the device. In this way, the high refractive index of the active circuit inside the OP device can be gradually transitioned to the low refractive index of air, allowing light to be more efficiently coupled into or out of the device, improving device efficiency and / or image quality. The coating is made of an organic-inorganic hybrid material made of a titanium dioxide polymer precursor and a compatible organic polymer.

[0010] Furthermore, international patent application WO2015 / 140090A1 describes a layered photonic device in the form of a transparent substrate consisting of electrodes. The device consists of layers arranged in a stack, a support layer, a barrier layer, a scattering layer, a smoothing layer, a barrier sublayer, a crystalline sublayer, a metal conductive layer and a buffer layer. According to WO2015 / 140090A1, the barrier layer protects the electrode layer from the influence of chemical substances, especially from the contamination of alkaline substances from the glass support. However, the document does not mention the refractive index value of the barrier layer, and does not make any restrictions on the selection of the barrier layer material. On the contrary, WO2015 / 140090A1 provides a variety of materials for the barrier layer, including titanium oxide, zirconium oxide, aluminum oxide, yttrium oxide, zinc-tin mixed oxide, zinc aluminum, zinc titanium, zinc indium, tin indium, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon oxycarbonitride, aluminum nitride, aluminum oxynitride, aluminum silicon mixed nitride and aluminum silicon mixed oxynitride. The thickness of the buffer sublayer can vary from 20nm to 200nm. The above parameters can only predict a very wide range of refractive index values, but are not mentioned in WO 2015 / 140090 A1.

[0011] As can be seen from the above-mentioned publications, the architecture of multilayer structures for OP devices is constantly evolving, with the goal of improving the light transmittance and blocking properties of OP devices to increase their efficiency and extend the service life of various OP devices.

[0012] Therefore, it is necessary to further develop a light-transmitting multilayer structure dedicated to the electrode function of an OP device to further improve its barrier properties, including improving light transmittance, limiting the penetration of oxygen and moisture into the interior of the OP device, and the chemical stability of the OP device using the multilayer structure in its OP cell design. In addition, it is also necessary to develop a multilayer structure that exhibits improved deformability (especially flexibility) to expand its application range. Summary of the invention

[0013] The present invention discloses a light-transmitting multilayer structure for an optoelectronic (OP) device, comprising: a substrate 11; an electrode structure 13; and a barrier structure 12 arranged between the substrate 11 and the electrode structure 13, wherein the barrier structure 12 comprises a barrier layer arranged in a barrier stack, wherein the barrier stack comprises a backing layer A adjacent to the substrate 11, a buffer layer C adjacent to the electrode structure 13, and a barrier layer B arranged between the backing layer A and the buffer layer C; the electrode structure 12 comprises an electrode layer arranged in an electrode stack, wherein the electrode stack comprises a dielectric layer E, and a metal layer D arranged between the buffer layer C and the dielectric layer E of the barrier structure 12; wherein the buffer layer C comprises at least one selected from TiO x 、ZrO 2 , Nb 2 O 5 、TeO 2 and ZnS, wherein the refractive index values ​​of all materials of the buffer layer C are in the range of 2.2 to 2.6, and wherein the total thickness of the buffer layer C is 10 to 60 nm; and wherein the metal layer D includes silver (Ag) and at least one metal selected from the group consisting of Al, Cu, Ti, Ge, Zn and Cr.

[0014] Preferably, the total thickness of the metal layer D is 4 to 13 mm.

[0015] Preferably, the dielectric layer E comprises at least one selected from indium oxide (In 2 O 3 ), tin oxide (SnO 2 )、ZnO、Vanadium Oxide (V 2 O 5 ), molybdenum oxide (MoO 3 ), tungsten oxide (WO 3 ), indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO) and indium gallium zinc oxide (IGZO).

[0016] Preferably, the total thickness of the dielectric layer E is 20 to 80 nm.

[0017] Preferably, the barrier layer B comprises at least one selected from AlO xSnO x 、ZnO x , HfO x 、Al y Ti z O、Al y Zr z O and Al y Zn z O, wherein the refractive index values ​​of all materials of the barrier layer B are in the range of 1.5 to 2.1.

[0018] Preferably, the total thickness of the barrier layer B is 10 to 100 nm.

[0019] Preferably, the backing layer A comprises at least one selected from TiO x SnO x 、ZrO x , HfO x 、Al y Ti z O and Al y Zr z O is a metal oxide in the group consisting of.

[0020] Preferably, the total thickness of the backing layer A is 2 to 20 nm.

[0021] Preferably, the refractive index values ​​(n) of all materials of the backing layer A are in the range of 1.6 to 2.6.

[0022] Preferably, the buffer layer C mainly comprises TiO x , wherein the refractive index values ​​(n) of all materials of the buffer layer C are in the range of 2.4 to 2.5.

[0023] Preferably, the total thickness of the buffer layer C is 20 to 50 nm.

[0024] Preferably, the barrier layer B is mainly composed of AlO x The composition comprises a barrier layer B wherein all materials of the barrier layer B have refractive index values ​​in the range of 1.6 to 2.0.

[0025] Preferably, the metal layer D consists of Ag and Cu, wherein the content of Ag is 90% and the content of Cu is 10%.

[0026] Preferably, layers AE are independently selected from a single layer structure or a multilayer structure, the multilayer structure comprising two or more sublayers.

[0027] Preferably, the substrate is made of a deformable foil comprising at least one material selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), polypropylene (PP), polyethersulfone (PES), polyimide (PI), polystyrene (PS), ethylene / tetrafluoroethylene copolymer (ETFE) and polyparaxylene. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The object of the present invention is illustrated by means of exemplary embodiments in the accompanying drawings, in which:

[0029] Figure 1 Schematically shows a multilayer structure for an optoelectronic device according to the present invention;

[0030] Figure 2 shows the light transmission experimental data of the multilayer structure according to Example 1 of the present invention;

[0031] Figure 3-4 Light transmission simulations of multilayer structures according to Example 2 and Example 3 of the present invention are shown. DETAILED DESCRIPTION

[0032] The multilayer structure according to the present invention can be provided as a deformable (e.g. flexible) light-transmitting (transparent or translucent) foil, which includes an electrode structure, which can be preferably arranged as a front electrode for a cathode or anode in various OP device designs (e.g., with perovskite or organic photosensitive areas (e.g. OLED)) according to special needs.

[0033] The multilayer structure includes a substrate, an electrode structure, and a barrier structure located between the substrate and the electrode structure. This design, the further development structure of the two structures (electrode and barrier layer), and the selected characteristics of the materials used in these structures, together improve the characteristics of the multilayer structure, including ultra-high barrier properties, enhanced chemical and thermal stability, high flexibility, higher light transmittance of the entire stack, and low sheet resistance of the electrode. Among other things, the multilayer structure also exhibits improved barrier properties, a water vapor transmission rate (WVTR) of 1×10 -6 -1×10 -3 g / m 2 / day (38 ° C / 90% RH (relative humidity)), higher flexibility - the barrier properties of the multilayer structure do not change even when its bending radius is as low as 0.5 cm (wherein the larger the bending radius, the smaller the curvature). In addition, the developed multilayer structure also has the following characteristics: the transmittance of the barrier structure and the electrode structure is increased to more than 80% AVT (average visible transmittance); low sheet resistance - less than 20Ohms / sq.

[0034] The above advantages are the effect of the developed specific sequence and selected materials of the layers in the multilayer structure, as well as the specific layer thicknesses and refractive index values ​​(n) of the selected materials of the layers, which can be regarded as the identification of specific sub-ranges for at least two layers, more preferably two layers, three layers or all layers arranged in the multilayer structure. According to the present invention, this special combination of material selection and layer arrangement in the stack provides new and superior functions, thereby improving the overall properties of the multilayer structure.

[0035] Therefore, one aspect of the present invention is to make a specific selection of materials for the multilayer structure of the OP device, taking into account the various characteristics of the materials used.

[0036] According to the present invention, Figure 1 Schematically shown, the multilayer structure for optoelectronic devices comprises: a substrate 11, preferably a deformable substrate 11, such as a flexible substrate 11. The substrate can be made of various transparent or translucent materials, preferably those materials that allow the substrate 11 to be deformed. For example, the substrate can include a foil, or be substantially entirely made of a foil, and the foil surface can be optionally provided with a primer coating. Preferred non-limiting examples of plastic materials suitable for the substrate 11 are polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), polypropylene (PP), polyether sulfone (PES), polyimide (PI), polystyrene (PS), ethylene / tetrafluoroethylene copolymer (ETFE) and polyparaxylene, or mixtures thereof. The thickness of the substrate 11 is determined as required. For example, the thickness of the substrate can be 25 to 300 microns.

[0037] The multilayer structure further comprises an electrode structure 13, which comprises a stack of electrode layers D and E arranged one above the other; and a barrier structure 12, which comprises a stack of barrier layers A, B, and C arranged one above the other. The barrier structure 12 is arranged between the substrate 11 and the electrode structure 13. The layers (D, E) of the electrode structure 13 and the layers (A, B, C) of the barrier structure 12 can be single-layer structures or multi-layer structures. Therefore, the layers of the multilayer structure can include at least two sub-layers, one above the other. According to the present invention, any of the layers A, B, C, D, and E of the multilayer structure can include the above-mentioned sub-layers.

[0038] In order to prepare the multilayer structure, various deposition techniques may be used to sequentially deposit the barrier layers A, B, C and the electrode layers D, E of the structures 12, 13 on the substrate 11. For example, each of the layers A, B, C may be deposited using ALD (atomic layer deposition) or MLD (molecular layer deposition) techniques, while each of the layers D and E may be deposited using magnetron sputtering, thermal evaporation, chemical vapor deposition, pulsed laser deposition, or similar techniques. If a sublayer is present in any of the layers A, B, C, D, E, the same applies to the sublayer.

[0039] The barrier structure 12 comprises a layer substantially made of metal oxide (or sulfide, such as ZnS in the C layer), wherein the barrier structure 12 comprises a backing layer A adjacent to the substrate 11 for isolating the remaining layers BE from the substrate. The backing layer A is made of at least one metal oxide, and the metal oxide is preferably selected from TiO x SnO x 、ZrO x , HfO x or a group consisting of composite metal oxides, the composite metal oxides comprising a combination of at least one metal atom selected from the group consisting of Ti, Sn, Zr and Hf and another metal atom (e.g., Al or Zn), a non-limiting example of the composite metal oxide is Al y Ti z O and Al y Zr z O, wherein y may be 0.25 to 1 (0.25≤y≤1), z may be 0.01 to 0.9 (0.01≤z≤0.9), wherein the preferred material of the backing layer A is TiO x , because it has good durability and environmental resistance. Preferably, the thickness of the backing layer A is 2 to 20 nm. Preferably, the refractive index (n) of the backing layer A is 1.6 to 2.6 (1.6≤n≤2.6), and more preferably, the refractive index value of each sublayer of layer A (if present) is within the above range. However, the refractive index value of the backing layer A is not so important for the optical transmission of the multilayer structure.

[0040] The thickness and selected material of the backing layer A provide the desired chemical stability for the multilayer structure, including reducing the hydrolysis effect of humid air on the multilayer structure. Therefore, in the developed multilayer structure, the backing layer A acts as a bottom buffer layer for the next layer B. The backing layer A can be composed of at least one oxide or more than one metal oxide (such as TiO x and / or SnO x ), or the backing layer A may include at least two sublayers, each sublayer is made of one metal oxide or more than one metal oxide, wherein preferably, one sublayer in the backing layer A is made of TiO x The other sublayer can be made of SnO x The backing layer A may be directly deposited on the substrate 11 , or may be deposited on a primer coating of the substrate 11 .

[0041] The barrier structure further comprises a buffer layer C and a barrier layer B, wherein the barrier layer B is arranged between the buffer layer C and the backing layer A.

[0042] The barrier layer B may be a single-layer structure or a multi-layer structure. In one embodiment of the single-layer structure, in the metal oxide structure, the barrier layer B may be made of at least one, more preferably two, metal oxides (optionally, lignite is added), the metal oxides being selected from SnO x 、AlO x 、ZnO x and HfO x or made of a composite metal oxide, the composite metal oxide comprising at least one metal atom selected from the group consisting of Sn, Al, Zn and Hf and another metal atom (such as Ti, Zr), a non-limiting example of the composite oxide is Al y Ti z O、Al y Zr z O and Al y Zn z O, wherein y may be 0.25 to 1 (0.25≤y≤1), and z may be 0.01 to 0.9 (0.01≤z≤0.9). Most preferably, the barrier layer B includes AlO as a metal oxide. x and SnO as another metal oxide x or ZnO x or HfO x In one embodiment of the multilayer structure, the barrier layer B may include two or more sublayers, wherein each sublayer may include at least one metal oxide. For example, the barrier layer B may include two sublayers, one of which is composed of AlO x made of SnO x or ZnO x or HfO x In another embodiment, the barrier layer B may include a plurality of sublayers, each of which is made of a different metal oxide. For example, the sublayers in a barrier layer B may be arranged between layer A and layer C in the following pattern: A / AlO x / SnO x / ZnO x / HfO x / New aluminum-based organic-inorganic composite film (alucone) / C. Preferably, the total thickness of the barrier layer B is 10 to 100 nm. Preferably, the refractive index (n) of the barrier layer B is between 1.5 and 2.1 (1.5≤n≤2.1), and most preferably, the refractive index of the barrier layer B is close to that of AlO x The refractive index is 1.6≤n≤1.8, and n=1.7 is more preferred. x In a manufactured example, the refractive index of this layer may be n=1.7.

[0043] The selected material for barrier layer B and its thickness together provide an effective barrier function for layer B. Due to the presence of barrier layer B and its arrangement in the multilayer structure, the multilayer structure exhibits improved barrier properties, including low water vapor permeability, with a water vapor transmission rate (WVTR) of 1×10 per day at 38°C / 90% RH. -6 -1×10 -3 g / m 2 , oxygen transmission rate (OTR) is less than 1×10 per day -2 cm 3 / m 2 Furthermore, the selected material of the barrier layer B provides a suitable refractive index value (n) of 1.5 to 2.1, preferably n=1.7, which helps to improve the light transmittance of the multilayer structure.

[0044] The buffer layer C may be a single-layer structure or a multi-layer structure. In the embodiment of the single-layer structure, the buffer layer C may be composed of one compound (oxide or sulfide) or more than one compound, and the compound is selected from TiO x 、ZrO 2 , Nb 2 O 5 、TeO 2 More preferably, the buffer layer C of the single-layer structure comprises TiO x , or completely composed of TiO x Because the TiO in the buffer layer C x Improved chemical resistance of the multilayer structure is provided, thereby protecting the electrode structure 13 contained therein, while helping to achieve the high refractive index values ​​required by the present invention at the desired thickness of the buffer layer C (as described below).

[0045] Preferably, the total thickness of the buffer layer C is at least 10 nm, more preferably, the total thickness of the buffer layer C is 10 to 60 nm, even more preferably 20 to 50 nm. The refractive index (n) of the buffer layer C is in the range of 2.2 to 2.6, more preferably the refractive index of the buffer layer C is n=2.45. Such a high refractive index value of the buffer layer C arranged between the electrode structure 13 and the barrier layer B can minimize the reflection losses at the interface of the electrode structure (D, E). The above characteristics, together with the selected electrode structure (metal-dielectric) design, provide improved stability and performance of the electrode structure 13 comprising layer D and layer E, respectively.

[0046] The developed barrier stack of the barrier structure 12 comprises layers A, B and C, each of which is made of at least one metal oxide (or sulfide). In addition, the buffer layer C arranged next to the electrode structure 13 is selected to have a high refractive index of 2.2≤n≤2.6, preferably n=2.45. These factors together provide improved light conversion through the multilayer structure, wherein the layer C (metal oxide and / or metal sulfide layer) is in contact with the metal layer D.

[0047] Furthermore, due to the good chemical stability achieved by the above structure, the multilayer structure can be laser etched in layers D and E of the electrode structure 12. Therefore, when the multilayer structure is applied to an OP device, the multilayer structure can be laser patterned to obtain a designed battery structure. Therefore, the architecture of the developed multilayer structure can provide improved patterning behavior - without damaging the underlying materials, i.e., layers C, B, and A. Therefore, the patterning performed does not impair the barrier properties of the barrier structure 12.

[0048] Preferably, layer B is further selected to have a high refractive index, 1.5≤n≤2.1, more preferably n=1.7. This, combined with the refractive index value of layer C, further improves the light conversion of the multilayer structure while ensuring good barrier properties, while the thickness of the lower layer B does not substantially exceed 100 nm.

[0049] The electrode structure 13 includes an electrode layer (E, D), a dielectric layer E, and a metal layer D between the dielectric layer E and the high refractive index buffer layer C. The metal layer D is composed of two or more metals. The metal layer D can be a single-layer structure, preferably in the form of a metal alloy, such as a bimetallic alloy, or the metal layer D can be a multilayer structure, including two or more sublayers, preferably each sublayer is made of a metal or metal alloy.

[0050] The metal layer D of the electrode structure 13 is preferably composed of silver (Ag) and one or more metals selected from the group consisting of Al, Cu, Ti, Ge, Zn and Cr. The metal layer D is preferably a bimetallic layer. The total thickness of the metal layer D is 4 to 13 nm. For example, layer D can be composed of a Cu / Ag alloy, wherein Cu=10% and Ag=90%. The layer D can be formed directly on layer C by sputtering, more preferably by co-sputtering, i.e. using two different metals (Ag and Cu). By co-sputtering, a metal layer with a thickness as low as 4 nm can be produced, thereby providing very good conductivity, Rsh≤20Ohm / sq. Alternatively, co-sputtering of a single silver / copper alloy target is used.

[0051] Preferably, the dielectric layer E of the electrode structure is a single-layer structure. The dielectric layer E is made of one or more than one TCO (transparent conductive oxide), and TCO is preferably selected from indium oxide (In 2 O 3), tin oxide (SnO 2 )、ZnO、Vanadium Oxide (V 2 O 5 ), molybdenum oxide (MoO 3 ), tungsten oxide (WO 3 ) or made of a composite metal oxide, in which the composite metal oxide contains at least one metal atom selected from the group consisting of In, Sn, Zn, V, Mo and W mentioned above and another doping metal, such as indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO) and indium gallium zinc oxide (IGZO) or similar composite metal oxides. The thickness of the dielectric layer E is 20-80nm. Preferably, the dielectric layer E has a high refractive index value of 1.8 to 2.2 (1.8≤n≤2.2). The thickness of the dielectric layer E is within the above range, and the thickness can be selected in the visible light or near infrared region according to different applications of the multilayer structure to optimize the required (preferably maximum) transmittance of the multilayer structure. Therefore, the layer TCO (E) combined with the underlying blocking structure 12 provides an anti-reflective coating effect of the dielectric layer E. In addition, layer E can also prevent oxidation of the metal layer D. In addition, layer E is also suitable for forming contacts thereon to combine the multilayer structure with, for example, a photosensitive material, and then combined with another electrode to form an OP device, such as a solar cell (such as a perovskite cell or an organic cell) or an OLED, etc.

[0052] The stack formed in the multilayer structure, including layer C (preferably also layer B) and layer E, can provide an anti-reflection effect for the thin metal layer D of the electrode structure. In more detail, in the developed multilayer structure, layer E acts as both a part of the electrode structure and as an anti-reflection coating for layer D - on one side of the multilayer structure, while layer C (preferably together with layer B) acts as an anti-reflection coating for layer D - on the other side. At the same time, layer B and layer C also have the above-mentioned blocking properties. Therefore, the selective combination of layers implemented in the multilayer structure can reduce reflection losses, thereby performing the function of an anti-reflection system as a whole.

[0053] According to the present invention, the general formula mentioned in any layer or respective sublayer of the multilayer structure is MeO x , such as SnO x 、TiO x 、ZnO x , HfO x The metal oxide may be a stoichiometric structure and / or a non-stoichiometric structure, and x may be 1 to 2 (1≤x≤2). This is because different oxidation states of the metal in each metal oxide may be obtained when preparing the desired material layer. For example, for SnO x For example, materials include SnO 2However, in practice, tin is usually not completely oxidized to Sn(IV), so SnO x Materials include SnO 2 and SnO, while SnO 2 The exact content of SnO phase depends on the exact deposition conditions. The same applies to other metal oxides, in this case MeO x For example, SnO x The exact chemical formula of the material can be SnO 1.8 Here, MeO x Non-limiting examples of materials represented are: TiO 2 SnO 2 SnO 1.8 、ZrO 2 , HfO 2 、ZnO、Al 2 O 3 .

[0054] In addition, in the multilayer structure of the present invention, the arrangement of the electrode structure including the metal layer D and the TCO layer E provides a metal-dielectric electrode structure. Compared with the known dielectric-metal-dielectric structure, this structure provides better flexibility, while the layer E made of dielectric material provides an anti-reflection effect for the metal layer D.

[0055] The materials of each layer B, C and E are selected according to their refractive index values, such as AlO x The refractive index of SnO is n = 1.7. x The refractive index of ZnO is n = 1.9. x The refractive index of TiO is n = 2.0. x The refractive index of ZrO is n = 2.45, the refractive index of ITO is n = 2.0, 2 The refractive index of n=2.2 is a typical n value for materials used in the following embodiments of the present invention.

[0056] In a preferred embodiment of the present invention, the multilayer structure may include a plastic substrate and a stack of the following layers:

[0057] - Layer A includes TiO x , more preferably TiO x Made of, the total thickness of layer A is 2-20nm, and the refractive index is 2.45;

[0058] - Layer B includes AlO x and another metal oxide with a refractive index close to AlO x The refractive index of the layer B is n=1.7; the total thickness of the layer B is 10-100 nm; the layer B may be a single layer or a multilayer structure;

[0059] - Layer C includes TiOx , TiO x The refractive index of the layer C is 2.45, or the layer C may include other metal oxides, and the refractive index of the other metal oxides is 2.2 to 2.6; the total thickness of the layer C is 20 to 50 nm;

[0060] -Layer D and layer E together provide a metal-dielectric (M-dielectric) electrode structure, wherein layer D is made of two metals, one of which is Ag, and the total thickness of layer D is 4 to 13 nm; dielectric layer E is made of TCO; therefore, the electrode structure including layer D and layer E can be patterned, preferably laser patterned or chemically patterned.

[0061] As mentioned above, due to the special selection of certain parameter sub-ranges, including the selected materials, thicknesses and reflective index values ​​of each layer - at least layer C, further preferably layer B and / or layer E, plus the implementation of the M dielectric electrode structure, the developed multilayer structure exhibits improved chemical stability, better adhesion of each layer (AD) in the stack, and adhesion of the AE layer to the substrate. In addition, this multilayer structure can also be used as a substantially thinner structure - the entire stack thickness of the AD layer can be less than 250nm, and the stack thickness of the AC layer can be less than 100nm, more preferably less than 60nm. This further provides higher flexibility of the multilayer structure, reflected in at least 1000 bending tests and no functional loss in bending radii as low as 0.5cm. In addition, the selected layer C material, preferably also the layer B and layer E materials - each material has a relatively high refractive index value, which can fully reduce the reflection loss at the interface of the barrier layer (AC) and the electrode (DE) structure - which constitutes another technical effect provided by the present invention. This has a positive impact on the incident light, which enters or emits from the transparent / semi-transparent substrate or through the electrode area of ​​the OP device. Therefore, OP devices with multilayer structures can improve efficiency.

[0062] Furthermore, according to the present invention, the barrier layer B (preferably composed of AlO x The ZnS layer (e.g., layer C) is effectively sandwiched together with other metal oxide (or sulfide) layers (e.g., ZnS of layer C), thereby encapsulating them together, so that the other layers A, C, and E have additional functions as described above. This extends the service life of the OP device using the multilayer structure according to the present invention.

[0063] It should be further noted that the above effects are achieved without using any organic additives in the multilayer structure. Therefore, according to the present invention, no organic layers and / or additives are required between the layers (AE) and / or within the layers (AE), and the only organic material within the multilayer structure can be the polymer substrate 11. Therefore, the preparation of the developed multilayer structure is very simple and cost-effective.

[0064] Example 1

[0065] The substrate is a PET foil, which is ultrasonically cleaned in IPA (70% isopropyl alcohol) and then dried with a nitrogen gun. Then, layers A, B, and C are deposited by ALD technology at 100°C without breaking the vacuum between each layer deposition. All layers are optimized to be as dense as possible to additionally enhance good permeation barrier properties and chemical stability. The layers are formed in the form of a stack on the substrate. The detailed composition of each layer is as follows:

[0066] - Barrier structure: Layer A: TiO x (5nm thick); Layer B: sublayer AlO x (20nm thick) / sublayer ZnO x (10nm thick), sublayer AlO x (20nm thick); Layer C: TiO x (32nm thick).

[0067] Next is the electrode area: depositing D+E layers, each of which is deposited by magnetron sputtering. The detailed composition of each layer is as follows:

[0068] - Electrode structure: Layer D: Cu / Ag (Cu: 10%; Ag: 90%) co-sputtered layer (7 nm thick). Co-sputtering was performed with two different metal targets (Ag and Cu) at different powers; Layer E: ITO layer (40 nm thick) on an ITO target.

[0069] The obtained multilayer structure is in the form of a flexible transparent foil, composed of the following layers: PET / TiO x (5nm) / AlO x (20nm) / ZnO x (10nm) / AlO x (20nm) / TiO x (32nm) / CuAg(7nm) / ITO(40nm).

[0070] The obtained multilayer structures were then tested to evaluate their transmission properties in the visible (VIS) and infrared (IR) spectral ranges. Figure 2 This is shown in the graph of , which shows the transmittance (center and corners) of the complete structure of the foil (multilayer structure) measured on a 10×10 cm2 sample. Figure 2 As can be seen from the graph, the average visible light transmittance at the center is 82%, and the average visible light transmittance at the corners is 80.4-81.6%. Therefore, an excellent transmittance of more than 80% can be achieved over a large area.

[0071] The other parameters of the obtained foil are as follows: Sheet resistance: 13.5 Ohm / sq (Rsh of a typical ITO with similar transmittance is over 20 Ohm / sq); WVTR of the barrier stack: ˜10 -6 g / m 2 / day; OTR of barrier stack: ≤5×10 - 4 cc / m 2 / day (OTR is below the detection limit).

[0072] Example 2

[0073] A multilayer structure in the form of a transparent flexible foil was prepared under the same conditions as in Example 1. The resulting foil structure was as follows:

[0074] Substrate: PET

[0075] Layer A: SnO x , 5nm thick, made by ALD

[0076] Layer B: AlO x , 50nm thick, made by ALD

[0077] Layer C: TiO x , 32nm thick, made by ALD

[0078] Region D: Cu / Ag (10 / 90 atomic %), 7 nm thick, made by sputtering

[0079] Region E: ITO, 40nm thick, made by sputtering

[0080] Computer simulations were performed on the above structure to evaluate its optical transmission performance. The data obtained are as follows Figure 3 As shown in the graph in . It can be seen that in the visible light spectral range of 400-800nm, the optical transmittance of the obtained foil is much higher than 80%.

[0081] Example 3

[0082] A multilayer structure in the form of a transparent flexible foil was prepared under the same conditions as in Example 1. The resulting foil structure was as follows:

[0083] Substrate: PET

[0084] Layer A: TiO x , 5nm thick, made by ALD

[0085] Layer B: Sublayer AlO x (10nm thick) / sublayer ZnO x (10nm thick) / sublayer AlO x(10nm thick) / sublayer ZnO x (10nm thick) / sublayer AlO x (10nm thick), all made by ALD

[0086] Layer C: ZrO x , 35nm thick, made by ALD

[0087] Layer D: Cu / Ag (10 / 90 atomic %), 7 nm thick, made by sputtering

[0088] Layer E: ITO, 40 nm thick, produced by sputtering.

[0089] like Figure 4 As shown in the simulations in , the obtained layer stack has the form of a flexible transparent foil, yielding an optical transmittance well above 80% in the visible light 400-800 nm spectral range.

Claims

1. A light-transmitting multilayer structure for an optoelectronic (OP) device, include: base(11); Electrode structure (13); and a barrier structure (12) arranged between the substrate (11) and the electrode structure (13), the barrier structure (12) comprising barrier layers arranged in a barrier stack, the barrier stack comprising a backing layer (A) adjacent to the substrate (11), a buffer layer (C) adjacent to the electrode structure (13), and a barrier layer (B) arranged between the backing layer (A) and the buffer layer (C); The electrode structure (13) comprises electrode layers arranged in an electrode stack, wherein the electrode stack comprises a dielectric layer (E) and a metal layer (D) arranged between a buffer layer (C) of a barrier structure (12) and the dielectric layer (E); wherein: The buffer layer (C) includes at least one selected from TiO x 、ZrO 2 , Nb 2 O 5 、TeO 2 and ZnS, wherein the refractive index values ​​of all materials of the buffer layer (C) are in the range of 2.2 to 2.6; and wherein the metal layer (D) comprises silver (Ag) and at least one metal selected from the group consisting of Al, Cu, Ti, Ge, Zn and Cr, It is characterized in that The total thickness of the buffer layer (C) is 10 to 60 nm, and wherein, The backing layer (A), barrier layer (B), buffer layer (C), metal layer (D), and dielectric layer (E) are directly adjacent to each other.

2. The multilayer structure according to claim 1, in, The total thickness of the metal layer (D) is 4 to 13 nm.

3. The multilayer structure according to claim 1 or 2, in, The dielectric layer (E) includes at least one selected from indium oxide (In 2 O 3 ), tin oxide (SnO 2 )、ZnO、Vanadium Oxide (V 2 O 5 ), molybdenum oxide (MoO 3 ), tungsten oxide (WO 3 ), indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO) and indium gallium zinc oxide (IGZO).

4. The multilayer structure according to claim 1 or 2, in, The total thickness of the dielectric layer (E) is 20 to 80 nm.

5. The multilayer structure according to claim 1 or 2, in, The barrier layer (B) comprises at least one selected from AlO x SnO x 、ZnO x , HfO x 、Al y Ti z O、Al y Zr z O and Al y Zn z O, wherein the refractive index values ​​of all materials of the barrier layer (B) are in the range of 1.5 to 2.

1.

6. The multilayer structure according to claim 1 or 2, in, The total thickness of the barrier layer (B) is 10 to 100 nm.

7. The multilayer structure according to claim 1 or 2, in, The backing layer (A) comprises at least one selected from TiO x SnO x 、ZrO x , HfO x 、Al y Ti z O and Al y Zr z O is a metal oxide in the group consisting of.

8. The multilayer structure according to claim 1 or 2, in, The total thickness of the backing layer (A) is 2 to 20 nm.

9. The multilayer structure according to claim 1 or 2, in, The refractive index values ​​(n) of all materials of the backing layer (A) are in the range of 1.6 to 2.

6.

10. The multilayer structure according to claim 1 or 2, in, The buffer layer (C) mainly comprises TiO x , wherein the refractive index values ​​(n) of all materials of the buffer layer (C) are in the range of 2.4 to 2.

5.

11. The multilayer structure according to claim 1 or 2, in, The total thickness of the buffer layer (C) is 20 to 50 nm.

12. The multilayer structure according to claim 1 or 2, in, The barrier layer (B) mainly comprises AlO x , wherein the refractive index values ​​of all materials of the barrier layer (B) are in the range of 1.6 to 2.

0.

13. The multilayer structure according to claim 1 or 2, in, The metal layer (D) includes Ag and Cu, with the content of Ag being 90 at %, and the content of Cu being 10 at %.

14. The multilayer structure according to claim 1 or 2, in, The substrate is made of a deformable foil, which includes at least one material selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), polypropylene (PP), polyether sulfone (PES), polyimide (PI), polystyrene (PS), ethylene / tetrafluoroethylene copolymer (ETFE) and polyparaxylene.

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