High-performance perovskite electroluminescent device and preparation method thereof

Abstract

The application discloses a high-performance perovskite electroluminescent device and a preparation method thereof. The device is provided with an independent and continuous inorganic interface engineering layer between a perovskite light-emitting layer and an electron transport layer, the material of the inorganic interface engineering layer is MX metal salt, the element at the M position is metal or alloy, and the element at the X position is at least one of F, Cl, Br, I and SCN. The preparation method comprises the following steps: sequentially depositing a hole injection layer and a hole transport layer on the surface of a conductive substrate; depositing a perovskite light-emitting layer on the surface of the hole transport layer, then in-situ vacuum thermal evaporation of an inorganic interface layer, and annealing treatment of the perovskite light-emitting layer and the inorganic interface layer; and finally, sequentially depositing an electron transport layer, an electron injection layer and a metal electrode layer on the surface of the inorganic interface layer. The application cooperatively improves the external quantum efficiency, the device lifetime and the stability of the electroluminescent spectrum in a single step. The method is highly compatible with the full vacuum thermal evaporation process, and provides an industrialization solution for solving the performance bottleneck of the perovskite LED.

Description

Technical Field

[0001] This invention relates to an electroluminescent device and its fabrication method, and more particularly to a high-performance perovskite electroluminescent device and its fabrication method. Background Technology

[0002] Perovskite electroluminescent devices, as an emerging light-emitting technology in recent years, are widely regarded as potential candidates for next-generation display and lighting technologies due to their outstanding advantages such as high color purity, high fluorescence quantum yield, low-cost solution processing, and easily tunable spectra. However, despite the achievement of high external quantum efficiency in the laboratory stage, their practical application and commercialization still face a series of interconnected and mutually restrictive performance bottlenecks, which constitute the current research difficulties and key areas of focus in this field.

[0003] The bottlenecks include: (1) Efficiency bottleneck: The luminous efficiency of the device is constrained by both material defects and energy level structure. This not only limits the peak external quantum efficiency of the device at low brightness, but also causes a significant efficiency roll-off at high current density, affecting the device's performance at high brightness. (2) Stability bottleneck: The device is affected by multiple stresses such as electric field, illumination and Joule heating during operation, making its stability problem particularly prominent. (3) Spectral performance bottleneck: During the driving process, due to the redistribution of ions induced by the electric field, the bandgap change caused by heating, and the change in the proportion of nonradiative transitions of defect states, the luminous peak position of the device is prone to dynamic drift. This spectral instability will cause the display color to change with working time or driving conditions, seriously affecting the color reproduction of the display and the consistency of long-term use, making it difficult to meet the strict requirements of high-end display applications for color fidelity.

[0004] Currently, common research strategies often focus on improving single problems, such as introducing passivating molecules to modify defects to improve initial efficiency, or optimizing encapsulation to block water and oxygen penetration to extend storage life. While these approaches can achieve progress in specific areas, they struggle to comprehensively address the intertwined issues of efficiency, stability, and spectral stability, lacking a simple, universally applicable integrated solution that can synergistically improve the overall performance of devices. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a high-performance perovskite electroluminescent device that can simultaneously achieve efficient carrier injection, defect suppression, ion migration retardation, and interface stability; the second purpose of this invention is to provide a method for fabricating the above-mentioned high-performance perovskite electroluminescent device.

[0006] Technical solution: The high-performance perovskite electroluminescent device of the present invention includes a conductive substrate, a hole injection layer, a hole transport layer, a perovskite luminescent layer, an electron transport layer, an electron injection layer, and a metal electrode layer stacked sequentially. An independent and continuous inorganic interface layer is disposed between the perovskite luminescent layer and the electron transport layer. The inorganic interface layer material is an MX metal salt, the M-site element is a metal or alloy, and the X-site element is selected from at least one of F, Cl, Br, I, and SCN.

[0007] The M-position element is selected from one or more alloys of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, and zinc.

[0008] The MX metal salt is selected from at least one of NaCl, KBr, RbI, CsSCN, MgF2, NaBr, and MgBr2.

[0009] The inorganic interface layer has a thickness of 0.5-30 nm.

[0010] Wherein, the conductive substrate is a conductive substrate with an anode, the anode electrode is indium tin oxide, and the conductive substrate is glass sputtered with indium tin oxide.

[0011] The above-mentioned method for fabricating high-performance perovskite electroluminescent devices includes the following steps:

[0012] (1) A hole injection layer and a hole transport layer are sequentially deposited on the surface of a conductive substrate;

[0013] (2) First, a perovskite light-emitting layer is deposited on the surface of the hole transport layer by vacuum thermal evaporation. Then, an inorganic interface layer is deposited in situ on the surface of the perovskite light-emitting layer by vacuum thermal evaporation. Finally, the perovskite light-emitting layer and the inorganic interface layer are annealed.

[0014] (3) An electron transport layer, an electron injection layer and a metal electrode layer are sequentially deposited on the surface of the annealed inorganic interface layer.

[0015] In step (2), the annealing temperature is 60-150 ℃ and the annealing time is 10-40 min.

[0016] In step (2), the thermal evaporation rate of the inorganic interface layer is 0.1-1 Å / s, and the vacuum degree of the coating chamber is 1×10⁻⁶. -4 -6×10 -4 Pa, substrate temperature is -10℃ to 90℃.

[0017] In step (2), the perovskite luminescent layer material is preferably cesium bromide and lead bromide; the deposition rate of the perovskite luminescent layer using vacuum thermal evaporation is 0.1-1 Å / s, and the vacuum degree in the coating chamber is 5×10⁻⁶. -5 -2×10 -4 Pa, substrate temperature is -10℃ to 90℃.

[0018] In steps (1) and (3), the methods for depositing the hole injection layer, hole transport layer, electron transport layer, electron injection layer and metal electrode layer are all vacuum thermal evaporation methods.

[0019] In step (1), the hole injection layer material is selected from at least one of molybdenum trioxide, nickel oxide, vanadium pentoxide, and copper oxide. The deposition rate of the hole injection layer is 0.1-0.5 Å / s, and the vacuum degree inside the coating chamber is 1×10⁻⁶. -4 -6×10 -4 Within the Pa range, with the substrate temperature at room temperature, the resulting hole injection layer thickness is 3-10 nm.

[0020] In step (1), the hole transport layer material is selected from at least one of 4,4',4''-tris(carbazole-9-yl)triphenylamine and 4,4'-cyclohexylbis(N,N-bis(p-tolyl)aniline), the hole transport layer deposition rate is 0.5-1 Å / s, and the vacuum degree in the coating chamber is 1×10⁻⁶. -4 -6×10 -4 Pa, substrate temperature is room temperature, and the hole transport layer thickness is 20-40 nm.

[0021] In step (3), the electron transport layer material is selected from at least one of 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene and 2-(4-(9,10-bis(naphthyl-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzimidazol, the electron transport layer deposition rate is 0.5-1 Å / s, and the vacuum degree in the coating chamber is 1×10⁻⁶. -4 -6×10 -4 Pa, substrate temperature is room temperature, and the resulting electron transport layer film thickness is 20-40 nm.

[0022] In step (3), the electron injection layer material is selected from at least one of lithium fluoride and cesium carbonate, the deposition rate of the electron injection layer is 0.05-0.2 Å / s, and the vacuum degree in the coating chamber is 1×10⁻⁶. -4 -6×10 -4 Pa, with the substrate temperature at room temperature, yielded an electron injection layer thickness of 0.8-1.5 nm.

[0023] In step (3), the metal electrode material is selected from at least one of gold, silver, and aluminum, the deposition rate of the metal electrode layer is 0.5-1 Å / s, and the vacuum degree inside the coating chamber is 1×10⁻⁶. -4 -6×10 -4 Pa, substrate temperature is room temperature, and the resulting metal electrode layer film thickness is 80-120 nm.

[0024] Invention Principle: After preparing the perovskite luminescent layer film, this invention involves in-situ deposition of a continuous MX metal salt inorganic interface layer in the same vacuum environment. By limiting the specific types of M-sites and X-sites, this invention constructs an MX metal salt interface layer that combines strong bonding, stress matching, functional tunability, and long-term stability. Compared to existing pure metal, oxide, sulfide, or polymer interface materials, the MX metal salt interface layer of this invention integrates multiple interface requirements within the same material system, making it particularly suitable for fields with stringent interface reliability requirements, such as flexible electronics, new energy batteries, and advanced protective coatings.

[0025] The selection of MX metal salts in this invention is based on the following principles: First, an interfacial bonding mechanism: M-site metals, especially transition metals with empty d orbitals, can form ionic bonds, coordination bonds, and even local metallic bonds with metal or ceramic substrates, achieving strong chemical anchoring; X-site halogens or SCN groups, as polar end groups, can form stable physical-chemical bonds with organic polymers, resins, or electrolytes through hydrogen bonds, dipole interactions, or Lewis acid-base interactions. This dual anchoring mechanism overcomes the limitations of traditional interfaces that rely solely on physical interlocking or single chemical interactions. Second, stress buffering and crack resistance: the selected MX compounds mostly exhibit ionic-covalent mixed-bond structures with a rigid in-plane framework. Interlayers, such as layered halides or pseudohalides, are connected by weak van der Waals forces, forming a slip-gradient modulus structure. By adjusting the type of element at the M-site, such as introducing light metals like Mg and Li to reduce the modulus and introducing high-melting-point metals like Ti and V to increase hardness, the in-plane modulus and interlaminar shear strength can be adjusted over a wide range, thereby effectively absorbing thermal mismatch stress and avoiding brittle cracking or creep failure. Thirdly, functional tunability: the overlap of d orbitals at the M-site endows these compounds with metallic-grade electronic conductivity, reaching up to 10. 4 -10 5S / cm; By selecting different halogens or SCN doping at the X site, surface energy, wettability, and pore structure can be controlled at the nanoscale, achieving efficient conduction of small-sized charge carriers such as lithium ions and protons, while blocking the penetration of harmful species such as water molecules, dissolved oxygen, and polysulfides. This characteristic allows the interface layer to simultaneously meet the dual requirements of low impedance and high barrier properties in electrochemical systems. Fourthly, durability and environmental stability: The selected MX metal salt is an atomically dense ionic crystal or layered structure with no penetrating grain boundaries, and its surface is passivated by chemically inert halogen end groups, such as -F, exhibiting excellent corrosion resistance in acidic, alkaline, and oxidizing environments, far superior to the long-term reliability of polymers or oxide ceramics.

[0026] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects:

[0027] (1) This invention introduces an inorganic interface layer in situ between the perovskite light-emitting layer and the electron transport layer, thereby simultaneously achieving defect passivation, ion migration suppression and energy level regulation, and thus achieving synergistic improvement in multiple key performance indicators such as device efficiency, working life and spectral stability.

[0028] (2) In this invention, after preparing the perovskite luminescent layer film, a continuous MX metal salt inorganic interface layer is deposited in situ in the same vacuum environment, and both the perovskite luminescent layer and the inorganic interface layer are simultaneously annealed. During the annealing process, the inorganic interface layer can simultaneously perform three functions: effectively passivating perovskite surface defects, inhibiting halide ion migration under working conditions, and optimizing interface energy level alignment. The thermal driving effect of annealing, on the one hand, allows the active ions in the MX metal salt to chemically bond with the perovskite surface defects, thereby effectively passivating the defects and anchoring halide ions to inhibit their migration; on the other hand, annealing promotes the formation of a dense film, constructing a physical barrier, while its own electronic structure forms an interface dipole layer, optimizing energy level alignment. Therefore, this process achieves three functions in the same annealing step through the synergistic effect of "chemical passivation and anchoring" and "physical barrier construction". Thus, multiple key performance characteristics of the device are synergistically improved in a single step, including external quantum efficiency, device lifetime, and stability of the electroluminescence spectrum.

[0029] (3) High efficiency and low roll-off are achieved: This inorganic interface layer effectively passivates perovskite surface defects (especially uncoordinated Pb). 2+ This method minimizes nonradiative recombination, thereby significantly improving the initial external quantum efficiency of the device. Simultaneously, its optimized band structure promotes an injection balance between electrons and holes, significantly improving the efficiency roll-off characteristics of the device at high current densities. Using the method of this invention, the key performance external quantum efficiency is increased from 1.98% to 10.57%.

[0030] (4) Achieved long working life: This inorganic interface layer, as a "buffer layer" and "migration barrier layer" for halide ions, effectively suppresses the long-range migration of halide ions under working conditions, fundamentally delaying device degradation caused by phase separation and defect proliferation, and extending the working life T of the device under constant current drive. 50 A significant improvement in brightness is achieved using the method of this invention, resulting in an initial luminance L0 = 10000 cd / m² for perovskite light-emitting diodes. 2 The working life T 50 ≈20 h. Based on brightness L and lifespan T 50 Accelerated Relationship Model (T) 50 ∝ L -n Where n is the acceleration factor (taken as 1.8), it can be estimated that at a conventional display brightness of 100 cd / m²... 2 The extrapolated lifetime exceeds 5.1 × 10⁻⁶. 3 h. Under the same conditions, the control device that was not treated with this method has a performance of 10000 cd / m. 2 T below 50 Only 0.8 h, equivalent to 100 cd / m 2 Less than 200 hours. This solution increases the device's operating life by approximately 25 times.

[0031] (5) Excellent spectral stability is achieved: Due to the suppression of ion migration, the peak position and full width at half maximum of the electroluminescence spectrum remain highly stable during long-term operation of the device, and the color coordinates are almost without drift, which meets the stringent requirements of color stability for high-precision display applications.

[0032] (6) Good process compatibility is achieved: The inorganic interface layer is prepared by vacuum thermal evaporation, which is perfectly compatible with the process of full vacuum evaporation perovskite thin film. No solution process is required, and the underlying film is not damaged. It is suitable for large-scale, homogenized industrial production.

[0033] (7) The method of the present invention is highly compatible with the full vacuum evaporation process, providing an effective and industrially suitable solution to the performance bottleneck of perovskite LEDs. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of the high-performance perovskite electroluminescent device of the present invention;

[0035] Figure 2 The external quantum efficiency-current density characteristic curves of the perovskite electroluminescent LEDs prepared in Examples 1, 2 and Comparative Example 1 are shown.

[0036] Figure 3 The external quantum efficiency-current density characteristic curves of the high-performance perovskite electroluminescent LEDs prepared in Examples 1 and 3-8 are shown. Detailed Implementation

[0037] The present invention will now be described in further detail.

[0038] Example 1

[0039] like Figure 1 As shown, a high-performance perovskite electroluminescent device with magnesium bromide metal salt as the interface engineered comprises a composite electrode structure 7 consisting of a substrate 1 with an etched anode electrode, a hole injection layer 2, a hole transport layer 3, a perovskite light-emitting layer 4, an inorganic interface layer 5, an electron transport layer 6, an electron injection layer, and a metal electrode, stacked sequentially. The inorganic interface layer 5 is a continuous film independently existing between the perovskite light-emitting layer 4 and the electron transport layer 6, and its material is MX metal salt. The thickness of the inorganic interface layer 5 is between 0.5 and 30 nm; in this embodiment, the thickness is 1 nm. The thickness varies depending on the type of MX metal salt.

[0040] The fabrication method of this device includes the following steps:

[0041] S1. The conductive glass with indium tin oxide (hereinafter referred to as ITO) etched on the anode electrode is used as substrate 1. It is repeatedly cleaned with detergent, deionized water and anhydrous ethanol respectively. Then it is cleaned with ultraviolet ozone machine for 10 min. The thickness of substrate 1 is 1.1 mm, and the thickness of the indium tin oxide layer is 300 nm.

[0042] S2. 0.05 mg of 99% pure molybdenum trioxide powder was deposited on the surface of substrate 1 using a vacuum thermal evaporation method at a deposition rate of 0.1 Å / s. The vacuum level inside the coating chamber was 2 × 10⁻⁶. -4 Pa, with the substrate temperature at room temperature, a hole injection layer 2 with a thickness of 10 nm was obtained;

[0043] S3. 0.5 mg of 99% pure 4,4',4''-tris(carbazole-9-yl)triphenylamine powder was deposited on the surface of hole injection layer 2 by vacuum thermal evaporation at a deposition rate of 0.5 Å / s and a vacuum degree of 2×10⁻⁶ within the coating chamber. -4 Pa, with the substrate temperature at room temperature, a hole transport layer 3 with a thickness of 40 nm was obtained;

[0044] S4. Using vacuum thermal evaporation, 0.3 mg of 99% pure cesium bromide and 0.6 mg of 99% pure lead bromide powder were sequentially deposited on the surface of hole transport layer 3. The deposition rate was 1 Å / s, and the vacuum degree inside the coating chamber was 2 × 10⁻⁶. -4At a substrate temperature of 0°C, a perovskite luminescent layer 4 with cesium bromide and lead bromide layers each 25 nm thick was fabricated. Then, without breaking the vacuum, 0.04 mg of 99% pure magnesium bromide powder was in-situ vacuum thermally evaporated onto the surface of the perovskite luminescent layer 4 to obtain an inorganic interface layer 5, which is a magnesium bromide thin film. The thermal evaporation rate was 1 Å / s, and the vacuum level inside the coating chamber was 2 × 10⁻⁶. -4 Pa, substrate temperature is 0℃, after thermal evaporation, perovskite light-emitting layer 4 and inorganic interface layer 5 are annealed at 90℃ for 10 min; wherein, the thickness of inorganic interface layer 5 is 1 nm.

[0045] S5. 0.25 mg of 99% pure 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene powder was deposited on the surface of the annealed inorganic interface layer 5 by vacuum thermal evaporation at a deposition rate of 0.5 Å / s and a vacuum degree of 2 × 10⁻⁶ Å / s in the coating chamber. -4 Pa was used to prepare an electron transport layer 6 with a thickness of 20 nm.

[0046] S6. First, 0.03 mg of lithium fluoride powder with a purity of 99% was deposited on the surface of electron transport layer 6 by vacuum thermal evaporation. Then, 3 mg of aluminum particles with a purity of 99% were deposited by vacuum thermal evaporation. The deposition rate for both depositions was 1 Å / s, and the vacuum level in the coating chamber for both depositions was 2 × 10⁻⁶. -4 Pa, the substrate temperature is room temperature, and a composite electrode structure 7 consisting of an electron injection layer with a thickness of 1 nm and a metal electrode layer with a thickness of 100 nm is obtained, denoted as LiF / Al.

[0047] Example 2

[0048] The only difference from Example 1 is that in step (S4), 0.04 mg of magnesium bromide powder with a purity of 99% is replaced with 0.12 mg of magnesium bromide powder with a purity of 99%, and the resulting inorganic interface layer 5 has a thickness of 3 nm.

[0049] Example 3

[0050] The only difference from Example 1 is that in step (S4), 0.04 mg of magnesium bromide powder with a purity of 99% is replaced with 0.03 mg of sodium bromide powder with a purity of 99%.

[0051] Example 4

[0052] The only difference from Example 1 is that in step (S4), the annealing temperature is 110 °C.

[0053] Example 5

[0054] The only difference from Example 1 is that in step (S4), the annealing temperature is 70 °C.

[0055] Example 6

[0056] The only difference from Example 1 is that in step (S4), the amount of magnesium bromide powder used is 0.02 mg, and the thickness of the resulting inorganic interface layer 5 is 0.5 nm.

[0057] Example 7

[0058] The only difference from Example 1 is that in step (S4), the annealing time is 40 min.

[0059] Example 8

[0060] The only difference from Example 1 is that the annealing time in step (S4) is 20 min.

[0061] Comparative Example 1

[0062] The only difference from Example 1 is that no inorganic interface layer is prepared in step (S4).

[0063] Performance testing:

[0064] The performance of the perovskite electroluminescent devices prepared in Comparative Example 1 and Example 1 was compared, and the results are as follows: Figure 2 As shown, the external quantum efficiency of the perovskite electroluminescent device prepared in Example 1 increased from 2.01% to 10.58% compared to Comparative Example 1. This is because, in the presence of the magnesium bromide interface layer, magnesium bromide can effectively passivate defects and suppress nonradiative recombination by coordinating magnesium ions with uncoordinated lead ions on the perovskite surface, while simultaneously optimizing the energy level arrangement to promote carrier injection and balance, thereby significantly improving the luminous efficiency and stability of the device.

[0065] The performance of the perovskite electroluminescent devices prepared in Comparative Example 1 and Example 2 was compared, and the results are as follows: Figure 2 As shown, the external quantum efficiency of the perovskite electroluminescent device prepared in Example 2 increased from 2.01% to 6.62% compared to Comparative Example 1. This is because, in the presence of the sodium bromide interface layer, sodium ions can assist in crystallization to regulate phase distribution and passivate bromine vacancy defects. At the same time, the interface dipole effect optimizes energy level alignment and reduces the injection barrier, thereby effectively suppressing nonradiative recombination and improving carrier injection efficiency, ultimately enhancing the device's luminescence performance.

[0066] The performance of the perovskite electroluminescent devices prepared in Example 1 and Example 2 was compared, and the results are as follows: Figure 2As shown, the improvement effect of Example 1 is better than that of Example 2. This is because, at a thickness of 1 nm, the inorganic interface layer exists in the form of dots or islands, which can effectively passivate defects and promote carrier tunneling injection. However, at a thickness of 3 nm, the inorganic interface layer has formed a continuous and dense film. Its high resistance and low carrier mobility become dominant, resulting in a sharp increase in series resistance and hindered carrier injection. At the same time, the energy level bending effect is weakened, which suppresses radiative recombination.

[0067] The performance of the perovskite electroluminescent devices prepared in Example 1 and Example 3 was compared, and the results are as follows: Figure 3 As shown, the improvement effect of Example 1 is better than that of Example 3. This is because magnesium ions, with their stronger ionic polarization ability and smaller ionic radius, are superior to sodium ions in passivating defects, improving film quality, and optimizing interfacial charge transport. Therefore, magnesium bromide is more effective as an interfacial layer.

[0068] The performance of the perovskite electroluminescent devices prepared in Example 1 and Example 4 was compared, and the results are as follows: Figure 3 As shown, the improvement effect of Example 1 is better than that of Example 4. This is because the annealing temperature of 90 ℃ is a gentler and more precise process window, which promotes crystallization and interface optimization while avoiding thermal damage to the material.

[0069] The performance of the perovskite electroluminescent devices prepared in Example 1 and Example 5 was compared, and the results are as follows: Figure 3 As shown, the improvement effect of Example 1 is better than that of Example 5. This is because the thermal energy provided by 70 °C is insufficient to drive the interface layer material and the perovskite material to form the optimal crystallization state. The annealing temperature directly determines the crystallization quality, defect density, and final device performance of the film.

[0070] The performance of the perovskite electroluminescent devices prepared in Example 1 and Example 6 was compared, and the results are as follows: Figure 3 As shown, the improvement effect of Example 1 is better than that of Example 6. This is because the 0.5 nm thick inorganic interface layer is too thin to form a continuous and uniform capping layer, resulting in insufficient passivation of perovskite surface defects. A large number of uncoordinated lead ions and other defects are still exposed, leading to serious non-radiative recombination losses, thus failing to effectively improve device performance. 1 nm is the optimal balance point for forming an effective passivation layer while also considering carrier transport.

[0071] The performance of the perovskite electroluminescent devices prepared in Example 1 and Example 7 was compared, and the results are as follows: Figure 3As shown, the improvement effect of Example 1 is better than that of Example 7. This is because the annealing time of the interface layer reached 40 min. The excessively long annealing time caused the perovskite film to over-crystallize or coarsen, which led to increased grain boundary stress, decomposition of organic components, or unfavorable diffusion reactions at the interface, thereby introducing more defects and disrupting the interface energy level alignment, which in turn reduced the radiative recombination efficiency of the device.

[0072] The performance of the perovskite electroluminescent devices prepared in Example 1 and Example 8 was compared, and the results are as follows: Figure 3 As shown, the improvement effect of Example 1 is better than that of Example 8. This is because the annealing time is only 20 min. The insufficient annealing time causes the crystallization process of the interface layer and the perovskite layer to be incomplete, resulting in insufficient grain development, high defect and grain boundary density, and large non-radiative recombination loss. Consequently, the luminous efficiency and stability of the device are lower than those of the sample annealed for 30 min.

Claims

1. A high-performance perovskite electroluminescent device, comprising a conductive substrate, a hole injection layer, a hole transport layer, a perovskite light-emitting layer, an electron transport layer, an electron injection layer, and a metal electrode layer, characterized in that, An independent and continuous inorganic interface layer is provided between the perovskite luminescent layer and the electron transport layer. The inorganic interface layer material is an MX metal salt, the M-site element is a metal or alloy, and the X-site element is selected from at least one of F, Cl, Br, I, and SCN.

2. The high-performance perovskite electroluminescent device according to claim 1, characterized in that, The M-position element is selected from one or more alloys of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, and zinc.

3. The high-performance perovskite electroluminescent device according to claim 1, characterized in that, The MX metal salt is selected from at least one of NaCl, KBr, RbI, CsSCN, MgF2, NaBr, and MgBr2.

4. The high-performance perovskite electroluminescent device according to claim 1, characterized in that, The thickness of the inorganic interface layer is 0.5-30 nm.

5. The high-performance perovskite electroluminescent device according to claim 1, characterized in that, The hole injection layer material is selected from at least one of molybdenum trioxide, nickel oxide, vanadium pentoxide, and copper oxide; the hole transport layer material is selected from 4,4',4''-tris(carbazole-9-yl)triphenylamine and / or 4,4'-cyclohexylbis(N,N-bis(p-tolyl)aniline); the electron transport layer material is selected from at least one of 1,3,5-tris(1-phenyl-1H-benzimidazole-2-yl)benzene and 2-(4-(9,10-bis(naphthyl-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzimidazole; the electron injection layer material is selected from lithium fluoride and / or cesium carbonate; and the metal electrode layer material is at least one of gold, silver, and aluminum.

6. The high-performance perovskite electroluminescent device according to claim 1, characterized in that, The hole injection layer has a thickness of 3-10 nm; the hole transport layer has a thickness of 20-40 nm; the perovskite luminescent layer has a thickness of 20-60 nm; the electron injection layer has a thickness of 0.8-1.5 nm; the electron transport layer has a thickness of 20-40 nm; and the metal electrode layer has a thickness of 80-120 nm.

7. A method for fabricating a high-performance perovskite electroluminescent device as described in claim 1, characterized in that, Includes the following steps: (1) A hole injection layer and a hole transport layer are sequentially deposited on the surface of a conductive substrate; (2) First, a perovskite light-emitting layer is deposited on the surface of the hole transport layer by vacuum thermal evaporation. Then, an inorganic interface layer is deposited in situ on the surface of the perovskite light-emitting layer by vacuum thermal evaporation. Finally, the perovskite light-emitting layer and the inorganic interface layer are annealed. (3) An electron transport layer, an electron injection layer and a metal electrode layer are sequentially deposited on the surface of the annealed inorganic interface layer.

8. The method for fabricating a high-performance perovskite electroluminescent device according to claim 7, characterized in that, In step (2), the annealing temperature is 60-150 ℃ and the annealing time is 10-40 min.

9. The method for fabricating a high-performance perovskite electroluminescent device according to claim 7, characterized in that, In step (2), the rate of thermal evaporation of the inorganic interface layer is 0.1-1 Å / s, and the vacuum degree of the coating chamber is 1×10⁻⁶. -4 -6×10 -4 Pa, substrate temperature is -10 to 90 ℃.

10. The method for fabricating a high-performance perovskite electroluminescent device according to claim 7, characterized in that, In step (2), the deposition rate of the perovskite luminescent layer is 0.1-1 Å / s, and the vacuum level inside the coating chamber is 5×10⁻⁶. -5 -2×10 -4 Pa, substrate temperature is -10 to 90 ℃.

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