Stable europium element doped two-dimensional perovskite single crystal material and preparation method and application thereof

Abstract

The invention provides a stable europium element doped two-dimensional perovskite single crystal material as well as a preparation method and application thereof. The molecular formula of the two-dimensional perovskite single crystal material is (C8NH11F) 2SnI4: xEu, and x ranges from 0.01 mol% to 10 mol%. According to the invention, the problems of stability and toxicity of the halide perovskite material are solved, and the europium element doped (C8NH11F) 2SnI4 two-dimensional perovskite single crystal material is obtained by introducing the europium element into the (C8NH11F) 2SnI4 single crystal wafer material, and the europium element doped (C8NH11F) 2SnI4 two-dimensional perovskite single crystal material is relatively good in morphology uniformity and repeatability and excellent in stability and luminescence property.

Description

Technical Field

[0001] The present invention belongs to the technical field of luminescent materials, and in particular relates to a two-dimensional perovskite single crystal material and a preparation method and application thereof. Background Art

[0002] Metal halide perovskite semiconductors have attracted great interest in various optoelectronic applications, such as solar cells, detectors, and light-emitting diodes, due to their excellent optoelectronic properties. Metal halide perovskites are promising candidates for optoelectronic active layers due to their low effective mass and high carrier mobility. In recent years, lead-based perovskite materials have attracted extensive attention from researchers at home and abroad. Due to their excellent properties such as high light absorption coefficient and long carrier lifetime, these materials have shown good application prospects in the field of optoelectronic devices. Despite the above outstanding advantages, they have great limitations in commercial applications due to the toxicity of lead. Therefore, in order to solve the toxicity of lead, it is urgent to develop other new non-toxic perovskite materials. Considering the tin-based system of the same main group, it has the characteristics of non-toxicity, lead-like electronic structure, adjustable band gap, and low exciton binding energy. At present, tin-based perovskites have become potential substitutes for toxic lead-based counterparts. However, the development of tin-based perovskite devices is still hindered by poor anti-oxidation stability, which is attributed to the low redox potential of tin (II) and easy oxidation to tin (IV). To date, tremendous efforts have been devoted to developing strategies to inhibit Sn(II) oxidation, including surface coordination based on Lewis acid-base coordination, coating and solvent engineering, low- / mixed-dimensional perovskite design, microstructure and composition regulation, and assistance from reducing agents or antioxidants.

[0003] Based on the difference in microscopic crystal structure, the vast family of metal halide perovskites can be divided into three-dimensional halide perovskites, two-dimensional halide perovskites, one-dimensional halide perovskites and zero-dimensional halide perovskite materials. Compared with the easily degradable three-dimensional halide perovskite materials, low-dimensional halide perovskite materials can maintain long-term stability under relatively harsh conditions, and can use other metal raw materials with lower toxicity to replace toxic lead raw materials, which can greatly improve the stability and toxicity problems of halide perovskite materials. So far, a series of low-dimensional halide perovskite materials and their derivatives have been reported and studied, and have been proven to be successfully applied in many research fields such as solar cells, light-emitting diodes, photodetectors, data storage devices, etc. Since 1999, two-dimensional perovskites have been widely studied because their layered structure effectively inhibits ion migration and the hydrophobic properties of bulky cations provide improved stability. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] A two-dimensional perovskite single crystal material doped with europium, the molecular formula of the two-dimensional perovskite single crystal material is (C8NH 11 F) 2SnI4:xEu, wherein x refers to the molar doping amount of Eu in each mole of the two-dimensional perovskite single crystal material, and x is 0.01 to 10 mol%, for example, 8 mol%.

[0006] According to an embodiment of the present invention, the europium-doped two-dimensional perovskite single crystal material emits red light, for example, under the excitation of 365nm ultraviolet light, it exhibits red light (630nm) emission.

[0007] According to an embodiment of the present invention, the europium-doped two-dimensional perovskite single crystal material has high luminescence intensity.

[0008] According to an embodiment of the present invention, the europium-doped two-dimensional perovskite single crystal material has a uniform morphology, and its average size is, for example, 1-50 μm, for example, 15 μm.

[0009] According to an embodiment of the present invention, the europium-doped two-dimensional perovskite single crystal material has air stability and water stability.

[0010] The present invention also provides a method for preparing the europium-doped two-dimensional perovskite single crystal material, the preparation method comprising the following steps:

[0011] S1. Preparing a precursor solution: mixing tin iodide, hydrated europium acetate, 2-(4-fluorophenyl)ethylamine hydroiodide, hydroiodic acid, and hypophosphorous acid to obtain a mixture, and heating and dissolving the mixture under the protection of an inert gas to obtain a precursor solution;

[0012] S2. The europium-doped two-dimensional perovskite single crystal material is obtained by precipitation through cooling.

[0013] According to an embodiment of the present invention, in step S1, the heating is specifically heating to 100-150° C. and then keeping the temperature for a period of time, preferably 120-150° C., for example 130° C. or 140° C. Preferably, the keeping time is 10-40 minutes, preferably 10-30 minutes, for example 15 minutes, 20 minutes.

[0014] According to an embodiment of the present invention, in step S1, in the mixture, the molar ratio of tin iodide to 2-(4-fluorophenyl)ethylamine hydroiodide is 0.1 to 3, preferably 0.5 to 2, for example, 1:1.

[0015] According to an embodiment of the present invention, in step S1, in the mixture, the molar ratio of tin iodide to hydrated europium acetate is 1:0.5-3, preferably 1:0.5-2, for example 1:1.

[0016] According to an embodiment of the present invention, in step S1, in the mixture, the volume ratio of hydroiodic acid to hypophosphorous acid is 0.5-10:0.5-5, preferably 1-5:1-2.5, for example 4.5:2.25.

[0017] According to an embodiment of the present invention, in step S1, in the mixture, the mass volume ratio of tin iodide to hydroiodic acid and hypophosphorous acid is 0.01-1 g:1-50 mL, for example, 0.15 g:6.75 mL.

[0018] According to an embodiment of the present invention, in step S2, the cooling rate is 10-50°C / h, such as 10-30°C / h, such as 20°C / h or 25°C / h.

[0019] According to an embodiment of the present invention, in step S2, the temperature is lowered to 20-50°C to stop the reaction, preferably 20-40°C, for example 30°C.

[0020] According to an embodiment of the present invention, in step S2, after cooling and precipitation, filtration and / or washing are further performed, and the filtration and washing can be performed by methods known in the art.

[0021] According to an embodiment of the present invention, the inert gas may be nitrogen and / or argon, preferably nitrogen.

[0022] The present invention also provides a europium-doped two-dimensional perovskite single crystal material obtained by the above preparation method, and the europium-doped two-dimensional perovskite single crystal material has the meaning as described above.

[0023] The present invention also provides an active light-emitting layer, which includes the above-mentioned europium-doped two-dimensional perovskite single crystal material.

[0024] The present invention also provides the application of the above-mentioned europium-doped two-dimensional perovskite single crystal material or active light-emitting layer in the fields of light-emitting display, optoelectronic devices, etc., preferably in optoelectronic devices, and further in light-emitting diodes, such as the active light-emitting layer for light-emitting diodes.

[0025] The present invention also provides an optoelectronic device, which contains the above-mentioned europium-doped two-dimensional perovskite single crystal material or active light-emitting layer.

[0026] Preferably, the optoelectronic component is, for example, a light emitting diode.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention uses a two-dimensional perovskite single crystal material doped with europium. The europium element can passivate the defect state of the material, thereby improving the structural stability of the material and optimizing the luminescence performance.

[0029] 2. The single crystal material provided by the present invention is simple and feasible to prepare, and can effectively control the thickness and lateral size of the two-dimensional tin-based perovskite single crystal material.

[0030] 3. The present invention not only solves the stability and toxicity problems of halide perovskite materials, but also 11 F)2SnI4 single crystal material is introduced with europium to obtain europium-doped (C8NH 11 F) 2SnI4 two-dimensional perovskite single crystal material has good morphology uniformity and repeatability, and excellent stability and luminescence performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The scanning electron microscope image and confocal fluorescence microscopy image of the europium-doped two-dimensional perovskite single crystal material in Example 1;

[0032] Figure 2 The X-ray powder diffraction pattern of the air stability and water stability of the europium-doped two-dimensional perovskite single crystal material in Example 1;

[0033] Figure 3 This is the fluorescence emission diagram of the europium-doped two-dimensional perovskite single crystal material in Example 1. DETAILED DESCRIPTION

[0034] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0035] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0036] In the following embodiments, the scanning electron microscope image of the europium-doped single crystal material was obtained by testing using an instrument with the model number SU-8010 and the manufacturer HITACHI; the confocal microscopic fluorescence image of the europium-doped two-dimensional perovskite single crystal material was obtained by testing using an instrument with the model number A1MP and the manufacturer Nikon; the X-ray powder diffraction image of the europium-doped two-dimensional perovskite single crystal material was obtained by testing using an instrument with the model number MiniFlex2 and the manufacturer Rigaku, and the copper target radiation wavelength was λ=0.154187nm; the emission spectrum of the europium-doped two-dimensional perovskite single crystal material was obtained by testing under the excitation of a 460W xenon lamp, the instrument model was FSP980, and the manufacturer was Edinburgh.

[0037] Example 1

[0038] Preparation of europium-doped two-dimensional perovskite single crystal materials:

[0039] (1) At room temperature, weigh 0.15 g of tin iodide, 0.13 g of hydrated europium acetate, 0.13 g of 2-(4-fluorophenyl)ethylamine hydroiodide, 4.5 ml of hydroiodic acid, and 2.25 ml of hypophosphorous acid, and add them to a 10 ml glass bottle. After stirring at room temperature for 20 minutes, heat to 140°C and keep warm for 20 minutes until the precursor is completely dissolved.

[0040] (2) Then, the temperature is lowered to 30°C at a cooling rate of 20°C / h, and the Eu-doped two-dimensional perovskite single crystal material is obtained by filtration and washing, and the molecular formula is (C8NH 11 F) 2SnI4:xEu, x=8 mol%;

[0041] X represents each mole (C8NH 11 F) In the 2SnI4 two-dimensional perovskite single crystal material, the doping amount of Eu is 8 mol%.

[0042] like Figure 1 As shown in (a) and (b), the europium-doped two-dimensional perovskite single crystal material obtained in this embodiment emits red light, has high luminescence intensity, uniform morphology, and an average size of about 15 μm.

[0043] like Figure 2 As shown, the red-luminescent europium-doped two-dimensional perovskite single crystal material obtained in this embodiment has good crystallinity and is air stable and water stable. For example, after being stored in the air for 30 days or immersed in water for 1 day, the crystal structure does not change.

[0044] like Figure 3 As shown, under the excitation of 365nm ultraviolet light, the europium-doped two-dimensional perovskite single crystal material obtained in this embodiment exhibits red light (630nm) emission.

[0045] The above is a description of the exemplary embodiments of the present invention. However, the protection scope of the present application is not limited to the above embodiments. Any modification, equivalent substitution, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A two-dimensional perovskite single crystal material doped with europium, characterized in that: The molecular formula of the two-dimensional perovskite single crystal material is (C8NH 11 F) 2SnI4:xEu, wherein x is 0.01 to 10 mol%.

2. The two-dimensional perovskite single crystal material according to claim 1, characterized in that: The europium-doped two-dimensional perovskite single crystal material emits red light. Preferably, the europium-doped two-dimensional perovskite single crystal material has high luminescence intensity.

3. The two-dimensional perovskite single crystal material according to claim 1 or 2, characterized in that: The europium-doped two-dimensional perovskite single crystal material has a uniform morphology and an average size of 1-50 μm. Preferably, the europium-doped two-dimensional perovskite single crystal material is air stable and water stable.

4. The method for preparing the europium-doped two-dimensional perovskite single crystal material according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: S1. Preparing a precursor solution: mixing tin iodide, hydrated europium acetate, 2-(4-fluorophenyl)ethylamine hydroiodide, hydroiodic acid, and hypophosphorous acid to obtain a mixture, and heating and dissolving the mixture under the protection of an inert gas to obtain a precursor solution; S2. The europium-doped two-dimensional perovskite single crystal material is obtained by precipitation through cooling.

5. The preparation method according to claim 4, characterized in that: In step S1, the heating is specifically heating to 100-150°C and then keeping the temperature for a period of time. Preferably, in step S1, in the mixture, the molar ratio of tin iodide to 2-(4-fluorophenyl)ethylamine hydroiodide is 0.1-3.

6. The preparation method according to claim 4 or 5, characterized in that: In step S1, in the mixture, the molar ratio of tin iodide to hydrated europium acetate is 1:0.5-3. Preferably, in step S1, in the mixture, the volume ratio of hydroiodic acid to hypophosphorous acid is 0.5-10:0.5-5. Preferably, in step S1, in the mixture, the mass volume ratio of tin iodide to hydroiodic acid and hypophosphorous acid is 0.01-1 g: 1-50 mL.

7. The preparation method according to any one of claims 4 to 6, characterized in that: In step S2, the cooling rate is 10-50°C / h. Preferably, in step S2, the temperature is lowered to 20-50°C to stop the reaction. Preferably, the inert gas is nitrogen and / or argon.

8. An active light-emitting layer, characterized in that: The active light-emitting layer comprises the europium-doped two-dimensional perovskite single crystal material as described in any one of claims 1 to 3.

9. Use of the europium-doped two-dimensional perovskite single crystal material according to any one of claims 1 to 3 or the active light-emitting layer according to claim 8 in light-emitting displays and optoelectronic devices.

10. An optoelectronic device, comprising the europium-doped two-dimensional perovskite single crystal material according to any one of claims 1 to 3 or the active light-emitting layer according to claim 8.

Images