Molybdenum-doped all-inorganic hole-ordered double perovskite and preparation method and application thereof

Abstract

The invention relates to the technical field of luminescent materials, in particular to molybdenum-doped all-inorganic hole-ordered double perovskite and a preparation method and application thereof. The first aspect of the invention provides tetravalent molybdenum doped, pentavalent molybdenum doped and tetravalent molybdenum and pentavalent molybdenum co-doped molybdenum-doped all-inorganic hole-ordered double calcium titanium, and the chemical formulas are respectively Cs2Sn1-xCl6: xMo < 4 + >, Cs2Sn1-y (OyCl6-y): yMo < 5 + > and Cs2Sn1-a-b (ObCl6-b): aMo < 4 + >, bMo < 5 + >. The second aspect of the invention is to provide preparation methods of tetravalent molybdenum-doped molybdenum, pentavalent molybdenum-doped molybdenum and tetravalent molybdenum and pentavalent molybdenum co-doped molybdenum-doped all-inorganic hole-ordered double calcium titanium. The third aspect is to provide application of the three kinds of molybdenum-doped all-inorganic hole-ordered double calcium titanium in the fields of product detection, anti-counterfeiting, safety monitoring, nondestructive analysis, light-emitting LEDs, solar cells, temperature detectors, multispectral imaging, ultra-wideband light sources or wide-spectrum photoelectric detectors. The fourth aspect is to provide a photoelectric device, and a luminescent material of the photoelectric device adopts the molybdenum-doped all-inorganic hole-ordered double perovskite.

Description

Technical Field

[0001] The present invention relates to the technical field of luminescent materials, and more specifically, to molybdenum-doped all-inorganic hole-ordered double perovskite and a preparation method and application thereof. Background Art

[0002] All-inorganic hole-ordered double perovskites (A2BX6), where A is a monovalent cation, B is a tetravalent metal ion, and X is an anion, have attracted widespread attention due to their unique electronic structure and excellent stability. By doping the double perovskite matrix with transition metal ions, their luminescence properties can be effectively manipulated, expanding their applications.

[0003] In recent years, molybdenum, as an important doping activator, has shown unique luminescence properties in various luminescent materials. For example, a literature report shows that a molybdenum-doped all-inorganic hole-ordered double perovskite near-infrared phosphor exhibits the advantages of high stability and high quantum efficiency ( Chem.mater. 2024, 36(2) , 901-910 / Chem.mater. 2024, 36(9) ,4561-4570 / Laser Photonics Rev. 2025, 2500311 / ACSmaterials Lett. 2025, 7 , 2190-2198 / Chem. Eng. J. 517(2025), 164543 / Laser Photonics Rev. 2025, e00755). However, the existing Mo-doped all-inorganic hole-ordered double perovskites generally exhibit a single-band emission in the near-infrared region. Summary of the Invention

[0004] The present invention aims to overcome at least one defect of the above-mentioned prior art and provide a molybdenum-doped all-inorganic hole-ordered double perovskite and its preparation method and application to solve the problem of a single emission spectrum band.

[0005] The first purpose of the present invention is to propose a tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite with the chemical formula Cs2Sn 1-x Cl6:xMo 4+ , where 0.1%≤x≤5%.

[0006] The tetravalent molybdenum doped all-inorganic hole ordered double perovskite of the present invention uses Cs2SnCl6 as a matrix, wherein x is the doping ion Mo 4+ The molar percentage of Sn relative to the matrix ion. Tests show that the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite of the present invention has a Cs2SnCl6 type crystal structure, in which some Sn 4+ Site or Mo 4+ions occupy the ions, thus forming luminescence centers. The X-ray diffraction (XRD) pattern shows that its main phase matches the standard card of Cs2SnCl6 (PDF#75-0376). Absorption spectrum analysis shows that the phosphor contains [MoCl6] 2- The characteristic absorption peaks of the associated charge transfer (CT) transitions confirm the presence of molybdenum ions in the +4 valence state. Scanning electron microscopy (SEM) observations revealed that the phosphors typically exhibit polygonal micron-sized particles with uneven particle size and a relatively smooth surface. Some particles exhibited good crystalline properties.

[0007] Furthermore, the fluorescence emission spectra of the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite are 700-800 nm and 1200-1600 nm.

[0008] Furthermore, the absorption spectrum of the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite is 250-450nm.

[0009] The second purpose of the present invention is to propose a method for preparing the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite, comprising: mixing CsCl, SnCl2 and MoCl5, adding concentrated hydrochloric acid and mixing evenly, heating, cooling, separating, washing and drying to obtain the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite.

[0010] The third object of the present invention is to propose the application of the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite in the fields of product detection, anti-counterfeiting, safety monitoring or non-destructive analysis.

[0011] The fourth purpose of the present invention is to propose a pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite with the chemical formula Cs2Sn 1-y (O y Cl 6-y ):yMo 5+ , among which, 0.1%≤y≤5%.

[0012] The pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite of the present invention uses Cs2Sn(OCl)6 as a matrix, wherein y is a doping ion Mo 5+ The molar percentage of Sn relative to the matrix ion. Tests show that the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite of the present invention has the same crystal structure as Cs2SnCl6, in which some Sn 4+ Site or Mo 5+ ions occupy the luminescent center, thus forming the absorption spectrum analysis. The absorption spectrum analysis shows that the pentavalent molybdenum doped all-inorganic hole ordered double perovskite has the same structure as [MoO x Cl 6-x ] 2-The relevant characteristic absorption peaks, such as the charge transfer (CT) transition absorption peak and the dd transition absorption peak, confirm that the molybdenum ion exists in the +5 valence state.

[0013] Furthermore, the fluorescence emission spectra of the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite are 450-750 nm and 800-1200 nm.

[0014] Furthermore, the absorption spectrum of the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite is 250-370 nm.

[0015] The fifth object of the present invention is to propose a method for preparing the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite, comprising: mixing CsCl, SnCl4.4H2O and MoCl5, adding concentrated hydrochloric acid and mixing evenly, heating, cooling, separating, washing and drying to obtain the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite.

[0016] The sixth object of the present invention is to propose the application of the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite in the preparation of light-emitting LEDs, anti-counterfeiting, solar cells or temperature detectors.

[0017] The seventh object of the present invention is to provide a tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite with a chemical formula of Cs2Sn 1-a-b (O b Cl 6-b ):aMo 4+ ,bMo 5+ , where 0.1%≤(a+b)≤5%, and .

[0018] The tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole ordered double perovskite of the present invention uses Cs2Sn(OCl)6 as a matrix, wherein a is a doping ion Mo 4+ Relative to the molar percentage of the matrix ion Sn, b is the doping ion Mo 5+ The molar percentage of Sn relative to the matrix ion. Tests show that the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite of the present invention has the same crystal structure as Cs2SnCl6, in which some Sn 4+ The site is Mo 4+ and Mo 5+ ions occupy the luminescent center, thus forming the absorption spectrum analysis. The absorption spectrum analysis shows that the tetravalent Mo and pentavalent Mo co-doped all-inorganic hole-ordered double perovskite exists with [MoOCl5] 2- and [MoCl6] 2- The relevant characteristic absorption peaks confirm that molybdenum ions have two valence states, +4 and +5.

[0019] Furthermore, the fluorescence emission spectrum of the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite covers a range of 500-1600 nm.

[0020] Furthermore, the absorption spectrum of the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite is 250-450nm.

[0021] The eighth purpose of the present invention is to propose a method for preparing the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite, comprising: mixing CsCl, SnCl2, SnCl4.4H2O and MoCl5, adding concentrated hydrochloric acid to mix, heating, cooling, separating, washing and drying to obtain the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite.

[0022] The ninth objective of the present invention is to propose the application of the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite in the fields of multispectral imaging, high-end anti-counterfeiting, ultra-wideband light source or wide-spectrum photodetector.

[0023] The tenth objective of the present invention is to provide a photoelectric device, the light-emitting material of which is the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite or the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite or the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite.

[0024] Compared with the existing technology, the beneficial effects of the present invention are as follows: 1) The tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite proposed in the present invention can simultaneously produce dual emission in the near-infrared region 1 (700-800nm) and the near-infrared region 2 (1200-160nm) under single wavelength excitation, which is different from the existing reported Mo 4+The phenomenon that doping mainly produces near-infrared single emission is significantly different, and it has potential application value in product detection, anti-counterfeiting, safety monitoring or non-destructive analysis. 2) The present invention successfully prepared pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite for the first time, expanding the research system of such materials. The pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite can produce dual emission in the visible light region (about 575nm) and the near-infrared region (about 950nm) at the same time under single wavelength excitation, and the total spectral coverage is wide, with a half-peak width of up to 312nm, which has great potential in luminous LEDs, anti-counterfeiting, solar cells, and other fields. It has potential application value in the fields of energy batteries and temperature sensing; 3) The tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite proposed in the present invention exhibits ultra-wideband luminescence characteristics from visible light to near-infrared band (500-1600nm) under single wavelength excitation. Based on its unique luminescence properties, the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite has potential application value in the fields of multi-spectral imaging, high-end anti-counterfeiting, ultra-wideband light sources or wide-spectrum photodetectors; 4) The hydrothermal synthesis process proposed in the present invention is relatively simple and easy to operate and scale up. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The tetravalent molybdenum doped all-inorganic hole-ordered double perovskite phosphors (Cs2Sn 1-x Cl6:xMo 4+ ,0.4%≤x≤1.4%) X-ray diffraction (XRD) pattern.

[0026] Figure 2 The tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite phosphor (Cs2Sn 0.996 Cl6:0.4%Mo 4+ )’s absorption spectrum.

[0027] Figure 3 The tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite phosphor (Cs2Sn 0.99 Cl6:1.0%Mo 4+ ) scanning electron microscope (SEM) photograph.

[0028] Figure 4 The tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite phosphor (Cs2Sn 0.996 Cl6:0.4%Mo 4+ ) Fluorescence emission spectrum under 310 nm excitation.

[0029] Figure 5 This is the absorption spectrum of the molybdenum-doped all-inorganic hole-ordered double perovskite phosphor prepared in Comparative Example 1.

[0030] Figure 6 The all-inorganic hole-ordered double perovskite phosphors [Cs2Sn 1-y (O y Cl 6-y ):yMo 5+ ,0.4%≤y≤1.4%].

[0031] Figure 7 The pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite phosphor [Cs2Sn 0.996 (O 0.004 Cl 5.996 ):0.4%Mo 5+ ]’s absorption spectrum.

[0032] Figure 8 The pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite phosphor [Cs2Sn 0.99 (O 0.01 Cl 5.99 ):1.0%Mo 5+ ] scanning electron microscope (SEM) photograph.

[0033] Figure 9 The pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite phosphor [Cs2Sn 0.996 (O 0.004 Cl 5.996 ):0.4%Mo 5+ ]Fluorescence emission spectrum under 310nm excitation.

[0034] Figure 10 This is the absorption spectrum of the molybdenum-doped all-inorganic hole-ordered double perovskite phosphor prepared in Comparative Example 2.

[0035] Figure 11 The tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite phosphor (Cs2Sn 0.996 (O 0.002 Cl 5.998 ):0.2%Mo 4+ ,0.2%Mo 5+ )’s X-ray diffraction (XRD) pattern.

[0036] Figure 12 The tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite phosphor [Cs2Sn 0.996 (O 0.002 Cl 5.998 ):0.2%Mo 4+ ,0.2%Mo5+ ]’s absorption spectrum.

[0037] Figure 13 The tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite phosphor [Cs2Sn 0.99 (O 0.002 Cl 5.998 ):0.8%Mo 4+ ,0.2%Mo 5+ ] scanning electron microscope (SEM) photograph.

[0038] Figure 14 These are fluorescence emission spectra of four types of tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite phosphors prepared in Example 12.

[0039] Figure 15 This is the emission spectrum of the molybdenum-doped all-inorganic hole-ordered double perovskite phosphor prepared in Comparative Example 3.

[0040] Figure 16 This is the absorption spectrum of the molybdenum-doped all-inorganic hole-ordered double perovskite phosphor prepared in Comparative Example 4. DETAILED DESCRIPTION

[0041] The first purpose of the present invention is to propose a tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite with the chemical formula Cs2Sn 1-x Cl6:xMo 4+ , where 0.1%≤x≤5%.

[0042] Preferably, 0.4%≤x≤1.4%.

[0043] The second purpose of the present invention is to propose a method for preparing the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite, comprising: placing CsCl, SnCl2 and MoCl5 in a polytetrafluoroethylene liner, adding concentrated hydrochloric acid as a solvent and reaction medium to mix; placing the polytetrafluoroethylene liner containing the mixture in a hydrothermal reactor and sealing it, then heating the hydrothermal reactor to a predetermined temperature and keeping it warm for a period of time to perform a hydrothermal reaction; after the reaction is completed, slowly cooling the reactor to room temperature; separating the generated crystalline product from the reaction mother liquor, washing it with a small amount of ethanol, and finally drying it in an oven at a specific temperature to obtain the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite, specifically, in the form of a phosphor.

[0044] In a specific implementation, the molar ratio of CsCl to SnCl2 is controlled at about 2:1, and the molar doping amount of MoCl5 relative to SnCl2 can be regulated in the range of 0.1% to 5%, preferably 0.4% to 1.4%, for example, such as 0.4%, 1.0%, 1.4%, etc.

[0045] In practice, the concentration of concentrated hydrochloric acid is typically commercially available, for example, 36%-38% (mass percentage). Furthermore, the amount of concentrated hydrochloric acid used also affects the morphology and crystallinity of the reaction product. Preferably, the amount of concentrated hydrochloric acid used is between 1 mL and 10 mL relative to 1 mmol of SnCl₂. For example, the amount of concentrated hydrochloric acid used can be 2 mL, 3 mL, 5 mL, 6 mL, 8 mL, or 10 mL.

[0046] In specific implementation, the heating temperature range of the hydrothermal reaction is 140 o C to 230 o C, for example, 140°C, 160 o C. 180 o C. 200 o C, 230° C. In addition, the holding time ranges from 5 hours to 30 hours, such as 5 hours, 10 hours, 12 hours, 15 hours, 20 hours, 25 hours, and 30 hours.

[0047] In specific implementation, the heating rate of the hydrothermal reaction is controlled at 1 o C / min to 10 o C / min, for example about 3 o C / min, 5 o C / min, 10 o C / min.

[0048] In specific implementation, the cooling rate is 10 to 30 o C / hour, for example, the cooling rate can be controlled to be 10 o C / hour, 15 o C / hour, 20 o C / hour, 25 o C / hour, 30 o C / hour. In specific implementation, the drying temperature is 40°C-80°C, for example, 40°C, 50°C, 60°C, 70°C, 80°C, etc., to ensure that the product is completely dried.

[0049] The purpose of ethanol washing is to remove impurities adsorbed on the product surface and residual reaction mother liquor. The number of washing times is usually 2 to 5 times.

[0050] A notable feature of the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite phosphor is its unique luminescence properties. Specifically, under excitation from ultraviolet to near-ultraviolet light with a wavelength of 250-450nm, the phosphor can simultaneously produce dual-peak emission in the near-infrared region I and near-infrared region II. Specifically, its near-infrared region I emission peak is centered at approximately 718nm, covering a spectral range of approximately 700-800nm; its near-infrared emission peak is centered at approximately 1350nm, covering a spectral range of approximately 1200-1600nm.

[0051] Based on this, the third purpose of the present invention is to propose the application of the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite in the fields of product detection, anti-counterfeiting, safety monitoring or non-destructive analysis.

[0052] When used for product inspection, the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite produces dual-band emissions in the near-infrared region 1 (700nm-800nm) and the near-infrared region 2 (1200nm-1600nm) under specific excitation. It can penetrate product packaging or surface materials (such as plastic, paper, coatings) to achieve high-sensitivity, high-resolution imaging detection of internal structures, defects (such as cracks, bubbles, foreign matter) or component distribution. It is particularly suitable for industrial and quality inspection fields such as internal packaging integrity inspection of electronic components, interface analysis of multi-layer composite materials, and screening of foreign matter inside food and drug packaging.

[0053] When used as an anti-counterfeiting material, the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite's dual emission properties under specific excitation can serve as a unique anti-counterfeiting mark. Leveraging its simultaneous emission of distinct, difficult-to-imitate near-infrared (NIR) I and NIR II fluorescence signals with distinct wavelength characteristics, a high-level dual-channel or ratiometric anti-counterfeiting mark can be constructed. This mark is invisible under conventional light sources and requires a specific excitation light source and dual-band NIR detection equipment for reading and verification. This significantly enhances the security and reliability of anti-counterfeiting labels, making them suitable for the anti-counterfeiting of important documents, branded goods, high-end packaging, and monetary securities.

[0054] In security monitoring applications, the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite's strong near-infrared (NIR) II penetration capability enables it to transmit signals through smoke, mist, turbid liquids, or non-metallic obstacles of a certain thickness. Leveraging this property, it can be made into markers or sensor probes for positioning in fire smoke environments, long-range tracking and monitoring of critical targets underwater or in turbid waters, and penetrating sensing of the internal conditions of specific confined spaces or pipelines, enhancing security monitoring capabilities in complex environments.

[0055] In nondestructive analytical applications, the deep penetration and dual-band emission characteristics of the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite, combined with its potential fluorescence response changes to specific environmental factors (such as temperature, pressure, and specific substances), can be used for non-contact, non-destructive composition and state analysis of fragile or precious samples. For example, applications include nondestructive assessment of the internal quality (maturity, lesions, moisture) of agricultural products (such as fruits and grains), analysis of the internal structure of cultural relics and restoration materials, and in-situ monitoring of the aging process of industrial materials (such as coatings and films).

[0056] The fourth purpose of the present invention is to propose a pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite with the chemical formula Cs2Sn 1-y (O y Cl 6-y ):yMo 5+ , among which, 0.1%≤y≤5%.

[0057] Preferably, 0.4%≤y≤1.4%.

[0058] The pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite has a Cs2Sn(OCl)6 type crystal structure, in which part of Sn 4+ Site or Mo 5+ ions occupy the ions, thus forming luminescence centers. The X-ray diffraction (XRD) pattern shows that its main phase matches the standard card of Cs2SnCl6 (PDF#75-0376). Absorption spectrum analysis shows that the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite contains [MoO x Cl 6-x ] 2- Characteristic absorption peaks, such as the charge transfer (CT) transition and the dd transition, confirm the presence of molybdenum ions in the +5 valence state. Scanning electron microscopy (SEM) observations reveal that the phosphor typically exhibits polygonal micron-sized particles, which may be uneven in size, with a relatively smooth surface and some particles exhibiting fine crystalline properties.

[0059] The fifth object of the present invention is to propose a method for preparing the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite, comprising: placing cesium chloride (CsCl), tin tetrachloride tetrahydrate (SnCl4·4H2O) and molybdenum pentachloride (MoCl5) as raw materials in a polytetrafluoroethylene liner, adding concentrated hydrochloric acid as a solvent and reaction medium to mix; placing the polytetrafluoroethylene liner containing the mixture in a hydrothermal reactor and sealing it, then heating the hydrothermal reactor to a predetermined temperature and keeping it warm for a period of time to perform a hydrothermal reaction; after the reaction is completed, slowly cooling the reactor to room temperature; separating the generated crystalline product from the reaction mother liquor, washing it several times with a small amount of ethanol, and finally drying it in an oven at a specific temperature to obtain the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite, specifically, in the form of a phosphor.

[0060] In a specific implementation, the molar ratio of CsCl to SnCl4·4H2O is controlled at about 2:1, and the molar doping amount of MoCl5 relative to SnCl4.4H2O can be controlled in the range of 0.1% to 5%, preferably 0.4% to 1.4%, specifically, for example, 0.4%, 1.0%, and 1.4%.

[0061] In a specific implementation, the amount of concentrated hydrochloric acid used can be between 1 mL and 10 mL relative to 1 mmol of SnCl4·4H2O.

[0062] In specific implementation, the heating temperature range of the hydrothermal reaction is 140 o C to 230 o C, for example, 140°C, 160 o C. 180 o C. 200 o C, 230° C. In addition, the holding time ranges from 5 hours to 30 hours, and in specific implementations, for example, 5 hours, 10 hours, 12 hours, 15 hours, 20 hours, 25 hours, or 30 hours.

[0063] In specific implementation, the heating rate of the hydrothermal reaction is controlled at 1 o C / min to 10 o C / min, for example about 3 o C / min, 5 o C / min, 10 o C / min.

[0064] In specific implementation, the cooling rate is 10 to 30 o C / hour, for example, the cooling rate can be controlled to be 10 o C / hour, 15 o C / hour, 20 o C / hour, 25 o C / hour, 30o C / hour. In specific implementation, the temperature condition adopted for drying is 40°C-80°C, for example, 40°C, 50°C, 60°C, 70°C, 80°C, etc., to ensure that the product is completely dried.

[0065] The purpose of ethanol washing is to remove impurities adsorbed on the product surface and residual reaction mother liquor. The number of washing times is usually 2 to 5 times.

[0066] A notable feature of the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite phosphor is its unique luminescence properties. Specifically, under excitation by ultraviolet to near-ultraviolet light with a wavelength of 250-370 nm, the phosphor can simultaneously emit a broadband spectrum covering both the visible and near-infrared regions. Specifically, its visible emission peak is centered at approximately 575 nm, covering a spectral range of approximately 450-750 nm; its near-infrared emission peak is centered at approximately 950 nm, covering a spectral range of approximately 800-1200 nm. This dual-emission characteristic enables a total spectral full width at half maximum (FWHM) of approximately 312 nm.

[0067] Based on this, the sixth object of the present invention is to propose the application of the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite in the preparation of light-emitting LEDs, anti-counterfeiting, solar cells or temperature detectors.

[0068] When used as a light-emitting LED, the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite can be combined with an ultraviolet LED chip to achieve the output of a specific spectrum through light color conversion, such as for generating broadband white light or visible light and near-infrared light in a specific band.

[0069] When used as an anti-counterfeiting material, the dual emission characteristics (visible yellow light and invisible near-infrared light) of the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite under specific excitation can serve as a unique anti-counterfeiting mark.

[0070] When used as a solar cell, the broadband absorption and near-infrared emission properties of the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite may help to improve the spectral response range or energy conversion efficiency of the solar cell.

[0071] When used as a temperature detector, the emission intensity, peak position or lifetime of visible light and / or near-infrared light of the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite may change regularly with temperature, thereby being used for non-contact temperature sensing.

[0072] The seventh object of the present invention is to provide a tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite with a chemical formula of Cs2Sn 1-a-b (O b Cl 6-b):aMo 4+ ,bMo 5+ , where 0.1%≤(a+b)≤5%, and .

[0073] Preferably, 0.4%≤(a+b)≤1.4%.

[0074] The eighth objective of the present invention is to propose a method for preparing the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite, comprising: placing cesium chloride (CsCl), tin dichloride (SnCl2), tin tetrachloride hydrate (SnCl4·5H2O) and molybdenum pentachloride (MoCl5) as raw materials in a polytetrafluoroethylene liner, adding concentrated hydrochloric acid as a solvent and reaction medium to mix; placing the polytetrafluoroethylene liner containing the mixture in a hydrothermal reactor and sealing it, then heating the hydrothermal reactor to a predetermined temperature and keeping it warm for a period of time to perform a hydrothermal reaction; after the reaction is completed, slowly cooling the reactor to room temperature; separating the generated crystalline product from the reaction mother liquor, washing it with a small amount of ethanol, and finally drying it in an oven at a specific temperature to obtain the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite in the form of a phosphor.

[0075] Among them, the molar ratio of CsCl, tin raw material (including SnCl2 and SnCl4.4H2O) and MoCl5 is optimized to obtain a product with target luminescence properties. In specific implementation, the molar ratio of CsCl to tin raw material is controlled at about 2:1, and the molar doping amount of MoCl5 relative to the tin raw material can be regulated in the range of 0.1% to 5%, preferably 0.4% to 1.4%, specifically 0.4%, 1.0%, and 1.4%. In addition, the molar ratio of tin dichloride to tin tetrachloride hydrate is controlled at 1:9 to 9:1 to ensure that a final product with target luminescence properties can be obtained. It should be noted that the above The specific ratio is determined by the molar ratio of tin dichloride and tin tetrachloride hydrate. The value can be 2:8, 4:6, 5:5, 6:4, 8:2, etc.

[0076] In a specific implementation, the amount of concentrated hydrochloric acid used can be between 1 mL and 10 mL relative to 1 mmol of the tin raw material. For example, the amount of concentrated hydrochloric acid used can be 2 mL, 3 mL, 5 mL, 6 mL, 8 mL, or 10 mL.

[0077] In specific implementation, the heating temperature range of the hydrothermal reaction is 140 o C to 230 o C, such as 140℃, 160 o C. 180 o C. 200 oC, 230° C. In addition, the holding time ranges from 5 hours to 30 hours, such as 5 hours, 10 hours, 12 hours, 15 hours, 20 hours, 25 hours, and 30 hours.

[0078] In specific implementation, the heating rate of the hydrothermal reaction is controlled at 1 o C / min to 10 o C / min, for example about 3 o C / min, 5 o C / min, 10 o C / min.

[0079] In specific implementation, the cooling rate to room temperature is 10 to 30 o C / hour, for example, the cooling rate can be controlled to be 10 o C / hour, 15 o C / hour, 20 o C / hour, 25 o C / hour, 30 o C / hour.

[0080] In a specific implementation, the temperature condition adopted for drying is 40°C-80°C. For example, the drying temperature can be set to 40°C, 50°C, 60°C, 70°C, 80°C, etc. to ensure that the product is completely dried.

[0081] A notable feature of the tetravalent and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite is its unique luminescence properties. Specifically, under excitation by ultraviolet to near-ultraviolet light with a wavelength of 250-450 nm, it can emit visible-to-near-infrared light covering a range of 500-1600 nm. Based on this, a ninth objective of the present invention is to propose the application of the tetravalent and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite in the fields of multispectral imaging, high-end anti-counterfeiting, ultra-broadband light sources, or broadband photodetectors.

[0082] When used for multispectral imaging, the ultra-wideband visible-near-infrared emission (500-1600nm) produced by the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite under specific excitation can synchronously capture high-resolution visible light signals of superficial tissues and penetrating signals of deep tissues in a single imaging, achieving a seamless connection from cellular-level observation to deep navigation of living tumors.

[0083] When used as a high-end anti-counterfeiting application, the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite can synergistically output dynamic colors in the visible region and multiple hidden codes in the near-infrared region (such as 718nm / 1350nm dual-channel fingerprints) under specific excitation, which can construct a two-level verification system of naked eye and machine, significantly improving the non-replicability of anti-counterfeiting labels.

[0084] When used as an ultra-wideband light source, the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite can directly cover the entire visible-shortwave infrared band (500-1600nm) under the drive of a single near-infrared laser, replacing the traditional multi-LED combination solution and providing a lightweight, low-power lighting core for night vision security and autonomous driving infrared imaging systems.

[0085] When used as a wide-spectrum photodetector, the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite expands the response boundary of the silicon-based detector from 1100nm to 1600nm through the fluorescence conversion layer, while retaining the visible light response capability, breaking through the material band gap limitation, and realizing "single device from visible light to short-wave infrared" full-spectrum perception.

[0086] The tenth objective of the present invention is to provide a photoelectric device, the light-emitting material of which is the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite or the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite or the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite.

[0087] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0088] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods, and instruments used are conventional in the art and can be obtained commercially by those skilled in the art unless otherwise specified.

[0089] Example 1 2 mmol of cesium chloride (CsCl, analytical grade), 1 mmol of tin dichloride (SnCl2, analytical grade), and 0.004 mmol, 0.006 mmol, 0.008 mmol, 0.01 mmol, 0.012 mmol, and 0.014 mmol of molybdenum pentachloride (MoCl5, analytical grade, corresponding to a Sn doping ratio of 0.4-1.4 mol%), respectively, were placed in a 25 mL polytetrafluoroethylene (PTFE) liner. 6 mL of concentrated hydrochloric acid (37% by mass) was added to the liner and stirred to mix thoroughly. The PTFE liner was placed in a 25 mL stainless steel hydrothermal reactor and sealed. The hydrothermal reactor was placed in an oven and heated to 180°C at a rate of 5°C / min and maintained at 180°C for 12 hours. After the reaction, the reactor was slowly cooled to room temperature at a rate of 10°C / hour. The product in the liner was separated from the reaction mother liquor. The resulting crystals were washed three times with a small amount of anhydrous ethanol to remove surface impurities. Finally, the washed product was placed in an oven at 60°C and dried to constant weight to obtain the target product. The obtained product was subjected to X-ray diffraction analysis, and the results were as follows: Figure 1 As shown. Figure 1 As can be seen in the figure, the main diffraction peaks of the prepared phosphors with different tetravalent molybdenum doping concentrations correspond well to the diffraction peaks of the cubic phase Cs2SnCl6 standard card PDF#75-0376, indicating that the products have the pure Cs2SnCl6 crystal structure, with no obvious impurity peaks. The incorporation of molybdenum does not significantly change the crystal structure of the matrix.

[0090] Example 2 1mmol CsCl, 0.5mmol SnCl2 and 0.002mmol MoCl5 (corresponding to 0.4mol% doping of Sn) were placed in a 15mL polytetrafluoroethylene liner. 3mL concentrated hydrochloric acid (37%) was added and mixed evenly. The liner was placed in a 15mL hydrothermal reactor and sealed. The reactor was heated to 180℃ at a rate of 5℃ / min and maintained for 12 hours, and then slowly cooled to room temperature at a rate of 10℃ / hour. Subsequent treatment was the same as in Example 1. The obtained product was subjected to absorption spectrum test, and the results were as follows: Figure 2 As shown, the absorption of the phosphor mainly shows [MoCl6] 2- The charge transfer (CT) transition characteristic absorption peak of the product is confirmed. This confirms that the molybdenum ions doped in the product mainly exist in the +4 valence state, that is, the chemical expression of the product can be written as: Cs2Sn 0.996 Cl6:0.4%Mo 4 + .

[0091] Example 3 2mmol CsCl, 1mmol SnCl2, and 0.010mmol MoCl5 (corresponding to 1.0mol% Sn doping) were placed in a 25mL polytetrafluoroethylene liner. 6mL concentrated hydrochloric acid (37%) was added and mixed. The reactor was heated to 160℃ at a rate of 3℃ / min and maintained for 15 hours. After the reaction was completed, it was slowly cooled to room temperature at a rate of 30℃ / hour. Subsequent treatment was the same as in Example 1 to obtain tetravalent molybdenum-doped Cs2Sn 0.99 Cl6:1.0%Mo 4+ The obtained product was observed by scanning electron microscope (SEM), as shown in FIG. Figure 3 As shown. Figure 3 It can be seen that the prepared phosphor is mainly composed of polygonal micron-sized particles with particle sizes ranging from a few microns to hundreds of microns. The surface is relatively smooth, and some particles show good crystal properties.

[0092] Example 4 2mmol CsCl, 1mmol SnCl2, and 0.004mmol MoCl5 (corresponding to 0.4% Sn doping) were placed in a polytetrafluoroethylene liner, 10mL concentrated hydrochloric acid was added and mixed, and then placed in a 25mL hydrothermal reactor. The reactor was heated to 200℃ at a rate of 3℃ / min and maintained for 10 hours, and then slowly cooled to room temperature at a rate of 10℃ / hour. Subsequent treatment was the same as in Example 1 to obtain tetravalent molybdenum-doped Cs2Sn 0.996 Cl6:0.4%Mo 4+ Phosphor. Figure 4 is the fluorescence emission spectrum of the synthesized phosphor at an excitation wavelength of 310 nm, Figure 4 It shows that the phosphor can simultaneously emit near-infrared light in the first region covering 700-800nm ​​with a center of 718nm, and near-infrared light in the second region covering 1200-1600nm with a center of 1350nm.

[0093] Comparative Example 1 2mmol CsCl, 1mmol tin tetrachloride hydrate (SnCl4·5H2O) and 0.004mmol MoCl5 (corresponding to 0.4mol% doping of Sn) were placed in a polytetrafluoroethylene liner, 6mL concentrated hydrochloric acid was added and mixed, and then loaded into a 25mL hydrothermal reactor. The reactor was heated to 180℃ at a rate of 5℃ / min and maintained for 12 hours, and then slowly cooled to room temperature at a rate of 10℃ / hour. After the crystals were separated from the acid solution, they were washed three times with a small amount of ethanol and finally dried in an oven at 60℃. Figure 5 This is the absorption spectrum of the synthesized phosphor. As can be seen from the figure, the phosphor has [MoOCl5] 2-The related charge transfer (CT) transition and dd transition absorption peaks prove that the phosphor contains [MoOCl5] 2- Octahedral group, and the doped molybdenum ion has a valence of +5.

[0094] Example 5 2 mmol of cesium chloride (CsCl, analytical grade), 1 mmol of tin tetrachloride tetrahydrate (SnCl4·4H2O, analytical grade), and 0.004 mmol, 0.006 mmol, 0.008 mmol, 0.01 mmol, 0.012 mmol, and 0.014 mmol of molybdenum pentachloride (MoCl5, analytical grade, corresponding to a Sn doping ratio of 0.4-1.4 mol%), respectively, were placed in a 25 mL polytetrafluoroethylene (PTFE) liner. 6 mL of concentrated hydrochloric acid (37% by mass) was added to the liner and stirred to mix thoroughly. The PTFE liner was placed in a 25 mL stainless steel hydrothermal reactor and sealed. The hydrothermal reactor was placed in an oven and heated to 180°C at a rate of 5°C / min and maintained at 180°C for 12 hours. After the reaction, the reactor was slowly cooled to room temperature at a rate of 10°C / hour. The product in the liner was separated from the reaction mother liquor. The obtained crystals were washed three times with a small amount of anhydrous ethanol to remove impurities adsorbed on the surface. Finally, the washed product was placed in an oven at 60°C and dried to constant weight to obtain the target product. The obtained product was subjected to X-ray diffraction analysis, and the results were as follows: Figure 6 As shown. Figure 6 As can be seen in the figure, the main diffraction peaks of the prepared phosphors with different pentavalent molybdenum doping concentrations correspond well to the diffraction peaks of the cubic phase Cs2SnCl6 standard card PDF#75-0376, indicating that the products have the same crystal structure as Cs2SnCl6 and are pure phases with no obvious impurity peaks. The incorporation of molybdenum does not significantly change the crystal structure of the matrix.

[0095] Example 6 1mmol CsCl, 0.5mmol SnCl4·4H2O and 0.002mmol MoCl5 (corresponding to 0.4mol% doping of Sn) were placed in a 15mL polytetrafluoroethylene liner. 3mL concentrated hydrochloric acid (37%) was added and mixed evenly. The liner was placed in a 15mL hydrothermal reactor and sealed. The reactor was heated to 180℃ at a rate of 5℃ / min and maintained for 12 hours, and then slowly cooled to room temperature at a rate of 10℃ / hour. Subsequent treatment was the same as in Example 5. The obtained product was subjected to absorption spectrum test, and the results were as follows: Figure 7 As shown, the absorption of the phosphor mainly shows [MoO x Cl 6-x ] 2-The characteristic absorption peaks of Cs2Sn include strong charge transfer (CT) transition absorption and weak dd transition absorption peak. This confirms that the molybdenum ions doped in the product are mainly in the +5 valence state and the matrix contains O elements, that is, the chemical expression of the product can be written as: Cs2Sn 0.996 (O 0.004 Cl 5.996 ):0.4%Mo 5+ .

[0096] Example 7 2 mmol CsCl, 1 mmol SnCl4·4H2O, and 0.010 mmol MoCl5 were placed in a 25 mL polytetrafluoroethylene liner. 6 mL concentrated hydrochloric acid (37%) was added and mixed. The reactor was heated to 160°C at a rate of 3°C / min and maintained for 15 hours. After the reaction was completed, the reaction was slowly cooled to room temperature at a rate of 30°C / hour. Subsequent treatment was carried out as in Example 5 to obtain pentavalent molybdenum-doped Cs2Sn 0.99 (O 0.01 Cl 5.99 ):1.0%Mo 5+ The obtained product was observed by scanning electron microscope (SEM), as shown in FIG. Figure 8 As shown. Figure 8 It can be seen that the prepared phosphor is mainly composed of polygonal micron-sized particles with particle sizes ranging from a few microns to tens of microns. The surface is relatively smooth, and some particles show good crystal properties.

[0097] Example 8 2mmol CsCl, 1mmol SnCl4∙4H2O and 0.004mmol MoCl5 were placed in a polytetrafluoroethylene liner, 10mL concentrated hydrochloric acid was added and mixed, and then placed in a 25mL hydrothermal reactor. The reactor was heated to 200℃ at a rate of 3℃ / min and maintained for 10 hours, and then slowly cooled to room temperature at a rate of 10℃ / hour. The subsequent treatment was the same as in Example 5 to obtain pentavalent molybdenum-doped Cs2Sn 0.996 (O 0.004 Cl 5.996 ):0.4%Mo 5+ Phosphor. Figure 9 The fluorescence emission spectrum of the phosphor synthesized in Example 8 is shown as follows when the excitation wavelength is 310 nm: Figure 9 The results show that the phosphor can simultaneously emit visible light centered at 575nm, covering the range of 450-750nm, and near-infrared light centered at 950nm, covering the range of 800-1200nm. The total spectral half-maximum width is 312nm.

[0098] Comparative Example 2 2mmol CsCl, 1mmol tin dichloride (SnCl2) and 0.004mmol MoCl5 were placed in a polytetrafluoroethylene liner, 6mL concentrated hydrochloric acid was added and mixed, and then placed in a 25mL hydrothermal reactor. The reactor was heated to 180℃ / min at a rate of 5℃ / min. o C and kept for 12 hours, then slowly cooled to room temperature at a rate of 10℃ / hour. After the crystals were separated from the acid solution, they were washed three times with a small amount of ethanol and finally dried in an oven at 60℃. Figure 10 This is the absorption spectrum of the synthesized phosphor. As can be seen from the figure, the phosphor has [MoCl6] 2- The related charge transfer (CT) transition absorption peak proves that the phosphor contains [MoCl6] 2- Octahedral group, and the doped molybdenum ion is +4 valence.

[0099] Example 9 2 mmol of cesium chloride (CsCl, analytical grade), 0.5 mmol of tin dichloride (SnCl2, analytical grade), 0.5 mmol of tin tetrachloride hydrate (SnCl4·5H2O, analytical grade), and 0.004 mmol of molybdenum pentachloride (MoCl5, analytical grade, corresponding to a 0.4 mol% Sn doping) were placed in a 25 mL polytetrafluoroethylene (PTFE) liner. 6 mL of concentrated hydrochloric acid (37% by mass) was added to the liner and stirred to mix thoroughly. The PTFE liner was placed in a 25 mL stainless steel hydrothermal reactor and sealed. The hydrothermal reactor was placed in an oven and heated to 180°C at a rate of 5°C / min and maintained at 180°C for 12 hours. After the reaction, the reactor was slowly cooled to room temperature at a rate of 10°C / hour. The product in the liner was separated from the reaction mother liquor. The resulting crystals were washed three times with a small amount of anhydrous ethanol to remove surface impurities. Finally, the washed product was placed in an oven at 60°C and dried to constant weight to obtain the target product. The obtained product was subjected to X-ray diffraction analysis, and the results were as follows: Figure 11 As shown. Figure 11 It can be seen that the main diffraction peak position of the prepared phosphor corresponds well to the diffraction peak of the standard card PDF#75-0376 of cubic phase Cs2SnCl6, indicating that the product has the same crystal structure as Cs2SnCl6 and is a pure phase with no obvious impurity peak. The incorporation of molybdenum does not significantly change the crystal structure of the matrix. The chemical formula can be expressed as Cs2Sn 0.996 (O 0.002 Cl 5.998 ):0.2%Mo 4+ ,0.2%Mo 5+ .

[0100] Example 10 1mmol CsCl, 0.25mmol SnCl2, 0.25mmol SnCl4·5H2O and 0.002mmol MoCl5 (corresponding to 0.4mol% doping of Sn) were placed in a 15mL polytetrafluoroethylene liner. 3mL concentrated hydrochloric acid (37%) was added and mixed evenly. The liner was placed in a 15mL hydrothermal reactor and sealed. The reactor was heated to 180℃ at a rate of 5℃ / min and maintained for 12 hours, and then slowly cooled to room temperature at a rate of 10℃ / hour. Subsequent treatment was the same as in Example 9. The obtained product was subjected to absorption spectrum test, and the results were as follows: Figure 12 As shown, the absorption of the phosphor shows [MoCl6] 2- Charge transfer (CT) and [MoOCl5] 2- The characteristic absorption peak of dd transition is shown in Figure 2. This confirms that the molybdenum ions doped in the product exist in both +4 and +5 valences and that the matrix contains oxygen elements, that is, the chemical expression of the product can be written as Cs2Sn 0.996 (O 0.002 Cl 5.998 ):0.2%Mo 4+ ,0.2%Mo 5+ .

[0101] Example 11 2mmol CsCl, 0.8mmol SnCl2, 0.2mmol SnCl4·5H2O, and 0.010mmol MoCl5 (corresponding to 1.0mol% Sn doping) were placed in a 25mL polytetrafluoroethylene liner. 6mL concentrated hydrochloric acid (37%) was added and mixed. The reactor was heated to 160℃ at a rate of 3℃ / min and maintained for 15 hours. After the reaction was completed, it was slowly cooled to room temperature at a rate of 30℃ / hour. Subsequent treatment was the same as in Example 9 to obtain a phosphor co-doped with tetravalent molybdenum and pentavalent molybdenum, whose chemical formula is Cs2Sn 0.99 (O 0.002 Cl 5.998 ):0.8%Mo 4+ ,0.2%Mo 5+ The obtained products were observed by scanning electron microscope (SEM). Figure 13 As shown. Figure 13 It can be seen that the prepared phosphor is mainly composed of polygonal micron-sized particles with particle sizes ranging from a few microns to tens of microns. The surface is relatively smooth, and some particles show good crystal properties.

[0102] Example 12 2mmol CsCl, 1mmol tin raw material (SnCl2:SnCl4=8:2, 6:4, 4:6, 2:8) and 0.010mmol MoCl5 (corresponding to 1.0mol% Sn doping) were placed in a polytetrafluoroethylene liner, 10mL concentrated hydrochloric acid was added and mixed, and then placed in a 25mL hydrothermal reactor. The reactor was heated to 200℃ at a rate of 3℃ / min and maintained for 10 hours, and then slowly cooled to room temperature at a rate of 10℃ / hour. Subsequent treatment was the same as in Example 9 to obtain four different tetravalent molybdenum and pentavalent molybdenum co-doped phosphors with the chemical formulas of Cs2Sn, 0.99 (O 0.002 Cl 5.998 ):0.8%Mo 4+ ,0.2%Mo 5+ ;Cs2Sn 0.99 (O 0.004 Cl 5.996 ):0.6%Mo 4+ ,0.4%Mo 5+ ;Cs2Sn 0.99 (O 0.006 Cl 5.994 ):0.4%Mo 4+ ,0.6%Mo 5+ ;Cs2Sn 0.99 (O 0.008 Cl 5.992 ):0.2%Mo 4 + ,0.8%Mo 5+ .in Figure 14 The fluorescence emission spectra of the four phosphors synthesized in Example 12 are as follows when the excitation wavelength is 310 nm: Figure 14 It shows that the emission spectra of the four phosphors can cover the visible-near-infrared light of 500-1600nm.

[0103] Comparative Example 3 2mmol CsCl, 1mmol tin tetrachloride hydrate (SnCl4·5H2O) and 0.004mmol MoCl5 (corresponding to 0.4mol% doping of Sn) were placed in a polytetrafluoroethylene liner, 6mL concentrated hydrochloric acid was added and mixed, and then loaded into a 25mL hydrothermal reactor. The reactor was heated to 180℃ at a rate of 5℃ / min and maintained for 12 hours, and then slowly cooled to room temperature at a rate of 10℃ / hour. After the crystals were separated from the acid solution, they were washed three times with a small amount of ethanol and finally dried in an oven at 60℃ to obtain Cs2Sn doped with only pentavalent molybdenum. 0.996 (O 0.004 Cl 5.996 ):0.4%Mo 5+ Phosphor. Figure 15This is the emission spectrum of the phosphor synthesized in Comparative Example 3 when the excitation wavelength is 310 nm. Figure 15 It was shown that the phosphor emits visible light of 450-750nm and near-infrared light of 800-1200nm.

[0104] Comparative Example 4 2mmol CsCl, 1mmol tin dichloride (SnCl2) and 0.004mmol MoCl5 (corresponding to 0.4mol% doping of Sn) were placed in a polytetrafluoroethylene liner, 6mL concentrated hydrochloric acid was added and mixed, and then placed in a 25mL hydrothermal reactor. The reactor was heated to 180℃ at a rate of 5℃ / min and maintained for 12 hours, and then slowly cooled to room temperature at a rate of 10℃ / hour. After the crystals were separated from the acid solution, they were washed three times with a small amount of ethanol and finally dried in an oven at 60℃ to obtain Cs2Sn doped with only tetravalent molybdenum. 0.996 Cl6:0.4%Mo 4+ Phosphor. Figure 16 This is the emission spectrum of the phosphor synthesized in Comparative Example 4 when the excitation wavelength is 310 nm. Figure 16 It was shown that the phosphor emitted near-infrared light of 700-800nm ​​and 1200-1600nm.

[0105] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the technical solutions of the present invention, and are not intended to limit the specific implementation methods of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A molybdenum-doped all-inorganic hole-ordered double perovskite, characterized in that: The molybdenum-doped all-inorganic hole-ordered double perovskite is a tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite, and its chemical formula is Cs2Sn 1-x Cl6:xMo 4+ , where 0.1%≤x≤5%.

2. The molybdenum-doped all-inorganic hole-ordered double perovskite according to claim 1, characterized in that: The fluorescence emission spectrum of the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite is 700-800 nm and 1200-1600 nm; and / or, The absorption spectrum of the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite is 250-450 nm.

3. A method for preparing the molybdenum-doped all-inorganic hole-ordered double perovskite according to claim 1 or 2, characterized in that: CsCl, SnCl2 and MoCl5 are mixed, concentrated hydrochloric acid is added and mixed evenly, and the mixture is heated, cooled, separated, washed and dried to obtain the tetravalent molybdenum-doped all-inorganic hole-ordered double perovskite.

4. A molybdenum-doped all-inorganic hole-ordered double perovskite, characterized in that: The molybdenum-doped all-inorganic hole-ordered double perovskite is a pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite, and its chemical formula is Cs2Sn 1-y (O y Cl 6-y ):yMo 5+ , among which, 0.1%≤y≤5%.

5. The molybdenum-doped all-inorganic hole-ordered double perovskite according to claim 4, characterized in that: The fluorescence emission spectrum of the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite is 450-750 nm and 800-1200 nm; and / or, The absorption spectrum of the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite is 250-370 nm.

6. A method for preparing the molybdenum-doped all-inorganic hole-ordered double perovskite according to claim 4 or 5, characterized in that: CsCl, SnCl4.4H2O and MoCl5 are mixed, concentrated hydrochloric acid is added and mixed evenly, and the mixture is heated, cooled, separated, washed and dried to obtain the pentavalent molybdenum-doped all-inorganic hole-ordered double perovskite.

7. A molybdenum-doped all-inorganic hole-ordered double perovskite, characterized in that: The molybdenum-doped all-inorganic hole-ordered double perovskite is a tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite, and its chemical formula is Cs2Sn 1-a-b (O b Cl 6-b ):aMo 4+ ,bMo 5+ , where 0.1%≤(a+b)≤5%, and .

8. The molybdenum-doped all-inorganic hole-ordered double perovskite according to claim 7, characterized in that: The fluorescence emission spectrum of the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite covers a range of 500-1600 nm; and / or, The absorption spectrum of the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite is 250-450nm.

9. A method for preparing the molybdenum-doped all-inorganic hole-ordered double perovskite according to claim 7 or 8, characterized in that: CsCl, SnCl2, SnCl4.4H2O and MoCl5 are mixed, concentrated hydrochloric acid is added and mixed evenly, and the mixture is heated, cooled, separated, washed and dried to obtain the tetravalent molybdenum and pentavalent molybdenum co-doped all-inorganic hole-ordered double perovskite.

10. A photoelectric device, characterized in that: The luminescent material of the optoelectronic device is the molybdenum-doped all-inorganic hole-ordered double perovskite according to any one of claims 1 to 9; and / or, Application of the molybdenum-doped all-inorganic hole-ordered double perovskite according to any one of claims 1 to 9 in the fields of product detection, anti-counterfeiting, safety monitoring, non-destructive analysis, light-emitting LEDs, solar cells, temperature detectors, multispectral imaging, ultra-wideband light sources or broadband photodetectors.

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