Three-dimensional organic vulcanized halogenated perovskite material, preparation method thereof and photoelectric detector

Abstract

The invention relates to a three-dimensional organic vulcanized halogenated perovskite material. The molecular formula of the three-dimensional organic vulcanized halogenated perovskite material is MTPA2Pb3I8. And the MTPA represents a 3-(methylthio) propylamine cation CH3-S-CH2CH2CH2-NH < 3 + >. The formula is shown in the description. The three-dimensional organic vulcanized halogenated perovskite material has long-term stability, can effectively improve the operation stability and photoelectric response sensitivity of a photoelectric detector, and prolongs the service life of the photoelectric detector. The invention also relates to a photoelectric detector made of the perovskite material, and solves the technical problem that the existing 3D OMHP is insufficient in long-term stability and limited in application.

Description

Technical Field

[0001] The present invention relates to the technical field of optoelectronic devices, and particularly to a three-dimensional organic sulfur halide perovskite material, a preparation method thereof, and a photodetector. Background Art

[0002] A photodetector is a device that converts incident light (ultraviolet, visible, infrared) into an electrical signal and is crucial for industrial and scientific applications such as imaging, biosensing, and communication. Among them, semiconductors play a key role. They can receive and absorb photons, and then generate electron-hole pairs. Subsequently, these photo-generated carriers will be captured and collected by the electrodes under the action of an electric field (either intrinsic or applied), and finally converted into an electric current. A variety of semiconductor materials have been applied to photodetectors, including silicon, silicon nitride, gallium nitride, organic waveguides, graphene, and molybdenum telluride (MoTe2). However, these materials are usually relatively expensive or complex to synthesize, which hinders their further commercial applications. At the same time, the relatively inexpensive organometallic halide perovskite material (OMHP) has become an excellent candidate for photodetector devices. OMHP has advantages such as a large absorption coefficient, low cost, simple synthesis method, high carrier mobility, and long excitation diffusion length (photo-generated carriers are more easily collected by the electrodes), and is considered a star material for making optoelectronic devices. 3D OMHP has excellent light absorption and charge transport capabilities, but its lack of long-term stability still limits its application.

[0003] For the above reasons, developing a three-dimensional organometallic halide perovskite material with stable structure is of great significance for improving the performance of photodetectors. Summary of the Invention

[0004] (I) Technical Problems to be Solved In view of the above-mentioned disadvantages of the prior art, the present invention provides a three-dimensional organic sulfur halide perovskite material, which has long-term stability, can effectively improve the operating stability and photoelectric response sensitivity of a photodetector, and extend the service life of the photodetector. The present invention also relates to a photodetector made using this perovskite material.

[0005] (II) Technical Solutions In a first aspect, the present invention provides a three-dimensional organic sulfur halide perovskite material with a molecular formula of MTPA2Pb3I8.

[0006] Preferably, the three-dimensional organic sulfur halide perovskite material is monoclinic with a space group of C2 / m.

[0007] Preferably, the crystal cell parameters of the three-dimensional organic sulfur halide perovskite material are: a= 15.9009(18) Å, b = 8.9121(17) Å, c = 22.681(9) Å, α = 90 °, β = 90.261(19) °, γ = 90 °, V = 3214.1(15) Å 3 , Z = 4.

[0008] The molecular formula of the three-dimensional organic sulfur halide perovskite material is C8H 24 I8N2Pb3S2, and its structural formula is MTPA2Pb3I8.

[0009] MTPA represents the 3-(methylthio)propylamine cation CH3-S-CH2CH2CH2-NH3 + , and this cation is first used in the A-site of perovskite. Pb 2+ occupies the B-site, and I - occupies the X-site. However, the molar ratio of Pb to I in the chemical formula is 3:8, which is different from 1:3 of the classical perovskite ABX3, indicating that its structure is a three-dimensional framework with high B-site filling. At room temperature, the MTPA2Pb3I8 crystal belongs to the monoclinic system, and the space group is C2 / m. The unit cell parameters of the crystal are: a = 15.9009(18) Å, b = 8.9121(17) Å, c = 22.681(9) Å, α = 90 °, β = 90.261(19) °, γ = 90 °, V = 3214.1(15) Å3, Z = 4. Among them, MTPA (3-(methylthio)propylamine) serves as both the A-site cation (-NH3 + ), and provides a sulfur source through the methylthio group (-SCH3) to form a sulfur-halogen mixed coordination layer (such as [PbI5S] 7- octahedron), creating a new system of organic-sulfur synergistic perovskite.

[0010] Second, the present invention also provides a preparation method of a three-dimensional organic sulfur halide perovskite material, which includes: S1. Weigh 3-(methylthio)propylamine (MTPA) and lead acetate hydrate and place them in a container, add hydroiodic acid, heat to 100 - 130 °C and stir to obtain a yellow clear solution; S2. Seal the yellow clear solution in a reactor, let it stand at room temperature until the three-dimensional organic sulfur halide perovskite material precipitates, and separate it to obtain the product.

[0011] Preferably, in S1, the molar ratio of 3-(methylthio)propylamine to lead acetate hydrate is 2:3; the molar ratio of lead acetate hydrate to HI is 1:(7 - 20), and slightly filtering HI can compensate for the volatilization loss.

[0012] Preferably, the mass fraction of HI in hydroiodic acid is 45 - 55%.

[0013] In a third aspect, the present invention provides a photodetector comprising a three-dimensional organic sulfur-containing halide perovskite material with the molecular formula MTPA2Pb3I8.

[0014] Preferably, the three-dimensional organic sulfur-containing halide perovskite material is monoclinic with a space group of C2 / m; The symmetry operations of the C2 / m space group include a two-fold rotation axis (2) along the b-axis and a mirror plane (m) perpendicular to the b-axis. The incorporation of sulfur breaks the cubic symmetry and forms chain-like [PbI5S] preferentially arranged along the b-axis 7- units. The crystal cell parameters of the three-dimensional organic sulfur-containing halide perovskite material are: a a = 15.9009(18) Å, b b = 8.9121(17) Å, c c = 22.681(9) Å, α α = 90 °, β β = 90.261(19) °, γ γ = 90 °, V V = 3214.1(15) Å 3 , Z Z = 4. The cell parameters have a certain volume expansion rate compared to the traditional MAPbI3, due to the insertion of the large-volume MTPA + and the octahedral distortion caused by the incorporation of sulfur.

[0015] (III) Beneficial effects A three-dimensional organic sulfur-containing halide perovskite material provided by the present invention, and a photodetector made of this three-dimensional organic sulfur-containing halide perovskite material enable the photodetector to achieve long-term stable photoelectric response; irradiating the photodetector with an excitation light with a wavelength of 637 nm, the device shows a current of 400 nA, which is increased by 0.74×10 3 times compared to 540 pA under non-excitation light irradiation (dark current), and the photodetector still maintains more than 90% of the photoelectric response after five months. This shows that the three-dimensional organic sulfur-containing halide perovskite material and the photodetector have high photoelectric response sensitivity and long-term stability, thereby extending the service life of the photodetector and improving the photoelectric detection performance. Description of the drawings

[0016] Figure 1Photograph of the MTPA2Pb3I8 crystal prepared in Example 1.

[0017] Figure 2 UV-Vis absorption spectrum of the MTPA2Pb3I8 crystal prepared in Example 1.

[0018] Figure 3 Schematic diagram of the structure of the photodetector based on the MTPA2Pb3I8 crystal.

[0019] Figure 4 Photocurrent-voltage curve of the photodetector based on the MTPA2Pb3I8 crystal.

[0020] Figure 5 Response time-photocurrent curve of the photodetector based on the MTPA2Pb3I8 crystal. Detailed implementation mode

[0021] For better explanation of the present invention and for easy understanding, the present invention will be described in detail below with reference to the accompanying drawings through specific implementation modes.

[0022] Example 1 In this example, a three-dimensional organic sulfur halide perovskite crystal with the molecular formula MTPA2Pb3I8 was synthesized by the cooling crystallization method, and its reaction process is shown as follows: MTPA + Pb(Ac)2·3H2O + 4HI → MTPA2Pb3I8 + 2H2O + 3HAc The preparation method of the three-dimensional organic sulfur halide perovskite crystal is as follows: Use a pipette to suck 1.94×10 -3 mol of 3-(methylthio)propylamine (MTPA), weigh lead acetate trihydrate (2.91×10 -3 mol) and dissolve it in 4 mL of hydroiodic acid (mass fraction 48%, a total of 2.25×10 -2 mol) solution, heat to 120 °C and stir until a yellow clear solution is obtained. Then seal the obtained yellow clear solution in a reactor, let it stand at room temperature, naturally cool to room temperature, separate, and obtain black block crystals with a size of 2 mm × 1 mm × 1 mm, filter and dry to obtain the three-dimensional organic sulfur halide perovskite crystal MTPA2Pb3I8.

[0023] As Figure 1 shown is a photograph of the MTPA2Pb3I8 crystal, and this crystal has a color and luster similar to graphite. Continue to detect it by X-ray single crystal diffraction, and the results show that: the molecular formula of this compound is C8H 24I8N2Pb3S2, with the structural formula MTPA2Pb3I8. Here, MTPA represents 3-(methylthio)propylamine. At room temperature, the MTPA2Pb3I8 crystal belongs to the monoclinic system with the space group C2 / m, and its crystal cell parameters are as follows: a a = 15.9009(18) Å, b b = 8.9121(17) Å, c c = 22.681(9) Å, α α = 90 °, β β = 90.261(19) °, γ γ = 90 °, V V = 3214.1(15) Å 3 , Z Z = 4.

[0024] The UV-visible absorption spectrum of the MTPA2Pb3I8 crystal prepared in this example was tested, and the test results are as Figure 2 shown. The MTPA2Pb3I8 crystal material exhibits obvious absorption characteristics in the UV-visible spectral range. The absorption edge at 670.9 nm indicates that this is the band-gap absorption edge of the material, which means that the material has a strong absorption ability for light with wavelengths lower than this wavelength and a weak absorption for light with wavelengths higher than this wavelength; the band-gap energy of the material is 1.88 eV.

[0025] Example 2 This example relates to a photodetector based on the MTPA2Pb3I8 crystal, and its structure is as Figure 3 shown. It includes a substrate material 1, an MTPA2Pb3I8 crystal material 2, and electrodes 3 provided on both sides of the surface of the MTPA2Pb3I8 crystal material 2. The substrate material 1 can be a quartz wafer. The electrodes 3 are made of metal copper, silver, or platinum electrodes. The preparation process of the photodetector is as follows: (1) The quartz wafer substrate was ultrasonically cleaned with deionized water and absolute ethanol for 30 min respectively, then dried with high-purity gas, and finally treated with UV-ozone for 30 min.

[0026] (2) The prepared three-dimensional organic sulfide halide perovskite crystal was adhered and coated on the surface of the quartz wafer substrate 1 with clean tweezers.

[0027] (3) Silver conductive glue was used to dot-coat electrodes 3 on the perovskite layer, and a galvanometer was connected between the two electrodes 3.

[0028] As Figure 4 shown, the photodetector prepared in this example was irradiated with an excitation light with a wavelength of 637 nm to test its optoelectronic performance. The excitation light intensities were Dark, 3.54 mW / cm 2, 10.73 mW / cm 2 , 18.47 mW / cm 2 , 26.05 mW / cm 2 , 32.8 mW / cm 2 , 37.22 mW / cm 2 , 43.81 mW / cm 2 . It can be seen from Figure 4 that under dark conditions (no light illumination), the current is 540 pA, indicating that the device has good dark current suppression ability; as the light intensity increases, the current also increases. This shows that the photodetector has a good light response, and the higher the light intensity, the greater the generated current. At all light intensities, the relationship between current and voltage shows a good linear relationship, especially in the lower voltage range. This linear relationship indicates that the photodetector has stable optoelectronic performance under these conditions. When the excitation light irradiates the device, a current of 400 nA appears in the device, which is 0.74×10 3 times larger than the 540 pA under non-excitation light irradiation (dark current).

[0029] As Figure 5 shown, after the prepared photodetector is placed at room temperature for 5 months, the photodetector prepared in this embodiment is irradiated again with excitation light with a wavelength of 637 nm, and the excitation light intensity refers to the aforementioned levels. At each light intensity, the photodetector still maintains more than 90% of its optoelectronic response. This result shows that the photodetector has long-term stability and a longer service life, and has good application prospects.

[0030] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements, or in the case where the technical features in the above embodiments do not conflict with each other, can be combined in the manner described in the embodiments, and these modifications, replacements or combinations do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A three-dimensional organic sulfide halide perovskite material, characterized in that: The molecular formula of the three-dimensional organic sulfide halide perovskite material is MTPA2Pb3I8.

2. The three-dimensional organic sulfide halide perovskite material according to claim 1, characterized in that: The three-dimensional organic sulfide halide perovskite material is a monoclinic crystal system with a space group of C2 / m.

3. The three-dimensional organic sulfide halide perovskite material according to claim 1, characterized in that: The crystal unit cell parameters of the three-dimensional organic sulfide halide perovskite material are: a = 15.9009(18) Å, b = 8.9121(17) Å, c =22.681(9) Å, α = 90°, β = 90.261(19)°, γ = 90°, V = 3214.1(15) Å 3 , Z = 4.

4. A method for preparing the three-dimensional organic sulfide halide perovskite material according to any one of claims 1 to 3, characterized in that: It includes the following steps: S1. Weigh 3-(methylthio)propylamine (MTPA) and lead acetate hydrate into a container, add hydroiodic acid, heat to 100-130° C. and stir to obtain a yellow clear solution; S2. Seal the yellow clear solution in a reactor and let it stand at room temperature until a three-dimensional organic sulfide halide perovskite material is precipitated and separated to obtain the product.

5. The preparation method according to claim 4, characterized in that: In S1, the molar ratio of 3-(methylthio)propylamine and lead acetate hydrate is 2:

3.

6. The preparation method according to claim 4, characterized in that: In S1, the molar ratio of lead acetate hydrate to HI is 1:(7-20); the mass fraction of HI in hydroiodic acid is 45-55%.

7. A photoelectric detector, characterized in that: It comprises the three-dimensional organic sulfide halide perovskite material according to any one of claims 1 to 3.

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