CN111808138A - A kind of organic-inorganic hybrid perovskite crystal based on methyl viologen ligand and its preparation method and application in the field of optoelectronics - Google Patents

Abstract

The invention provides an organic-inorganic hybrid perovskite crystal based on a methyl viologen ligand, a preparation method and an application in the field of optoelectronics, and belongs to the technical field of optoelectronic materials. The present invention provides an organic-inorganic hybrid perovskite crystal based on methyl viologen ligand, the molecular formula is (MV)[SbI ₅ ], wherein (MV) is an organic ligand, and the structural formula of (MV) is as follows As shown in formula 1, the space group of (MV)[SbI ₅ ] is P21, and the unit cell parameter is

α=90°, β=101.936(2)°, γ=90°. The organic-inorganic hybrid perovskite crystal based on the methyl viologen ligand provided by the invention has good photoelectric effect, good stability, and does not pollute the environment.

Description

A kind of organic-inorganic hybrid perovskite crystal based on methyl viologen ligand and its preparation Methods and applications in the field of optoelectronics

technical field

The invention relates to the technical field of optoelectronic materials, in particular to an organic-inorganic hybrid perovskite crystal based on a methyl viologen ligand, a preparation method thereof, and an application in the optoelectronic field.

Background technique

Photodetectors based on semiconductor materials can convert optical signals into electrical signals and have a wide range of applications in optical imaging sensors, security monitoring, and chemical/biological sensing. Most photodetectors are made of inorganic materials, such as InSe, ZnO, MoS ₂ , WS ₂ , but such materials are still limited in their applications due to the disadvantages of slow photoresponse, high material preparation costs, and complex preparation processes. limit.

Lead halide-based organic-inorganic hybrid perovskites exhibit extremely high optical absorption coefficients and balanced electron and hole mobilities, ultralong photogenerated carrier diffusion lengths and lifetimes, low trap densities, and small excitons Combined with advantages such as binding energy, it has great application potential in the field of optoelectronics, for example, the power conversion efficiency of MAPbI ₃ -based solar cells can reach 23.3%. However, lead halide-based hybrid perovskites have poor stability and are easily decomposed under conditions of heat, ultraviolet light and humidity; and lead halide-based hybrid perovskites contain lead elements, which are detrimental to the environment. effect.

SUMMARY OF THE INVENTION

In view of this, the purpose of the present invention is to provide a kind of organic-inorganic hybrid perovskite crystal based on methyl viologen ligand and its preparation method and application in the field of optoelectronics. The organic-inorganic hybrid perovskite crystal has good photoelectric effect, good stability, and does not pollute the environment.

In order to realize the purpose of the above invention, the present invention provides the following technical solutions:

The present invention provides an organic-inorganic hybrid perovskite crystal based on methyl viologen ligand, the molecular formula is (MV)[SbI ₅ ], wherein (MV) is an organic ligand, and the structural formula of (MV) is as follows Equation 1 shows:

α＝90°，β＝101.936(2)°，γ＝90°。The space group of (MV)[SbI ₅ ] is P21, and the unit cell parameters are

α=90°, β=101.936(2)°, γ=90°.

The present invention provides the above-mentioned preparation method of the organic-inorganic hybrid perovskite crystal based on methyl viologen ligand, comprising the following steps:

4'4-bipyridine, SbI ₃ , hydriodic acid and methanol are mixed to carry out a solvothermal reaction, and the organic-inorganic hybrid perovskite crystal based on methyl viologen ligand is obtained after cooling down.

Preferably, the molar ratio of the 4'4-bipyridine to SbI is ₁ :1 to 1:1.05;

The mass ratio of the 4'4-bipyridine to methanol is 1 g: 190-230 mL.

Preferably, the mass concentration of the hydroiodic acid is 55-57%, and the volume ratio of the mass of the 4'4-bipyridine to the hydroiodic acid is 1 g: 11-12 mL.

Preferably, the temperature of the solvothermal reaction is 170-200° C., and the time is 10-20 h.

Preferably, the cooling time is 40-48h.

Preferably, after the solvothermal reaction, it also includes post-processing the obtained solvothermal reaction solution, and the post-processing includes the following steps:

The solvothermal reaction solution is washed, filtered and dried in sequence to obtain an organic-inorganic hybrid perovskite crystal based on a methyl viologen ligand.

Preferably, the washing detergent is methanol, the drying temperature is 20-60° C., and the time is 10-20 min.

The invention provides the application of the organic-inorganic hybrid perovskite crystal based on methyl viologen ligand in the field of optoelectronics.

Preferably, the optoelectronic field is the field of laser, solar cell, phototransistor and photodetector.

The present invention provides an organic-inorganic hybrid perovskite crystal based on methyl viologen ligand, the molecular formula is (MV)[SbI ₅ ], wherein (MV) is an organic ligand, and the structural formula of (MV) is as follows Equation 1 shows:

α＝90°，β＝101.936(2)°，γ＝90°。The space group of (MV)[SbI ₅ ] is P21, and the unit cell parameters are

α=90°, β=101.936(2)°, γ=90°.

In the present invention, methyl viologen (N,N'-dimethyl-4,4'-bipyridine, MV for short) has good electron-deficient properties, and is an ideal organic electron donor acceptor; Cytoviologen is a long molecule with symmetrical structure, which is favorable for hybridization with the inorganic ligand SbI5 ^2- . After SbI ₅ ^2- is hybridized with methyl viologen dication, the obtained (MV)[SbI ₅ ] organic-inorganic hybrid perovskite crystal has high photoresponsivity and external quantum efficiency, and the detection rate as a photodetector can be improved At the same time, the obtained (MV)[ ^SbI ₅ ] organic-inorganic hybrid perovskite crystal has a strong light absorbance in the ultraviolet band to the near-infrared band, and has a very high light response speed as a solar cell. Meanwhile, the organic-inorganic hybrid perovskite crystal based on the methyl viologen ligand provided by the present invention has good stability under the conditions of heat, ultraviolet light irradiation and humidity, does not contain elements harmful to the environment, and is environmentally friendly.

The present invention provides a method for preparing the above-mentioned organic-inorganic hybrid perovskite crystal based on methyl viologen ligands.

Description of drawings

Fig. 1 is the structural schematic diagram of (MV)[SbI ₅ ] crystal;

Fig. 2 is the inorganic structure diagram of (MV)[SbI ₅ ] crystal;

Figure 3 shows the IV curves of the (MV)[SbI ₅ ] crystal photodetector under laser irradiation at 375 nm and 532 nm, respectively;

Figure 4 shows the responsivity and external quantum efficiency curves of the (MV)[SbI ₅ ] crystal photodetector under laser irradiation at 375 nm and 532 nm, respectively;

Figure 5 shows the detectivity curves of the (MV)[SbI ₅ ] crystal photodetector under laser irradiation at 375 nm and 532 nm, respectively;

Fig. 6 is the photoresponse rate of (MV)[SbI ₅ ] crystal photodetector under 532nm laser irradiation;

FIG. 7 is the ultraviolet-visible-near-infrared absorption spectrum of the solar cell of Application Example 2.

Detailed ways

The present invention provides an organic-inorganic hybrid perovskite crystal based on methyl viologen ligand, the molecular formula is (MV)[SbI ₅ ], wherein (MV) is an organic ligand, and the structural formula of (MV) is as follows Equation 1 shows:

α＝90°，β＝101.936(2)°，γ＝90°。The space group of (MV)[SbI ₅ ] is P21, and the unit cell parameters are

α=90°, β=101.936(2)°, γ=90°.

In the present invention, the schematic structural diagram of the (MV)[SbI5] crystal provided by the present invention is shown in FIG. 1 , and the inorganic structure diagram of the (MV)[ _SbI5 ] crystal is shown in FIG. 2 . It can be seen that in (MV)[SbI ₅ ], the SbI ₅ quadrangular pyramids alternately form a chain-like inorganic framework along the a-axis, and the methyl viologen dication (MV ²⁺ ) is interspersed in the inorganic framework and interacts with the metal halide chain. are combined in the form of intermolecular forces.

The present invention provides the above-mentioned preparation method of the organic-inorganic hybrid perovskite crystal based on methyl viologen ligand, comprising the following steps:

4'4-bipyridine, SbI ₃ , hydriodic acid and methanol are mixed to carry out a solvothermal reaction, and the organic-inorganic hybrid perovskite crystal based on methyl viologen ligand is obtained after cooling down.

In the present invention, the molar ratio of the 4'4-bipyridine to SbI is preferably ₁ :1 to 1:1.05; the mass ratio of the 4'4-bipyridine to methanol is preferably 1 g: 190 to 1 g. 230mL. In the present invention, the mass concentration of the hydroiodic acid is preferably 55-57%, more preferably 56%; the mass ratio of the 4'4-bipyridine to the hydroiodic acid is preferably 1 g: 11-12 mL .

The present invention has no special requirements on the mixing method, and a mixing method well known to those skilled in the art can be used. In the present invention, 4'4-bipyridine, SbI ₃ , hydroiodic acid and methanol are preferably added into the inner lining of the reaction kettle for mixing.

In the present invention, the solvothermal reaction is preferably carried out in a closed reactor. In the present invention, the temperature of the solvothermal reaction is preferably 190° C., and the time is preferably 14h. In the present invention, the heating rate to the solvothermal reaction is preferably 33° C./h; the present invention starts to calculate the reaction time after the temperature is raised to the solvothermal reaction temperature.

In the present invention, the reaction formula of the solvothermal reaction is shown in formula 2.

C ₁₀ H ₈ N ₂ +SbI ₃ +2HI+2CH ₃ OH→C ₁₂ H ₁₄ I ₅ N ₂ Sb Formula 2.

In the present invention, after the solvothermal reaction, the present invention preferably lowers the temperature of the obtained solvothermal reaction solution. In the present invention, the cooling time is preferably 40-48 h, and the present invention can control the growth rate of crystals through the cooling, so as to obtain crystals of good quality.

After the solvothermal reaction, the present invention also preferably includes post-processing the obtained solvothermal reaction solution, and the post-processing preferably includes the following steps:

The solvothermal reaction solution is washed, filtered and dried in sequence to obtain an organic-inorganic hybrid perovskite crystal based on a methyl viologen ligand.

In the present invention, the solvothermal reaction solution is preferably transferred to a beaker before the washing. In the present invention, the washing detergent is preferably methanol; the present invention preferably conducts the washing under stirring conditions. The present invention has no special requirements on the filtering method, and a filtering method well known to those skilled in the art can be used. In the present invention, the steps of washing and filtering are preferably repeated to remove the soluble substances in the filter residue, and the number of repetitions is preferably 3 times. In the present invention, the drying is preferably performed in a drying oven, the drying temperature is preferably 40° C., and the drying time is preferably 10-20 min, more preferably 15 min.

After the drying is completed, the black crystals in the obtained solid are organic-inorganic hybrid perovskite crystals based on methyl viologen ligands. In the present invention, the black crystals are picked out and sealed for preservation.

The present invention provides the application of the above-mentioned organic-inorganic hybrid perovskite crystal based on methyl viologen ligand in the field of optoelectronics. In the present invention, the optoelectronic field is preferably the field of lasers, solar cells, phototransistors and photodetectors.

In the present invention, when the organic-inorganic hybrid perovskite crystal based on methyl viologen ligand is used in the field of solar cells, the components of the solar cell include sequentially stacked transparent conductive substrate layers, methyl-based Organic-inorganic hybrid perovskite crystal layer of viologen ligands (referred to as (MV)[SbI ₅ ] layer) and metal electrode layer.

In the present invention, the material of the transparent conductive substrate layer is preferably strontium titanate doped niobate, and the thickness is preferably 0.5-0.6 mm; the thickness of the (MV)[SbI ₅ ] layer is preferably 10-50 nm; the metal The material of the electrode layer is preferably platinum, and the thickness is preferably 400 nm to 600 nm.

In the present invention, the preparation method of the solar cell preferably includes the following steps:

(1) placing the organic-inorganic hybrid perovskite crystal of methyl viologen ligand on the surface of a transparent conductive substrate, and heating to obtain a transparent conductive substrate with a (MV)[SbI ₅ ] layer grown on the surface;

(2) plating a metal electrode layer on the surface of the (MV) [SbI ₅ ] layer to obtain a solar cell component;

(3) encapsulating the solar cell component to obtain a solar cell.

In the present invention, the heating temperature is preferably 350° C., and the time is preferably 0.5 h. The present invention has no special requirements on the method of metal electrode layer plating, and the method of metal electrode layer plating well known to those skilled in the art can be used. The present invention has no special requirements on the packaging method, and the packaging method well-known to those skilled in the art can be used.

In the present invention, when the organic-inorganic hybrid perovskite crystal based on methyl viologen ligand is used for a photodetector, the preparation method of the photodetector includes the following steps:

Electrode layers are deposited on the upper and lower surfaces of the organic-inorganic hybrid perovskite crystal of the methyl viologen ligand to obtain a photodetector.

In the present invention, the deposition method is preferably pulsed laser deposition, and the present invention has no special requirements for the specific operating conditions of the deposition, and the operating conditions well known to those skilled in the art can be used. In the present invention, the material of the electrode layer is preferably platinum, and the thickness of the electrode layer is preferably 600 nm.

The organic-inorganic hybrid perovskite crystal based on methyl viologen ligands provided by the present invention and its preparation method and application in the field of optoelectronics are described in detail below in conjunction with the examples, but they cannot be understood as the protection scope of the present invention. limit.

Example 1

(1) 0.044g of 4'4-bipyridine, 0.141g of SbI ₃ , 0.5mL of hydroiodic acid (55～57wt%), 10mL of methanol were added to the reactor lining successively, and the reactor liner was put into In the reactor, sealed;

(2) the sealed reaction kettle is placed in the electric heating blast drying oven, the temperature parameter is set to be warming up to 190 ℃ from 25 ℃ in 5 hours, carry out solvothermal reaction, the holding time is 14 hours, and finally reduce to room temperature 25 ℃ with 48 hours °C;

(3) Sample treatment: transfer the sample in the reaction kettle to a 20mL small beaker, add an appropriate amount of methanol to the beaker with a plastic tip dropper, stir with another plastic tip dropper, filter, and stir and clean with methanol again. Repeat three times to clean the soluble substances in the product, dry the remaining substances in a drying oven at 40°C, and then pick out the black (MV)[SbI ₅ ] crystals with a toothpick and seal the bottle for preservation.

The structure of the obtained (MV)[SbI ₅ ] crystal was determined as follows:

The diffraction intensity of (MV)[SbI ₅ ] crystals was measured on a Brukes APEX II CCD diffractometer at ambient temperature using γ-ω scanning technique. There was no evidence of crystal decay during data collection.

The semi-empirical absorption correction (SADABS) program SARE was used for the integration of the diffraction profiles. The structure is solved by direct methods and refined with full matrix least squares using the Selx-2014 program.

The crystal data and structural information of the obtained (MV)[SbI ₅ ] are shown in Table 1.

Table 1 Crystal data and structural information of (MV)[SbI ₅ ]

The atomic coordinates of the obtained (MV)[SbI ₅ ] are shown in Table 2.

Table 2 (MV) Atomic coordinates of [SbI ₅ ]

Table 3 shows the interatomic bond length (A) and bond angle (deg) of the obtained (MV)[SbI ₅ ].

Table 3 (MV) Interatomic bond length (A) and bond angle (deg) of [SbI ₅ ]

Application example 1

The resulting (MV)[SbI ₅ ] crystals were used in photodetectors as follows:

A crystal (MV) [SbI ₅ ] crystal with regular shape and few defects was selected, and a parallel structure platinum electrode with a thickness of about 600 nm was prepared on the crystal surface by pulsed laser deposition (PLD) technology. The circuit is made into a simple photodetector.

The resulting photodetectors were subjected to current-voltage (I-V) tests. Using 375nm and 532nm light sources with different powers to measure the I-V curves under different laser powers, the results are shown in Figure 3. The left picture in Figure 3 is the I-V curve at 375nm, and the right picture is the I-V curve at 532nm.

Calculate the optical responsivity (R) and external quantum efficiency (EQE) of the (MV) [SbI ₅ ] crystal according to the measured IV curve, wherein the optical responsivity (R) is calculated according to formula a, and the external quantum efficiency (EQE) Calculated according to formula b:

In formula a, I _p and I _dark are the currents measured with and without laser irradiation, respectively, P ₀ is the laser power density, and S is the effective illumination area.

In formula b, R is the optical responsivity, h is Planck's constant, e is the elementary charge, c is the speed of light, and λ is the wavelength of the incident light.

The calculated results of the obtained photoresponsivity (R) and external quantum efficiency (EQE) are shown in Fig. 4. The left graph in Fig. 4 is the photoresponsivity and external quantum efficiency at 375 nm, and the right graph is the photoresponsivity at 532 nm. and external quantum efficiency.

The detectivity of the (MV)[SbI ₅ ] crystal photodetector was calculated from the photoresponsivity (R) and external quantum efficiency (EQE), and the detectivity was calculated according to formula c:

In formula c, R is the responsivity, I _dark is the dark current, and e is the elementary charge.

The calculation results of the obtained detectivity are shown in Fig. 5, the left graph in Fig. 5 is the detectivity at 375 nm, and the right graph is the detectivity at 532 nm.

It can be seen from FIG. 5 that the detection rate of the photodetector can be as high as 10 ¹¹ Jones under laser irradiation, and it is shown that under different wavelengths, the detector is sensitive to strong light and weak light, respectively. Therefore, the (MV) )[SbI5] crystals can be applied to detect light in a wide power range.

The response speed is one of the key parameters of the photodetector's response speed to the light signal. Figure 6 shows the time-dependent current of the (MV)[SbI ₅ ] photodetector under 532 nm laser irradiation. It can be seen that the photocurrent of the (MV)[SbI ₅ ] single crystal photodetector is repeatable and stable under laser irradiation. When the laser was turned on, the current rapidly increased to a maximum value and leveled off. When the laser is turned off, the current drops rapidly, returning to its original state. Rise time (t _rise ) is defined as the time taken for the photodetector current to rise from 10% to 90% of the peak value, similarly, decay time (t _decay ) is defined as the time taken for the photodetector current to drop from 90% to 10% of the peak value time. The rise and decay times of the (MV)[SbI ₅ ] single crystal photodetector in the present invention are 0.017s and 0.012s, respectively.

Application example 2

50 mg of the (MV)[SbI ₅ ] crystal obtained in Example 1 was placed in a quartz boat and placed in a glass tube of a tube furnace. The position of the material was adjusted by an iron rod so that the material was directly under the heating wire. The strontium acid transparent conductive substrate is placed on one end of the glass tube, the glass tube of the tube furnace is sealed, and the temperature parameters of the tube furnace are adjusted to heat from room temperature to 350 °C, keep at 350 °C for half an hour, turn off the instrument, and reduce the temperature of the instrument to room temperature. A transparent conductive substrate on which a (MV)[SbI ₅ ] layer was grown was obtained, wherein the thickness of the (MV)[SbI ₅ ] layer was 10 nm.

Take out the transparent conductive substrate with the (MV)[SbI ₅ ] layer grown, and coat a platinum electrode layer with a thickness of 600 nm on the surface of the (MV) [SbI ₅ ] layer, and connect the solar energy components in series by encapsulation to obtain solar energy Battery.

The absorption spectrum of the obtained solar cell was tested, and the obtained ultraviolet-visible-near-infrared absorption spectrum is shown in FIG. 7 . As can be seen from FIG. 7 , when the (MV)[SbI ₅ ] crystal provided by the present invention is used in a solar cell, the obtained solar cell has a strong absorbance of light in the ultraviolet band to the near-infrared band, and has the characteristic of absorbing most of the wavelengths of sunlight, and It has high optoelectronic properties, and the solar cell using (MV)[SbI ₅ ] material has an extremely high photoresponse speed, which can effectively improve the sensitivity of the solar cell.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. An organic-inorganic hybrid perovskite crystal based on methyl viologen ligand has a molecular formula of (MV) [ SbI₅]Wherein (MV) is an organic ligand, and the structural formula of the (MV) is shown as a formula 1:

the (MV) [ SbI₅]Has a space group of P21 and a unit cell parameter of

α＝90°，β＝101.936(2)°，γ＝90°。

2. The method for preparing organic-inorganic hybrid perovskite crystal based on methyl viologen ligand as claimed in claim 1, which is characterized by comprising the following steps:

4' 4-bipyridine and SbI₃Mixing hydriodic acid and methanol, carrying out solvothermal reaction, and cooling to obtain the organic-inorganic hybrid perovskite crystal based on the methyl viologen ligand.

3. The method of claim 2, wherein the 4' 4-bipyridine and SbI are present₃The molar ratio of (A) to (B) is 1: 1-1: 1.05;

the volume ratio of the mass of the 4' 4-bipyridyl to the methanol is 1g: 190-230 mL.

4. The preparation method according to claim 2, wherein the mass concentration of the hydroiodic acid is 55-57%, and the volume ratio of the mass of the 4' 4-bipyridyl to the hydroiodic acid is 1g: 11-12 mL.

5. The preparation method according to claim 2, wherein the temperature of the solvothermal reaction is 170-200 ℃ and the time is 10-20 h.

6. The preparation method according to claim 2, wherein the cooling time is 40-48 h.

7. The method according to claim 2, further comprising, after the solvothermal reaction, subjecting the obtained solvothermal reaction solution to a post-treatment, wherein the post-treatment comprises the steps of:

and washing, filtering and drying the solvothermal reaction solution in sequence to obtain the organic-inorganic hybrid perovskite crystal based on the methyl viologen ligand.

8. The method according to claim 7, wherein the washing detergent is methanol, and the drying temperature is 20 to 60 ℃ and the drying time is 10 to 20 min.

9. Use of organic-inorganic hybrid perovskite crystals based on methyl viologen ligands as claimed in claim 1 in the field of optoelectronics.

10. Use according to claim 9, characterized in that the optoelectronic fields are the fields of lasers, solar cells, phototransistors and photodetectors.

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