CN112251815A

CN112251815A - One-dimensional DMAPbI3Method for growing large single crystal

Info

Publication number: CN112251815A
Application number: CN202010953206.1A
Authority: CN
Inventors: 高凯歌; 王一鸣
Original assignee: Yangzhou University
Current assignee: Yangzhou University
Priority date: 2020-09-11
Filing date: 2020-09-11
Publication date: 2021-01-22
Anticipated expiration: 2040-09-11
Also published as: CN112251815B

Abstract

The invention relates to a one-dimensional DMAPbI in the field of organic-inorganic hybrid perovskite crystal materials₃A method of growing a large single crystal, the method comprising the steps of: 1) benzylamine and PbI₂Stirring and dissolving in DMF to form clear yellow solution; 2) dripping the hydriodic acid solution into the solution, and then dripping the phosphorous acid aqueous solution to stabilize the hydriodic acid, wherein the finally formed solution is a clear yellow solution; 3) heating the obtained yellow solution at 55-65 deg.C to volatilize liquid, and decomposing DMF to obtain dimethylamine, to obtain DMAPbI₃A saturated solution; 4) volatilizing the solvent from the obtained solution at room temperature, and growing large yellow single crystals after 10-30 days. The invention grows the one-dimensional DMAPbI with the size of 2 mm multiplied by 4 mm multiplied by 8 mm by an improved solution method₃The large single crystal can be used as a photoelectric material and can be well applied to the field of photoelectric conversion.

Description

One-dimensional DMAPbI3Method for growing large single crystal

Technical Field

The invention relates to a perovskite crystal, in particular to the technical field of preparation of organic and inorganic hybrid perovskite crystal materials.

Background

In the prior art, organic and inorganic hybrid perovskites are receiving much attention because of their excellent photoelectric effects. Wherein methylamine lead iodide (MAPbI) is used₃) The photoelectric efficiency of the representative three-dimensional organic-inorganic hybrid perovskite solar cell reaches 22 percent, and the solar cell can be comparable to a silicon solar cell. One-dimensional organic-inorganic hybrid perovskites have received much attention because of their good moisture tolerance and excellent optoelectronic properties. In one-dimensional chain compoundIn the method, the one-dimensional inorganic chains are separated by organic ions to form a quantum line structure. In such a quantum wire, carriers are confined in a one-dimensional inorganic framework. Therefore, the research on the one-dimensional organic-inorganic hybrid perovskite has considerable application prospect.

DMAPbI₃ ((CH₃)₂NH₂PbI₃) Is a one-dimensional organic-inorganic hybrid perovskite comprising [ PbI₆]The octahedron is coplanar to form infinite long one-dimensional chains, and dimethylamine ions ((CH) are arranged between the one-dimensional chains₃)₂NH₂ ⁺) And (4) isolating. Due to the defect formed by one-dimensional chain fracture, the one-dimensional organolead-iodine perovskite can be long along the chain, but is difficult to be thick in the direction vertical to the chain. Literature reported DMAPbI₃The shortest side of the single crystal is only less than 0.2 mm in size. The application of the material in photoelectric conversion is limited.

Disclosure of Invention

The invention aims to provide a one-dimensional DMAPbI₃The method for growing the large single crystal can prepare the one-dimensional lead-iodine-calcium-titanium ore large single crystal.

Therefore, the technical scheme provided by the invention is as follows: a method for growing a one-dimensional DMAPbI3 large single crystal comprises the following steps:

1) benzylamine and PbI₂Dissolving in DMF (N, N-dimethylformamide) with stirring to form a clear yellow solution;

2) dripping the hydriodic acid solution into the solution, and then dripping the phosphorous acid aqueous solution to stabilize the hydriodic acid, wherein the finally formed solution is a clear yellow solution;

3) heating the obtained yellow solution at 55-65 deg.C to volatilize liquid, and decomposing DMF to obtain dimethylamine, to obtain DMAPbI₃A saturated solution;

4) volatilizing the solvent from the obtained solution at room temperature, and growing large yellow single crystals after 10-30 days.

Further, the benzylamine and PbI₂The net mass ratio of DMF, hydroiodic acid and phosphorous acid is as follows: (21-107): 426: (4700-9440): (4200-8500):(2000-4000).

The mass concentration of HI in the hydroiodic acid was 57%. The phosphorous acid mass concentration in the phosphorous acid aqueous solution is 50%. The hydriodic acid and the phosphorous acid with the concentrations are easy to obtain and convenient to manufacture.

In the present invention, DMF + HI + H₂O → DMAI + HCOOH, dynamic reaction to dimethylamine ion, followed by DMAI + PbI₂Reaction to obtain DMAPbI₃And (3) single crystal. The solvent adopted by the invention is not a single solvent, but a dynamic solvent formed by DMF and hydriodic acid, and the solvent comprises DMF, hydriodic acid solution, formic acid and water. Benzylamine is also added into the solution to assist the one-dimensional DMAPbI₃And (4) growing a large single crystal. Benzylamine will react with excess hydroiodic acid in the solution to form a benzylamine hydrochloride solution, which may follow PbI₂Clusters are formed. Benzylamine assisted DMAPbI₃The mechanism for growing large single crystals may be: benzylamine hydrochloride with PbI₂Reacted to form (benzylammonium)₂PbI₄(BA₂PbI₄) However, in the dynamic solution system of the present invention, BA₂PbI₄Has a much higher saturation solubility than DMAPbI₃So that only DMAPbI is present in the initial stage of crystal growth in solution₃Can grow and grow. DMAPbI grown in solution due to imperfect crystals₃There are a large number of one-dimensional chain-breaking defects, which make it difficult to grow a single crystal larger. And benzylamine can be present by forming BA₂PbI₄And redissolved DMAPbI in solution₃The more defective part of the crystal, thus promoting DMAPbI₃Growing the single crystal to obtain the unprecedented one-dimensional organic lead iodine large single crystal. Compared with the prior art, the invention has the beneficial effects that: the invention grows the one-dimensional DMAPbI with the size of 2 mm multiplied by 4 mm multiplied by 8 mm by an improved solution method₃Large single crystals, which are the largest size one-dimensional lead-iodine perovskite single crystals known to date. The obtained large-size one-dimensional lead-iodine perovskite single crystal can be used as a photoelectric material and can be well applied to the field of photoelectric conversion. The one-dimensional perovskite has a unique electro-optical effect due to the quantum confinement effect. Very small dimensions are required unlike perovskitesHigh-efficiency light emission can be realized, and even if the size of the one-dimensional perovskite is large, the one-dimensional perovskite can also realize high-efficiency light emission. Compared with the three-dimensional lead-iodine perovskite, the one-dimensional lead-iodine perovskite has higher stability, so that the one-dimensional lead-iodine perovskite has higher application potential in the field of luminescence.

Drawings

FIG. 1 is a photograph of a large single crystal of 1-dimensional DMAPbI3 grown by the present invention.

FIG. 2 shows a hysteresis loop of a grown large single crystal at a temperature of 231K.

FIG. 3 is a schematic diagram showing the temperature-varying pyroelectric current of a large single crystal grown and the polarization value obtained by integrating the pyroelectric current with temperature.

Detailed Description

Example 1

21 mg of chemically pure benzylamine and 461 mg of chemically pure PbI₂Dissolved in 9.44g of chemically pure DMF with stirring to form a clear yellow solution, and then 14.91g of hydriodic acid solution (HI concentration 57% by mass) was added dropwise to the solution, and 8g of an aqueous phosphorous acid solution (phosphorous acid concentration 50% by mass) was added dropwise to the solution to stabilize the hydriodic acid. The resulting solution was a clear yellow solution. Heating the solution at 60 deg.C for 5-24 hr to volatilize the liquid and decompose dimethylamine to obtain DMAPbI₃The solution is saturated, then the solvent is volatilized from the obtained solution at room temperature, and large yellow single crystals grow after 10 to 30 days.

The following table is DMAPbI in this example₃The saturated solution grows yellow single crystal size through different times:

as shown in the above table, DMAPbI is present between 5 and 10 days₃The single crystal has smaller size, larger size after 10 days, and then gradually grows and grows, but the change is not large after 20 days, and the value is more reasonable within 10-30 days.

Example 2

107 mg of chemically pure benzylamine and 461 mg of chemically pure PbI₂Stirring and dissolvingIn 4.7g of chemically pure DMF, a clear yellow solution was formed, and then 7.38g of hydriodic acid solution (HI concentration 57% by mass) was dropped into the solution, and 4g of an aqueous phosphorous acid solution (phosphorous acid concentration 50% by mass) was dropped into the solution to stabilize the hydriodic acid. The resulting solution was a clear yellow solution. Heating the solution on a 65 ℃ heating table to volatilize the liquid, and decomposing dimethylamine to obtain DMAPbI₃The solution is saturated, then the solvent is volatilized from the obtained solution at room temperature, and large yellow single crystals grow after 10 to 30 days.

Example 3

60 mg of chemically pure benzylamine and 461 mg of chemically pure PbI₂Dissolved in 7.07g of chemically pure DMF with stirring to form a clear yellow solution, 11.14g of hydriodic acid solution (HI concentration 57% by mass) was added dropwise to the solution, and 6g of an aqueous phosphorous acid solution (phosphorous acid concentration 50% by mass) was added dropwise to the solution to stabilize the hydriodic acid. The resulting solution was a clear yellow solution. Heating the solution on a heating table at 55 ℃ to volatilize the liquid, and decomposing dimethylamine to obtain DMAPbI₃The solution is saturated, then the solvent is volatilized from the obtained solution at room temperature, and large yellow single crystals grow after 10 to 30 days.

Example 4

87 mg of chemically pure benzylamine and 461 mg of chemically pure PbI₂Dissolved in 9.44g of chemically pure DMF with stirring to form a clear yellow solution, 7.38g of hydriodic acid solution (HI concentration 57% by mass) were added dropwise to the solution, and 6g of an aqueous phosphorous acid solution (phosphorous acid concentration 50% by mass) were added dropwise to the solution to stabilize the hydriodic acid. The resulting solution was a clear yellow solution. Heating the solution on a heating table at 55 deg.C for about 8-15 hr to volatilize the liquid and decompose dimethylamine to obtain DMAPbI₃The solution is saturated, then the solvent is volatilized from the obtained solution at room temperature, and large yellow single crystals grow after 10 to 30 days.

Comparative example

With dimethylamine iodine (CH)₃NH₂CH₃I) As a raw material, with PbI₂Reacting according to a molar ratio of 1:1, dissolving in DMF, and obtaining the following reaction formula: CH (CH)₃NHCH₃+HI+PbI_2→DMAPbI₃Volatilizing the solvent from the solution obtained by the reaction at room temperature, and growing a yellow single crystal after 30 days, namely DMAPbI₃。

DMAPbI obtained in the above examples and comparative examples₃The dimensions after 30 days of growth are shown in the table below:

the above table shows that one-dimensional DMAPbI can be obtained by the process of the invention₃Large single crystals, which cannot be achieved by the comparative example.

The large single crystal grown in FIG. 2 was measured for a measured hysteresis loop at a temperature of 231K. Surface of hysteresis loop DMAPbI₃Is ferroelectric at low temperature and has a spontaneous polarization value of about 0.2 μ C/cm².

FIG. 3 is a schematic diagram showing the temperature variation of a large crystal grown by measuring a temperature-variable pyroelectric current and the polarization value obtained by integrating the pyroelectric current with the temperature. The pyroelectric current test shows that the temperature is below 263K, and DMAPbI₃Is ferroelectric.

The present invention is not limited to the above-mentioned embodiments, and based on the technical solutions disclosed in the present invention, those skilled in the art can make some substitutions and modifications to some technical features without creative efforts according to the disclosed technical contents, and these substitutions and modifications are all within the protection scope of the present invention.

Claims

1. One-dimensional DMAPbI₃A method for growing a large single crystal, characterized by comprising the steps of:

1) benzylamine and PbI₂Stirring and dissolving in DMF to form clear yellow solution;

2. The one-dimensional DMAPbI of claim 1₃A method for growing a large single crystal, comprising: the benzylamine and PbI₂The net mass ratio of DMF, hydroiodic acid and phosphorous acid is as follows: (21-107): 461(4700-9440): (4200-8500): (2000-4000).

3. The one-dimensional DMAPbI of claim 2₃A method for growing a large single crystal, comprising: the mass concentration of HI in the hydroiodic acid was 57%.

4. The one-dimensional DMAPbI of claim 2₃A method for growing a large single crystal, comprising: the phosphorous acid mass concentration in the phosphorous acid aqueous solution is 50%.