CN104141166A

CN104141166A - Preparing method for methylamine bromide lead crystals of large-size perovskite structure

Info

Publication number: CN104141166A
Application number: CN201410340812.0A
Authority: CN
Inventors: 苏静; 仲坤; 缪菊红; 雷勇; 史鹏飞; 朱万祺
Original assignee: Nanjing University of Information Science and Technology
Current assignee: Nanjing University of Information Science and Technology
Priority date: 2014-07-17
Filing date: 2014-07-17
Publication date: 2014-11-12
Anticipated expiration: 2034-07-17
Also published as: CN104141166B

Abstract

The invention discloses a preparing method for methylamine bromide lead crystals of a large-size perovskite structure. According to the preparing method, PbBr2 is dissolved with a HBr solution to obtain a Pb <2+>-HBr solution; the HBr solution and a CH3NH2 solution are mixed according to the mole ratio of 1:1, and react for two hours at the temperature of 0 DEG C to obtain a CH3NH2Br solution; then the obtained Pb <2+>-HBr solution and the CH3NH2Br solution are mixed and preheated for 48 hours at the temperature of 70 DEG C to obtain a CH3NH3PbBr3 super-saturated solution which is filtered to obtain clear yellow liquid, the clear yellow liquid is preheated for 12 hours in water bath with the temperature of 70 DEG C, the temperature falls to 50 DEG C, and the clear yellow liquid is evaporated at the constant temperature to obtain the CH3NH3PbBr3 crystals. According to the preparing method, in the process, the HBr solution participates in raw material synthesis and is the solvent for growth of the crystals, and the method has the advantages that the synthetic process is simple, and the side reaction is less; the growth device is simple, and the high-quality and large-size crystals can grow.

Description

The preparation method of large size perovskite structure methylamine bromine leading crystal

Technical field

The present invention relates to the preparation method of large size perovskite structure methylamine bromine leading crystal, is a kind of method that adopts solution evaporation method artificial culture crystal, belongs to crystalline material preparing technical field.

Background technology

From 2009 to 2013, CH ₃nH ₃pbX ₃(X=Cl, Br, I) power-conversion efficiencies of perovskite typed solar cell from 3.8% to exceeding 15%, worldwide, the research of perovskite typed solar cell is reached to unprecedented temperature, the 2013 year ten large technological breakthroughs that selected " Science " magazine is announced.This class material has carrier mobility and good easy the to be flexible processing characteristics of organic constituent element that inorganic constituent element is high concurrently, can absorb efficiently the broad-spectrum light from visible ray to wavelength 800nm, and also having can be at TiO ₂, Al ₂o ₃react directly synthetic feature Deng on porous material by solution chemistry, be applicable to the advantages such as coating processes.From the angle of commercial value, the energy waste of its photovoltaic process (0.4eV) is suitable with crystal silicon solar energy battery, far below traditional DSSCs and organic solar batteries (being about 0.7eV – 0.8eV).In addition, perovskite structural material is better than silicon aspect absorption blueness and green photon.The top scientist in a lot of photovoltaic solars field foretells CH optimistically ₃nH ₃pbX ₃perovskite structural materials such as (X=Cl, Br, I) will become the first-selection of high-efficient full solid-state solar cell of new generation.But from practical angle, the performance of this class solar cell is also urgently optimized.Due to CH ₃nH ₃pbX ₃there is changeable structure and the difficulty of growing technology in (X=Cl, Br, I), the optics of structural chemistry to this crystal, crystal chemistry, many uniquenesses, and also there is many queries in the aspects such as electricity and magnetic performance.For CH ₃nH ₃pbBr ₃monocrystalline, the overall dimension that retrieval obtains is at present 2mm.In order to obtain material structure and performance information accurately, we adopt solution growth method to prepare the CH of large-size ₃nH ₃pbBr ₃monocrystalline is research CH ₃nH ₃pbBr ₃the physical and chemical performance of material, optical property, electric property and photoelectric properties etc. provides material foundation, simultaneously by the research of these performances, for optimizing CH ₃nH ₃pbBr ₃the performance of solar cell provides theoretical foundation.

Summary of the invention

For current large size perovskite structure methylamine bromine leading crystal (CH ₃nH ₃pbBr ₃crystal) the shortcoming of technology of preparing, in order to obtain large-sized CH ₃nH ₃pbBr ₃monocrystalline, the new CH of special proposition ₃nH ₃pbBr ₃the method of cultivation of monocrystalline.

The preparation method of large size perovskite structure methylamine bromine leading crystal, adopts solution evaporation method, comprises the steps:

1) by the PbBr of 0.01 mole ₂the HBr solution that is 48% by 25 ml mass concentrations dissolves, preparation Pb ²⁺-HBr solution;

2) by HBr solution and CH ₃nH ₂solution in molar ratio 1:1 mixes, and at 0～10 DEG C, reacts 2h, obtains CH ₃nH ₂br solution;

3) Pb step 1) being obtained ²⁺-HBr solution and step 2) CH that obtains ₃nH ₂br solution mixes, wherein Pb ²⁺with CH ₃nH ₂the mol ratio of Br is 1:(1～2), be preferably 1:1.5; Be placed in preheating 48～72h at 60～70 DEG C, obtain CH ₃nH ₃pbBr ₃supersaturated solution, filters, and obtains the yellow liquid of clarification as CH ₃nH ₃pbBr ₃the mother liquor of crystal growth;

4) mother liquor step 3) being obtained is preheating 12h-24h under temperature of saturation, is then cooled to 50 DEG C with the speed of 1 DEG C/h, obtains orange red CH ₃nH ₃pbBr ₃crystal, at 50 DEG C of evaporation at constant temperatures to liquid level of solution higher than plane of crystal 2-3mm;

5) under 50 DEG C of temperature constant states, take out orange red CH ₃nH ₃pbBr ₃crystal, removes the solution of plane of crystal, obtains size and reach the large size CH of 5mm ₃nH ₃pbBr ₃crystal, is large size perovskite structure methylamine bromine leading crystal.

Step 1) and step 2) in the mass percentage concentration of HBr solution be 48%.

In step 1), adopt the PbBr of 0.01 mole ₂use 25 ml, 48% HBr solution dissolves, preparation Pb ²⁺-HBr solution, PbBr in this step ₂determine to obtain the size of saturated solution and crystal with the proportionlity of HBr;

Step 2) middle CH ₃nH ₂the mass percentage concentration of solution is 40%.

In step 4), rate of temperature fall is 1 DEG C/h.

Beneficial effect:

1) technique of the present invention, it is synthetic that HBr solution had both participated in raw material, is again the solvent of crystal growth, has synthesis technique simple, the advantage that side reaction is few;

2) the present invention is with PbBr ₂, HBr solution, CH ₃nH ₂solution is raw material, and growing apparatus is simple and easy, can grow high quality, large-sized crystal, and the crystalline size growing is up to 5mm.

Brief description of the drawings

Fig. 1 is CH of the present invention ₃nH ₃pbBr ₃crystal preparation technology schema;

Fig. 2 CH ₃nH ₃pbBr ₃crystal prototype picture;

Fig. 3 CH ₃nH ₃pbBr ₃the XRD figure spectrum of crystal.

Embodiment

Now in conjunction with the embodiments, the present invention is described in further detail as follows:

The purity of experiment agents useful for same is

PbBr ₂(solute) purity 99.99%

HBr(solution) concentration expressed in percentage by weight 48%

CH ₃nH ₂(solution) concentration expressed in percentage by weight 40%

Embodiment 1:

The preparation method of large size perovskite structure methylamine bromine leading crystal, step is as follows:

1) take the PbBr of 0.01mol ₂, with 25ml, the HBr solution that mass concentration is 48% at room temperature dissolves, preparation Pb ²⁺-HBr solution;

2) according to HBr and CH ₃nH ₂mol ratio be 1:1, measure respectively the HBr solution of mass concentration 48%, the CH of mass concentration 40% ₃nH ₂the each 2.32ml of solution, 1.72ml, mixes these two solution and sealing, is placed in 0 DEG C of ice-water bath 2h, obtains CH ₃nH ₂br solution;

3) at room temperature, by Pb ²⁺-HBr solution and CH ₃nH ₂br solution mixes, and orange red solid matter appears in bottom at once, and this solution is placed in to 70 DEG C of water-bath preheating 48h;

4) keeping solution temperature is in 70 DEG C of situations, removes by filter orange red solid matter.Using the yellow liquid of the clarification obtaining as CH ₃nH ₃pbBr ₃the mother liquor of crystal growth;

5) above-mentioned mother liquor is positioned over to preheating 12h in the water-bath of 70 DEG C;

6) design cooling process, rate of temperature fall is 1 DEG C/h, and solution temperature is dropped to 50 DEG C, at 50 DEG C of evaporation at constant temperatures, is evaporated to liquid level of solution higher than plane of crystal 2mm;

7) under 50 DEG C of constant temperatures, separate out liquid, orange red bottom crystal is carefully taken out;

8) blot the solution of plane of crystal with filter paper, obtain being of a size of the CH of 5mm ₃nH ₃pbBr ₃crystal.

Fig. 1 is CH ₃nH ₃pbBr ₃crystal preparation flow figure, Fig. 2 is for obtaining CH ₃nH ₃pbBr ₃crystallogram, crystalline size is larger, and crystal face is bright and clean.Fig. 3 is CH ₃nH ₃pbBr ₃the XRD figure spectrum of crystal, confirms that obtaining crystal is isometric system CH ₃nH ₃pbBr ₃crystal.

These results suggest that, adopt above solution method evaporation crystal growth technique, can obtain large-size, high-quality CH ₃nH ₃pbBr ₃crystal.

Claims

1. the preparation method of large size perovskite structure methylamine bromine leading crystal, is characterized in that being: adopt solution evaporation method, comprise the steps:

3) Pb step 1) being obtained ²⁺-HBr solution and step 2) CH that obtains ₃nH ₂br solution mixes, wherein Pb ²⁺with CH ₃nH ₂the mol ratio of Br is 1:(1～2); Be placed in preheating 48～72h at 60～70 DEG C, obtain CH ₃nH ₃pbBr ₃supersaturated solution, filters, and obtains the yellow liquid of clarification as CH ₃nH ₃pbBr ₃the mother liquor of crystal growth;

4) mother liquor step 3) being obtained is preheating 12h-24h at 60～70 DEG C, is then cooled to 50 DEG C, obtains orange red CH ₃nH ₃pbBr ₃crystal, at 50 DEG C of evaporation at constant temperatures to liquid level of solution higher than plane of crystal 2-3mm;

5) under 50 DEG C of temperature constant states, take out orange red CH ₃nH ₃pbBr ₃crystal, removes the solution of plane of crystal, obtains size and reach the large size CH of 5mm ₃nH ₃pbBr ₃crystal, i.e. large size perovskite structure methylamine bromine leading crystal.

2. the preparation method of large size perovskite structure methylamine bromine leading crystal according to claim 1, is characterized in that being: step 2) in the mass percentage concentration of HBr solution be 48%.

3. the preparation method of large size perovskite structure methylamine bromine leading crystal according to claim 1, is characterized in that being:

4. the preparation method of large size perovskite structure methylamine bromine leading crystal according to claim 1, is characterized in that being:

In step 4), cooling declines with the speed of 1 DEG C/h.

5. the preparation method of large size perovskite structure methylamine bromine leading crystal according to claim 1, is characterized in that being:

Pb in step 3) ²⁺with CH ₃nH ₂the mol ratio of Br is 1:1.5.