CN109912459A

CN109912459A - A kind of bimetallic perovskite nano material and preparation method thereof

Info

Publication number: CN109912459A
Application number: CN201910176566.2A
Authority: CN
Inventors: 戴武斌; 周佳; 许硕; 胡金; 黄珂; 徐慢
Original assignee: Wuhan Institute of Technology
Current assignee: Wuhan Institute of Technology
Priority date: 2019-03-08
Filing date: 2019-03-08
Publication date: 2019-06-21
Anticipated expiration: 2039-03-08
Also published as: CN109912459B

Abstract

The present invention relates to a kind of bimetallic perovskite nano material and preparation method thereof, the bimetallic perovskite nano material is the nano material of the perovskite structure of 10~20nm of partial size, expression formula FA₄Ge^ⅡSb^ⅢCl₁₂, wherein FA is NH₂CH=NH₂ ⁺.Preparation method are as follows: 1) antimony oxide and germanous chloride are added to preparation in hydrochloric acid solution and obtain mixed solution；2) under room temperature, carbonamidine chloride is added in mixed solution obtained by step 1), is precipitated after stirring 0.5-1h, is then filtered using glass sand core, filter residue is dried under reduced pressure to obtain bimetallic perovskite compound powder sample.Bimetallic perovskite material provided by the invention high humility, long-term illumination and it is heated under conditions of show relatively high stability, overcome at present common perovskite material there are the shortcomings that；And there is lower direct band gap, be conducive to generate electron transition, to improve incident photon-to-electron conversion efficiency.

Description

A kind of bimetallic perovskite nano material and preparation method thereof

Technical field

The invention belongs to perovskite technical field of solar batteries, and in particular to a kind of bimetallic perovskite compound FA₄Ge^ⅡSb^ⅢCl₁₂Nano material and preparation method thereof.

Background technique

Due to having many advantages, such as high extinction coefficient, low defect state concentration and long carrier lifetime, in recent years with MAPbI₃(MA=CH₃NH₃ ⁺) be representative the hybrid inorganic-organic halide perovskite material for possessing higher-wattage transfer efficiency (general formula AMX₃, A=organic molecule, M=bivalent metal ion, X=halide) application in solar cells cause it is wide General concern.MAPbI₃With wider absorption region and direct band gap, as the light absorption in perovskite solar battery Agent may be implemented higher power conversion efficiency by optimizing battery structure, but restrict MAPbI₃Type photovoltaic device is extensive The critical issue of commercial applications is: 1) material is unstable under high humility, long-term illumination and heating condition, is easy to happen point Solution；2) metal ion lead ion has toxicity；3) photovoltaic device power output is unstable.

The study found that using carbonamidine FA (NH₂CH=NH₂ ⁺) substitution methyl ammonium MA, its chemical stability can be made to obtain Improving, this is primarily due to relative to MA, 1) FA can form more symmetrical crystal structure；2) lesser band gap allows close red The absorption of outer light；3) FA possesses higher decomposition temperature.In addition, Pb element is replaced using similar single metallic elements, such as 14 Race element (Ge²⁺Or Sn²⁺), alkali earth metal (Ca²⁺, Mg²⁺, Sr²⁺Deng), transition metal element (V²⁺, Mn²⁺, Fe²⁺, Co²⁺ Deng) or p p-block element p (Ga²⁺, In²⁺), stable, nontoxic, environmental sound the member of performance is found in these elements usually to be replaced Pb.Studies have found that the above most elements are due to having the following problems: 1) band gap is excessively high；2) there is toxicity or radioactivity (Ge of the invention^Ⅱ-Sb^ⅢRich content in nontoxic and soil)；3) unstable etc. under+2 valence, cause them to form perovskite Ability it is limited or be not suitable for photovoltaic art.Therefore in current research field, the unleaded of stability and high efficiency is prepared Perovskite material only achieves limited success.

Most of in monometallic perovskite at present all to use the metal for replacing (+divalent) with valence, it can be considered to make Monometallic is substituted with bimetallic, the valence state of two of them metal is respectively+trivalent and+1 valence or be all+divalent, this method can To keep overall charge to balance.But most of bimetallic perovskite material synthesized at present have indirect band gap or its directly Band gap is not suitable for being applied to photovoltaic art, therefore is restricted.

A kind of bimetallic perovskite chemical combination in view of these limitations, the present invention provides stability and high efficiency, without lead element Object FA₄Ge^ⅡSb^ⅢCl₁₂, this lead-free bimetallic perovskite material photo and thermal stability with higher and moisture-proof, and compare Other types of solar battery uses this semiconductor material FA₄Ge^ⅡSb^ⅢCl₁₂The perovskite solar battery of preparation has Higher power-conversion efficiencies.

Summary of the invention

The technical problem to be solved by the present invention is to be directed to the shortcomings of the prior art, a kind of bimetallic is provided Perovskite compound FA₄Ge^ⅡSb^ⅢCl₁₂And preparation method thereof, which stablizes with stronger photo-thermal Property and moisture-proof, compare other types of solar battery, use FA₄Ge^ⅡSb^ⅢCl₁₂The perovskite of semiconductor material preparation is too Positive energy battery has higher power-conversion efficiencies.

In order to solve the above technical problems, present invention provide the technical scheme that

A kind of bimetallic perovskite nano material is provided, the bimetallic perovskite nano material is 10~20nm's of partial size Perovskite structure nano material, expression formula FA₄Ge^ⅡSb^ⅢCl₁₂, wherein FA is NH₂CH=NH₂ ⁺。

The present invention also provides the preparation methods of above-mentioned bimetallic perovskite nano material, comprising the following steps:

1) by antimony oxide (Sb₂O₃) and germanous chloride (GeCl₂) be added in hydrochloric acid solution prepare obtain mixing it is molten Liquid；

2) under room temperature, by carbonamidine chloride (HC (NH₂)₂Cl it) is added in mixed solution obtained by step 1), stirs 0.5-1h After precipitated, then filtered using glass sand core, gained filter residue is dried under reduced pressure to obtain bimetallic perovskite compound FA₄Ge^Ⅱ Sb^ⅢCl₁₂Powder sample.

According to the above scheme, the step 1) concentration of hydrochloric acid solution is 1.5~2.5mol/L.

According to the above scheme, elemental mole ratios Ge:Sb:Cl=1~2:4~6:10~20 in the step 1) mixed solution.

According to the above scheme, step 2) the carbonamidine chloride and Ge elemental mole ratios in mixed solution are 0.2~0.8:1.

According to the above scheme, step 2) is described is dried under reduced pressure condition are as follows: temperature is 90-110 DEG C, drying time 1-2h, pressure Power is set as 2.67kPa or less.

The invention also includes according to above-mentioned bimetallic perovskite compound nano material FA₄Ge^ⅡSb^ⅢCl₁₂It is prepared Perovskite solar cell photovoltaic device.

The beneficial effects of the present invention are: 1, provided by the invention bimetallic perovskite material FA₄Ge^ⅡSb^ⅢCl₁₂In high humidity Degree, long-term illumination and it is heated under conditions of show relatively high stability, overcome common perovskite material at present and exist The shortcomings that；And has lower direct band gap (1.3eV), be conducive to generate electron transition, to improve incident photon-to-electron conversion efficiency； Higher electric conductivity makes the material be suitably applied single-stage absorption solar battery, and (present invention uses FA₄Ge^ⅡSb^ⅢCl₁₂Calcium titanium The optimal solar energy battery device circuit photocurrent density Jsc=23.1mAcm of pit wood material preparation^-2, open-circuit voltage Voc= 4.7%) 0.73eV, FF=0.53, power-conversion efficiencies are up to.2, the present invention is prepared using relatively simple solwution method, is used Bimetallic germanium-antimony of rich content replaces the lead in conventional solar cell perovskite material in nontoxic and soil, avoids Potential pollution of the perovskite material to environment.

Detailed description of the invention

Fig. 1 is FA prepared by the embodiment of the present invention 1₄Ge^ⅡSb^ⅢCl₁₂The XRD spectrum (a) and its standard card of powder (b)；

Fig. 2 is FA prepared by embodiment 1₄Ge^ⅡSb^ⅢCl₁₂The SEM of powder schemes；

Fig. 3 is FA prepared by embodiment 1₄Ge^ⅡSb^ⅢCl₁₂The absorbance and photoluminescence spectra of powder；

Fig. 4 is FA prepared by embodiment 1₄Ge^ⅡSb^ⅢCl₁₂The Tauc curve of powder；

Fig. 5 is FA prepared by embodiment 1₄Ge^ⅡSb^ⅢCl₁₂The thermogravimetric curve of powder；

Fig. 6 is FA prepared by embodiment 1-3₄Ge^ⅡSb^ⅢCl₁₂The room temperature ring that perovskite material is 60% in relative humidity Under border, the XRD spectrum measured after different time is placed；

Fig. 7 is FA prepared by embodiment 1,4,5,6₄Ge^ⅡSb^ⅢCl₁₂Perovskite material is in different light application times and humidity The XRD spectrum measured under environment；

Fig. 8 is perovskite solar cell device structural schematic diagram prepared by embodiment 7；

Fig. 9 is the J-V curve of perovskite solar cell device prepared by embodiment 7.

Specific embodiment

Technical solution in order to enable those skilled in the art to better understand the present invention, with reference to the accompanying drawing to the present invention make into One step detailed description.

Embodiment 1

Prepare bimetallic perovskite nano material FA₄Ge^ⅡSb^ⅢCl₁₂, the specific steps are as follows:

1) by 2.5mmol antimony oxide (Sb₂O₃) and 1.5mmol germanous chloride (GeCl₂) to be added to 5.0mL hydrochloric acid molten It is prepared in liquid (2mol/L) and obtains mixed solution；

2) under room temperature, by 0.5mmol carbonamidine chloride (HC (NH₂)₂Cl it) is added in mixed solution obtained by step 1), often It is precipitated after temperature stirring 1h, is then filtered using glass sand core, gained filter residue is dried under reduced pressure (to be dried, temperature after vacuumizing Degree is set in 100 DEG C, and drying time 1.5h, pressure is set as 2.67kPa) obtain bimetallic perovskite compound FA₄Ge^ⅡSb^ⅢCl₁₂Powder sample.

The XRD diagram (see Fig. 1) of the present embodiment powder sample is measured by x-ray powder diffraction instrument (model D8Advance), Showing it has and FA₄Ge^ⅡSb^ⅢCl₁₂Corresponding crystal structure.

The present embodiment powder sample is measured by field emission scanning electron microscope (model JEOL JSM-7600F) SEM schemes (see Fig. 2), it is seen that its partial size is 10~20nm.

By microspectrophotometer (model SD1200-LS-HA) measure the present embodiment powder sample absorbance and Emission spectrum (see Fig. 3), Detection wavelength range are 300-1000nm, and absorption spectrum shows broad absorption band, shows the powder-like Product have semiconductor property.Photoluminescence spectra observes most strong emission peak at 950nm, belongs near infrared emission, shows this Powder sample is suitable as the light absorbent in solar battery.

The present embodiment semiconductor powder sample is carried out by microspectrophotometer (model SD1200-LS-HA) Optical density test is absorbed, Tauc curve is made into order to determine the band gap (see Fig. 4) of material, shows the energy band of the sample powder Gap is about 1.3eV, consistent with Fig. 3 result, and the direct band gap for further proving that the dusty material has is suitable as solar energy Absorbing material in battery.

The thermogravimetric curve (see Fig. 5) that the powder sample is measured by thermogravimetric analyzer (model SDT-Q600), can see The material does not decompose under 235 DEG C of high temperature out, illustrates that the dusty material has stronger thermal stability.

Embodiment 2

Sample powder prepared by embodiment 1 is placed in the environment of relative humidity is 60% 1 month, then carries out XRD It can characterization.

Embodiment 3

Sample powder prepared by embodiment 1 is placed in the environment of relative humidity is 60% 3 months, then carries out XRD It can characterization.

The XRD diagram of the powder sample of embodiment 1-3 is measured (see figure by x-ray powder diffraction instrument (model D8Advance) 6), wherein (a) is FA₄Ge^ⅡSb^ⅢCl₁₂Standard card, (b), (c) and (d) be respectively in embodiment 1, embodiment 2 and embodiment 3 The XRD spectrum of powder sample, it can be seen that three kinds of powder samples all have and FA₄Ge^ⅡSb^ⅢCl₁₂Corresponding crystal structure, shows The fluorescent powder is not decomposed, has stronger moisture-proof.

Embodiment 4

By sample powder prepared by embodiment 1 be placed on relative humidity be 60% in the environment of, using simulated solar illumination After penetrating 3 days, then carry out XRD performance characterization.

Embodiment 5

By sample powder prepared by embodiment 1 be placed on relative humidity be 60% in the environment of, using simulated solar illumination After penetrating 15 days, then carry out XRD performance characterization.

Embodiment 6

The difference is that in the environment of sample powder placement relative humidity prepared by embodiment 1 is 0%, using simulation After sunlight irradiates 15 days, then carry out XRD performance characterization.

Embodiment 1, embodiment 4, embodiment 5 and embodiment are measured by x-ray powder diffraction instrument (model D8Advance) The XRD diagram (see Fig. 7) of powder sample in 6, wherein (a) is FA₄Ge^ⅡSb^ⅢCl₁₂Standard card, (b), (c), (d) and (e) respectively For the XRD spectrum of powder sample in embodiment 1, embodiment 4, embodiment 5 and embodiment 6, it is seen that four kinds of samples all have with FA₄Ge^ⅡSb^ⅢCl₁₂Corresponding crystal structure shows that the fluorescent powder is not decomposed, under illumination and moist environmental conditions With stronger stability.

Embodiment 7

Bimetallic perovskite nano material FA prepared by embodiment 1₄Ge^ⅡSb^ⅢCl₁₂It applies in solar battery and prepares Corresponding solar cell device out, comprising the following steps:

1) TiO is prepared in FTO substrate surface₂Barrier layer；

2) by 1 gained bimetallic perovskite compound FA of embodiment₄Ge^ⅡSb^ⅢCl₁₂Nano-powder material is made by spin-coating method Its within the 30s time uniform deposition on substrate；

3) Spiro-OMeTAD is dissolved in chlorobenzene (75mg/mL) and is spin-coated on substrate, passed with forming good hole Defeated layer, then Au electrode is deposited on substrate by thermal evaporation, and the perovskite solar cell device of preparation is from bottom to up Successively are as follows: FTO substrate, TiO₂Barrier layer, perovskite material FA₄Ge^ⅡSb^ⅢCl₁₂, Spiro-OMeTAD and Au electrode is prepared Perovskite solar cell device structural schematic diagram it is as shown in Figure 8.By digital sourcemeter (model keithley 2400), The J-V curve (see Fig. 9) of the perovskite solar cell device is measured, photovoltaic parameter is respectively as follows: circuit photocurrent density Jsc=23.1mAcm^-2, open-circuit voltage Voc=0.73eV, FF=0.53, power-conversion efficiencies are up to 4.7%.

Claims

1. a kind of bimetallic perovskite nano material, which is characterized in that the bimetallic perovskite nano material be partial size 10~ The nano material of the perovskite structure of 20nm, expression formula FA₄Ge^ⅡSb^ⅢCl₁₂, wherein FA is NH₂CH=NH₂ ⁺。

2. a kind of preparation method of bimetallic perovskite nano material described in claim 1, which is characterized in that including following step It is rapid:

1) antimony oxide and germanous chloride are added to prepare in hydrochloric acid solution and obtain mixed solution；

2) under room temperature, carbonamidine chloride is added in mixed solution obtained by step 1), is precipitated after stirring 0.5-1h, then It is filtered using glass sand core, gained filter residue is dried under reduced pressure to obtain bimetallic perovskite compound FA₄Ge^ⅡSb^ⅢCl₁₂Powder sample.

3. the preparation method of bimetallic perovskite nano material according to claim 2, which is characterized in that step 1) is described Concentration of hydrochloric acid solution is 1.5~2.5mol/L.

4. the preparation method of bimetallic perovskite nano material according to claim 2, which is characterized in that step 1) is described Elemental mole ratios Ge:Sb:Cl=1~2:4~6:10~20 in mixed solution.

5. the preparation method of bimetallic perovskite nano material according to claim 2, which is characterized in that step 2) is described Ge elemental mole ratios are 0.2~0.8:1 in carbonamidine chloride and mixed solution.

6. the preparation method of bimetallic perovskite nano material according to claim 2, which is characterized in that step 2) is described It is dried under reduced pressure condition are as follows: temperature is 90-110 DEG C, and drying time 1-2h, pressure is set as 2.67kPa or less.

7. a kind of perovskite solar battery light that bimetallic perovskite nano material according to claim 1 is prepared Lie prostrate device.