阅读说明：本技术 一种水稳定锑碘基杂化钙钛矿及其合成与应用 (Water-stable antimony-iodine-based hybrid perovskite and synthesis and application thereof ) 是由 赵若愚 刘广宁 许让栋 牛鹏飞 王子菡 李村成 于 2019-10-10 设计创作，主要内容包括：本发明公开了一种水稳定锑碘基无机-有机杂化钙钛矿及其制备方法与应用。所述的杂化钙钛矿分子结构式为Et4ppi-SbI<Sub>4</Sub>,式中的Et4ppi是带有一个单位正电荷的4-苯基吡啶阳离子,由4-苯基吡啶中的N原子乙基化形成；该材料中的SbI<Sub>4</Sub>阴离子则是三价锑离子和碘离子配位形成的一维阴离子链。通过选择三氯化锑,4-苯基吡啶,丙酮和氢碘酸为反应原料,通过溶剂热反应获得了Et4ppi-SbI<Sub>4</Sub>的单晶,该材料作为一种环境友好型材料,同时具有优异的水稳定性和光电转换性能,在光电子器件领域具有重要应用价值。(The invention discloses a water-stable antimony-iodine-based inorganic-organic hybrid perovskite and a preparation method and application thereof. The molecular structural formula of the hybrid perovskite is Et4ppi-SbI 4 Et4ppi in the formula is a 4-phenylpyridine cation with one unit of positive charge, formed by ethylation of the N atom in 4-phenylpyridine; SbI in the material 4 The anion is a one-dimensional anion chain formed by the coordination of trivalent antimony ions and iodine ions. Et4ppi-SbI is obtained by selecting antimony trichloride, 4-phenylpyridine, acetone and hydroiodic acid as reaction raw materials and carrying out solvothermal reaction 4 The material is used as an environment-friendly material, has excellent water stability and photoelectric conversion performance, and has important application value in the field of optoelectronic devices.)

1. Water-stable antimony-iodine-based hybrid perovskite Et4ppi-SbI₄Et4ppi in the formula represents a 4-phenylpyridine cation having a single positive charge, and is formed by ethylation of the N atom in 4-phenylpyridine, and this compound is a monoclinic crystal crystallized in P2₁The crystal color of the material is orange yellow, the crystal is represented by an anionic-cationic organic-inorganic hybrid structure, the cation is a 4-phenylpyridine cation with a unit positive charge, the anion is a one-dimensional anion chain formed by coordination of trivalent antimony ions and iodine ions, the whole structure is electrically neutral, the anions and cations are combined together through C-H … I weak hydrogen bonds and coulomb interaction, and the cation and external water molecules do not form a strong hydrogen bond.

2. Use of an antimony iodine based hybrid perovskite material as defined in claim 1, characterized in that: the material has enhanced water stability and excellent photoelectric conversion performance, and is used for manufacturing photoelectric devices.

Technical Field

The invention relates to the field of inorganic-organic hybrid perovskites, in particular to a water-stable antimony-iodine-based hybrid perovskite Et4ppi-SbI₄Et4ppi is an ethylated 4-phenylpyridine cation.

Background

In recent years, fossil energy consumption and air environment deterioration become more serious, and a novel method for providing clean renewable energy for human is urgently needed, so people aim at inexhaustible solar energy, and a photovoltaic technology for directly converting the solar energy into electric energy has a wide development prospect in alternative schemes of solar energy conversion modes.

Using star material methyl ammonium lead iodine calcium titanium ore (MAPbI)₃Wherein MA = CH₃NH₃ ⁺) For example, although the certified efficiency as a solar light absorber has broken through 23%, solar cells that have gradually approached silicon-based are also considered as the most promising materials in the photovoltaic field, but have not yet reached true commercial use for two main reasons, one is due to the toxicity of heavy metal lead and the second is the self-decomposition property when exposed to water or even humid air. In general, the organic components in the hybrid material can greatly affect the hydrogen bonding ability of the material with water molecules, which will ultimately directly affect the water stability of the material. Thus MAPbI₃The very poor water stability is mainly due to the presence of a strong hydrophilic group-NH on the methylamine cation₃ ⁺. However, many studies aiming at improving the water stability of the hybrid perovskite only replace methyl groups with longer or larger alkyl chains, and hydrophilic amine groups are not eliminated, so that the hydrophilic characteristics of the hybrid perovskite cannot be fundamentally solved.

The design of the structure directing agent without strong hydrophilic group amido is a key link for constructing the hybrid material with strong stability. The alkyl is taken as a typical hydrophobic group, and the N atom on the aromatic heterocycle is blocked by designing a corresponding alkylation reaction, so that the possibility of forming a strong hydrogen bond with water molecules can be fundamentally avoided, and therefore, the hybrid perovskite synthesized by taking the N-alkylated organic cation as a structure directing agent is presumed to have higher water stability than the hybrid containing the hydrophilic group. The lead-free hybrid perovskite light absorption material is synthesized based on antimony and iodine reaction raw materials, so that the characteristic of direct band gap of the hybrid perovskite is maintained, the material has the advantages of high absorption coefficient, high carrier mobility and easiness in film formation, and the pollution of heavy metal lead to the environment is fundamentally avoided. The material has excellent photoelectric conversion performance and has important research value in the fields of photoelectric detection and solar cells.

Disclosure of Invention

The invention aims to construct a water-stable antimony-iodine-based hybrid perovskite material by a 'strong hydrogen bond-free' strategy, and the N atom of the aromatic heterocyclic structure directing agent is sealed by alkyl, so that the possibility of forming strong N-H … O hydrogen bonds between the material and external water molecules is fundamentally eliminated, and the defect of the antimony-based hybrid perovskite material in the aspect of water stability at the present stage is overcome; the synthesized material has good water stability, shows stronger optical absorption capacity in the range of 300-550 nm, has higher light dark current ratio and can be applied to the field of photoelectric devices.

The technical scheme of the invention comprises the following contents:

1. antimony-iodine-based hybrid perovskite Et4ppi-SbI with stable water₄In the formula, Et4ppi represents a 4-phenylpyridine cation having one unit positive charge and formed by ethylation of the N atom in 4-phenylpyridine. The compound is monoclinic system, and is crystallized in P2₁The/n space group, unit cell parameters a = 7.69 angstrom, b = 19.94 angstrom, c = 13.04 angstrom, α = 90 degrees, β = 100.59 degrees, γ = 90 degrees. The crystal color of the material is orange yellow, and the material is represented by an ionic organic-inorganic hybrid structure. The structure is characterized in that cations in the structure are 4-phenylpyridine cations with a unit positive charge, anions are one-dimensional anion chains formed by coordination of trivalent antimony ions and iodide ions, and the chains are used for balancing the positive charges of the 4-phenylpyridine cations, so that the whole structure is electrically neutral; antimony ions in the anion chain all adopt SbI₆An octahedral coordination mode, wherein iodine ions are coordinated by adopting a terminal group or a mu 2 bridging groupBit-pattern linking adjacent antimony ions; the cations and anions in the molecules are combined together through C-H … I weak hydrogen bonds and coulomb interaction, and the cations and external water molecules do not form strong hydrogen bonds.

2. The use of the inorganic-organic hybrid antimony iodine perovskite as described in the item 1, characterized in that: the compound has water stability which is beyond the reach of hydrophilic methylamine cation perovskite, and has excellent photoelectric conversion performance, and the compound is used as an alternative material of a photoelectric detector.

The invention has the beneficial effects that a novel synthesis strategy is provided for constructing the water-stable antimony-iodine-based hybrid perovskite material, the strategy is simple and effective, and under the guidance of the strategy, the prepared antimony-iodine-based hybrid perovskite not only has excellent photoelectric conversion performance, but also has enhanced water stability, and can be used for manufacturing photoelectric devices.

Drawings

FIG. 1a and FIG. 1b are respectively water-stable antimony-iodine-based hybrid perovskites Et4ppi-SbI₄Asymmetric unit and SbI₆And (5) a structural unit diagram.

FIG. 2 is a water-stable antimony-iodine based hybrid perovskite Et4ppi-SbI₄Spatial packing of molecules within a cell along the a-axis.

FIGS. 3a and 3b are respectively water-stable antimony-iodine based hybrid perovskites Et4ppi-SbI₄And hydrophilic amine type cationic perovskite (MA)₃Sb₂I₉ (MA = CH₃NH₃ ⁺) Powder diffraction pattern under the same conditions. As can be seen, hydrophilic amine type cationic perovskite (MA)₃Sb₂I₉ Can not bear three days in an environment with 75 percent of relative humidity, and has obviously inferior stability to Et4ppi-SbI₄。

FIG. 4 is a water-stable antimony-iodine based hybrid perovskite Et4ppi-SbI₄The current-voltage curve under light and dark shows that the ratio of light to dark current of the material is close to 2.

FIG. 5 is a water-stable antimony-iodine based hybrid perovskite Et4ppi-SbI₄I-T curves immediately after synthesis and three days at 75% relative humidity; after three days of 75% relative humidity treatment, the material remained highThe material has very good stability of photocurrent response, which is proved by the fact that the photocurrent response is high and no obvious current attenuation occurs after five cycles.

FIG. 6 is a water-stable antimony-iodine based hybrid perovskite Et4ppi-SbI₄The current-voltage curve under different light power density light source irradiation, the light response intensity of the material gradually increases along with the increase of the light power density of the irradiation light source.

FIG. 7 is a water-stable antimony-iodine based hybrid perovskite Et4ppi-SbI₄Under the irradiation of monochromatic light with different wavelengths, the current-voltage curve of the material gradually increases along with the blue shift of the wavelength of the irradiation light, and reaches the maximum value under the irradiation of a light source with the wavelength of 365 nm, namely the light current value of the material is in negative correlation with the wavelength of the irradiation light source.

FIG. 8a is a water stable antimony iodine based hybrid perovskite Et4ppi-SbI₄The absorption spectrum in the range of 200 to 900 nm has strong absorption in both ultraviolet and visible light regions, and fig. 8b is a photocurrent-wavelength curve of the material under the condition of constant bias of 5 volts, which has the same trend as fig. 7, i.e. the material has excellent light absorption and photoelectric conversion performance.

Detailed Description

(1) Compound Et4ppi-SbI₄Synthesis of (2)

0.059 g of SbCl₃And 0.031 g 4-phenylpyridine are put into a 25 ml polytetrafluoroethylene inner container which is internally sleeved with a glass small bottle, 0.3 ml HI, 1 ml ethanol and 5 ml acetone are added, then the polytetrafluoroethylene inner container is put into a stainless steel reaction kettle, the stainless steel inner container is heated in a 140 ℃ oven after being screwed, the temperature is kept constant for three days, then the mixture is cooled to the room temperature, and orange yellow crystals are obtained after treatment, namely the compound Et4ppi-SbI₄。

(2) Photoelectrochemical testing

5 mg of fully ground Et4ppi-SbI₄Dispersing the powder in 0.3 ml ethanol, ball milling for thirty minutes, mixing, dripping 3.5 microliter of the dispersion on an interdigital electrode with the square centimeter of 1 multiplied by 1, repeating for five times, vacuum drying at 40 ℃ for four hours to obtain a thin film photoelectrode, and filtering to obtain the thin film photoelectrodeThe xenon lamp with the adjustable light sheet is used as a light source for linear volt-ampere scanning and timing potential scanning. The linear voltammetric scan voltage range is-5-5 volts, the scan rate is 50 millivolts/second, the timed potential scan potential is 2 volts, and the shutter time is set to 5 seconds.