阅读说明：本技术 一种链状碘化物材料及其制备与应用 (Chain-like iodide material and preparation and application thereof ) 是由 唐江 姚利 高亮 牛广达 于 2019-09-19 设计创作，主要内容包括：本发明属于光电材料领域,公开了一种链状碘化物材料及其制备与应用,其中,链状碘化物材料为有机无机杂化卤素复合物,具有链状结构；其化学式满足LI<Sub>6</Sub>,其中,L为有机二胺阳离子,I代表碘元素。本发明通过对其关键的有机分子进行筛选,选择链状二胺有机分子去诱导碘原子的线性排列,与现有材料相比能够有效满足稳定性好,简单易得,及强的各向异性吸收差异,尤其适用于在偏振片、太阳能电池、各向异性传输和各向异性探测中应用。并且,本发明不需要施加外电场,晶体能够自主形成链状。(The invention belongs to the field of photoelectric materials, and discloses a chain iodide material and preparation and application thereof, wherein the chain iodide material is an organic-inorganic hybrid halogen compound and has a chain structure, the chemical formula of the chain iodide material meets LI 6 , L is an organic diamine cation, and I represents an iodine element.)

1. A chain iodide material is characterized in that the chain iodide material is an organic-inorganic hybrid halogen compound and has a chain structure; whose chemical formula satisfies LI₆Wherein, L is organic diamine cation, I represents iodine element; in the chain iodide material, the organic diamine is arranged and distributed in a chain structure, and the iodine atoms are also arranged and distributed in a chain structure.

2. The chain iodide material as set forth in claim 1, wherein the compound represented by the formula LI is₆In (1) [₆]The whole is-2 valent; for the chain iodide material, L is an N-N' -dimethylethylenediamine cation, i.e., CH₃NH₂CH₂CH₂NH₂CH₃ ²⁺(ii) a The bond length of the chain structure of iodine atoms is The key angles are 179.1 °, 176.0 °, 176.9 ° respectively.

3. Process for the preparation of chain iodide material according to claim 1 or 2, in particular according to LI₆Respectively weighing iodine elementary substance powder and an organic diamine material according to the stoichiometric ratio of the intermediate L to the intermediate I, then mixing the iodine elementary substance powder and the organic diamine material in HI acid for reaction, and removing the HI acid after the reaction to obtain the polycrystalline powder or the single crystal containing the target chain iodide material.

4. The method for producing the chain iodide material according to claim 1 or 2, wherein the method comprises adding an organic diamine material to HI acid, and standing to wait for oxidation of iodine in the HI acid to iodine molecules, thereby growing a single crystal containing the target chain iodide material in the HI acid.

5. The production method according to claim 3 or 4, wherein the chain iodide material is specifically a chain iodide single crystal thin film, and the production method further comprises the steps of:

Dissolving the obtained polycrystalline powder or single crystal containing the target chain iodide material into an organic solvent to enable the concentration to reach 2-3 mol/L, so as to obtain a chain iodide solution; then, the chain iodide solution is dropped between two substrates, and the chain iodide single crystal thin film is obtained by the treatment of evaporating the solvent by raising the temperature.

6. The method according to claim 5, wherein the solvent is evaporated by heating the solvent to 90 to 100 ℃; preferably, the thickness of the obtained single crystal thin film of chain iodide is 12 to 18 μm.

7. The method of claim 5, wherein the organic solvent is N, N-Dimethylformamide (DMF), or dimethyl sulfoxide (DMSO), or γ -butyrolactone (GBL).

8. Use of the chain iodide material according to claim 1 or 2 for polarizing plates, solar cells, anisotropic transmission, anisotropic absorption and anisotropic detection.

Technical Field

The invention belongs to the field of photoelectric materials, and particularly relates to a chain iodide material, and a preparation method and an application thereof.

Background

In the last decade, the anisotropic absorption material has shown great application value in the fields of polarizer, solar cell, liquid crystal display and anisotropic detection, etc., and is one of the hot spots of international material research. However, most anisotropic absorption materials in the present stage mostly utilize the anisotropy of two-dimensional materials, or limit the size of three-dimensional materials, or utilize metal wire grids, and have the disadvantages of complex process, unobvious anisotropy, or high price (the price of a linear polarizer with the diameter of 1cm is 200-.

One feasible scheme is based on the idea that the mixture of iodide ions and macromolecular polymers is regularly arranged under the action of an electric field and is generally applied to a liquid crystal display, and the iodide autonomously forms chain-shaped arrangement under the induction of organic molecules to obtain the compound which is stable, simple and easy to obtain and has strong anisotropic absorption difference. The existing chain iodide adopts large organic molecules, the iodine atom arrangement is not a perfect straight line, and the distance between adjacent triiodine is far, so that the requirement cannot be met.

Disclosure of Invention

In view of the above defects or improvement needs of the prior art, an object of the present invention is to provide a chain iodide material, and a preparation method and an application thereof, wherein the chain iodide material is prepared by screening key organic molecules thereof and selecting organic molecules of chain diamine to induce linear arrangement of iodine atoms, and compared with the existing material, the chain iodide material can effectively satisfy the requirements of good stability, simplicity, easy obtaining and strong anisotropic absorption difference, and is particularly suitable for application in a polarizing plate, a solar cell, anisotropic transmission and anisotropic detection. In addition, the invention does not need to apply an external electric field, and the crystal can form a chain shape independently.

In order to achieve the above object, according to one aspect of the present invention, there is provided a chain iodide material, characterized in that the chain iodide material is an organic-inorganic hybrid halogen compound having a chain structure; whose chemical formula satisfies LI₆Wherein, L is organic diamine cation, I represents iodine element; in the chain iodide material, the organic diamine is arranged and distributed in a chain structure, and the iodine atoms are also arranged and distributed in a chain structure.

As a further preferred feature of the invention, in the formula LI₆In (1) [₆]The whole is-2 valent; for the chain iodide material, L is an N-N' -dimethylethylenediamine cation, i.e., CH₃NH₂CH₂CH₂NH₂CH₃ ²⁺(ii) a The bond length of the chain structure of iodine atoms is the key angles are 179.1 °, 176.0 °, 176.9 ° respectively.

According to another aspect of the present invention, there is provided a process for producing the above chain iodide material, characterized in that the process is carried out specifically according to LI₆Respectively weighing iodine elementary substance powder and an organic diamine material according to the stoichiometric ratio of the intermediate L to the intermediate I, then mixing the iodine elementary substance powder and the organic diamine material in HI acid for reaction, and removing the HI acid after the reaction to obtain the polycrystalline powder or the single crystal containing the target chain iodide material.

According to still another aspect of the present invention, there is provided a method for producing the above chain iodide material, characterized in that the method comprises adding an organic diamine material to HI acid, and standing to wait for oxidation of iodine in the HI acid to iodine molecules, thereby growing a single crystal containing the target chain iodide material in the HI acid.

As a further preferable aspect of the present invention, the chain iodide material is specifically a chain iodide single crystal thin film, and the preparation method further includes the steps of:

Dissolving the obtained polycrystalline powder or single crystal containing the target chain iodide material into an organic solvent to enable the concentration to reach 2-3 mol/L, so as to obtain a chain iodide solution; then, the chain iodide solution is dropped between two substrates, and the chain iodide single crystal thin film is obtained by the treatment of evaporating the solvent by raising the temperature.

As a further preference of the present invention, the solvent is evaporated by raising the temperature to 90 ℃ to 100 ℃; the thickness of the obtained chain iodide single crystal thin film is 12-18 μm.

As a further preferred of the present invention, the organic solvent is N, N-Dimethylformamide (DMF), or dimethyl sulfoxide (DMSO), or γ -butyrolactone (GBL).

According to still another aspect of the present invention, the present invention provides use of the above-mentioned chain iodide material in a polarizing plate, a solar cell, anisotropic transmission, anisotropic absorption and anisotropic detection.

Compared with the prior art, the technical scheme of the invention has the advantages that the key coordination organic molecule types in the chain iodides are selected, the chain diamine organic molecules are selected to induce the linear arrangement of iodine atoms, the condition that the length of the organic molecules is similar to the length of three iodides is obtained, and hydrogen atoms on nitrogen on the organic molecules can form hydrogen bond action with iodide ions, so that the diamine triiodide compound formed by the specific structure has a nearly perfect one-dimensional structure and has the characteristic of strong anisotropy. The chain iodide material has a one-dimensional structure, wherein iodine is arranged into a chain, chain organic molecules are also arranged into a chain (certainly, eyes are put on the integral three-dimensional space structure of the chain iodide material, organic diamine is arranged and distributed according to a plurality of chain structures, iodine atoms are also arranged and distributed according to a plurality of chain structures, the bond length and bond angle parameters between any two chains are correspondingly equal, and only the positions of the chain structures are different in the integral material), the energy band structure is basically determined by the iodine, and the organic molecules are inserted into the energy band structure. Obtaining triiodine atoms in iodine chains through single crystal structure analysisIs 179.1 deg. and the angle between triiodine and triiodine is 176.0 deg. and 176.9 deg.; meanwhile, the distances between iodine atoms were 2.77, 3.37 andThese angle and length data indicate that the triiodide compounds of the present invention are straight and short in distance and thus interact strongly and are anisotropic as compared to all triiodides of the prior art.

In the invention, the chain iodide material is a chain triiodide compound material, and the chemical formula of the chain triiodide compound material meets the following requirements: LI (lithium ion) powder₆Wherein, L is organic diamine cation, I represents iodine element, and is organic iodide. Taking L as N-N' -dimethylethylenediamine cation as an example, L is DMDEA²⁺(i.e., CH)₃NH₂CH₂CH₂NH₂CH₃ ²⁺The +2 cation of N-N' -dimethylethylenediamine). DMDEA²⁺(i.e., CH)₃NH₂CH₂CH₂NH₂CH₃ ²⁺) Compared with the common valence equilibrium DMEDA, 1H atom, CH is additionally connected to each nitrogen atom₃NH₂CH₂CH₂NH₂CH₃ ²⁺The whole is additionally connected with 2H atoms, so that the valence is + 2; these 2H atoms are also naturally introduced by charge balance, in the formula LI₆In (I)₆]The whole body is in a valence state of-2, and the valence state characteristics of the iodine element integrally represent the same with the valence state of the iodine element in other triiodine compounds in the prior art (the related prior art comprises I reported in the literature₃ ^-To I₂₉ ^3-And polyiodide compounds, see, for example: svensson, P.H.&Kloo, L.Synthesis, Structure, and Bonding in Polymer and Metal Iodi-Iodine systems, chemical Reviews 103,1649-1684, doi:10.1021/cr0204101(2003), etc.). In the invention, the DMDAA is selected as an organic molecule participating in the construction of the chain iodide material (correspondingly, the DMDAA organic molecule material can be used as an organic diamine raw material), so that the obtained chain iodide is a strong anisotropic chain iodide and presents a strong anisotropic absorption difference. For the chainTheoretical calculations for triiodo-complex materials show that in the visible range the absorption coefficient parallel to the chain is about 100 times that perpendicular to the chain. And around 500nm, the difference in absorption can be up to 1000 times. In the experiment, the reflection spectrum of the crystal was tested, and it was also found that the reflectance in the reflection spectrum in parallel with the chain and in perpendicular with the chain was about 10% and 80%, respectively, in the vicinity of 500 nm. The polarization absorption of the single crystal thin film was tested, and it was also found that the difference in anisotropic absorption at 700nm was 10 times for the 12 μm single crystal thin film, taking the single crystal thin film having a thickness of 12 μm as an example. Due to its large absorption coefficient (10)⁶cm^-1) And therefore has greater advantages in anisotropic absorption and detection for thinner films. According to the invention, through research on the absorption and band gap properties of the triiodide, compared with the existing anisotropic absorption materials applied to LCDs and polarizing plates, the chain iodide material in the invention is stable, theoretically has a narrow band of more than 99.9% and a polarization degree of more than 99% (the theoretical simulation band gap of the chain iodide material is 1.26eV, and the optical band gap calculated through an absorption spectrum in an experiment is 1.43eV), and is particularly suitable for being applied to the fields of polarizing plates, solar cells, anisotropic transmission and anisotropic detection, anisotropic heat conduction, anisotropic absorption and the like.

Compared with the prior anisotropic two-dimensional material or the anisotropy obtained by controlling the geometric dimension to be hundreds of nm compared with the optical wavelength, the chain iodide material has the advantages that perfect single crystals can be easily obtained, the iodine element reserves are rich, toxic heavy metals such As As and Pb are not contained, the pollution to the environment and the damage to the human body are reduced, and the large-area synthesis and use are facilitated. And no special control of the geometric dimension to the nm level is needed, so that the application sustainability is greater. Compared with most anisotropic materials, the crystal axis needs to be determined through complex spectral characterization, or the required size is obtained through theoretically simulating the distribution of a light field and needs to be accurately controlled, the chain iodide does not need to be designed and controlled in a complex way to achieve the anisotropic effect, and does not need to be controlled in a multi-step fine mode to purify the final product. And the obtained chain iodide material has better thermal stability and can be used as a polarizing plate, a solar cell or an active layer for anisotropic detection.

The method adopts hydriodic acid and organic molecules to mix, can be kept stand at normal temperature for crystal growth, and is mainly based on the characteristic that hydriodic acid can be oxidized into iodine molecules in the air, or iodine molecules are directly added. And controlling normal temperature or cooling crystallization according to whether the final product needs a large single crystal.

Taking L as DMDEA²⁺For example, the present invention utilizes the dissolution of CH₃NH₂CH₂CH₂NH₂CH₃I₆The solution can grow single crystal films with target thickness and target crystal growth quality between transparent substrates by controlling the temperature of the temperature-rising evaporation solvent treatment, so that the solution can show great application in the fields of polaroids, anisotropic transmission, anisotropic detection and the like, or the solution can be used for preparing a light solar cell by utilizing the strong absorption performance of the iodide. The method utilizes a solution in which polycrystalline powder or single crystal containing a target chain iodide material is dissolved, wherein the concentration of the solution is controlled to be 2-3 mol/L, and the solution is used for growing the chain iodide single crystal film. When the chain-shaped iodide single crystal film is grown by utilizing the heating evaporation solvent treatment, the thickness of the obtained chain-shaped iodide single crystal film can be controlled by controlling the concentration of the solution; the invention can correspondingly obtain the chain iodide single crystal film with the thickness of 12-18 mu m, wherein the thickness of the single crystal film obtained by the solution with the concentration of 2mol/L is 12 mu m, and the thickness of the single crystal film obtained by the solution with the concentration of 3mol/L is 18 mu m.

most of the traditional iodides are monoamine-based organic molecules or inorganic ions, and the invention explores a novel chain iodide material based on diamine organic molecules. The structure is characterized by having an iodine chain and an organic chain which are close to straight lines, and a perfect one-dimensional structure can be obtained. Due to the strong structural anisotropy, the material has strong anisotropy in light absorption, electric conduction and heat conduction.

Drawings

FIG. 1 is a crystal representation of a chain iodide prepared in example 1.

fig. 2 is a schematic view of the crystal structure of the chain iodide prepared in example 1.

Fig. 3 is a schematic view of bond length and bond angle information of the chain iodide prepared in example 1. FIG. 3 shows the bond lengths (units are each) of chain structures of iodine atoms) And the bond angle and the bond length are respectively as follows: The key angles are respectively: 179.1 °, 176.0 °, 176.9 °.

fig. 4 is a schematic view of a crystal perspective structure (projected along the a-axis direction of the crystal) of the chain iodide prepared in example 1.

Fig. 5 is thermogravimetric characterization data of the crystals of the chain iodide prepared in example 2, and it can be seen that the crystals can be stabilized to 150 ℃.

FIG. 6 is a powder absorption spectrum of a chain iodide. The optical band gap was calculated to be 1.43eV from the absorption spectrum of fig. 6.

Fig. 7 is a graph of the bandgap of a chain iodide simulation. As can be seen from fig. 7, the simulated band gap is 1.26 eV.

FIG. 8 shows the anisotropy absorption of chain iodide theoretically simulated (legends a, b, and c in the figure correspond to the a-axis, b-axis, and c-axis, respectively).

Fig. 9 is a picture of a thin film single crystal of the chain iodide prepared in example 3.

FIG. 10 shows the polarization absorption spectrum of a single-crystal thin film of chain iodide prepared in example 3, in which the thickness of the central region of the thin film was 12 μm (of course, the thickness of the thin film in the edge region was higher than this value).

FIG. 11 is a polarization absorption spectrum of a single crystal thin film of chain iodide prepared in example 4, in which the thickness of the central region of the thin film was 18 μm (of course, the thickness of the thin film in the edge region was higher than this value).

FIG. 12 is a graph showing a comparison of photoelectric effects of the photo-detector device of the chain iodide single crystal prepared in example 2 under light conditions and dark conditions; the wavelength used in the illumination condition is 430nm, and the light intensity is 30mW/cm²。

Fig. 13 is a schematic diagram of a test light path and experimental results of a polarization detection device based on chain iodide single crystals in example 5.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.