阅读说明：本技术 复合材料及其制备方法和太阳能电池 (Composite material, preparation method thereof and solar cell ) 是由 杨青松 杨一行 于 2018-07-24 设计创作，主要内容包括：本发明属于纳米材料技术领域,具体涉及一种复合材料及其制备方法和太阳能电池。所述复合材料包括纳米晶体颗粒和连接在所述纳米晶体颗粒表面的羧酸；其中,所述纳米晶体颗粒含有金属阳离子和阴离子,所述羧酸与所述纳米晶体颗粒表面的金属阳离子相连接。该复合材料中的羧酸增强了纳米晶体颗粒表面的电负性,进而增强了纳米晶体颗粒表面的电荷传输与分离效果,将该复合材料用于电池器件时,可以提高电池器件的效率。(The invention belongs to the technical field of nano materials, and particularly relates to a composite material, a preparation method thereof and a solar cell. The composite material comprises nanocrystalline particles and carboxylic acid attached to the surfaces of the nanocrystalline particles; wherein the nanocrystal particle contains a metal cation and an anion, and the carboxylic acid is linked to the metal cation on the surface of the nanocrystal particle. The carboxylic acid in the composite material enhances the electronegativity of the surface of the nanocrystal particle, further enhances the charge transmission and separation effect of the surface of the nanocrystal particle, and can improve the efficiency of a battery device when the composite material is used for the battery device.)

1. A composite material comprising nanocrystalline particles and carboxylic acid attached to the surface of the nanocrystalline particles; wherein the nanocrystal particle contains a metal cation and an anion, and the carboxylic acid is linked to the metal cation on the surface of the nanocrystal particle.

2. The composite material of claim 1, wherein the nanocrystalline particles have a particle size of 100-500 nm; and/or

The molar ratio of the metal cation to the carboxyl group in the carboxylic acid is 1: (1.5-2.5); and/or

The nanocrystal particles are binary phase nanocrystal particles.

3. The composite material of claim 1, wherein the metal cation is selected from at least one of zinc ions, lead ions, indium ions, copper ions, iron ions, silver ions, and mercury ions; and/or

The anion is selected from at least one of sulfur ion, selenium ion, tellurium ion and phosphorus ion; and/or

The carboxylic acid is selected from at least one of formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid and caprylic acid.

4. The preparation method of the composite material is characterized by comprising the following steps:

providing an organometallic cation precursor, an anion precursor, and a carboxylic acid;

mixing the organic metal cation precursor and carboxylic acid to obtain a mixed solution;

and heating the mixed solution, and then adding the anion precursor into the mixed solution to perform nanocrystalline self-assembly reaction to obtain the composite material.

5. The method according to claim 4, wherein the organometallic cation precursor is at least one selected from the group consisting of zinc fatty acid, lead fatty acid, indium fatty acid, copper fatty acid, iron fatty acid, silver fatty acid, and mercury fatty acid; and/or

The anion precursor is selected from S-ODE, S-TOP, S-OA, Se-TOP, S-OLA, S-TBP, Se-TBP, Te-ODE, Te-OA, Te-TOP, Te-TBP, (TMS)₂At least one of P and TMSP; and/or

The carboxylic acid is selected from at least one of formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid and caprylic acid.

6. The method according to claim 4, wherein the temperature of the heat treatment is 80 to 300 ℃; and/or

The time of the nanocrystalline self-assembly reaction is 1-30 min; and/or

And carrying out the nanocrystalline self-assembly reaction in an inert atmosphere.

7. The process according to claim 4, wherein the molar ratio of the metal cation to the carboxyl group in the carboxylic acid is 1: (1.5-2.5) mixing the organometallic cation precursor and a carboxylic acid; and/or

According to the molar ratio of the metal cation to the anion of 1: (0.1-0.5), adding the anion precursor into the mixed solution to carry out nanocrystalline self-assembly reaction.

8. The method according to any one of claims 5 to 7, further comprising a step of precipitation separation by adding a precipitant after the step of self-assembly reaction.

9. The method according to claim 8, wherein the precipitating agent is selected from at least one of methanol, ethanol, and acetone; and/or

According to the mass volume ratio of the composite material to the precipitant of 1 g: 50-100ml, adding the precipitant to separate.

10. A solar cell comprising an electrode, a charge transport layer and a light absorbing layer, which are stacked, wherein the material of the light absorbing layer is the composite material according to any one of claims 1 to 4.

Technical Field

The invention belongs to the technical field of nano materials, and particularly relates to a composite material, a preparation method thereof and a solar cell.

Background

Nanoscience and nanotechnology are emerging scientific technologies and have potential application value and economic benefits, so that the nano-technology has the attention of scientists worldwide. Nanocrystalline (NCs) water refers to crystalline material on the nanometer scale, or nanoparticles having a crystalline structure. Nanocrystals are of great research value, and their electrical and thermodynamic properties exhibit a strong size dependence, so that they can be controlled through careful manufacturing processes. Nanocrystals are capable of exhibiting very interesting phenomena, mainly depending on their electrical, optical, magnetic and electrochemical properties, which are not achievable with bulk materials.

The preparation technology of the nano-particles is various, different nano-particles can be obtained by different preparation technologies, and the corresponding photoelectric properties of the nano-particles are different. There are also many techniques for preparing nanoparticles with larger particles, such as continuous growth techniques, self-assembly techniques, epitaxy techniques, etc. The self-assembly technology is utilized to prepare not only the nano-particles, but also various nano-sheets or nano-rods and other various nano-materials. In the field of nanomaterial application, nanoparticles of different shapes will give rise to different physicochemical properties. For the nano-particles with larger particle size, the corresponding application range is also provided, such as memory material, detection sensing material and the like.

The charge transport properties of the current nanocrystal particles need to be improved.

Disclosure of Invention

The present invention aims to overcome the above disadvantages of the prior art, and provides a composite material, a preparation method thereof and a solar cell, aiming to solve the technical problems of the selection of the existing high-charge-transport nanocrystals.

In order to achieve the purpose, the invention adopts the following technical scheme:

in one aspect, the present invention provides a composite material comprising nanocrystalline particles and carboxylic acid attached to the surface of the nanocrystalline particles; wherein the nanocrystal particle contains a metal cation and an anion, and the carboxylic acid is linked to the metal cation on the surface of the nanocrystal particle.

The composite material provided by the invention is a composite nanocrystalline material, which comprises nanocrystalline particles and carboxylic acid connected to the surfaces of the nanocrystalline particles, wherein the carboxylic acid is connected with metal cations on the surfaces of the nanocrystalline particles, and carboxyl groups on adjacent carboxylic acids have dipole interaction with carboxyl groups, and the dipole interaction enables the surfaces of the nanocrystalline particles to generate polarization charges, so that the electronegativity of the surfaces of the nanocrystalline particles is enhanced, the charge transmission and separation effects on the surfaces of the nanocrystalline particles are further enhanced, and when the composite material is used for a battery device, the efficiency of the battery device can be improved.

The invention also provides a preparation method of the composite material, which comprises the following steps:

providing an organometallic cation precursor, an anion precursor, and a carboxylic acid;

mixing the organic metal cation precursor and carboxylic acid to obtain a mixed solution;

and heating the mixed solution, and then adding the anion precursor into the mixed solution to perform nanocrystalline self-assembly reaction to obtain the composite material.

The preparation method of the composite material is a preparation method based on a nanocrystalline self-assembly technology, and comprises the steps of firstly mixing an organic metal cation precursor and carboxylic acid to prepare a mixed solution, connecting the carboxylic acid and the metal cation in the mixed solution, then adding an anion precursor into the mixed solution under a heating condition to carry out nanocrystalline self-assembly reaction, wherein in the initial stage of the self-assembly reaction, anions and cations connected with the carboxylic acid are combined to form a nanocrystalline domain, dipolar interaction between carboxyl groups attached to the nanocrystalline domain drives the nanocrystalline domain to carry out accumulation growth according to a certain crystalline phase, and then the nanocrystalline particle composite material with the carboxylic acid connected to the surface is generated by self-assembly. The composite material has good charge transmission and separation effects, and when the composite material is used for a battery device, the efficiency of the battery device can be improved.

The invention finally provides a solar cell, which comprises an electrode, a charge transmission layer and a light absorption layer which are arranged in a laminated manner, and is characterized in that the material of the light absorption layer is the composite material.

The light absorption layer material in the solar cell provided by the invention is composed of the specific composite material of the invention, the composite material is the nanocrystal particles with carboxylic acid connected on the surface, the carboxyl groups on the adjacent carboxylic acid and the carboxyl groups have dipole interaction, and the dipole interaction enables the surface of the nanocrystal particles to generate polarized charges, so that the electronegativity of the surface of the nanocrystal particles is enhanced, and further the charge transmission and separation effects of the surface of the nanocrystal particles are enhanced, so that the light absorption layer composed of the composite material can improve the efficiency of a cell device.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the following 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 one aspect, embodiments of the present invention provide a composite material including a nanocrystal particle and a carboxylic acid attached to a surface of the nanocrystal particle; wherein the nanocrystal particle contains a metal cation and an anion, and the carboxylic acid is linked to the metal cation on the surface of the nanocrystal particle.

The composite material provided by the embodiment of the invention is a composite nanocrystalline material, which comprises nanocrystalline particles and carboxylic acid connected to the surfaces of the nanocrystalline particles, wherein the carboxylic acid is connected with metal cations on the surfaces of the nanocrystalline particles, and the carboxyl groups on adjacent carboxylic acids have dipole interaction with the carboxyl groups, and the dipole interaction enables the surfaces of the nanocrystalline particles to generate polarization charges, so that the electronegativity of the surfaces of the nanocrystalline particles is enhanced, the charge transmission and separation effects on the surfaces of the nanocrystalline particles are further enhanced, and when the composite material is used for a battery device, the efficiency of the battery device can be improved.

In the composite material provided by the embodiment of the invention, the particle size of the nanocrystal particle is 100-500 nm; the nano crystal particles in the size range have small relative body surface area, and the energy interaction between the particles is relatively weak, so that the transmission of charges between solid films can be enhanced when the nano crystal particles are prepared into the solid films, the nano crystal particles can be applied to the fields of storage materials, detection sensing materials, active functional layers of battery devices and the like, and have good charge transmission performance.

Further, in the composite material provided by the embodiment of the present invention, the molar ratio of the metal cation to the carboxyl group in the carboxylic acid is 1: (1.5-2.5). In the range of the molar ratio, the carboxylic acid is connected to the surface of the nanocrystal particles, so that the charge transport performance of the nanocrystal particles can be improved, and the intrinsic crystal performance of the nanocrystal particles is not influenced, so that the composite material has the best comprehensive performance.

Further, in the composite material provided in the embodiment of the present invention, the metal cation is at least one selected from the group consisting of zinc ion, lead ion, indium ion, copper ion, iron ion, silver ion, and mercury ion, but not limited thereto, and the anion is at least one selected from the group consisting of sulfur ion, selenium ion, tellurium ion, and phosphorus ion, but not limited thereto; that is, the nanocrystalline particles in the composite material of the embodiment of the present invention are composed of the above metal cations and anions. More preferably, the nanocrystal particles are binary phase nanocrystal particles, i.e., nanocrystal particles formed from a compound of one metal cation and one anion, such as ZnS, ZnSe, ZnTe, PbS, PbSe, InS, InSe, InP, HgS, HgSe, HgTe, and the like. More preferably, the binary phase nanocrystal particles are narrow band gap materials, wherein the band gap is smaller than 1.6ev, and the nanocrystal particles in the band gap range can more effectively utilize sunlight from an ultraviolet region to a near infrared region, so that the photoelectric conversion performance of a solar cell device can be improved. Still further, the carboxylic acid is a small molecule containing a carboxyl group, and is selected from at least one of formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid and caprylic acid, but not limited thereto, and is preferably acetic acid, propionic acid, and most preferably acetic acid.

On the other hand, the embodiment of the invention also provides a preparation method of the composite material, which comprises the following steps:

s01: providing an organometallic cation precursor, an anion precursor, and a carboxylic acid;

s02: mixing the organic metal cation precursor and carboxylic acid to obtain a mixed solution;

s03: and heating the mixed solution, and then adding the anion precursor into the mixed solution to perform nanocrystalline self-assembly reaction to obtain the composite material.

The preparation method of the composite material provided by the embodiment of the invention is a preparation method based on a nanocrystalline self-assembly technology, and comprises the steps of firstly mixing an organic metal cation precursor and carboxylic acid to prepare a mixed solution, connecting the carboxylic acid and metal cations in the mixed solution, then adding an anion precursor into the mixed solution under a heating condition to carry out nanocrystalline self-assembly reaction, wherein in the initial stage of the self-assembly reaction, anions and cations connected with the carboxylic acid are combined to form a nanocrystalline domain, and dipolar interaction between carboxyl groups attached to the nanocrystalline domain drives the nanocrystalline domain to carry out accumulation growth according to a certain crystalline phase, so that the nanocrystalline particle composite material with the carboxylic acid connected to the surface is generated by self-assembly. The composite material has good charge transmission and separation effects, and when the composite material is used for a battery device, the efficiency of the battery device can be improved.

Further, in the above step S01, the organometallic cation precursor is at least one selected from the group consisting of zinc fatty acid, lead fatty acid, indium fatty acid, copper fatty acid, iron fatty acid, silver fatty acid, and mercury fatty acid. The organic metal cation precursor may be prepared by using metal oxide (e.g., cadmium oxide, zinc oxide, lead oxide, silver oxide, mercury oxide, etc.) or metal salt (e.g., cadmium salt, zinc salt, lead salt, silver salt, mercury salt, etc.) and fatty acid (e.g., organic alkanoic acid) under certain conditions, and in the embodiment of the present invention, the organic metal cation precursor is preferably cadmium oleate, zinc oleate, lead oleate, silver oleate, mercury oleate, etc., but is not limited thereto. Still further, the anionic precursor is selected from the group consisting of S-ODE, S-TOP, S-OA, Se-TOP, S-OLA, S-TBP, Se-TBP, Te-ODE, Te-OA, Te-TOP, Te-TBP, (TMS)₂At least one of P and TMSP (wherein ODE is octadecene, TOP is trioctylphosphine, OA is oleic acid, OLA is oleylamine, TBP is tributyl phosphate, TMS is tetramethylsilane) but not limited thereto. And the carboxylic acid is selected from at least one of formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid and caprylic acid.

Further, in the above step S02, the ratio of the metal cation to the carboxyl group in the carboxylic acid is 1: (1.5-2.5) mixing the organometallic cation precursor and a carboxylic acid; if the molar ratio of the metal cations to the carboxyl groups is too high, the subsequent attachment of various nano-crystalline domains cannot be caused due to the small amount of the carboxyl groups, and if the molar ratio of the metal cations to the carboxyl groups is too high or too low, the ordered attachment of the nano-crystalline domains is not facilitated due to the strong charge polarity of a large amount of the carboxyl groups. Therefore, in this molar ratio range, the effect of the subsequent production is the best when the organometallic cation precursor and the carboxylic acid are mixed.

Further, in the above step S03, the ratio of metal cations to anions is 1: (0.1-0.5), adding the anion precursor into the mixed solution to carry out nanocrystalline self-assembly reaction. Too high a molar ratio of metal cations to anions may cause fewer nanocrystalline domains, so that nanocrystalline particles with large particle sizes may not be obtained, and too low a molar ratio of metal cations to anions may cause more nanocrystalline domains, so that final nanocrystalline particles may have large size differences, so that uniform nanocrystalline particles may not be obtained. Thus, the molar ratio of metal cation to anion is 1: (0.1-0.5), adding the anion precursor into the mixed solution to carry out nanocrystal self-assembly reaction, and finally obtaining nanocrystal particles with particle size within the range of 100-500nm and relatively uniform particle size.

Further, the temperature of the heating treatment is 80-300 ℃; in the mixed solution obtained under the temperature condition, the carboxylic acid can be fully connected with the metal cation, so that the subsequent nanocrystalline self-assembly reaction is more favorably carried out. More preferably, the time of the nanocrystal self-assembly reaction is 1-30 min. In this time range, the nano-crystal particle composite material with carboxylic acid attached to the surface can be generated by self-assembly.

In the self-assembly reaction process, an anion precursor can be added into the mixed solution in an injection mode, carboxyl is attached to the surface of a binary crystal domain formed by the anion precursor and the cation precursor in the initial self-assembly reaction after the anion precursor is injected, and the nano-crystal domain is driven to carry out stacking growth according to a certain crystal phase by the dipole interaction between the carboxyl attached to the surface of the nano-crystal domain. In addition, the crystal growth direction of the nanocrystal particles is faster in the <100> crystal plane than in the <111> crystal plane due to the polarity of the carboxyl group, so that the nanocrystals which are finally formed are in a geometric crystal form of a three-dimensional octahedral rhombohedral structure.

Further, after the step of self-assembly reaction, a step of adding a precipitant to perform precipitation separation is also included. A precipitator is added for precipitation separation, so that the purity of the composite material can be further improved; preferably, the precipitant is selected from at least one of methanol, ethanol, and acetone. More preferably, the mass-to-volume ratio of the composite material to the precipitant is 1 g: 50-100ml, adding the precipitant to separate. The effect of such separation is better.

The invention is described in further detail with reference to a part of the test results, which are described in detail below with reference to specific examples.