KR20120023452A - Light absorption nano-particle precursor, method for producing the precursor, light absorption nano-particle using the precursor and the method for producing the nano-particle - Google Patents

Abstract

PURPOSE: A nanoparticle precursor for optical absorption, a manufacture method thereof, and nano particle for the high quality optical absorption using thereof are provided to manufacture the nanoparticle precursor without using toxic material. CONSTITUTION: A manufacturing method of nano particle precursor for optical absorption comprises the following steps: preparing reaction solution which includes Cu, S and at least one of In and Ga; adjusting pH of the reaction solution; forming nanoparticle precursor for optical absorption by irradiating Microwave to the pH adjusted reaction solution; and separating nanoparticle precursor for optical absorption. A composition ratio of Cu, S, In, or Ga are adjusted in accordance with pH of the reaction solution. The nano particle precursor for optical absorption is one of the following precursors: CuInS2[CIS]nano particle precursor, Cu(In,Ga)S2[CIGS] nano particle precursor, CuIn(S,Se)2[CISS]nano particle precursor, or Cu(In,Ga)(S,Se)2[CIGSS] nano particle precursor. The Microwave irradiates in 100-700W power for 5 minutes to 1 hour.

Description

Light absorption nano-particle precursor, method for producing the precursor, light absorption nano-particle using the precursor and the method for producing the nano-particle}

The present invention relates to light absorbing nanoparticles, and more specifically, light absorbing nanoparticle precursors that can be used in solar cell thin films through environmentally friendly and less expensive processes without using toxic substances, and methods of manufacturing the same and precursors thereof It relates to a high quality light absorption nanoparticles and a method for producing the nanoparticles.

Recently, due to fossil energy depletion and environmental problems, much attention has been focused on the development and distribution of solar cells that do not produce carbon dioxide. In addition, in order to secure the economics of solar cells, the necessity of developing low cost and high efficiency solar cells is increasing.

However, crystalline silicon solar cells, which currently dominate the solar cell market, are limited to lower production costs because they use substrates of about 200 μm. In particular, the supply of silicon raw materials is also pointed out as a big problem. Accordingly, in order to reduce the production cost, a thin film solar cell using a glass or a flexible substrate, or a thin layer having a light absorbing material that replaces silicon and having a thickness of about 5 μm or the like is attracting attention as a new alternative.

Recently, the New Renewable Energy Research Institute (NREL), a solar cell using Se-based thin films such as Cu (In, Ga) Se ₂ (CIGS or CIS), having high light absorption coefficient and chemical stability, It shows high conversion efficiency and is considered to have high possibility of industrialization in the future.

There are various methods for synthesizing nano-sized CIGS or CIS, but the synthesis at relatively low temperature includes CIGS or CIS colloid synthesis method and solvent thermal method.

Solvothermal method has the advantage of being able to synthesize particles directly and inexpensively by a simple process at relatively low temperature and low pressure, and easily control stoichiometry, but since the inner wall of the reaction vessel is Teflon, When the reaction temperature is high, it is difficult to seal the reaction vessel, and it is difficult to obtain a long time reaction result.

In order to solve this problem, according to the Korean Patent No. 10-0588604 as a conventional method for manufacturing nano-powder for solar cell light absorption layer, in addition to Cu, In, Se elements by utilizing the solvent heat method used for the synthesis of CuInGaSe2 in the form of nanorods. A Ga element is added and prepared by reacting it in a reactor using ethylenediamine as a solvent. In other words, by providing a method for producing spherical CIGS nanoparticles at a lower temperature, the reaction temperature required for the synthesis of CIGS is lowered, thereby overcoming the disadvantages of the conventional elemental solvent heat method. It was intended to provide a method for synthesis.

However, the above method is a method of synthesizing rod-shaped nanoparticles using ethylene diamine, ethylenediamine (ethylenediamine) as the solvent is a very expensive material, the manufacturing cost increases, volatile and toxic hydrazine material In addition, various toxic substances are used. These toxic substances have a very fatal effect on the human body and have a serious effect on environmental pollution.

In addition, when the reaction temperature is 200 ℃ or more, the reaction time is made in 20 to 60 hours, the reaction temperature is still high, the reaction time is also long, there is a problem causing inefficiency of the production.

The present inventors have completed the present invention by developing a method for synthesizing the light-absorbing nanoparticle precursor without using toxic substances as a result of trying to solve the above disadvantages and problems of the prior art.

Accordingly, an object of the present invention is to provide a light absorption nanoparticle precursor used in the synthesis of light absorption nanoparticles used in the thin film of the solar cell that can be produced eco-friendly with little use of toxic substances and a method of manufacturing the same. .

Another object of the present invention is to provide a light absorption nanoparticles and a method for manufacturing the same, which can be provided at low cost by reducing the production cost of light absorption nanoparticles that can be used as a substitute material of a conventional thin film solar cell.

Still another object of the present invention is to provide a high quality light-absorbing nanoparticles and a method of manufacturing the same, which can implement ultra-low cost solar cells using a precursor thin film manufacturing technology such as doctor blading or spin coating.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention provides a light-absorbing nanoparticle precursor, characterized in that synthesized by irradiating microwave to the reaction solution containing any one or more of Cu and S and In or Ga.

In a preferred embodiment, the composition ratio of Cu, S, In or Ga to be contained in the light absorption nanoparticle precursor is adjusted according to the pH of the reaction solution.

In a preferred embodiment, the light absorption nanoparticle precursor is CuInS ₂ [CIS] Nanoparticle Precursor, Cu (In, Ga) S ₂ [CIGS] Nanoparticle Precursor, CuIn (S, Se) ₂ [CISS] Nanoparticle Precursor or Cu (In, Ga) (S, Se) ₂ [CIGSS] Nanoparticle Any one of the precursors.

In a preferred embodiment, the microwave irradiation is carried out for 5 minutes to 1 hour in the range of 100 to 700W microwave power.

In addition, as a method for producing a light-absorbing nanoparticle precursor of any one of claims 1 to 4, preparing a reaction solution containing any one or more of Cu and S and In or Ga; pH of the prepared reaction solution Irradiating the pH-controlled reaction solution to form a light-absorbing nanoparticle precursor; And it provides a light absorption nanoparticle precursor manufacturing method comprising the step of separating the formed light absorption nanoparticle precursor.

In a preferred embodiment, the pH is adjusted to a range of pH 2-10 using acidic or basic materials.

In a preferred embodiment, the microwave irradiation is carried out for 5 minutes to 1 hour in the range of 100 to 700W microwave power.

In a preferred embodiment, further comprising the step of drying the separated light-absorbing nanoparticle precursor.

In a preferred embodiment, the reaction solution is a water-soluble salt of Cu, the molar concentration of In 0.01 to 0.025 M, the molar concentration of In 0.01 to 0.025 M when the light absorption nanoparticle precursor is a CIS and CISS nanoparticle precursor Phosphorus In water-soluble salt, and water-soluble sulfur having a molar concentration of S from 0.02M to 0.08, and when the light-absorbing nanoparticles are CIGS and CIGSS nanoparticle precursors, the water-soluble Cu having a molar concentration of Cu of 0.01 to 0.025 M Salts, In water-soluble salts with a molar concentration of In from 0.007 to 0.0175 M, Ga water-soluble salts with a molar concentration of Ga from 0.003 to 0.0075 M, and water-soluble sulfur having a molar concentration of S from 0.02 M to 0.08.

In a preferred embodiment, the Cu water-soluble salt, In water-soluble salt and Ga water-soluble salt is at least one of acetate salt, hydrochloride salt or sulfate salt.

In a preferred embodiment, the water soluble sulfur is either thiourea or thioacetamide.

In another aspect, the present invention provides a high-quality light-absorbing nanoparticles, characterized in that the light-absorbing nanoparticle precursor of any one of claims 1 to 4 synthesized by sulfidation heat treatment or selenization heat treatment.

In a preferred embodiment, the high quality light absorbing nanoparticles synthesized by sulfidation heat treatment of the light absorption nanoparticle precursor are CIS and CIGS nanoparticles, and the high quality light absorbing nanoparticles synthesized by selenization heat treatment are CISS and CIGSS nanoparticles. .

In a preferred embodiment, the light absorbing nanoparticles exhibit a light absorption coefficient of at least 10 ⁴ in the UV-vis region, and the bandgap is from 1.0 eV to 1.5 eV.

In a preferred embodiment, the sulfidation heat treatment is performed by treating the light-absorbing nanoparticle precursor at 500 to 600 ℃ 30 minutes to 90 minutes under a nitrogen atmosphere containing hydrogen sulfide 1-10%, the selenization heat treatment is hydrogen sulfide Se pellet is heat-treated at 350 ° C. to 550 ° C. using a nitrogen mixed gas containing 1-10% as a carrier gas, thereby allowing the vaporized Se to react with the light absorbing nanoparticle precursor for 30 minutes to 90 minutes. It is carried out by heat treatment at 500 to 600 ℃.

In addition, the present invention comprises the steps of preparing a light-absorbing nanoparticle precursor by the method for producing a light-absorbing nanoparticle precursor of claim 5; And it provides a high-quality light-absorbing nanoparticles manufacturing method comprising the step of sulfidation heat treatment or selenization heat treatment of the prepared light-absorbing nanoparticle precursor.

In a preferred embodiment, the step of selenization heat treatment is disposed by separating the Se pellet and the light-absorbing nanoparticle precursor; Heat treating the Se pellets spaced apart; And reacting Se vaporized from the heat-treated Se pellet with the light-absorbing nanoparticle precursor using a nitrogen gas containing 1-10% hydrogen sulfide as a carrier gas.

In a preferred embodiment, the Se pellet is heat-treated at 350 ℃ to 550 ℃, the amount of Se is evaporated according to the temperature to be heat-controlled.

In a preferred embodiment, the step of reacting the vaporized Se with the light absorbing nanoparticle precursor is carried out by heat treatment of the light absorbing nanoparticle precursor at 500 to 600 ℃ 30 minutes to 90 minutes.

In a preferred embodiment, the sulfidation heat treatment step is carried out by treatment for 30 to 90 minutes at 500 to 600 ℃ under a nitrogen atmosphere containing hydrogen sulfide 1-10%.

The present invention has the following excellent effects.

First, according to the present invention, it is possible to manufacture light-absorbing nanoparticle precursors that can be used for synthesizing light-absorbing nanoparticles with little use of toxic substances.

In addition, according to the present invention can be provided at low cost by reducing the production cost of the light-absorbing nanoparticles that can be used as a substitute material of the conventional thin film solar cell.

In addition, according to the present invention, it is possible to implement ultra-low cost solar cells with respect to the existing solar cell manufacturing method by using precursor thin film manufacturing technology such as doctor blading or spin coating method.

1 is a schematic diagram of a manufacturing method for synthesizing CISS or CIGSS nanoparticles from a light absorbing nanoparticle precursor according to one embodiment of the present invention;
2 is an X-ray diffraction pattern of CIS nanoparticles according to the pH of the reaction solution in the method for preparing light absorbing nanoparticles of the present invention;
3 is an X-ray diffraction pattern of the CISS nanoparticles according to the pH of the reaction solution in the light-absorbing nanoparticles manufacturing method of the present invention,
Figure 4 is an X-ray diffraction pattern of the CIGS nanoparticles according to the pH of the reaction solution in the light-absorbing nanoparticles manufacturing method of the present invention,
5 is an X-ray diffraction pattern of the CIGSS nanoparticles according to the pH of the reaction solution in the light-absorbing nanoparticles manufacturing method of the present invention,
Figure 6 is a graph showing the light absorption coefficient of the CIS nanoparticles according to the pH of the reaction solution in the light absorbing nanoparticles manufacturing method of the present invention,
7 is a graph showing the light absorption coefficient of the CISS nanoparticles according to the pH of the reaction solution in the method for preparing light absorbing nanoparticles of the present invention;
8 is a graph showing the light absorption coefficient of CIGS nanoparticles according to the pH of the reaction solution in the method for preparing light absorbing nanoparticles of the present invention;
9 is a graph showing the light absorption coefficient of the CIGSS nanoparticles according to the pH of the reaction solution in the method for preparing light-absorbing nanoparticles of the present invention,
10 is a graph showing the band gap energy of the CIS nanoparticles according to the pH of the reaction solution in the light-absorbing nanoparticles manufacturing method of the present invention,
11 is a graph showing the band gap energy of the CISS nanoparticles according to the pH of the reaction solution in the light-absorbing nanoparticles manufacturing method of the present invention,
12 is a graph showing the band gap energy of the CIGS nanoparticles according to the pH of the reaction solution in the light-absorbing nanoparticles manufacturing method of the present invention,
Figure 13 is a graph showing the band gap energy of CIGSS nanoparticles according to the pH of the reaction solution in the light-absorbing nanoparticles manufacturing method of the present invention,
14 is a graph showing the chemical composition ratio of CISS nanoparticles according to the pH of the reaction solution in the light-absorbing nanoparticles manufacturing method of the present invention,
15 is a graph showing the chemical composition ratio of the CIGSS nanoparticles according to the pH of the reaction solution in the light-absorbing nanoparticles manufacturing method of the present invention.

The terms used in the present invention were selected as general terms as widely used as possible, but in some cases, the terms arbitrarily selected by the applicant are included. In this case, the meanings described or used in the detailed description of the present invention are considered, rather than simply the names of the terms. The meaning should be grasped.

Hereinafter, with reference to the accompanying drawings and preferred embodiments will be described in detail the technical configuration of the present invention.

However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Like reference numerals used to describe the present invention throughout the specification denote like elements.

Technical features of the present invention provide light-absorbing nanoparticle precursors that can be used in the synthesis of environmentally friendly light-absorbing nanoparticles with little use of toxic substances by forming light-absorbing nanoparticle precursors through microwave irradiation. It is. Here, the light-absorbing nanoparticle precursor is CuInS ₂ [hereinafter "CIS"] Nanoparticle Precursor, CuIn (S, Se) ₂ [hereinafter “CISS”] Nanoparticle Precursor, Cu (In, Ga) S ₂ [hereinafter “CIGS”] Nanoparticle Precursor or Cu (In, Ga) (S, Se) ₂ [hereinafter referred to as "CIGSS"] nanoparticle precursor.

First, the light-absorbing nanoparticle precursor of the present invention (CIS, CISS, CIGS, CIGSS nano-particle Precursor) is characterized in that synthesized by irradiating microwave to the reaction solution containing any one or more of Cu and S and In or Ga The composition ratio of the Cu, In, Ga, and S is adjusted according to the pH of the reaction solution. Here, the microwave irradiation is preferably carried out for 5 minutes to 1 hour in the microwave power range of 100 to 700W.

Therefore, in the method for preparing the light absorbing nanoparticle precursor, after preparing a reaction solution containing any one or more of Cu and S and In or Ga to have a constant molar concentration, the pH of the prepared reaction solution is adjusted, and the pH adjusted reaction solution is prepared. Microwave irradiation to form a light absorbing nanoparticle precursor, and then separating the formed light absorbing nanoparticle precursor. Here, the pH is adjusted to a range of pH 2-10 using an acidic or basic substance, and the reaction solution is a molar concentration of Cu of 0.01 to 0.025 M when the light absorbing nanoparticle precursors are CIS and CISS nanoparticle precursors. When Cu water-soluble salts, In water-soluble salts with a molar concentration of In 0.01 to 0.025 M, and water-soluble sulfur with a molar concentration of S 0.02M to 0.08, and the light-absorbing nanoparticles are CIGS and CIGSS nanoparticle precursors Cu water-soluble salt having a molar concentration of Cu of 0.01 to 0.025 M, In water-soluble salt having a molar concentration of In of 0.007 to 0.0175 M, Ga water-soluble salt having a molar concentration of Ga of 0.003 to 0.0075 M, and a molar concentration of 0.02 M of S Water-soluble sulfur, wherein the water-soluble salt may be any one or more of an acetate salt, a hydrochloride salt or a sulfate salt, and the water-soluble sulfur is either thiourea or thioacetamide.

In addition, the high quality light-absorbing nanoparticles are synthesized by sulfide heat treatment or selenization heat treatment of the light-absorbing nanoparticle precursor, exhibiting a light absorption coefficient of 10 ⁴ or more in the UV-vis region, the band gap is 1.5 at 1.0 eV eV. Here, the sulfidation heat treatment is performed by treating the light-absorbing nanoparticle precursor at 500 to 600 ° C. for 30 minutes to 90 minutes under a nitrogen atmosphere containing 1-10% hydrogen sulfide, and the selenization heat treatment includes 1-10% hydrogen sulfide. Se pellet is heat treated at 350 ° C. to 550 ° C. using a nitrogen gas mixture as a carrier gas, and the light absorbing nano particle precursor is heat treated at 500 ° C. to 600 ° C. for 30 minutes to 90 minutes so that the vaporized Se reacts with the light absorbing nano particle precursor. It is preferable to carry out.

Therefore, the method for preparing high quality light absorbing nanoparticles includes preparing a light absorbing nanoparticle precursor with a method for preparing light absorbing nanoparticle precursors; And sulfidation heat treatment or selenization heat treatment of the prepared light absorbing nanoparticle precursor, wherein the selenization heat treatment comprises: disposing a Se pellet and the light absorbing nanoparticle precursor; Heat treating the Se pellets spaced apart; And reacting Se vaporized from the heat-treated Se pellet with the light-absorbing nanoparticle precursor using a nitrogen gas containing 1-10% hydrogen sulfide as a carrier gas. Here, the se pellet is heat-treated at 350 ℃ to 550 ℃, the amount of Se vaporized according to the temperature to be heat-treated is controlled. In addition, the step of reacting the vaporized Se with the light absorbing nanoparticle precursor is carried out by heat-treating the light absorbing nanoparticle precursor at 500 to 600 ℃ 30 minutes to 90 minutes.

Example 1-1

The reaction solution was prepared by mixing Cu acetate 0.01M, InCl ₂ 0.01M, and Thioacetamide 0.02M dissolved in DI in that order using a magnetic mixer for 10 minutes. It was then adjusted to pH 3 with hydrochloric acid (29%). CIS and CISS precursors were formed by irradiating the microwave solution to the pH-controlled reaction solution for 10 minutes at 700 W using household microwaves. The reaction solution was placed in a centrifuge and rotated for 30 minutes to separate the solution and the precursor to obtain CIS and CISS nano-particle precursor 1-1 (pH 3). It is more preferable to dry the obtained precursor in a 90 degree oven for 12 hours.

Example 1-2

A CIS and CISS nano-particle precursor 1-2 (pH 5) were obtained in the same manner as in Example 1 except that the pH of the reaction solution was adjusted to pH 5.

Example 1-3

The CIS and CISS nano-particle precursors 1-3 (pH 7) were obtained in the same manner as in Example 1 except that the pH of the reaction solution was adjusted to pH 7 using ammonia water instead of hydrochloric acid.

Example 1-4

The CIS and CISS nano-particle precursors 1-4 (pH 9) were obtained in the same manner as in Example 1 except that the pH of the reaction solution was adjusted to pH 9 using ammonia water instead of hydrochloric acid.

Example 2-1

The reaction solution was prepared in the same manner as in Example 1-1 except that Cu acetate 0.01M, InCl ₂ 0.0066M, GaNO ₃ 0.0033M, and Thioacetamide 0.02M were used for CIGS and CIGSS nano-particle precursors 2-1 ( pH 3) was obtained.

Example 2-2

CIGS and CIGSS nano-particle precursor 2-2 (pH 5) were obtained in the same manner as in Example 2-1 except that the pH of the reaction solution was adjusted to pH 5.

Example 2-3

CIGS and CIGSS nano-particle precursor 2-3 (pH 7) were obtained in the same manner as in Example 2-1 except that the pH of the reaction solution was adjusted to pH 7 using ammonia water instead of hydrochloric acid.

Examples 2-4

CIGS and CIGSS nano-particle precursors 2-4 (pH 9) were obtained in the same manner as in Example 2-1, except that the pH of the reaction solution was adjusted to pH 9 using ammonia water instead of hydrochloric acid.

Example 3

The CIS nano-particle precursors 1-1 to 1-4 were obtained by the same method as Example 1-1 to Example 1-4. Thereafter, the obtained precursors 1-1 to 1-4 were heat-treated at 550 ° C. for 1 hour in N ₂ (95%) + H ₂ S (5%) atmosphere to obtain high quality CIS nano-particles 1-1 to 1-4. Prepared. At this time, the precursors are more preferably dried.

Example 4

The CISS nano-particle precursors 1-1 to 1-4 were obtained by the same method as Example 1-1 to Example 1-4. Thereafter, the obtained CISS nano-particle precursors 1-1 to 1-4 were treated as shown in FIG. 1, respectively. That is, as shown in FIG. 1, the se pellet is disposed on one side of the furnace divided into two zones, and the precursor is placed on the other side, and the Se pellet is heat-treated at 350 ° C., whereby N ₂ (95%) + H ₂ S (5 %) In the atmosphere, that is, nitrogen and hydrogen sulfide mixed gas as a carrier gas, heat-treated at 550 ° C. for 1 hour so that the vaporized Se reacts with the CISS nano-particle precursors 1-1 to 1-4. 1-4 were prepared respectively.

Example 5

CIGS nano-particle precursors 2-1 to 2-4 were obtained by the same method as Example 2-1 to Example 2-4. Thereafter, the obtained precursors 2-1 to 2-4 were treated in the same manner as in Example 3 to prepare high quality CIGS nano-particles 2-1 to 2-4.

Example 6

The CIGSS nano-particle precursors 2-1 to 2-4 were obtained in the same manner as in Example 2-1 to Example 2-4. Thereafter, the obtained CIGSS nano-particle precursors 2-1 to 2-4 were treated in the same manner as in Example 4 to prepare high quality CIGSS nanoparticles 2-1 to 2-4, respectively.

Experimental Example 1

High quality CIS nano-particles 1-1 to 1-4 obtained in Example 3 and high quality CISS nano-particles 1-1 to 1-4 obtained in Example 4 to confirm the structural characteristics of the CIS nano particles and CISS nano particles. The X-ray diffractometer (X-ray diffractometer: X`pert PRO, Philips, Eindhoven, Netherlands) was analyzed, and the X-ray diffraction pattern is shown in Figs. 2 and 3, CIS and CISS nanoparticles 1-1 to 1-4 are represented as pH 3, pH 5, pH 7, and pH 9, respectively, pH of the reaction solution.

As can be seen from Figure 2 and Figure 3, the X-ray diffraction pattern was not observed abnormal in the pH of all the reaction solution. Several diffraction pattern peaks were observed in nano-particles after sulfidation and selenization heat treatment. These peaks are the CIS or CISS of the tetragonal structure. These are diffracted in the (112), (220), and (312) directions of the phase.

Experimental Example 2

To confirm the structural characteristics of the CIGS nanoparticles and the CIGSS nanoparticles, the CIGS nano-particles 2-1 to 2-4 obtained in Example 5 and the CIGSS nano-particles 2-1 to 2-4 obtained in Example 6 were The X-ray diffractometer (X-ray diffractometer: X'pert PRO, Philips, Eindhoven, Netherlands) was analyzed and the X-ray diffraction patterns are shown in FIGS. 4 and 5, respectively. In FIGS. 4 and 5, CIGS and CIGSS nanoparticles 2-1 to 2-4 are represented as pH 3, pH 5, pH 7, and pH 9, respectively.

As can be seen from Figure 4 and 5, the X-ray diffraction pattern was slightly abnormal when the pH of the reaction solution is 9, but no abnormality was observed at the pH of all other reaction solutions. Several diffraction pattern peaks were observed in nano-particles after sulfidation and selenization heat treatment. These peaks are CIGS or CIGSS in tetragonal structure. These are diffracted in the (112), (220), and (312) directions of the phase.

Experimental Example 3

In order to confirm the optical properties of CIS, CISS, CIGS and CIGSS nanoparticles, high quality CIS nano-particles 1-1 to 1-4 obtained in Example 3 and high quality CISS nano-particles 1-1 to 1- obtained in Example 4 The light absorption coefficients of the high quality CIGS nano-particles 2-1 to 2-4 obtained in Example 4 and Example 5 and the high quality CIGSS nano-particles 2-1 to 2-4 obtained in Example 6 were analyzed and the graphs of the results are shown in FIG. 9 to 9 are shown. 6 to 9, CIS and CISS nanoparticles 1-1 to 1-4 and CIGS and CIGSS nanoparticles 2-1 to 2-4 are respectively pH 3, pH 5, pH 7, and pH 9 of the reaction solution. Displayed.

According to the previously reported literature, if the light absorption coefficient is 10 ⁴ or more in the UV-vis region, it is reported that light can be absorbed well. As shown in FIGS. 6 to 9, the CIS and CISS nanoparticles 1-1 to 1-4 and the CIGS and CIGSS nanoparticles 2-1 to 2-4 all exhibited light absorption coefficients of 10 ⁴ or more in the UV-vis region. . Therefore, it is expected that the performance of the solar cell having good properties when manufacturing the solar cell with the light absorbing nanoparticles of the present invention.

Experimental Example 4

In order to confirm the optical properties of CIS, CISS, CIGS and CIGSS nanoparticles, high quality CIS nano-particles 1-1 to 1-4 obtained in Example 3 and high quality CISS nano-particles 1-1 to 1- obtained in Example 4 The bandgap energies of the high quality CIGS nano-particles 2-1 to 2-4 obtained in Example 4 and Example 5 and the high quality CIGSS nano-particles 2-1 to 2-4 obtained in Example 6 were UV-visible spectroscopy (Cary 100, Varian, Mulfrave, Australia) and the results are shown in FIGS. 10 to 13. In FIGS. 10 to 13, CIS and CISS nanoparticles 1-1 to 1-4 and CIGS and CIGSS nanoparticles 2-1 to 2-4 are respectively pH 3, pH 5, pH 7, and pH 9 of the reaction solution. Displayed.

As shown in Figure 10 to Figure 13, it can be seen that the bandgap showed a value between 1.15 eV and 1.4 eV depending on the pH of the reaction solution.

The experimental results show that the pH of the reaction solution and the absorption edge and bandgap energy of the prepared high-quality light-absorbing nano-particles are proportional to each other.

Experimental Example 5

In order to confirm the chemical properties of the CISS and CIGSS nanoparticle nanoparticles of the high quality CISS nano-particles 1-1 to 1-4 obtained in Example 4 and the high quality CIGSS nano-particles 2-1 to 2-4 obtained in Example 6 The chemical composition was analyzed using EDS (JNS-7500F, JEOL, Japan) mounted on FE-SEM, and the results are shown in FIGS. 14 and 15, respectively. In FIGS. 14 and 15, CISS nanoparticles 1-1 to 1-4 and CIGSS nanoparticles 2-1 to 2-4 are represented as pH 3, pH 5, pH 7, and pH 9, respectively, pH of the reaction solution.

As shown in FIG. 14, in the case of CISS nanoparticles, as the pH is increased, the element ratio of Se is increased, and the overall composition of Cu rich is shown. In the case of CIGSS as shown in FIG. 15, the composition ratio of In and Ga was increased until pH of the reaction solution was increased to 7 and decreased at pH 9 of the reaction solution. CIGSS nano-particles also exhibited Cu rich composition.

The above results indicate that the light-absorbing nanoparticle precursor and the light-absorbing nanoparticles prepared from the environmentally friendly precursors using little toxic substances by the method of manufacturing the light-absorbing nanoparticle precursors and the light-absorbing nanoparticles of the present invention can be used as an alternative material for various thin film solar cells. Shows that it has excellent properties.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, Various changes and modifications will be possible.

Claims (20)

Light absorbing nanoparticle precursor, characterized in that synthesized by irradiating microwave to the reaction solution containing any one or more of Cu and S and In or Ga.
The method of claim 1,
The light absorption nanoparticle precursor, characterized in that the composition ratio of Cu, S, In or Ga to be contained in the light absorption nanoparticle precursor according to the pH of the reaction solution.
The method of claim 1,
The light absorption nanoparticle precursor is CuInS ₂ [CIS] Nanoparticle Precursor, Cu (In, Ga) S ₂ [CIGS] Nanoparticle Precursor, CuIn (S, Se) ₂ [CISS] Nanoparticle Precursor or Cu (In, Ga) (S, Se) ₂ [CIGSS] Nanoparticle Light absorption nanoparticle precursor, characterized in that any one of the precursor.
The method of claim 1,
The microwave irradiation is light absorption nanoparticle precursor, characterized in that performed for 5 minutes to 1 hour in the range of 100 to 700W microwave power.
As a method for producing a light absorption nanoparticle precursor of any one of claims 1 to 4,
Preparing a reaction solution containing any one or more of Cu and S and In or Ga;
Adjusting the pH of the prepared reaction solution;
irradiating the pH-controlled reaction solution with microwaves to form light-absorbing nanoparticle precursors; And
Method for producing a light absorption nanoparticle precursor comprising the step of separating the light absorption nanoparticle precursor formed.
The method of claim 5, wherein
The pH is light absorption nanoparticle precursor manufacturing method characterized in that it is adjusted to the range of pH 2-10 using an acidic or basic material.
The method of claim 5, wherein
The microwave irradiation is a light absorption nanoparticle precursor manufacturing method, characterized in that performed for 5 minutes to 1 hour in the range of 100 to 700W microwave power.
The method of claim 5, wherein
Method for producing a light absorption nanoparticle precursor further comprises the step of drying the separated light-absorbing nanoparticle precursor.
The method of claim 5, wherein
The reaction solution is a Cu water-soluble salt having a molar concentration of 0.01 to 0.025 M, In a water-soluble salt having a molar concentration of In 0.01 to 0.025 M when the light absorption nanoparticle precursor is a CIS and CISS nanoparticle precursor, and A water-soluble sulfur having a molar concentration of S of 0.02 M to 0.08,
When the light-absorbing nanoparticles are CIGS and CIGSS nanoparticle precursors, Cu water-soluble salts having a molar concentration of 0.01 to 0.025 M, In water-soluble salts having a molar concentration of In 0.007 to 0.0175 M, and a molar concentration of Ga are 0.003 Ga-soluble salts of 0.0075 M, and water-soluble nanoparticle precursor manufacturing method comprising a water-soluble sulfur of 0.02M to 0.08 S.
The method of claim 5, wherein
The Cu water-soluble salts, In water-soluble salts and Ga water-soluble salts is a method for producing a light absorption nanoparticle precursor, characterized in that at least one of acetate salts, hydrochloride salts or sulfates.
The method of claim 10,
The water-soluble sulfur is thiourea (thiourea) or thioacetamide (thioacetamide), characterized in that any one of the nanoparticle precursor for light absorption manufacturing method.
High-quality light-absorbing nanoparticles, characterized in that synthesized by sulfidation heat treatment or selenization heat treatment nanoparticle precursor of any one of claims 1 to 4.
The method of claim 12,
The high quality light absorbing nanoparticles synthesized by sulfiding heat treatment of the light absorbing nanoparticle precursors are CIS and CIGS nanoparticles,
The high quality light absorbing nanoparticles synthesized by selenization heat treatment are CISS and CIGSS nanoparticles.
The method of claim 12,
The light absorbing nanoparticles exhibit a light absorption coefficient of 10 ⁴ or more in the UV-vis region, and the band gap is 1.0 eV to 1.5 eV.
The method of claim 12,
The sulfidation heat treatment is performed by treating the light absorbing nanoparticle precursor at 500 to 600 ° C. for 30 to 90 minutes under a nitrogen atmosphere containing 1-10% of hydrogen sulfide,
The selenization heat treatment is a nitrogen gas mixture containing 1-10% hydrogen sulfide as a carrier gas, and the se pellet is heat-treated at 350 ° C. to 550 ° C., so that the vaporized Se reacts with the light-absorbing nanoparticle precursor. High-quality light-absorbing nanoparticles, characterized in that carried out by heat-treating the light-absorbing nanoparticle precursor at 500 to 600 ℃.
Preparing a light absorbing nanoparticle precursor using the light absorbing nanoparticle precursor manufacturing method of claim 5; And
High-quality light-absorbing nanoparticles manufacturing method comprising the step of sulphide heat treatment or selenization heat treatment of the prepared light-absorbing nanoparticle precursor.
The method of claim 16, wherein the selenization heat treatment is
Disposing the se pellet from the light absorbing nanoparticle precursor;
Heat treating the Se pellets spaced apart; And
A method of manufacturing high quality light absorbing nanoparticles, the method comprising: reacting Se vaporized from the heat treated Se pellet with the light absorbing nanoparticle precursor using a nitrogen mixed gas containing 1-10% hydrogen sulfide as a carrier gas.
The method of claim 17,
The Se pellet is heat-treated at 350 ℃ to 550 ℃, the high-quality light-absorbing nanoparticles manufacturing method, characterized in that the amount of Se is evaporated according to the temperature to be heat-treated.

The method of claim 17,
The step of reacting the vaporized Se with the light-absorbing nanoparticle precursor is a high-quality light-absorbing nanoparticles manufacturing method, characterized in that carried out by heat-treating the light-absorbing nanoparticle precursor at 500 to 600 ℃ 30 minutes to 90 minutes.
17. The method of claim 16,
The sulfiding heat treatment step is a high-quality light-absorbing nanoparticles manufacturing method, characterized in that carried out for 30 to 90 minutes at 500 to 600 ℃ under a nitrogen atmosphere containing hydrogen sulfide 1-10%.

Images