CN103915528A - Method for synthesizing copper-zinc-tin-sulfur-copper sulfide-copper-tin-sulfur thin film - Google Patents

Abstract

The invention discloses a synthesis method of copper-zinc-tin-sulfur-copper-sulfide-copper-tin-sulfur film, which comprises the following steps: (1) preparation of electrolyte: copper salt, zinc salt, tin salt, sodium thiosulfate, citric acid Trisodium and tartaric acid were dissolved in water respectively, and then mixed, and the pH value was adjusted after mixing evenly; (2) Cleaning the substrate: the metal Mo sheet was used as the substrate, and the surface was wiped with sodium hydroxide solution to remove surface rust, and then washed in ethanol , Ultrasonic cleaning in deionized water one by one to remove surface oil stains; (3) Electrochemical deposition: put the cleaned substrate into the prepared electrolyte, set the deposition voltage and time and start, after the deposition is completed, the substrate Take out the piece, rinse it with a large amount of deionized water and ethanol, and blow it dry; (4) Calcinate the sample obtained in step (3) in nitrogen or argon for 1 hour to obtain a copper zinc tin sulfur-copper sulfide-copper tin sulfur film . The method is low in cost, simple in process, and the prepared samples have excellent properties.

Description

A kind of synthetic method of copper zinc tin sulfur-copper sulfide-copper tin sulfur thin film

technical field

The invention relates to a method for synthesizing a film, in particular to a method for synthesizing a copper-zinc-tin-sulfur-copper-sulfide-copper-tin-sulfur film.

Background technique

In recent years, energy and environmental issues have attracted people's attention, and research on efficient and low-cost solar absorbing materials has also increased. Copper zinc tin sulfur material (abbreviated as CZTS) has many advantages, such as: the light absorption coefficient exceeds 10 ⁴ cm ^-1 , the band gap is about 1.5eV, copper, zinc, tin, and sulfur elements are abundant in nature, and do not pollute the environment. It is currently applied to the efficiency of solar cells has reached 12%. For the preparation of copper-zinc-tin-sulfur thin films, physical methods are usually used, including co-evaporation, magnetron sputtering, etc. These methods are too expensive to be suitable for large-scale production. Therefore, in recent decades, the preparation of copper-zinc-tin-sulfur thin films by chemical methods has become a top priority. Commonly used chemical methods include electrochemical method, continuous ion layer absorption reaction, hydrothermal method and so on. However, the copper-zinc-tin-sulfur thin films prepared by these methods must undergo sulfuration (very toxic) during further crystallization. Among them, the electrochemical method is relatively the lowest cost. For quaternary sulfides such as copper, zinc, tin, and sulfur, the resulfurization method of prefabricated metal layers is widely used. However, this method not only requires sulfuration, but also 2 to 3 times of electrochemical deposition.

For these considerations, those skilled in the art wish to adopt a synthetic method with low cost, simple process, safety and non-toxicity. At the same time, actively develop the application field of one-step electrochemical method to prepare polysulfides.

Contents of the invention

In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a method for one-step electrochemical synthesis of copper zinc tin sulfur-copper sulfide-copper tin sulfur film (Cu ₂ ZnSnS ₄ -CuS-Cu ₃ SnS ₄ ) method.

In order to achieve the above object, the invention provides a one-step electrochemical synthesis method of copper zinc tin sulfur-copper sulfide-copper tin sulfur film, no surfactant is used in the synthesis process, and the synthesis steps are as follows:

(1) Preparation of electrolyte: Dissolve copper salt, zinc salt, tin salt, sodium thiosulfate, trisodium citrate and tartaric acid into water respectively, then mix them, adjust the pH value after mixing evenly;

(2) Clean the substrate: metal Mo sheet is used as the substrate, and the surface is wiped with sodium hydroxide solution to remove surface rust, and then ultrasonically cleaned in ethanol and deionized water one by one to remove surface oil stains;

(3) Electrochemical deposition: Put the cleaned substrate into the prepared electrolyte, set the deposition voltage and time and start, take out the substrate after deposition, rinse with a large amount of deionized water and ethanol and blow dry;

(4) Calcining the sample obtained in step (3) in nitrogen or argon for 1 hour to obtain a copper zinc tin sulfur-copper sulfide-copper tin sulfur film.

Preferably, in step (1), in terms of moles, copper salt: zinc salt: tin salt: sodium thiosulfate: trisodium citrate: tartaric acid=0.5～3:1:0.5～3:1～5:4～ 10:2～8; Among them, when copper salt: zinc salt: tin salt: sodium thiosulfate: trisodium citrate: tartaric acid = 2:3:2:3:20:10, the performance of the synthesized film is better .

Preferably, the copper salt in step (1) is copper sulfate, copper nitrate or copper chloride, the zinc salt is zinc sulfate, zinc nitrate or zinc chloride, and the tin salt is stannous chloride or stannous sulfate.

Preferably, the pH range is adjusted to be 2-7 in step (1).

Preferably, during the substrate cleaning process, the concentration of sodium hydroxide used to wipe the substrate is 1-15 mol/liter, and the ultrasonic time is 5-30 minutes. The cleanliness of the substrate has a great influence on the film formation.

Preferably, the voltage used in the electrochemical deposition process is -0.8V--1.5V, and the deposition time is 15-60 minutes. The voltage and time of deposition can significantly affect the thickness and quality of the film.

Preferably, the calcination temperature ranges from 200 to 600°C.

The beneficial effects of the present invention are:

(1) The preparation method is simple and easy, the cost is very low, safe and non-toxic, and suitable for industrial production;

(2) The copper-zinc-tin-sulfur-copper-sulfide-copper-tin-sulfur thin film prepared by this method has good performance;

(3) It can be widely used in the production of semiconductor thin films and in the field of photocatalysis.

The idea, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings, so as to fully understand the purpose, features and effects of the present invention.

Description of drawings

Fig. 1 is the X-ray diffraction pattern of the copper zinc tin sulfur-copper sulfide-copper tin sulfur thin film that embodiment 1 makes;

Fig. 2 is the 10000 times scanning electron micrograph of the thin film that embodiment 1 makes;

Fig. 3 is the 50000 times scanning electron micrograph of the thin film that embodiment 1 makes;

Fig. 4 is the 10000 times scanning electron micrograph of the thin film that embodiment 2 makes;

Fig. 5 is the 50000 times scanning electron micrograph of the thin film that embodiment 2 makes;

Figure 6 is the current-voltage curves of the films prepared in Example 1 and Example 2. The silver/silver chloride electrode is used as the reference electrode, the platinum sheet (2x2cm ² ) is used as the counter electrode, and 0.2 mol/liter of sodium sulfate is used as the electrolyte , the test light intensity is 15mW cm ^-2 , and the scan rate is 0.01V/s.

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Example 1

Prepare 0.02 mol/L copper sulfate, 0.03 mol/L zinc sulfate, 0.02 mol/L stannous chloride, 0.02 mol/L sodium thiosulfate, 0.2 mol/L trisodium citrate and 0.1 mol/L tartaric acid respectively at room temperature Aqueous solutions, equal volumes of these solutions were uniformly mixed, and the pH was adjusted to 5. Wipe the Mo substrate with 15 mol/L concentrated NaOH solution and ultrasonically clean it in ethanol and water for 30 min, respectively. Put the substrate into the electrolyte that has been stirred evenly. After deposition for 45 minutes under the condition of constant voltage -1.05V (relative to silver/silver chloride), the sample was taken out, rinsed with a large amount of deionized water and dried. The obtained film is calcined at 350° C. for 1 hour in argon or nitrogen, and the obtained sample is a copper zinc tin sulfur-copper sulfide-copper tin sulfur film. Name it Thin Film 1.

Example 2

Prepare 0.02 mol/L copper sulfate, 0.03 mol/L zinc sulfate, 0.02 mol/L stannous chloride, 0.03 mol/L sodium thiosulfate, 0.2 mol/L trisodium citrate and 0.1 mol/L tartaric acid respectively at room temperature Aqueous solutions, equal volumes of these solutions were uniformly mixed, and the pH was adjusted to 5. Wipe the Mo substrate with 15 mol/L concentrated NaOH solution and ultrasonically clean it in ethanol and water for 30 min, respectively. Put the substrate into the electrolyte that has been stirred evenly. After deposition for 45 minutes under the condition of constant voltage -1.05V (relative to silver/silver chloride), the sample was taken out, rinsed with a large amount of deionized water and dried. The obtained film is calcined at 350° C. for 1 hour in argon or nitrogen, and the obtained sample is a copper zinc tin sulfur-copper sulfide-copper tin sulfur film. Name it Thin Film 2.

Fig. 1 is the X-ray diffraction diagram of the copper zinc tin sulfur-copper sulfide-copper tin sulfur thin film synthesized in this example. It can be seen from Fig. 1 that copper zinc tin sulfur (CZTS), copper sulfide (CuS) and copper tin sulfur (Cu ₃ SnS ₄ ) are present in the sample at the same time. In the figure, the peak of Mo on the substrate is very strong, making the peak of sulfide appear very weak.

Figure 2, Figure 3, Figure 4, and Figure 5 are the scanning electron microscope (SEM) pictures of copper zinc tin sulfur-copper sulfide-copper tin sulfur thin films, corresponding to 10000x (film 1), 50000x (film 1), 10000x (film 2), 50000x (Film 2). It can be seen from Fig. 2, Fig. 3, Fig. 4, and Fig. 5 that the copper-zinc-tin-sulfur-copper-tin-sulfur film is formed by agglomeration of very small particles, and the particles on the surface of the film 1 tend to aggregate into more Large spherical, particles on the surface of film 2 tend to aggregate into short chains.

FIG. 6 is the current-voltage curves of film 1 and film 2. The silver/silver chloride electrode is used as the reference electrode, the platinum sheet (2x2cm ² ) is used as the counter electrode, 0.2 mol/liter sodium sulfate is used as the electrolyte, the test light intensity is 15mW cm ^-2 , and the scan rate is 0.01V/s. It can be seen from the figure that the performance of film 2 is better than that of film 1, probably because the short chain structure increases the specific surface area of the film.

Example 3

Prepare 0.02 mol/L copper sulfate, 0.03 mol/L zinc sulfate, 0.02 mol/L stannous chloride, 0.03 mol/L sodium thiosulfate, 0.2 mol/L trisodium citrate and 0.1 mol/L tartaric acid respectively at room temperature These solutions were uniformly mixed in equal volumes, and the pH was adjusted to 7. Wipe the Mo substrate with 15 mol/L concentrated NaOH solution and ultrasonically clean it in ethanol and water for 20 min, respectively. Put the substrate into the electrolyte that has been stirred evenly. After deposition at a constant voltage of -1.5V (relative to silver/silver chloride) for 15 minutes, the sample was taken out, rinsed with a large amount of deionized water and dried. The obtained film is calcined at 350° C. for 1 hour in argon or nitrogen, and the obtained sample is a copper zinc tin sulfur-copper sulfide-copper tin sulfur film.

Example 4

Prepare 0.02 mol/L copper nitrate, 0.03 mol/L zinc nitrate, 0.02 mol/L stannous sulfate, 0.03 mol/L sodium thiosulfate, 0.2 mol/L trisodium citrate and 0.1 mol/L tartaric acid aqueous solution respectively at room temperature , these solutions were uniformly mixed in equal volumes, and the pH was adjusted to 5. Wipe the Mo substrate with 12 mol/L concentrated NaOH solution and ultrasonically clean it in ethanol and water for 10 min, respectively. Put the substrate into the electrolyte that has been stirred evenly. After deposition at a constant voltage of -1.05V (relative to silver/silver chloride) for 25 minutes, the sample was taken out, rinsed with a large amount of deionized water and dried. The obtained film is calcined at 350° C. for 1 hour in argon or nitrogen, and the obtained sample is a copper zinc tin sulfur-copper sulfide-copper tin sulfur film.

Example 5

Prepare 0.02 mol/L copper chloride, 0.03 mol/L zinc chloride, 0.02 mol/L stannous chloride, 0.03 mol/L sodium thiosulfate, 0.2 mol/L trisodium citrate and 0.1 mol/L respectively at room temperature liter of tartaric acid aqueous solution, these solutions are uniformly mixed in equal volumes, and the pH is adjusted to 5. Wipe the Mo substrate with 12 mol/L concentrated NaOH solution and ultrasonically clean it in ethanol and water for 20 min, respectively. Put the substrate into the electrolyte that has been stirred evenly. After deposition for 45 minutes under the condition of a constant voltage of -1.3V (relative to silver/silver chloride), the samples were taken out, rinsed with a large amount of deionized water and dried. The obtained film is calcined at 350° C. for 1 hour in argon or nitrogen, and the obtained sample is a copper zinc tin sulfur-copper sulfide-copper tin sulfur film.

Example 6

Prepare 0.02 mol/L copper sulfate, 0.03 mol/L zinc sulfate, 0.02 mol/L stannous chloride, 0.03 mol/L sodium thiosulfate, 0.2 mol/L trisodium citrate and 0.1 mol/L tartaric acid respectively at room temperature Aqueous solutions, equal volumes of these solutions were uniformly mixed, and the pH was adjusted to 2. Wipe the Mo substrate with 15 mol/L concentrated NaOH solution and ultrasonically clean it in ethanol and water for 5 min, respectively. Put the substrate into the electrolyte that has been stirred evenly. After deposition at a constant voltage of -1.3V (relative to silver/silver chloride) for 35 minutes, the sample was taken out, rinsed with a large amount of deionized water and dried. The obtained film is calcined at 350° C. for 1 hour in argon or nitrogen, and the obtained sample is a copper zinc tin sulfur-copper sulfide-copper tin sulfur film.

Example 7

Prepare 0.02 mol/L copper nitrate, 0.03 mol/L zinc nitrate, 0.02 mol/L stannous chloride, 0.03 mol/L sodium thiosulfate, 0.2 mol/L trisodium citrate and 0.1 mol/L tartaric acid at room temperature Mix these solutions uniformly in equal volumes and adjust the pH to 6. Wipe the Mo substrate with 8 mol/L NaOH solution and ultrasonically clean it in ethanol and water for 30 min, respectively. Put the substrate into the electrolyte that has been stirred evenly. After deposition at a constant voltage of -1.5V (relative to silver/silver chloride) for 25 minutes, the sample was taken out, rinsed with a large amount of deionized water and dried. The obtained film is calcined at 350° C. for 1 hour in argon or nitrogen, and the obtained sample is a copper zinc tin sulfur-copper sulfide-copper tin sulfur film.

Example 7

Prepare 0.02 mol/L copper sulfate, 0.03 mol/L zinc sulfate, 0.02 mol/L stannous chloride, 0.03 mol/L sodium thiosulfate, 0.2 mol/L trisodium citrate and 0.1 mol/L tartaric acid respectively at room temperature Aqueous solutions, equal volumes of these solutions were uniformly mixed, and the pH was adjusted to 5. Wipe the Mo substrate with 12 mol/L concentrated NaOH solution and ultrasonically clean it in ethanol and water for 30 min, respectively. Put the substrate into the electrolyte that has been stirred evenly. After deposition at a constant voltage of -0.8V (relative to silver/silver chloride) for 60 minutes, the sample was taken out, rinsed with a large amount of deionized water and dried. The obtained film is calcined at 350° C. for 1 hour in argon or nitrogen, and the obtained sample is a copper zinc tin sulfur-copper sulfide-copper tin sulfur film.

Example 8

Prepare 0.02 mol/L copper sulfate, 0.03 mol/L zinc sulfate, 0.02 mol/L stannous chloride, 0.03 mol/L sodium thiosulfate, 0.2 mol/L trisodium citrate and 0.1 mol/L tartaric acid respectively at room temperature Aqueous solutions, equal volumes of these solutions were uniformly mixed, and the pH was adjusted to 5. Wipe the Mo substrate with 15 mol/L concentrated NaOH solution and ultrasonically clean it in ethanol and water for 30 min, respectively. Put the substrate into the electrolyte that has been stirred evenly. After deposition for 35 minutes under the condition of constant voltage -0.8V (relative to silver/silver chloride), the sample was taken out, rinsed with a large amount of deionized water and dried. The obtained film is calcined at 350° C. for 1 hour in argon or nitrogen, and the obtained sample is a copper zinc tin sulfur-copper sulfide-copper tin sulfur film.

Example 9

Prepare 0.02 mol/L copper chloride, 0.03 mol/L zinc chloride, 0.02 mol/L stannous chloride, 0.03 mol/L sodium thiosulfate, 0.2 mol/L trisodium citrate and 0.1 mol/L respectively at room temperature liter of tartaric acid aqueous solution, these solutions are uniformly mixed in equal volumes, and the pH is adjusted to 5. Wipe the Mo substrate with 15 mol/L concentrated NaOH solution and ultrasonically clean it in ethanol and water for 20 min, respectively. Put the substrate into the electrolyte that has been stirred evenly. After deposition at a constant voltage of -1.3V (relative to silver/silver chloride) for 25 minutes, the sample was taken out, rinsed with a large amount of deionized water and dried. The obtained film is calcined at 350° C. for 1 hour in argon or nitrogen, and the obtained sample is a copper zinc tin sulfur-copper sulfide-copper tin sulfur film.

Example 10

Prepare 0.015 mol/L copper sulfate, 0.03 mol/L zinc sulfate, 0.015 mol/L stannous chloride, 0.03 mol/L sodium thiosulfate, 0.12 mol/L trisodium citrate and 0.06 mol/L tartaric acid respectively at room temperature Aqueous solutions, equal volumes of these solutions were uniformly mixed, and the pH was adjusted to 5. Wipe the Mo substrate with 15 mol/L concentrated NaOH solution and ultrasonically clean it in ethanol and water for 30 min, respectively. Put the substrate into the electrolyte that has been stirred evenly. After deposition for 45 minutes under the condition of constant voltage -1.05V (relative to silver/silver chloride), the sample was taken out, rinsed with a large amount of deionized water and dried. The obtained film is calcined at 350° C. for 1 hour in argon or nitrogen, and the obtained sample is a copper zinc tin sulfur-copper sulfide-copper tin sulfur film.

Example 11

Prepare 0.09 mol/L copper sulfate, 0.03 mol/L zinc sulfate, 0.09 mol/L stannous chloride, 0.15 mol/L sodium thiosulfate, 0.3 mol/L trisodium citrate and 0.24 mol/L tartaric acid at room temperature Mix these solutions uniformly in equal volumes and adjust the pH to 6. Wipe the Mo substrate with 12 mol/L concentrated NaOH solution and ultrasonically clean it in ethanol and water for 30 min, respectively. Put the substrate into the electrolyte that has been stirred evenly. After deposition for 45 minutes under the condition of constant voltage -1.05V (relative to silver/silver chloride), the sample was taken out, rinsed with a large amount of deionized water and dried. The obtained film is calcined at 350° C. for 1 hour in argon or nitrogen, and the obtained sample is a copper zinc tin sulfur-copper sulfide-copper tin sulfur film.

The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make many modifications and changes according to the concept of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art shall be within the scope of protection defined by the claims.

Claims (10)

1. a synthetic method of copper zinc tin sulfur-copper sulfide-copper tin sulfur thin film is characterized in that, synthetic steps are as follows: (1) Preparation of electrolyte: Dissolve copper salt, zinc salt, tin salt, sodium thiosulfate, trisodium citrate and tartaric acid into water respectively, then mix them, adjust the pH value after mixing evenly; (2) Clean the substrate: metal Mo sheet is used as the substrate, and the surface is wiped with sodium hydroxide solution to remove surface rust, and then ultrasonically cleaned in ethanol and deionized water one by one to remove surface oil stains; (3) Electrochemical deposition: Put the cleaned substrate into the prepared electrolyte, set the deposition voltage and time and start, take out the substrate after deposition, rinse with a large amount of deionized water and ethanol and blow dry; (4) Calcining the sample obtained in step (3) in nitrogen or argon for 1 hour to obtain a copper zinc tin sulfur-copper sulfide-copper tin sulfur film. 2. The synthesis method as claimed in claim 1, characterized in that, in the step (1), in terms of moles, copper salt: zinc salt: tin salt: sodium thiosulfate: trisodium citrate: tartaric acid=0.5 ~3:1:0.5~3:1~5:4~10:2~8. 3. The synthesis method as claimed in claim 1, characterized in that, in the step (1), in terms of moles, copper salt: zinc salt: tin salt: sodium thiosulfate: trisodium citrate: tartaric acid=2 :3:2:3:20:10. 4. The synthesis method according to claim 1, wherein the copper salt in the step (1) is copper sulfate, copper nitrate or copper chloride. 5. The synthesis method according to claim 1, characterized in that the zinc salt in the step (1) is zinc sulfate, zinc nitrate or zinc chloride. 6. The synthesis method according to claim 1, wherein the tin salt in the step (1) is stannous chloride or stannous sulfate. 7. The synthesis method according to claim 1, characterized in that, in the step (1), the pH value is adjusted in the range of 2-7. 8. The synthesis method according to any one of claims 1-6, characterized in that the concentration of the sodium hydroxide solution in the step (2) is 1-15 mol/liter, and the ultrasonic time is 5-30 minutes. 9. The synthesis method according to any one of claims 1-6, characterized in that, the voltage used in the electrochemical deposition process in the step (3) is -0.8V～-1.5V, and the deposition time is 15 ~60 minutes. 10. The synthesis method according to any one of claims 1-6, characterized in that the calcination temperature range in the step (4) is 200-600°C.