Method for enhancing photoelectric property of device by modifying surface of nano material

Abstract

The invention provides a method for enhancing the photoelectric property of a device by modifying the surface of a nano material, and relates to the field of semiconductor device manufacturing, and the method comprises the steps of S1, nano material pretreatment, S2, modification solution preparation, S3, surface modification, S4, post-treatment, S5, silver seed preparation, S6, seed loading, and S7, silver layer wrapping. According to the method, the sulfur-antimony-copper nano-material is subjected to surface modification and silver layer wrapping, the sulfur-antimony-copper nano-material with the silver layer evenly wrapped is obtained, the bonding strength between the silver layer and the nano-material is high, and then the semiconductor device with high stability and high performance is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor device manufacturing, and in particular to a method for enhancing the photoelectric performance of a device by modifying the surface of a nano material. Background Art

[0002] In order to solve the urgent problems of shortage of non-renewable resources and environmental pollution, semiconductor devices such as solar energy conversion devices are constantly being strengthened and developed and applied; at the same time, with the continuous in-depth research on the performance of nanomaterials, various semiconductor devices are constantly developing in the direction of miniaturization; due to the size of nanomaterials, it is possible to develop wearable, wireless, micro-nano semiconductor devices, thereby ensuring that semiconductor devices are widely used in construction, transportation, mobile devices, communications and other fields.

[0003] Among them, copper antimony sulphide (i.e. Cu-Sb-S system, for example: Cu 3 Sb 4 , Cu 12 Sb 4 S 13 、CuSbS 2 , Cu 3 Sb 3 Nanomaterials have excellent optical properties, electrical properties and material stability (the optical band gap is around 1.5eV to 1.8eV, and the absorption rate in visible light and near infrared reaches 10 5 cm -1The above), is a relatively excellent optoelectronic application material. However, the copper and other elements in the sulfur antimony copper nanomaterial are easily oxidized in the air, affecting the overall performance and service life of the material; and the sulfur antimony copper nanomaterial will be corroded by acid, alkali and other chemical substances during use, further affecting its performance; the existing method is to wrap a layer of precious metal layer (for example: Ag) on ​​the surface of the sulfur antimony copper nanomaterial, which can not only form a physical barrier to prevent the oxidation of the sulfur antimony copper nanomaterial and resist the erosion of chemical substances, but also to a certain extent improve the electrical and optical properties of the nanomaterial (silver has extremely high electrical conductivity and can improve electrical conductivity; at the same time, silver can also change the optical absorption and scattering properties of the sulfur antimony copper nanomaterial). However, due to the high sulfur content and active surface sulfur vacancies in the sulfur antimony copper nanomaterial, under the influence of light and temperature, sulfur atoms will migrate from the lattice to the surface, react with silver to form an amorphous silver sulfide structure, destroy the interface bonding, and affect the performance of the nanomaterial; at the same time, the thermal expansion mismatch and lattice mismatch between silver and sulfur antimony copper nanomaterials are easy to increase the interface stress between the silver layer and the nanomaterial, reduce the bonding strength, and then cause the silver layer to crack or peel off. In addition, due to the influence of the characteristics of the nanomaterial itself and the influence of silver ion concentration and reaction temperature, it is easy to cause a large amount of silver to be generated locally in the nanomaterial, resulting in agglomeration problems, resulting in the inability to evenly coat the silver layer, thereby affecting the preparation and protection of the silver layer and the uniformity of the photoelectric properties of the semiconductor material. Summary of the invention

[0004] In view of the problems existing in the above prior art, the purpose of the present invention is to provide a method for enhancing the photoelectric performance of a device by modifying the surface of a nanomaterial. The method modifies the surface of a copper antimony sulfide nanomaterial to achieve uniform wrapping of the copper antimony sulfide nanomaterial by a silver layer and high bonding strength between the silver layer and the nanomaterial, thereby preparing a semiconductor device with excellent photoelectric performance.

[0005] The purpose of the present invention is achieved through the following technical solutions: A method for enhancing the photoelectric performance of a device by modifying the surface of a nanomaterial, comprising: Step S1, pretreatment of nanomaterials: pretreatment of the sulfur antimony copper nanomaterials with anhydrous ethanol; Step S2, preparing a modification solution: dissolving the mixed modifier in anhydrous ethanol, adjusting the pH to 2.5 with hydrochloric acid, and performing ultrasonic dissolution; Step S3, surface modification: disperse the pretreated nanomaterials in deionized water, slowly add the modification solution, stir evenly, and place in a constant temperature water bath, during which the pH is adjusted to 8.0-8.5; Step S4, post-processing: post-processing the surface-modified solution; Step S5, silver seed preparation: quickly adding silver nitrate solution into sodium borohydride under ice bath condition to obtain silver colloid; Step S6, seed loading: adding silver colloid to the modified nano solution after post-treatment in step S4, adjusting the pH to 8.0-9.0, stirring, centrifuging, and washing; Step S7, silver layer coating: the nanomaterial washed in step S6 is redispersed, and a silver nitrate solution and ascorbic acid are added, and stirred evenly to obtain a silver-coated nanomaterial.

[0006] Based on the further optimization of the above scheme, the sulfur antimony copper nanomaterial adopts Cu 3 Sb 4 , Cu 12 Sb 4 S 13 、CuSbS 2 , Cu 3 Sb 3 Any of .

[0007] Based on the further optimization of the above scheme, the step S1 is specifically as follows: first, the sulfur antimony copper nanomaterial is dispersed in anhydrous ethanol, the mass volume ratio of the sulfur antimony copper nanomaterial to anhydrous ethanol is: 1 mg: 1-1.5 ml, and ultrasonic treatment is performed for 12-18 minutes to remove impurities and agglomerates on the surface of the nanomaterial; then, centrifugation is performed for 10-15 minutes to remove the supernatant; and the above steps are repeated for washing 2-3 times with anhydrous ethanol to complete the pretreatment.

[0008] Based on further optimization of the above scheme, the mixed modifier includes o-mercaptobenzoic acid, 4-mercaptophenylacetic acid and 1,4-dimercaptobenzene, and the mass ratio between them is 8-10:0.5-1.5:3-5.

[0009] The present invention uses a mixed modifier composed of o-mercaptobenzoic acid, 4-mercaptophenylacetic acid and 1,4-dimercaptobenzene. Before silver wraps the sulfur antimony copper nanomaterial, the mixed modifier is combined with sulfur vacancies on the surface of the sulfur antimony copper nanomaterial to form a stable bond, thereby avoiding the subsequent formation of an amorphous silver sulfide structure between silver and sulfur vacancies, and ensuring the stability of the structure and interface bonding; at the same time, the mixed modifier also provides an anchor point for silver, effectively inhibits the spontaneous nucleation of silver ions in the solution, promotes its migration to the surface of the modified nanomaterial, improves the bonding strength between the final silver layer and the nanomaterial, reduces internal stress, and effectively avoids cracking, peeling and other problems in the prepared silver layer. In addition, o-mercaptobenzoic acid, 4-mercaptophenylacetic acid and 1,4-dimercaptobenzene in the mixed modifier are used to construct a two-dimensional ordered superstructure, improve the carrier transmission efficiency, and thus effectively enhance the photoelectric conversion efficiency of the device and improve the stability of the photoelectric device.

[0010] The method of pre-preparing silver seeds, loading them with silver nitrate solution and ascorbic acid to form a silver layer coating (the coordination effect of the mixed modifier can effectively fix the seeds and prevent them from falling off), compared with directly reducing silver nitrate for silver layer coating, the growth area of ​​silver is restricted by using seeds, and the anchoring point effect of the mixed modifier is combined to make the silver ions orderly reduced and grown on the surface of the seeds and its vicinity, reducing the probability of silver ions freely gathering and growing in the solution to form large particles, thereby improving the uniformity of the coating; at the same time, the seed-mediated growth and the anchoring point effect of the mixed modifier can effectively balance the deposition rate and diffusion rate of silver on the surface of the nanomaterial, thereby avoiding local accumulation and the formation of agglomerates, and further promoting the uniform growth of the silver layer.

[0011] Based on further optimization of the above scheme, the mass volume ratio between the mixed modifier and anhydrous ethanol in step S2 is 1 mg: 1-1.5 ml; the concentration of hydrochloric acid is 1 mol / L; and the ultrasonic dissolution time is 8-12 min.

[0012] Based on further optimization of the above scheme, the mass ratio of the nanomaterial to the mixed modifier in step S3 is 1:0.8-1.2; the constant temperature water bath temperature is 38-43°C, and the time is 1.8-2.2h; and ammonia water is used to adjust the pH value.

[0013] Based on further optimization of the above scheme, the step S4 is specifically as follows: first, the surface-modified solution is centrifuged for 14 to 17 minutes, and after the centrifugation, the supernatant is removed and the precipitate is retained; then, the precipitate is washed by a mixed washing method of deionized water-anhydrous ethanol-deionized water, wherein anhydrous ethanol is used 2 to 3 times; finally, the modified nanomaterial after washing is redissolved in deionized water, the mass volume ratio of the modified nanomaterial to deionized water is: 1 mg: 1.8 to 2.2 ml, and ultrasonic treatment is performed for 15 to 18 minutes to obtain a stable suspension.

[0014] Based on further optimization of the above scheme, the concentration of the silver nitrate solution in step S5 is 1 mmol / L, and the concentration of the sodium borohydride solution is 2 mmol / L; the molar ratio of the silver nitrate solution to the sodium borohydride solution is 1:2-3; the ice bath temperature is -2°C to 0°C, and the stirring time is 2 to 5 min.

[0015] Based on further optimization of the above scheme, the mass ratio of the modified nanomaterial to the silver colloid in step S6 is 1:0.25-0.35, and ammonia water is used to adjust the pH value; the stirring time is 10-12 hours, and the centrifugation time is 8-10 minutes; the number of washing times is 3-4 times, and the washing is carried out with deionized water.

[0016] Based on further optimization of the above scheme, the concentration of the silver nitrate solution in step S7 is 0.01-0.03 mol / L, the concentration of ascorbic acid is 0.01 mol / L, and the mass ratio of the silver nitrate solution to ascorbic acid is 2:1.2-1.5; the mass ratio of the silver nitrate solution to the washed nanomaterial is 2-8:1; during the uniform stirring process, the temperature is maintained at 57-63°C, and the stirring time is 0.8-1.2h.

[0017] Based on further optimization of the above scheme, steps S5 to S7 are all performed in a protective gas environment such as nitrogen and helium to avoid oxidation reactions.

[0018] The following are the technical effects of this solution: Compared with the prior art, the present invention uses a mixed modifier composed of o-mercaptobenzoic acid, 4-mercaptophenylacetic acid and 1,4-dimercaptobenzene to modify the surface of the nanomaterial before silver wraps the sulfur antimony copper nanomaterial, thereby effectively avoiding the combination of silver and the active sulfur vacancies on the surface of the sulfur antimony copper nanomaterial, the generation of an amorphous silver sulfide structure, and the interface stress between the silver and the sulfur antimony copper nanomaterial is large, the bonding strength is low, and cracking and falling off are prone to occur. The problem ensures the close and stable combination between the nanomaterial and the silver layer, thereby ensuring the antioxidant and corrosion resistance of the silver layer as a protective layer, and also improves the overall photoelectric conversion efficiency of the nanomaterial. At the same time, the present invention not only inhibits the spontaneous growth and aggregation of silver ions in the solution through the cooperation between the seed-mediated growth method and the mixed modifier, but also utilizes the anchor point effect and seed restriction to promote the uniform growth of silver ions on the surface of the nanomaterial, avoiding the problem of uneven thickness of the silver layer caused by agglomeration, accumulation, and uneven growth rate, effectively ensuring the uniformity of the silver layer wrapping, and enhancing the photoelectric performance of the device using the nanomaterial as the raw material. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 These are SEM and EDS images of the silver-encapsulated nanomaterials prepared in the examples of the present invention.

[0020] Figure 2 This is a SEM image of the silver-wrapped nanomaterial prepared in the comparative example of the present invention. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0022] Embodiment 1: A method for enhancing the photoelectric performance of devices by modifying the surface of nanomaterials, targeting Cu 3 Sb 4Nanomaterials (made by existing methods), including: Step S1: Pretreatment of nanomaterials: using anhydrous ethanol to 3 Sb 4 The nanomaterials were pretreated, specifically: first, Cu 3 Sb 4 Nanomaterials were dispersed in anhydrous ethanol, Cu 3 Sb 4 The mass volume ratio of the nanomaterial to anhydrous ethanol is 1 mg: 1 ml, and ultrasonic treatment is used for 12 minutes to remove impurities and agglomerates on the surface of the nanomaterial; then, centrifugal treatment is performed for 10 minutes (the centrifugal speed is 8000-10000 r / min), and the supernatant is removed; the above steps are repeated twice with anhydrous ethanol to complete the pretreatment.

[0023] Step S2, preparing a modification solution: dissolving the mixed modifier in anhydrous ethanol, with the mass volume ratio of the mixed modifier to anhydrous ethanol being 1 mg:1 ml; adjusting the pH to 2.5 with hydrochloric acid, with the concentration of hydrochloric acid being 1 mol / L; and performing ultrasonic dissolution for 8 min.

[0024] The mixed modifier includes o-mercaptobenzoic acid, 4-mercaptophenylacetic acid and 1,4-dimercaptobenzene, and the mass ratio between them is 8:0.5:3.

[0025] Step S3, surface modification: disperse the pretreated nanomaterial in deionized water (the mass volume ratio of nanomaterial to deionized water is 1 mg: 1 ml), slowly add the modification solution, the mass ratio of nanomaterial to mixed modifier is 1: 0.8; stir evenly (stirring can be carried out by magnetic stirring, the stirring speed is 280-330 r / min), constant temperature water bath, the temperature is 38°C, the time is 1.8h; during this period, ammonia water is used to adjust the pH to 8.0.

[0026] Step S4, post-treatment: the surface-modified solution is post-treated, specifically: first, the surface-modified solution is centrifuged for 14 minutes (the centrifugal speed is 8000-10000r / min), and the supernatant is removed after centrifugation and the precipitate is retained; then, the precipitate is washed by a mixed washing method of deionized water-anhydrous ethanol-deionized water, wherein anhydrous ethanol is used twice (i.e., a washing method of deionized water-anhydrous ethanol-deionized water-anhydrous ethanol-deionized water); finally, the washed modified nanomaterial is redissolved in deionized water, the mass volume ratio of the modified nanomaterial to deionized water is: 1mg:1.8ml, and ultrasonic treatment is performed for 15 minutes to obtain a stable suspension.

[0027] Step S5, silver seed preparation: under ice bath conditions and at a temperature of -2°C (salt may be added in an appropriate amount to lower the freezing point), quickly add silver nitrate solution into sodium borohydride, wherein the concentration of the silver nitrate solution is 1 mmol / L, the concentration of the sodium borohydride solution is 2 mmol / L, and the molar ratio of the silver nitrate solution to the sodium borohydride solution is 1:2, and stir evenly (stirring speed is 320-350 r / min) for 2 min to obtain silver colloid.

[0028] Step S6, seed loading: adding silver colloid to the modified nano solution after post-treatment in step S4, the mass ratio of modified nano material to silver colloid is 1:0.25, adjusting the pH to 8.0 with ammonia water, stirring (stirring speed is 280-330r / min), stirring time is 10h, centrifuging (centrifugal speed is 8000-10000r / min), centrifuging time is 8min, washing, washing times are 3 times and washing is carried out with deionized water.

[0029] Step S7, silver layer coating: the nanomaterial washed in step S6 is redispersed, and a silver nitrate solution and ascorbic acid are added, wherein the concentration of the silver nitrate solution is 0.01 mol / L, the concentration of the ascorbic acid is 0.01 mol / L, the mass ratio of the silver nitrate solution to the ascorbic acid is 2:1.2, and the mass ratio of the silver nitrate solution to the washed nanomaterial is 3:1. The mixture is stirred evenly (stirring speed is 280-330 r / min) for 0.8 h, and the temperature is maintained at 57° C. to obtain a silver-coated nanomaterial.

[0030] Steps S5 to S7 are all performed in a nitrogen protective gas environment to avoid oxidation reactions.

[0031] Embodiment 2: A method for enhancing the photoelectric performance of devices by modifying the surface of nanomaterials, targeting Cu 3 Sb 4 Nanomaterials (made by existing methods), including: Step S1: Pretreatment of nanomaterials: using anhydrous ethanol to 3 Sb 4 The nanomaterials were pretreated, specifically: first, Cu 3 Sb 4 Nanomaterials were dispersed in anhydrous ethanol, Cu 3 Sb 4 The mass volume ratio of the nanomaterial to anhydrous ethanol is: 1 mg: 1.3 ml, and ultrasonic treatment is used for 15 minutes to remove impurities and agglomerates on the surface of the nanomaterial; then, centrifugal treatment is performed for 12 minutes (the centrifugal speed is 8000-10000 r / min), and the supernatant is removed; the above steps are repeated 3 times with anhydrous ethanol to complete the pretreatment.

[0032] Step S2, preparing a modification solution: dissolving the mixed modifier in anhydrous ethanol, the mass volume ratio of the mixed modifier to anhydrous ethanol being 1 mg:1.3 ml; adjusting the pH to 2.5 with hydrochloric acid, the concentration of which is 1 mol / L; performing ultrasonic dissolution, the ultrasonic dissolution time being 10 min.

[0033] The mixed modifier includes o-mercaptobenzoic acid, 4-mercaptophenylacetic acid and 1,4-dimercaptobenzene, and the mass ratio between them is 9:1:4.

[0034] Step S3, surface modification: disperse the pretreated nanomaterials in deionized water, slowly add the modification solution, the mass ratio of the nanomaterials to the mixed modifier is 1:1; stir evenly (magnetic stirring can be used for stirring, the stirring speed is 280-330r / min), constant temperature water bath, the temperature is 40°C, the time is 2h; during this period, ammonia water is used to adjust the pH to 8.2.

[0035] Step S4, post-treatment: the surface-modified solution is post-treated, specifically: first, the surface-modified solution is centrifuged for 15 minutes, the supernatant is removed after the centrifugation (the centrifugal speed is 8000-10000r / min), and the precipitate is retained; then, the precipitate is washed by a mixed washing method of deionized water-anhydrous ethanol-deionized water, wherein anhydrous ethanol is used 3 times (i.e., a washing method of deionized water-anhydrous ethanol-deionized water-anhydrous ethanol-deionized water-anhydrous ethanol-deionized water); finally, the washed modified nanomaterial is redissolved in deionized water, the mass volume ratio of the modified nanomaterial to deionized water is: 1mg:2ml, and ultrasonic treatment is performed for 16 minutes to obtain a stable suspension.

[0036] Step S5, silver seed preparation: under ice bath conditions and at a temperature of 0°C, quickly add a silver nitrate solution into sodium borohydride, wherein the concentration of the silver nitrate solution is 1 mmol / L, the concentration of the sodium borohydride solution is 2 mmol / L, and the molar ratio of the silver nitrate solution to the sodium borohydride solution is 1:2.5, and stir evenly (stirring speed is 320-350 r / min) for 3.5 min to obtain a silver colloid.

[0037] Step S6, seed loading: adding silver colloid to the modified nano solution after post-treatment in step S4, the mass ratio of modified nano material to silver colloid is 1:0.3, adjusting the pH to 8.5 with ammonia water, stirring (stirring speed is 280-330r / min), stirring time is 11h, centrifuging (centrifugal speed is 8000-10000r / min), centrifuging time is 9min, washing, washing times are 3 times and washing is carried out with deionized water.

[0038] Step S7, silver layer coating: the nanomaterial washed in step S6 is redispersed, and a silver nitrate solution and ascorbic acid are added, wherein the concentration of the silver nitrate solution is 0.02 mol / L, the concentration of the ascorbic acid is 0.01 mol / L, the mass ratio of the silver nitrate solution to the ascorbic acid is 2:1.3, and the mass ratio of the silver nitrate solution to the washed nanomaterial is 5:1. The mixture is stirred evenly (stirring speed is 280-330 r / min) for 1 h, and the temperature is maintained at 60°C to obtain a silver-coated nanomaterial.

[0039] Steps S5 to S7 are all performed in a nitrogen protective gas environment to avoid oxidation reactions.

[0040] Figure 1 The SEM (scanning electron microscope) and EDS (energy dispersive spectrophotometer) of the nanomaterials finally prepared in this embodiment (ie, embodiment 2) are as follows: Figure 1 It can be clearly seen that the surface of the copper antimony sulfide nano-microspheres in this embodiment is coated with a silver layer and the silver element is evenly coated on the surface of the copper antimony sulfide nano-microspheres.

[0041] Embodiment 3: A method for enhancing the photoelectric performance of devices by modifying the surface of nanomaterials, targeting Cu 3 Sb 4 Nanomaterials (made by existing methods), including: Step S1: Pretreatment of nanomaterials: using anhydrous ethanol to 3 Sb 3 The nanomaterials were pretreated, specifically: first, Cu 3 Sb 3 Nanomaterials were dispersed in anhydrous ethanol, Cu 3 Sb 3 The mass volume ratio of the nanomaterial to anhydrous ethanol is 1 mg: 1.5 ml, and ultrasonic treatment is used for 18 minutes to remove impurities and agglomerates on the surface of the nanomaterial; then, centrifugal treatment is performed for 15 minutes (the centrifugal speed is 8000-10000 r / min), and the supernatant is removed; the above steps are repeated 3 times with anhydrous ethanol to complete the pretreatment.

[0042] Step S2, preparing a modification solution: dissolving the mixed modifier in anhydrous ethanol, the mass volume ratio of the mixed modifier to anhydrous ethanol being 1 mg:1.5 ml; adjusting the pH to 2.5 with hydrochloric acid, the concentration of which is 1 mol / L; performing ultrasonic dissolution, the ultrasonic dissolution time being 12 min.

[0043] The mixed modifier includes o-mercaptobenzoic acid, 4-mercaptophenylacetic acid and 1,4-dimercaptobenzene, and the mass ratio thereof is 10:1.5:5.

[0044] Step S3, surface modification: disperse the pretreated nanomaterials in deionized water, slowly add the modification solution, the mass ratio of nanomaterials to mixed modifiers is 1:1.2; stir evenly (magnetic stirring can be used for stirring, the stirring speed is 280-330r / min), constant temperature water bath, the temperature is 43°C, the time is 2.2h; during this period, ammonia water is used to adjust the pH to 8.5.

[0045] Step S4, post-treatment: the surface-modified solution is post-treated, specifically: first, the surface-modified solution is centrifuged for 17 minutes, the supernatant is removed after the centrifugation (the centrifugal speed is 8000-10000r / min), and the precipitate is retained; then, the precipitate is washed by a mixed washing method of deionized water-anhydrous ethanol-deionized water, wherein anhydrous ethanol is used 3 times (i.e., a washing method of deionized water-anhydrous ethanol-deionized water-anhydrous ethanol-deionized water-anhydrous ethanol-deionized water); finally, the washed modified nanomaterial is redissolved in deionized water, the mass volume ratio of the modified nanomaterial to deionized water is: 1mg:2.2ml, and ultrasonic treatment is performed for 18min to obtain a stable suspension.

[0046] Step S5, silver seed preparation: under ice bath conditions and at a temperature of 0°C, quickly add a silver nitrate solution into sodium borohydride, wherein the concentration of the silver nitrate solution is 1 mmol / L, the concentration of the sodium borohydride solution is 2 mmol / L, and the molar ratio of the silver nitrate solution to the sodium borohydride solution is 1:3, and stir evenly (stirring speed is 320-350 r / min) for 5 min to obtain a silver colloid.

[0047] Step S6, seed loading: adding silver colloid to the modified nano solution after post-treatment in step S4, the mass ratio of modified nano material to silver colloid is 1:0.35, adjusting the pH to 9.0 with ammonia water, stirring (stirring speed is 280-330r / min), stirring time is 12h, centrifuging (centrifugal speed is 8000-10000r / min), centrifuging time is 10min, washing, washing times are 4 times and washing is carried out with deionized water.

[0048] Step S7, silver layer coating: the nanomaterial washed in step S6 is redispersed, and a silver nitrate solution and ascorbic acid are added, wherein the concentration of the silver nitrate solution is 0.03 mol / L, the concentration of the ascorbic acid is 0.01 mol / L, the mass ratio of the silver nitrate solution to the ascorbic acid is 2:1.5, and the mass ratio of the silver nitrate solution to the washed nanomaterial is 7:1. The mixture is stirred evenly (stirring speed is 280-330 r / min) for 1.2 h, and the temperature is maintained at 57-63° C. to obtain a silver-coated nanomaterial.

[0049] Steps S5 to S7 are all performed in a helium protective gas environment to avoid oxidation reactions.

[0050] Embodiment 4: As a preferred embodiment of the scheme of the present invention, a method for preparing a silver layer-wrapped nanomaterial semiconductor device is provided. On the basis of any one of Examples 1 to 3, centrifugation, washing and drying are further performed after step S7, and the solution of step S7 is centrifuged at a speed of 12000 to 15000 r / min for 15 minutes to remove the supernatant; then, anhydrous ethanol and deionized water are used for alternating washing 2 to 3 times; then, the solid particles obtained by washing are dried at 40 to 60° C. to obtain a silver layer-wrapped antimony copper sulfide nanomaterial with high bonding strength and high photoelectric performance; finally, the silver layer-wrapped antimony copper sulfide nanomaterial is used in a thin-film solar cell to obtain a semiconductor device.

[0051] Comparative Example 1: A method for modifying the surface of nanomaterials, targeting Cu 3 Sb 4 Nanomaterials (made by existing methods), including: Step S1, nanomaterial pretreatment: the same as the steps in Example 2.

[0052] Step S2, preparing a modification solution: dissolving o-mercaptobenzoic acid in anhydrous ethanol, wherein the mass volume ratio of o-mercaptobenzoic acid to anhydrous ethanol is 1 mg:1.3 ml; adjusting the pH to 2.5 with hydrochloric acid, wherein the concentration of the hydrochloric acid is 1 mol / L; and performing ultrasonic dissolution, wherein the ultrasonic dissolution time is 10 min.

[0053] Step S3, surface modification: the same as the step in Example 2.

[0054] Step S4, post-processing: the same as the steps in Example 2.

[0055] Step S5, silver seed preparation: the same as the step in Example 2.

[0056] Step S6, seed loading: the same as the step in Example 2.

[0057] Step S7, silver layer wrapping: the same as the step in Example 2.

[0058] Steps S5 to S7 are all performed in a nitrogen protective gas environment to avoid oxidation reactions.

[0059] Comparative Example 2: A method for modifying the surface of nanomaterials, targeting Cu 3 Sb 4 Nanomaterials (made by existing methods), including: Step S1, nanomaterial pretreatment: the same as the steps in Example 2.

[0060] Step S2, preparing a modification solution: dissolving the mixed modifier in anhydrous ethanol, the mass volume ratio of the mixed modifier to anhydrous ethanol being 1 mg:1.3 ml; adjusting the pH to 2.5 with hydrochloric acid, the concentration of which is 1 mol / L; performing ultrasonic dissolution, the ultrasonic dissolution time being 10 min.

[0061] The mixed modifier includes o-mercaptobenzoic acid, 4-mercaptophenylacetic acid and 3-mercapto-4-methylbenzoic acid, and the mass ratio between them is 9:1:4.

[0062] Step S3, surface modification: the same as the step in Example 2.

[0063] Step S4, post-processing: the same as the steps in Example 2.

[0064] Step S5, silver seed preparation: the same as the step in Example 2.

[0065] Step S6, seed loading: the same as the step in Example 2.

[0066] Step S7, silver layer wrapping: the same as the step in Example 2.

[0067] Steps S5 to S7 are all performed in a nitrogen protective gas environment to avoid oxidation reactions.

[0068] Comparative Example 3: A method for modifying the surface of nanomaterials, targeting Cu 3 Sb 4 Nanomaterials (made by existing methods), including: Step S1, nanomaterial pretreatment: the same as the steps in Example 2.

[0069] Step S2, preparing a modification solution: dissolving the mixed modifier in anhydrous ethanol, the mass volume ratio of the mixed modifier to anhydrous ethanol being 1 mg:1.3 ml; adjusting the pH to 2.5 with hydrochloric acid, the concentration of which is 1 mol / L; performing ultrasonic dissolution, the ultrasonic dissolution time being 10 min.

[0070] The mixed modifier includes thioglycolic acid, 4-mercaptophenylacetic acid and 1,4-dimercaptobenzene, and the mass ratio between them is 9:1:4.

[0071] Step S3, surface modification: the same as the step in Example 2.

[0072] Step S4, post-processing: the same as the steps in Example 2.

[0073] Step S5, silver seed preparation: the same as the step in Example 2.

[0074] Step S6, seed loading: the same as the step in Example 2.

[0075] Step S7, silver layer wrapping: the same as the step in Example 2.

[0076] Steps S5 to S7 are all performed in a nitrogen protective gas environment to avoid oxidation reactions.

[0077] Comparative Example 4: A method for modifying the surface of nanomaterials, targeting Cu 3 Sb 4 Nanomaterials (made by existing methods), including: Step S1, nanomaterial pretreatment: the same as the steps in Example 2.

[0078] Step S2, preparing the modification solution: the same as the step in Example 2.

[0079] Step S3, surface modification: the same as the step in Example 2.

[0080] Step S4, post-processing: the same as the steps in Example 2.

[0081] Step S5, silver layer coating: first, adjust the pH of 0.02 mol / L silver nitrate solution to 8.5 with ammonia water, then add the modified nano solution after post-treatment in step S4 to the silver nitrate solution, the volume ratio of the modified nano solution to the silver nitrate solution is 1:5, and stir at room temperature for 30 minutes; then, slowly add 0.1 mol / L ascorbic acid solution, the mass ratio of the silver nitrate solution to ascorbic acid is 2:1.3, heat to 60°C, and stir and mix evenly.

[0082] Step S5 is performed in a nitrogen protective gas environment to avoid oxidation reaction.

[0083] Figure 2 is the SEM picture in this comparative example (i.e. comparative example 4), Figure 2 It can be clearly seen that the silver layer wrapping of antimony sulfide copper nanomaterials by the treatment method in this comparative example will cause local accumulation of silver and agglomeration, which will lead to unclear separation boundaries of the generated silver-wrapped antimony sulfide copper nanomaterials and poor dispersion of the nanomaterials.

[0084] The silver-coated sulfur antimony copper nanomaterials prepared in Examples 1 to 3 and the silver-coated nanomaterials prepared in Comparative Examples 1 to 4 were respectively packaged into thin-film solar cells through conventional processes. First, the photoelectric conversion efficiency of the thin-film solar cells prepared from the nanomaterials in Examples 1 to 3 and Comparative Examples 1 to 4 was tested respectively. The photoelectric conversion efficiencies of Examples 1 to 3 were 4.33%, 4.35%, and 4.34%, respectively, and the photoelectric conversion efficiencies of Comparative Examples 1 to 4 were 3.52%, 3.63%, 3.75%, and 3.43%, respectively; it is proved that the scheme in this embodiment can effectively enhance the photoelectric performance of the sulfur antimony copper nanomaterial, that is, the photoelectric conversion efficiency.

[0085] Then, the thin film solar cells prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were placed in an air environment at 15° C. and a relative humidity of 50% for storage, and the resistivity of the corresponding thin film solar cells was tested every one month. The specific results are shown in the following table:

[0086] It can be clearly seen from the above table that under continuous storage conditions, the resistivity in Examples 1 to 3 does not change significantly, proving that the silver layer of the present invention can effectively prevent the oxidation of the sulfur-antimony copper nanomaterials and ensure that they have excellent electrical conductivity; and the solution of this embodiment can ensure the stable wrapping of the silver layer on the sulfur-antimony copper nanomaterials, that is, there will be no problems such as peeling and detachment of the silver layer, thereby ensuring the stability of the electrical conductivity under long-term storage conditions. In Comparative Examples 1 to 4, due to the unevenness of the silver layer wrapping or the peeling and detachment between the silver layer and the sulfur-antimony copper nanomaterial under long-term storage conditions, the sulfur-antimony copper nanomaterials are oxidized during storage, thereby affecting their electrical conductivity.

Claims

1. A method for enhancing the photoelectric performance of a device by modifying the surface of a nanomaterial, characterized in that: include: Step S1, pretreatment of nanomaterials: pretreatment of the sulfur antimony copper nanomaterials with anhydrous ethanol; Step S2, preparing a modification solution: dissolving the mixed modifier in anhydrous ethanol, adjusting the pH to 2.5 with hydrochloric acid, and performing ultrasonic dissolution; Step S3, surface modification: disperse the pretreated nanomaterials in deionized water, slowly add the modification solution, stir evenly, and place in a constant temperature water bath, during which the pH is adjusted to 8.0-8.5; Step S4, post-processing: post-processing the surface-modified solution; Step S5, silver seed preparation: quickly adding silver nitrate solution into sodium borohydride under ice bath condition to obtain silver colloid; Step S6, seed loading: adding silver colloid to the modified nano solution after post-treatment in step S4, adjusting the pH to 8.0-9.0, stirring, centrifuging, and washing; Step S7, silver layer coating: the nanomaterial washed in step S6 is redispersed, and a silver nitrate solution and ascorbic acid are added, and stirred evenly to obtain a silver-coated nanomaterial.

2. The method for enhancing the photoelectric performance of a device by modifying the surface of a nanomaterial according to claim 1, characterized in that: The sulfur antimony copper nanomaterial is made of Cu3SbS4, Cu 12 Sb4 13 , CuSbS2, Cu3SbS3.

3. A method for enhancing the photoelectric performance of a device by modifying the surface of a nanomaterial according to claim 1 or 2, characterized in that: The step S1 specifically comprises: first, dispersing the sulfur antimony copper nanomaterial in anhydrous ethanol, wherein the mass volume ratio of the sulfur antimony copper nanomaterial to the anhydrous ethanol is 1 mg: 1-1.5 ml, and performing ultrasonic treatment for 12-18 minutes to remove impurities and aggregates on the surface of the nanomaterial; then, performing centrifugal treatment for 10-15 minutes to remove the supernatant; and repeating the above steps of washing 2-3 times with anhydrous ethanol to complete the pretreatment.

4. A method for enhancing the photoelectric performance of a device by modifying the surface of a nanomaterial according to claim 2 or 3, characterized in that: The mixed modifier comprises o-mercaptobenzoic acid, 4-mercaptophenylacetic acid and 1,4-dimercaptobenzene, and the mass ratio thereof is 8-10:0.5-1.5:3-5.

5. The method for enhancing the photoelectric performance of a device by modifying the surface of a nanomaterial according to claim 3, characterized in that: In the step S2, the mass volume ratio between the mixed modifier and the anhydrous ethanol is 1 mg: 1-1.5 ml; the concentration of hydrochloric acid is 1 mol / L; and the ultrasonic dissolution time is 8-12 min.

6. The method for enhancing the photoelectric performance of a device by modifying the surface of a nanomaterial according to claim 3, characterized in that: In step S3, the mass ratio of the nanomaterial to the mixed modifier is 1:0.8-1.2; the constant temperature water bath temperature is 38-43°C, and the time is 1.8-2.2 hours; and ammonia water is used to adjust the pH value.

7. The method for enhancing the photoelectric performance of a device by modifying the surface of a nanomaterial according to claim 3, characterized in that: The step S4 is specifically as follows: first, centrifuge the surface-modified solution for 14 to 17 minutes, remove the supernatant after centrifugation and retain the precipitate; then, wash the precipitate by a mixed washing method of deionized water-anhydrous ethanol-deionized water, wherein anhydrous ethanol is used 2 to 3 times; finally, dissolve the washed modified nanomaterial in deionized water again, wherein the mass volume ratio of the modified nanomaterial to deionized water is: 1 mg: 1.8 to 2.2 ml, and perform ultrasonic treatment for 15 to 18 minutes to obtain a stable suspension.

8. The method for enhancing the photoelectric performance of a device by modifying the surface of a nanomaterial according to claim 3, characterized in that: In step S5, the concentration of the silver nitrate solution is 1 mmol / L, and the concentration of the sodium borohydride solution is 2 mmol / L; the molar ratio of the silver nitrate solution to the sodium borohydride solution is 1:2-3; the ice bath temperature is -2°C-0°C, and the stirring time is 2-5 min.

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