Photovoltaic-thermoelectric laminated laser cell based on embedding of low-thermal-conductivity nanocrystals and preparation method of photovoltaic-thermoelectric laminated laser cell

Abstract

The invention provides a photovoltaic-thermoelectric laminated laser cell based on low-thermal-conductivity nanocrystalline embedding and a preparation method thereof. The laser cell is sequentially provided with a conductive substrate, an electron transport layer, a cesium-lead-bromine-based optical active layer, a carbon electrode layer, heat-conducting glue and a thermoelectric module from top to bottom, and the cesium-lead-bromine-based optical active layer contains modified nanocrystals with low thermal conductivity. According to the photovoltaic-thermoelectric laminated laser cell embedded based on the low-thermal-conductivity nanocrystals, when laser is subjected to high-intensity irradiation, a thermoelectric part in the laminated laser cell enables the photovoltaic cell to work in a better temperature region by reducing the working temperature of the photovoltaic cell; and the embedding of the low-thermal-conductivity nanocrystalline further reduces the working temperature of the photovoltaic module and isolates more heat in the thermoelectric module so as to generate more electric energy, so that the photoelectric conversion efficiency of the whole power generation device is improved, the working stability of the laminated laser battery is enhanced, and the service life of the laminated laser battery is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of photoelectric conversion, and in particular relates to a photovoltaic-thermoelectric tandem laser cell based on low thermal conductivity nanocrystal embedding and its preparation method. Background Technology

[0002] Compared to solar power generation, laser power generation systems offer advantages such as high energy conversion efficiency, strong directionality, concentrated energy, high controllability, low energy loss, and high stability. Under the same incident light power, the energy conversion efficiency and maximum output power of laser cells are significantly improved compared to sunlight. Furthermore, the irradiation time and angle of the laser can be artificially controlled, enabling uninterrupted power supply to the target, reducing the need for energy storage devices, and avoiding energy loss caused by the non-responsiveness of certain wavelengths in the solar spectrum. This provides a stable power supply and is suitable for long-distance wireless power transmission scenarios such as powering aircraft and space equipment, and emergency power supply in remote areas.

[0003] High-intensity laser irradiation generates waste heat in the power generation device. This heat not only hinders the efficient utilization of incident photons but can also affect the device's performance due to increased operating temperature. Therefore, effectively utilizing this heat is crucial. Introducing thermoelectric devices to convert waste heat into electrical energy not only improves the overall conversion efficiency of the tandem solar cell but also aids in heat dissipation for the photovoltaic power generation component within the laser cell. This ensures the operational stability of the perovskite laser cell and effectively extends its service life while improving overall efficiency.

[0004] When subjected to high-intensity laser irradiation, the photoactive layer is made of material selected for its optimal response wavelength, and most of the waste heat in the power generation device is generated in the carbon layer. This heat generation not only hinders the efficient utilization of incident photons but may also affect the device's performance due to increased operating temperature. Therefore, the introduction of a heat-insulating nanocrystalline semiconductor layer becomes essential. This layer allows for the creation of a unidirectional heat-conducting channel between the photovoltaic and thermoelectric devices. This unidirectional heat-conducting channel precisely guides the direction of heat transfer, promoting heat transfer from the carbon electrode layer to the thermoelectric device and hindering heat transfer from the carbon layer to the photoactive layer, effectively mitigating the adverse effects of heat on the normal operation of the multilayer device. Summary of the Invention

[0005] In view of this, the present invention aims to overcome the defects in the prior art and proposes a photovoltaic-thermoelectric tandem laser cell based on low thermal conductivity nanocrystal embedding and its preparation method.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows: This invention provides a photovoltaic-thermoelectric tandem laser cell based on low thermal conductivity nanocrystal embedding. The laser cell is provided from top to bottom with a conductive substrate, an electron transport layer (ETL), a cesium lead bromine-based photoactive layer, a carbon electrode layer, a thermally conductive adhesive, and a thermoelectric module (TE). The cesium lead bromine-based photoactive layer contains modified low thermal conductivity nanocrystals.

[0007] Furthermore, the preparation method of the cesium lead bromide-based photoactive layer includes the following steps: dispersing modified low thermal conductivity nanocrystals in a cesium bromide solution, mixing them evenly to obtain a precursor solution, annealing the surface of the PbBr2 layer, coating it with the precursor solution, and obtaining the cesium lead bromide-based photoactive layer after heat treatment.

[0008] Furthermore, the modified low thermal conductivity nanocrystals are formed by surface grafting carboxyl groups onto antimony sulfide selenide nanocrystals; the antimony sulfide selenide nanocrystals contain at least two of antimony sulfide, antimony selenide, or antimony sulfide selenide; the modified low thermal conductivity nanocrystals are at least one of nanoparticles, nanorods, or two-dimensional nanosheets.

[0009] Furthermore, the diameter of the nanoparticles is 3-50 nm; the preparation method of the nanoparticles includes the following steps: dissolving potassium antimony tartrate, sodium thiosulfate, and sodium selenosulfate in deionized water, adding PVP, and preparing the modified low thermal conductivity nanocrystals through a hydrothermal reaction; the temperature of the hydrothermal reaction is 120-180℃, and the time is 2-6 hours; the molar ratio of potassium antimony tartrate, sodium thiosulfate, and sodium selenosulfate is 0.05-0.2:0.1-0.4:0.02-0.1; the amount of PVP added is 5-10% of the mass of potassium antimony tartrate.

[0010] The nanoparticles are enhanced by adding PVP during the hydrothermal reaction process to increase the content of surface carboxyl groups, thereby strengthening the chemical bond between the nanoparticles and cesium lead bromide. The pyrrolidone groups on the PVP molecular chain are polar groups, capable of forming non-specific adsorptions with polar sites (such as hydroxyl and carboxyl groups) on the surface of antimony sulfoselenide nanocrystals. This adsorption typically covers all exposed crystal faces of the nanocrystals, without significantly favoring any particular facet. Simultaneously, the long molecular chains of PVP form a uniform steric hindrance layer on the nanocrystal surface, preventing rapid growth of the nanoparticles in any direction. The growth rate of each crystal facet is equally suppressed, ultimately naturally leading to spherical nanoparticles with the lowest surface energy.

[0011] Furthermore, the nanorods have a diameter of 10-40 nm and a length of 50-300 nm; the preparation method of the nanorods includes the following steps: dissolving potassium antimony tartrate, sodium thiosulfate, and sodium selenosulfate in deionized water, adding sodium citrate, and preparing the modified low thermal conductivity nanocrystals through a hydrothermal reaction; the hydrothermal reaction temperature is 120-180℃, and the time is 2-6 hours; the molar ratio of potassium antimony tartrate, sodium thiosulfate, and sodium selenosulfate is 0.05-0.2:0.1-0.4:0.02-0.1; the amount of sodium citrate added is 40-80% of the mass of potassium antimony tartrate.

[0012] The nanorods described herein promote carboxyl group retention by adding sodium citrate during the hydrothermal reaction. The three carboxyl groups of sodium citrate can coordinate with Sb... 3+ The adsorption of sodium citrate onto the surface of antimony sulfoselenide nanocrystals directly introduces carboxyl groups to the surface. Simultaneously, these carboxyl groups can form hydrogen bonds with the residual tartrate ions (containing carboxyl groups) of potassium antimony tartrate, reducing carboxyl desorption and significantly increasing the surface carboxyl density. The multi-carboxyl structure of sodium citrate can selectively adsorb onto specific crystal planes of antimony sulfoselenide (such as the (001) non-polar crystal plane), inhibiting the growth of this crystal plane, while growth along the

[100] or

[010] polar crystal directions is unimpeded, thereby guiding the nanocrystals to extend along a one-dimensional direction to form rod-like structures.

[0013] Furthermore, the thickness of the two-dimensional nanosheets is 3-20 nm, and the length is less than or equal to 600 nm; the preparation method of the two-dimensional nanosheets includes the following steps: dissolving potassium antimony tartrate, sodium thiosulfate, and sodium selenosulfate in deionized water, adding disodium ethylenediaminetetraacetate, and preparing the modified low thermal conductivity nanocrystals through a hydrothermal reaction; the temperature of the hydrothermal reaction is 120-180℃, and the time is 2-6 hours; the molar ratio of potassium antimony tartrate, sodium thiosulfate, and sodium selenosulfate is 0.05-0.2:0.1-0.4:0.02-0.1; the amount of disodium ethylenediaminetetraacetate added is 20-60% of the mass of potassium antimony tartrate.

[0014] The two-dimensional nanosheets described herein promote carboxyl group retention by adding disodium ethylenediaminetetraacetate (EDTA-2Na) during the hydrothermal reaction process. EDTA-2Na, as a chelating agent containing multiple carboxyl groups, has four carboxyl groups and two amino groups; the carboxyl groups can bind with Sb on the surface of antimony sulfoselenide. 3+A stable five-membered chelate ring is formed, firmly anchoring the carboxyl groups to the surface; simultaneously, uncoordinated carboxyl groups can remain directly, increasing the surface carboxyl group density. Two-dimensional growth guidance: The molecular structure of EDTA-2Na is planar, and it can preferentially adsorb onto the layered crystal plane (001) of antimony sulfoselenide through geometric matching. The chelation effect strongly inhibits interlayer stacking (i.e., growth along the c-axis), forcing the crystal to expand only along the in-plane direction, forming thinner nanosheets.

[0015] Furthermore, the cesium bromide solution is an aqueous solution of cesium bromide or a methanol solution; the concentration of the cesium bromide solution is 200-300 mg / mL; the amount of modified nanocrystals added is 0.2-1 wt% of the mass of cesium bromide; and the temperature of the heat treatment is 230-280℃.

[0016] This invention also provides a method for fabricating a photovoltaic-thermoelectric tandem laser cell based on low thermal conductivity nanocrystal embedding, comprising the following steps: (1) A precursor solution for an electron transport layer is coated on the surface of a conductive substrate to form an electron transport layer; (2) A PbBr2 solution is spin-coated onto the surface of the electron transport layer and then heated to form a PbBr2 layer; (3) Cesium bromide and modified nanocrystals are dispersed in a solvent under heating conditions to obtain a mixed dispersion of cesium bromide-antimony sulfoselenide nanocrystals. The mixed dispersion of cesium bromide-antimony sulfoselenide nanocrystals is spin-coated onto the surface of a PbBr2 layer and then heated to obtain a cesium lead bromine-based photoactive layer. (4) A carbon paste is coated onto the cesium lead bromine-based photoactive layer to obtain a carbon electrode layer; (5) After cleaning and drying the carbon electrode layer, thermally conductive adhesive is applied to its surface, and then the thermoelectric module and the carbon electrode layer are hot-pressed together.

[0017] Furthermore, the precursor solution of the electron transport layer in step (1) contains at least one of TiO2, ZnO or SnO2; the PbBr2 solution in step (2) is an N,N-dimethylformamide solution and / or a dimethyl sulfoxide solution of PbBr2; and the temperature of the heat treatment in step (2) is 80-100℃.

[0018] Furthermore, the amount of modified nanocrystals added in step (3) is 0.2-1 wt% of cesium bromide; the temperature of the heating conditions in step (3) is 50-80℃; and the temperature of the heat treatment in step (3) is 230-280℃.

[0019] This invention first coats an electron transport layer (ETL) onto a conductive glass surface, which can be TiO2, ZnO, SnO2, etc. Then, a solution of PbBr2 in N,N-dimethylformamide and / or dimethyl sulfoxide is spin-coated onto the electron transport layer surface. After heat treatment, a PbBr2 layer is obtained. A precursor solution is then spin-coated onto the PbBr2 surface and heat-treated to obtain a photoactive layer containing / semi-inserted nanocrystals. Finally, carbon paste is coated onto the CsPbBr3 layer to prepare a carbon electrode.

[0020] The integration of the photovoltaic module and the thermoelectric module is carried out using the following method: First, the surface of the carbon layer is cleaned with isopropanol and then dried with high-pressure nitrogen. Next, a layer of thermally conductive adhesive is applied to the surface. After aligning the carbon electrode with the thermoelectric module, the thermoelectric module and the carbon electrode layer are connected together using a hot press. The structure of the tandem laser cell from bottom to top is: conductive substrate, electron transport layer, cesium lead bromine-based photoactive layer (containing embedded / semi-embedded low thermal conductivity nanocrystals), carbon electrode, thermally conductive adhesive, and thermoelectric module.

[0021] The photovoltaic-thermoelectric tandem laser cell based on low thermal conductivity nanocrystal embedding described in this invention has the following characteristics: 1. Waste heat recovery and reuse: Laser batteries generate a lot of heat when operating under high-power laser irradiation. This waste heat will reduce the photoelectric conversion efficiency and service life of the battery. By introducing a thermoelectric module, this waste heat can be converted into electrical energy, realizing secondary output of electrical energy, thereby improving the overall photoelectric conversion efficiency of the laser battery. 2. Unidirectional transmission channel: By embedding low thermal conductivity semiconductor nanocrystals into the photoactive layer, a thermal barrier structure can be formed, which can effectively prevent the reverse conduction of heat generated by the carbon electrode to the cesium lead bromine photoactive layer, effectively reducing the operating temperature of the photoactive layer and avoiding thermal performance degradation; at the same time, it can increase the hot end temperature of the thermoelectric module and increase the temperature difference of the thermoelectric module to further improve the thermoelectric conversion efficiency. 3. Active thermal management to extend lifespan: The nanocrystalline optimized stacked laser cell can maintain the laser cell within the optimal operating temperature range, improving output power stability and device lifespan. 4. Simple assembly process and low cost: The raw materials used in photovoltaic-thermoelectric laser tandem cells are relatively inexpensive, the assembly process is simple and does not use complex and expensive equipment, the assembly cycle is short and the cost is low. 5. Integrated Design: The thermoelectric module is small in size and has no moving parts. Compared with traditional heat sinks, its integration with laser batteries can achieve a compact structure, which is especially suitable for space-constrained working environments, such as spacecraft and drones. 6. Good electrical and thermal conductivity: The carbon electrode has low resistivity and high thermal conductivity, which can effectively conduct current and heat, ensuring efficient carrier transmission in the photovoltaic module while quickly transferring excess waste heat to the thermoelectric module. 7. High photoelectric conversion efficiency: High photoelectric conversion efficiency can be obtained by irradiating the photovoltaic module with a laser of the optimal light response wavelength; when the laser is irradiated with high power, the waste heat generated by the photovoltaic module is further utilized by the thermoelectric module, thereby improving the overall photoelectric conversion efficiency of the photovoltaic-thermoelectric tandem laser cell. 8. High energy transfer rate: The laser beam is flexible and movable, highly directional, and can easily achieve long-distance charging.

[0022] Compared with the prior art, the present invention has the following advantages: The photovoltaic-thermoelectric tandem laser cell based on low thermal conductivity nanocrystal embedding described in this invention integrates a carbon-based cesium lead-bromine photovoltaic cell and a thermoelectric device to assemble a photovoltaic-thermoelectric tandem laser power generation device. During high-intensity laser irradiation, the thermoelectric component in the tandem laser cell lowers the operating temperature of the photovoltaic cell, allowing it to operate in a more optimal temperature range. Furthermore, the embedding of low thermal conductivity nanocrystals further reduces the operating temperature of the photovoltaic module and isolates more heat within the thermoelectric module, enabling it to generate more electrical energy. Ultimately, this improves the overall photoelectric conversion efficiency of the power generation device while enhancing the operational stability and service life of the tandem laser cell. Lifetime: By adding low thermal conductivity nanocrystals to the photoactive layer, the photoelectric conversion efficiency of the laser power generation device is improved and its working life is effectively extended based on the improvement of the crystallinity of the photoactive layer and the separation / transport / extraction of charge carriers in the device by nanocrystal embedding. On the other hand, the heat conduction flux from the carbon layer to the cesium lead bromine layer is significantly suppressed, and a directional and efficient heat transport path is constructed, thereby reducing the working temperature of the photoactive layer in the photovoltaic module, increasing the temperature of the hot end in the thermoelectric device, ensuring the temperature difference between the hot and cold ends of the thermoelectric device, realizing active thermal management of the stacked device, and effectively ensuring the working efficiency of the laser power generation device.

[0023] The photovoltaic-thermoelectric tandem laser cell based on low thermal conductivity nanocrystal embedding described in this invention solves the technical problems that laser power generation devices may face, such as limited energy conversion efficiency, insufficient long-term operational reliability, and imperfect thermal control methods. By constructing an integrated structure of carbon-based CsPbBr3 photovoltaic module and thermoelectric conversion unit, the tandem device can maintain the photovoltaic module within a good operating temperature range under strong laser irradiation environment through the thermal management effect of the nanocrystal embedded / semi-embedded photoactive layer, thereby improving the photoelectric conversion efficiency of the tandem system. At the same time, by introducing ultra-low thermal conductivity nanocrystal materials into the light absorption layer, the crystal quality of the photoactive layer is optimized, and carrier recombination is reduced. While improving energy conversion efficiency, a thermal barrier is constructed from the carbon electrode to the photoactive layer, realizing directional heat transport and ensuring the temperature difference between the hot and cold ends of the thermoelectric module. Attached Figure Description

[0024] Figure 1This is a schematic diagram of the low thermal conductivity nanocrystalline photovoltaic-thermoelectric tandem laser cell described in Embodiment 1 of the present invention. Detailed Implementation

[0025] Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; and the experimental methods described are conventional methods.

[0026] The present invention will be described in detail below with reference to embodiments.

[0027] Example 1 A photovoltaic-thermoelectric tandem laser cell based on low thermal conductivity nanocrystal embedding includes the following steps: (1) Coating a titanium dioxide electron transport layer onto the surface of conductive glass; (2) A PbBr2 layer was obtained by spin-coating a solution of N,N-dimethylformamide and dimethyl sulfoxide (volume ratio of N,N-dimethylformamide and dimethyl sulfoxide was 4:1) onto the surface of the electron transport layer and then heating it at 90°C. (3) Dissolve potassium antimony tartrate, sodium thiosulfate and sodium selenose in deionized water with a molar ratio of 0.2:0.4:0.05, add PVP with an antimony source content of 5%, and carry out hydrothermal reaction at 140°C for 2 hours to obtain the modified antimony thioselenate nanoparticles. (4) Weigh 0.4% of modified antimony sulfide selenide nanoparticles, uniformly disperse the modified antimony sulfide selenide nanocrystals and cesium bromide in water, and sonicate under heating at 60°C to obtain a mixed dispersion of cesium bromide-nanocrystals (the concentration of cesium bromide is 250 mg / mL). Keep the above solution at 65°C for later use. Spin-coat the above solution onto the surface of PbBr2 and heat it at 250°C to obtain a photoactive layer with embedded / semi-embedded nanocrystals. (5) A carbon electrode was prepared by coating a CsPbBr3 layer with carbon paste; (6) After cleaning the carbon layer surface with isopropanol, the surface is dried with high-pressure nitrogen. Then, a layer of thermally conductive adhesive is brushed onto the surface. After aligning the carbon electrode with the thermoelectric module, the thermoelectric module and the carbon electrode layer are connected together by a hot press. The structure of the stacked laser cell from bottom to top is: conductive substrate, electron transport layer, cesium lead bromine-based photoactive layer (containing embedded / semi-embedded low thermal conductivity nanocrystals), carbon electrode, thermally conductive adhesive, and thermoelectric module. Based on the fact that the hot end temperature of the thermoelectric module increases by 10 degrees after the nanocrystals are embedded, the temperature of the cesium lead bromine photoactive layer of the photoelectric module decreases by 10 degrees. This is beneficial to the improvement of the conversion efficiency of the thermoelectric module and allows the photoelectric module to work in a better temperature range. The photoelectric conversion efficiency of the stacked laser cell (laser wavelength of 520nm) after embedding nanocrystals increases from the original 53% to 60%, and the working stability increases from the original 85% of the initial efficiency maintained for 5 hours to 96%.

[0028] Example 2 A photovoltaic-thermoelectric tandem laser cell based on low thermal conductivity nanocrystal embedding includes the following steps: (1) Coating a titanium dioxide electron transport layer onto the surface of conductive glass; (2) A PbBr2 layer was obtained by spin-coating a solution of N,N-dimethylformamide and dimethyl sulfoxide (volume ratio of N,N-dimethylformamide and dimethyl sulfoxide was 4:1) onto the surface of the electron transport layer and then heating it at 90°C. (3) Dissolve potassium antimony tartrate, sodium thiosulfate and sodium selenose in deionized water with a molar ratio of 0.2:0.4:0.05, add sodium citrate with an antimony source content of 60%, and carry out hydrothermal reaction at 140°C for 3 hours to obtain the modified antimony thioselenate nanorods. (4) Weigh 0.4% of modified antimony sulfide selenide nanorods, uniformly disperse the modified antimony sulfide selenide nanorods and cesium bromide in water, and sonicate under heating at 65°C to obtain a mixed dispersion of cesium bromide-nanocrystalline (the concentration of cesium bromide is 250 mg / mL). Keep the above solution at 65°C for later use. Spin-coat the above solution onto the surface of PbBr2 and heat it at 250°C to obtain a photoactive layer with embedded / semi-embedded nanocrystalline. (5) A carbon electrode was prepared by coating a CsPbBr3 layer with carbon paste; (6) After cleaning the carbon layer surface with isopropanol, the surface is dried with high-pressure nitrogen. Then, a layer of thermally conductive adhesive is brushed onto the surface. After aligning the carbon electrode with the thermoelectric module, the thermoelectric module and the carbon electrode layer are connected together by a hot press. The structure of the stacked laser cell from bottom to top is: conductive substrate, electron transport layer, cesium lead bromine-based photoactive layer (containing embedded / semi-embedded low thermal conductivity nanorods), carbon electrode, thermally conductive adhesive, and thermoelectric module. Based on the fact that the hot end temperature of the thermoelectric module increases by 8 degrees after nanocrystal embedding, and the temperature of the cesium lead bromine photoactive layer of the photoelectric module decreases by 9 degrees, this is beneficial to the improvement of the conversion efficiency of the thermoelectric module and allows the photoelectric module to work in a better temperature range. The photoelectric conversion efficiency of the stacked laser cell (laser wavelength of 520nm) after embedding nanocrystals increases from the original 53% to 59%, and the working stability increases from the original 85% of the initial efficiency maintained for 5 hours to 94%.

[0029] Example 3 A photovoltaic-thermoelectric tandem laser cell based on low thermal conductivity nanocrystal embedding includes the following steps: (1) Coating a titanium dioxide electron transport layer onto the surface of conductive glass; (2) A PbBr2 layer was obtained by spin-coating a solution of N,N-dimethylformamide and dimethyl sulfoxide (volume ratio of N,N-dimethylformamide and dimethyl sulfoxide was 4:1) onto the surface of the electron transport layer and then heating it at 90°C. (3) Dissolve potassium antimony tartrate, sodium thiosulfate and sodium selenose in deionized water with a molar ratio of 0.2:0.4:0.05, add disodium ethylenediaminetetraacetate with an antimony source content of 30%, and carry out hydrothermal reaction at 150°C for 2 hours to obtain the modified antimony thioselenate two-dimensional nanosheets. (4) Weigh 0.4% of modified antimony sulfide selenide two-dimensional nanosheets, uniformly disperse the modified antimony sulfide selenide two-dimensional nanosheets and cesium bromide in water, and sonicate under heating at 60°C to obtain a cesium bromide-nanocrystalline mixed dispersion (the concentration of cesium bromide is 250 mg / mL). Keep the above solution at 65°C for later use. Spin-coat the above solution onto the surface of PbBr2 and heat it at 250°C to obtain a photoactive layer with embedded / semi-embedded nanocrystals. (5) A carbon electrode was prepared by coating a CsPbBr3 layer with carbon paste; (6) After cleaning the carbon layer surface with isopropanol, the surface is dried with high-pressure nitrogen. Then, a layer of thermally conductive adhesive is brushed onto the surface. After aligning the carbon electrode with the thermoelectric module, the thermoelectric module and the carbon electrode layer are connected together by a hot press. The structure of the stacked laser cell from bottom to top is: conductive substrate, electron transport layer, cesium lead bromine-based photoactive layer (containing embedded / semi-embedded low thermal conductivity nanocrystals), carbon electrode, thermally conductive adhesive, and thermoelectric module. Based on the fact that the hot end temperature of the thermoelectric module increases by 9 degrees after the nanocrystals are embedded, the temperature of the cesium lead bromine photoactive layer of the photoelectric module decreases by 10 degrees, which is beneficial to the improvement of the conversion efficiency of the thermoelectric module and allows the photoelectric module to work in a better temperature range. The photoelectric conversion efficiency of the stacked laser cell (laser wavelength of 520nm) after embedding nanocrystals increases from the original 53% to 57%, and the working stability increases from the original 85% of the initial efficiency maintained for 5 hours to 93%.

[0030] Example 4 A method for fabricating a low thermal conductivity nanocrystalline photovoltaic-thermoelectric tandem laser cell includes the following steps: (1) Coating a titanium dioxide electron transport layer onto the surface of conductive glass; (2) A PbBr2 layer was obtained by spin-coating a solution of N,N-dimethylformamide and dimethyl sulfoxide (volume ratio of N,N-dimethylformamide and dimethyl sulfoxide was 4:1) onto the surface of the electron transport layer and then heating it at 90°C. (3) Weigh 1% of modified antimony sulfide selenide nanocrystals by mass, and uniformly disperse the modified antimony sulfide selenide nanocrystals and cesium bromide in water. Under the condition of heating at 60°C, sonicate to obtain a mixed dispersion of cesium bromide-nanocrystals (the concentration of cesium bromide is 250 mg / mL). Keep the above solution at 65°C for later use. Spin-coat the above solution onto the surface of PbBr2 and heat it at 250°C to obtain a photoactive layer with embedded / semi-embedded nanocrystals. (4) A carbon electrode was prepared by coating a CsPbBr3 layer with carbon paste; (5) After cleaning the surface of the carbon layer with isopropanol, the surface is dried with high-pressure nitrogen. Then, a layer of thermally conductive adhesive is brushed on the surface. After aligning the carbon electrode with the thermoelectric module, the thermoelectric module and the carbon electrode layer are connected together by a hot press.

[0031] The photoelectric conversion efficiency of the laser tandem solar cell assembled based on this nanocrystal embedding is 58%, and the photoelectric efficiency is 93% of the initial efficiency value after 5 hours of operation.

[0032] Comparative Example 1 The only difference from Example 1 is that the modified antimony sulfide nanocrystals are replaced with copper sulfide nanocrystals. The preparation method of copper sulfide nanocrystals includes the following steps: dissolving 0.1g of acetone and 0.125g of thiourea in 50mL of deionized water, stirring evenly, and then hydrothermally heating at 140℃ for 5 hours. After centrifuging and washing the product, copper sulfide nanocrystals are obtained.

[0033] Copper sulfide nanocrystals exhibit significantly higher thermal conductivity than antimony sulfide selenide nanocrystals. The laser tandem solar cell assembled using these nanocrystals achieved a photoelectric conversion efficiency of 49%, reaching 81% of its initial efficiency after 5 hours of operation. All related performance parameters are lower than those of the device optimized using antimony sulfide selenide nanocrystals.

[0034] The only difference between Comparative Example 2 and Example 1 is that the preparation method of the antimony sulfoselenide nanoparticles is as follows: potassium antimony tartrate, sodium thiosulfate, and sodium selenosulfate in a molar ratio of 0.2:0.4:0.05 are dissolved in deionized water and subjected to a hydrothermal reaction at 140°C for 2 hours to obtain the modified antimony sulfoselenide nanoparticles. After embedding the nanoparticles synthesized without PVP into a cesium lead bromide photoactive layer, the assembled stacked device exhibits a photoelectric conversion efficiency of 56%, and after 5 hours of operation, the photoelectric efficiency reaches 90% of the initial efficiency value.

[0035] Comparative Example 3 The only difference from Example 1 is that no nanocrystals were added. The device's photoelectric conversion efficiency is 53%, and after 5 hours of operation, the photoelectric efficiency reaches 85% of the initial efficiency value.

[0036] The batteries obtained from each embodiment and the comparative example were tested, and the results are shown in Table 1.

[0037] Table 1 Test Results As shown in Table 1, the experimental results of the examples and comparative examples demonstrate that the photoelectric conversion efficiency and operational stability of the tandem solar cell device are significantly improved through the embedding of antimony sulfide selenide nanocrystals. This is attributed to the improvement in the crystal quality of the photoactive layer by the nanocrystals and the optimization of the carrier separation and extraction process at the interface between the photoactive layer and the carbon electrode. The construction of unidirectional heat transfer channels near the carbon layer by the nanocrystals also ensures that the photovoltaic module operates within its optimal temperature range and that the temperature difference between the hot and cold ends in the thermoelectric module is minimized. A comparison of the photoelectric performance of devices assembled with and without the addition of surfactants that retain carboxyl groups during the synthesis of the nanoparticles shows that the carboxyl groups on the surface of the nanocrystals also contribute to the improved photoelectric performance by promoting the chemical bonding between the nanocrystals and cesium, lead, and bromine.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A photovoltaic-thermoelectric stack laser cell based on low thermal conductivity nanocrystal embedding, characterized by: The laser cell is sequentially provided with a conductive base, an electron transport layer, a cesium lead bromide-based photoactive layer, a carbon electrode layer, a heat-conducting glue and a thermoelectric module from top to bottom.

2. The low thermal conductivity nanocrystal-embedded photovoltaic-thermoelectric stack laser cell of claim 1, wherein: The preparation method of the cesium lead bromide-based photoactive layer comprises the following steps: dispersing the modified low-thermal-conductivity nanocrystals in a cesium bromide solution, uniformly mixing to obtain a precursor solution, performing annealing treatment on the surface of a PbBr2 layer, then coating the precursor solution, and performing heat treatment to obtain the cesium lead bromide-based photoactive layer.

3. The low thermal conductivity nanocrystal-embedded photovoltaic-thermoelectric stack laser cell of claim 2, wherein: The modified low-thermal-conductivity nanocrystals are formed by grafting carboxyl groups on the surface of antimony sulfoselenide nanocrystals; the antimony sulfoselenide nanocrystals contain at least two of antimony sulfide, antimony selenide or antimony sulfoselenide; and the modified low-thermal-conductivity nanocrystals are at least one of nanoparticles, nanorods or two-dimensional nanosheets.

4. The low thermal conductivity nanocrystal-embedded photovoltaic-thermoelectric stack laser cell of claim 3, wherein: The diameter of the nanoparticles is 3-50 nm; the preparation method of the nanoparticles comprises the following steps: dissolving potassium antimonyl tartrate, sodium thiosulfate and sodium selenosulfate in deionized water, adding PVP thereto, and preparing the modified low-thermal-conductivity nanocrystals through hydrothermal reaction; the temperature of the hydrothermal reaction is 120-180 DEG C, and the time is 2-6 hours; the molar ratio of the potassium antimonyl tartrate, the sodium thiosulfate and the sodium selenosulfate is 0.05-0.2:0.1-0.4:0.02-0.1; and the addition amount of the PVP is 5-10% of the mass of the potassium antimonyl tartrate.

5. The low thermal conductivity nanocrystal-embedded photovoltaic-thermoelectric stack laser cell of claim 3, wherein: The diameter of the nanorods is 10-40 nm, and the length is 50-300 nm; the preparation method of the nanorods comprises the following steps: dissolving potassium antimonyl tartrate, sodium thiosulfate and sodium selenosulfate in deionized water, adding sodium citrate thereto, and preparing the modified low-thermal-conductivity nanocrystals through hydrothermal reaction; the temperature of the hydrothermal reaction is 120-180 DEG C, and the time is 2-6 hours; the molar ratio of the potassium antimonyl tartrate, the sodium thiosulfate and the sodium selenosulfate is 0.05-0.2:0.1-0.4:0.02-0.1; and the addition amount of the sodium citrate is 40-80% of the mass of the potassium antimonyl tartrate.

6. The low thermal conductivity nanocrystal-embedded photovoltaic-thermoelectric stack laser cell of claim 3, wherein: The thickness of the two-dimensional nanosheets is 3-20 nm, and the length is less than or equal to 600 nm; the preparation method of the two-dimensional nanosheets comprises the following steps: dissolving potassium antimonyl tartrate, sodium thiosulfate and sodium selenosulfate in deionized water, adding disodium ethylenediaminetetraacetate thereto, and preparing the modified low-thermal-conductivity nanocrystals through hydrothermal reaction; the temperature of the hydrothermal reaction is 120-180 DEG C, and the time is 2-6 hours; the molar ratio of the potassium antimonyl tartrate, the sodium thiosulfate and the sodium selenosulfate is 0.05-0.2:0.1-0.4:0.02-0.1; and the addition amount of the disodium ethylenediaminetetraacetate is 20-60% of the mass of the potassium antimonyl tartrate.

7. The low thermal conductivity nanocrystal-embedded photovoltaic-thermoelectric stack laser cell of claim 2, wherein: The cesium bromide solution is an aqueous solution or a methanol solution of cesium bromide; the concentration of the cesium bromide solution is 200-300 mg / mL; the addition amount of the modified nanocrystals is 0.2-1 wt% of the mass of the cesium bromide; and the temperature of the heat treatment is 230-280 DEG C.

8. The method for the production of a low thermal conductivity nanocrystal-embedded photovoltaic-thermoelectric stack laser cell according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: (1) coating a precursor solution of an electron transport layer on the surface of a conductive substrate to form an electron transport layer; (2) spin-coating a PbBr2 solution on the surface of the electron transport layer, and then performing a heating treatment to form a PbBr2 layer; (3) dispersing cesium bromide and modified nanocrystals in a solvent under heating to obtain a mixed dispersion liquid of cesium bromide and antimony sulfoselenide nanocrystals, spin-coating the mixed dispersion liquid on the surface of the PbBr2 layer, and then performing a heating treatment to obtain a cesium-lead-bromine-based photoactive layer; (4) applying a carbon paste on the cesium-lead-bromine-based photoactive layer by doctor blading to obtain a carbon electrode layer; (5) cleaning and drying the carbon electrode layer, coating a heat-conducting adhesive on the surface of the carbon electrode layer, and then performing a hot pressing of a thermoelectric module and the carbon electrode layer.

9. The method for preparing a low thermal conductivity nanocrystal-embedded photovoltaic-thermoelectric laminated laser cell according to claim 8, characterized in that: The precursor solution of the electron transport layer in step (1) contains at least one of TiO2, ZnO or SnO2; the PbBr2 solution in step (2) is a PbBr2 solution in N,N-dimethylformamide and / or dimethyl sulfoxide; and the heating treatment in step (2) is performed at a temperature of 80-100℃.

10. The method of claim 8, wherein the method further comprises: The modified nanocrystals in step (3) are added in an amount of 0.2-1wt% of the cesium bromide; the heating condition in step (3) is performed at a temperature of 50-80℃; and the heating treatment in step (3) is performed at a temperature of 230-280℃.

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