A method for improving the output performance of optoelectronic materials by utilizing light-heat coupling

Abstract

The present invention provides a method for improving the output performance of photoelectric materials by using light-heat coupling, which generates electrons and then generates electromotive force by using the photoelectric effect of the material, and at the same time increases the temperature difference between the two ends of the thermoelectric material to improve the thermoelectric effect conversion efficiency of the material. Compared with the existing thermoelectric conversion method, the present invention further improves the conversion efficiency of thermoelectric materials by using the method of coupling the photoelectric effect and the thermoelectric effect. The preparation process of the present invention is pollution-free, and the preparation method is simple, convenient, economical and practical.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic material power generation, and in particular relates to a method for improving the output performance of photovoltaic materials by utilizing light-heat coupling. Background Art

[0002] As an environmentally friendly technology that converts thermal energy into electrical energy, thermoelectric technology can convert thermal energy and electrical energy into each other, has excellent reliability and availability, and has received widespread attention. However, their widespread application is hindered by their relatively low energy conversion efficiency. The thermoelectric conversion efficiency of thermoelectric materials mainly depends on the figure of merit ZT. With the advancement of technology, how to improve the ZT value has become one of the urgent problems to be solved in the near future. In general, the ZT value of optoelectronic materials is less than 2. However, the ZT value is still not large enough to meet the requirements of reality.

[0003] γ-CuI is a wide-gap semiconductor with high hole mobility and p-type conductivity. In view of the insufficient output efficiency of the thermoelectric effect, the photoelectric effect is also a feasible and simple method to generate electromotive force. The applicant proposes to combine the thermoelectric effect with the photoelectric effect to improve the electromotive force of thermoelectric materials and construct a new photo-thermoelectric material coupling system. Therefore, the present invention proposes a new method to improve the conversion efficiency of thermoelectric materials through the photo-thermoelectric coupling effect. Make up for the shortcomings and defects of a single photoelectric material and maximize the use of light energy to improve the output efficiency of thermoelectric conversion. Therefore, the present invention has obvious technical advancement and practical application prospects. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above problems and the problems existing in the prior art, the present invention is proposed.

[0006] Therefore, the object of the present invention is to provide a method for improving the output performance of photovoltaic materials by utilizing light-heat coupling, so as to improve the power generation efficiency of photovoltaic materials in the prior art.

[0007] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solution: a method for improving the output performance of optoelectronic materials by utilizing light-heat coupling, comprising:

[0008] The treated substrate is placed on a constant temperature heat source, and two insulating cooling devices are placed above the substrate. There is a certain gap between the two cooling devices, and there is a temperature difference between the heat source and the cold source. The light source irradiates the sample through the gap to form a voltage.

[0009] As a preferred solution of the method of improving the output performance of optoelectronic materials by utilizing light-heat coupling according to the present invention, the substrate treatment includes:

[0010] The substrate was immersed in a cation precursor solution for 10 seconds, and the substrate was rinsed with deionized water for 5 seconds to remove cations that were not stably adsorbed on the surface. The substrate was then immersed in an anion precursor solution for 20 seconds, and the substrate was rinsed with deionized water for 5 seconds to remove powdery substances or loosely bound ions.

[0011] The above steps are repeated 40 times as a cycle to obtain a treated base material. Finally, the treated base material is dried in air at room temperature.

[0012] As a preferred embodiment of the method for improving the output performance of optoelectronic materials by utilizing light-heat coupling of the present invention, the substrate is a pretreated N-type Si substrate; the cationic precursor solution contains 100 ml of 0.1 mol / dm 3 CuSO4·5H2O and 40ml 0.1mol / dm 3 The anion precursor solution is 0.025 mol / dm 3 Aqueous solution of KI; the treated substrate material forms a P-type transparent γ-CuI film on the surface of the Si substrate.

[0013] As a preferred solution of the method of improving the output performance of optoelectronic materials by utilizing light-heat coupling of the present invention, the pretreatment comprises ultrasonically cleaning the N-type Si substrate in 95% ethanol and acetone for 15 minutes respectively.

[0014] As a preferred solution of the method of improving the output performance of optoelectronic materials by utilizing light-heat coupling described in the present invention, the size of the substrate is 10×10×0.65 mm.

[0015] As a preferred solution of the method of improving the output performance of optoelectronic materials by utilizing light-heat coupling as described in the present invention, the constant temperature heat source is a 200mm×150mm adjustable temperature constant temperature heating plate, and the temperature difference at both ends of the sample is adjusted by changing the temperature of the heating plate.

[0016] As a preferred solution of the method of improving the output performance of optoelectronic materials by utilizing light-heat coupling as described in the present invention, the insulating cooling device is an aluminum cooling device wrapped with two 40mm×80mm×12mm insulating tapes, and constant temperature water is passed into the device, and the water is continuously circulated to ensure the constant temperature of the cooling device.

[0017] As a preferred solution of the method of improving the output performance of optoelectronic materials by utilizing light-heat coupling described in the present invention, the light source is an incandescent lamp.

[0018] As a preferred solution of the method of improving the output performance of optoelectronic materials by utilizing light-heat coupling described in the present invention, the light source is an incandescent lamp with a power of 30W and a wavelength between 400 and 780nm, and the total illumination time is within 5s.

[0019] As a product obtained by the method of improving the output performance of optoelectronic materials by utilizing light-heat coupling according to the present invention, wherein: the application includes,

[0020] The base, the insulating cooling device and the constant temperature heat source together constitute a power source, which is used after forming a closed loop.

[0021] Beneficial effects of the present invention:

[0022] The present invention utilizes the photoelectric effect of the material to generate electrons and then generate electromotive force, while increasing the temperature difference between the two ends of the thermoelectric material to improve the thermoelectric effect conversion efficiency of the material. Compared with the existing thermoelectric conversion method, the present invention further improves the conversion efficiency of the thermoelectric material by coupling the photoelectric effect and the thermoelectric effect. The preparation process of the present invention is pollution-free, and the preparation method is simple, convenient, economical and practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0024] Figure 1 This is the experimental principle diagram of the photothermal coupling structure;

[0025] Figure 2 The surface SEM microscopic morphology of the γ-CuI film prepared by the SILAR method;

[0026] Figure 3 The surface SEM microscopic morphology of the thickness of the γ-CuI film prepared by the SILAR method;

[0027] Figure 4 is the X-ray diffraction pattern of γ-CuI thin film;

[0028] Figure 5 is the optical transmittance spectrum of γ-CuI film;

[0029] Figure 6 This is a comparison chart of the relationship between the output voltage and temperature difference of the material. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with specific embodiments.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0033] In order to achieve the above object, the present invention provides the following technical solutions:

[0034] A method for improving the conversion performance of photoelectric materials by using light-heat coupling. In the scheme, a P-type transparent γ-CuI photoelectric material and an N-type Si are connected to form a photoelectric couple, a heat source is provided at one end, and a cold source is provided at the other end, forming a fixed temperature difference to generate an electromotive force by using the thermoelectric effect. After forming a closed loop with an external circuit, the electrons diffused to the cold end of the N-type semiconductor due to the Seebeck effect will flow to the cold end of the P-type semiconductor through the wire and the load, and will recombine and disappear with the holes that also diffused and gathered to the cold end of the P-type semiconductor due to the Seebeck effect. Similarly, at the hot end, the electrons in the closed loop (through the conductive metal sheet) flow from the hot end of the P-type semiconductor to the hot end of the N-type semiconductor, so that the movement of electrons and holes generated by the Seebeck effect can be maintained. At the same time, a stable light source is used to irradiate the material, and photons are converted into electrons, and then voltage is formed.

[0035] Therefore, this paper proposes a new method to improve the output voltage of materials through the photo-thermoelectric coupling effect. γ-CuI-Si is prepared as a test sample. The photo-thermoelectric coupling effect is evaluated by measuring the output voltage of the sample.

[0036] All raw materials used in the following examples are commercially available products.

[0037] Embodiment 1:

[0038] Preparation of γ-CuI thin film for photoelectric materials:

[0039] The γ-CuI thin film was deposited on a Si substrate with a size of 10×10×0.65 mm at room temperature using the SILAR method. The cationic precursor solution contained 100 ml of 0.1 mol / dm 3 CuSO4·5H2O and 40ml0.1mol / dm 3 Na2S2O3 and releases Cu through the following reversible reaction + :

[0040]

[0041] This reaction acts as a cation source. 0.025 mol / dm 3 An aqueous solution of KI was used as an anion precursor. The Si substrate was ultrasonically cleaned in 95% ethanol and acetone for 15 min, respectively.

[0042] First, the Si substrate was immersed in the cationic precursor solution for 10 seconds to absorb Cu on the substrate surface. + Then, the Si substrate was rinsed with deionized water for 5 seconds to remove the unstably adsorbed Cu + ions. Then, the substrate was immersed in the anion precursor solution for 20 seconds, and then the substrate was rinsed in deionized water for 5 seconds to remove powdery substances or loosely bound ions. The above steps were repeated 40 times as a cycle to obtain a Si substrate material covered with a γ-CuI film. Finally, the Si substrate material was air-dried at room temperature.

[0043] The scanning electron microscope (SEM) morphology of the treated substrate surface is as follows Figure 2 , Figure 3 shown. Figure 3 The cross section of the surface of the material is at an angle of 30 degrees to the bottom. The bottom is a layered network structure with flaky and granular structures arranged vertically on the network structure. The film thickness is about 1.73μm. As the number of cycles increases, the network structure cannot be stably superimposed and then breaks, forming a large number of flaky structures. At the same time, voids are formed inside the film, resulting in a significant increase in thickness. The granular and flaky solids on the surface of the film cause the surface of the film to become rough.

[0044] Embodiment 2:

[0045] Characterization and Measurements:

[0046] The crystal structure of CuI thin film was confirmed by X-ray diffraction. The optical properties of the film were measured and analyzed by UV-VIS-NIR spectrophotometer (UV-3600, Shimadzu). All measurements were performed at room temperature.

[0047] Specific as Figure 4-5 shown.

[0048] Figure 4 This is the X-ray diffraction pattern of the γ-CuI film. The main diffraction peaks are (111), (220) and (311) of the γ-CuI zinc blende structure, which are consistent with the values ​​in the standard card. All diffraction peaks are pure face-centered cubic structure of γ-CuI. It is worth noting that the (111) peak is the highest of the three narrow and sharp peaks, which indicates that the γ-CuI single crystal grows on the Si substrate through the preferential growth orientation of 111. No other impurities are found in the γ-CuI film. This shows that the γ-CuI film prepared by this method has a high purity.

[0049] Figure 5 is the optical transmission spectrum of γ-CuI film. Figure 5 It can be seen that the γ-CuI film has high transmittance and considerable absorption. The transmittance in the visible light range is generally above 60%. The results show that when the CuI-Si heterojunction is illuminated, the photovoltaic effect mainly occurs on the contact surface between the Si wafer and the CuI film.

[0050] Embodiment 3:

[0051] Method implementation:

[0052] The sample was placed on a 200mm×150mm constant temperature heating plate with adjustable temperature. Two 40mm×80mm×12mm aluminum cooling devices wrapped with insulating tape were placed above the sample, with a 1.5mm interval between the aluminum cooling devices, and the light source irradiated the sample through the interval.

[0053] Inject 15℃ constant temperature water into the cooling device, and the water circulates to ensure the constant temperature of the cooling device. The temperature difference at both ends of the sample is adjusted by changing the temperature of the heating plate. The light source is an incandescent lamp with a power of 30W and a wavelength between 400 and 780nm. The total illumination time is strictly controlled within 5s to avoid temperature changes of the sample caused by illumination. The light-thermal coupling effect of the sample is evaluated by measuring the output voltage.

[0054] In the experiment, the output voltages of the photoelectric effect, thermoelectric effect and photothermoelectric coupling were measured under the same conditions. The results are shown in Table 1 and Figure 6 shown.

[0055] Table 1 Output voltages of photoelectric effect, thermoelectric effect and photothermoelectric coupling under different temperature differences

[0056]

[0057]

[0058] It can be seen from Table 1 that the output voltage of the photothermoelectric coupling effect is significantly greater than the sum of the output voltages of the photoelectric effect and the thermoelectric effect. Figure 6The output voltage of the sample is shown as a function of temperature. We measured the output voltage of the sample under different physical conditions, including temperature difference, illumination, and their coupling. As the temperature difference increases, the output voltage of the sample gradually increases, and for illumination, the voltage decreases significantly with increasing temperature. There is a large difference in the effect of the heating plate temperature on the output voltages of the thermoelectric voltage and the photovoltaic voltage. The photovoltaic voltage is greatly affected by temperature, and when the temperature increases from 290K to 373K, the output voltage decreases from 25.93mV to 10.53mV. Under the same conditions, the output voltage of the thermoelectric effect increases by 3.30mV. Their output voltages show opposite trends with increasing temperature, which indicates that the output voltages have the potential to compensate each other at different temperatures.

[0059] Therefore, the photo-thermoelectric coupling method was proposed to obtain a larger sample output voltage. It can be concluded that the photo-thermoelectric coupling effect will provide a potential method for further improving the output voltage of thermoelectric materials. The mechanism of the photo-thermoelectric coupling effect phenomenon may be caused by the accelerated movement of photoexcited charge carriers under the influence of temperature gradient. In addition, this strategy is an effective method to further improve the output performance of other thermoelectric materials.

[0060] The present invention utilizes the photoelectric effect of the material to generate electrons and then generate electromotive force, while increasing the temperature difference between the two ends of the thermoelectric material to improve the thermoelectric effect conversion efficiency of the material. Compared with the existing thermoelectric conversion method, the present invention further improves the conversion efficiency of the thermoelectric material by coupling the photoelectric effect and the thermoelectric effect. The preparation process of the present invention is pollution-free, and the preparation method is simple, convenient, economical and practical.

[0061] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for improving the output performance of optoelectronic materials by utilizing light-heat coupling, characterized in that: include, The substrate was immersed in a cation precursor solution for 10 seconds, and the substrate was rinsed with deionized water for 5 seconds to remove cations that were not stably adsorbed on the surface. The substrate was then immersed in an anion precursor solution for 20 seconds, and the substrate was rinsed with deionized water for 5 seconds to remove powdery substances or loosely bound ions. The above steps are repeated 40 times as a cycle to obtain a treated substrate material. Finally, the treated substrate material is dried in air at room temperature. The substrate is a pretreated N-type Si substrate, and the cationic precursor solution contains 100 ml of 0.1 mol / dm 3 CuSO4·5H2O and 40ml 0.1mol / dm 3 of Na2S2O3; the anion precursor solution is 0.025 mol / dm 3 KI aqueous solution; the treated substrate material forms a P-type transparent γ-CuI film on the surface of the Si substrate; The treated substrate material is placed on a constant temperature heat source, and two insulating cooling devices are placed above the substrate. There is a gap between the two cooling devices, and there is a certain temperature difference between the heat source and the cold source. The light source irradiates the sample through the gap to form a voltage. The light source is an incandescent lamp with a power of 30 W and a wavelength between 400 and 780 nm, and the total illumination time is within 5 s.

2. The method for improving the output performance of optoelectronic materials by utilizing light-heat coupling as claimed in claim 1, characterized in that: The pretreatment includes ultrasonically cleaning the N-type Si substrate in 95% ethanol and acetone for 15 minutes respectively.

3. The method for improving the output performance of optoelectronic materials by utilizing light-heat coupling as claimed in claim 2, characterized in that: The substrate size is 10×10×0.65 mm.

4. The method for improving the output performance of optoelectronic materials by utilizing light-heat coupling as claimed in claim 1, characterized in that: The constant temperature heat source is a 200 mm×150 mm temperature-adjustable constant temperature heating plate, and the temperature difference between the two ends of the sample is adjusted by changing the temperature of the heating plate.

5. The method for improving the output performance of optoelectronic materials by utilizing light-heat coupling as claimed in claim 1, characterized in that: The insulating cooling device is an aluminum cooling device wrapped with two 40 mm×80 mm×12 mm insulating tapes. Constant temperature water is passed into the device, and the water circulates continuously to ensure the constant temperature of the cooling device.

6. A product using the method for improving the output performance of optoelectronic materials by utilizing light-heat coupling as claimed in any one of claims 1 to 5, characterized in that: The application includes, The base, the insulating cooling device and the constant temperature heat source together constitute a power source, which is used after forming a closed loop.

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