Method for testing P-N junction temperature of perovskite photovoltaic cell

Abstract

The invention belongs to the technical field of solar cells, and particularly relates to a method for testing the P-N junction temperature of a perovskite photovoltaic cell. The method for testing the P-N junction temperature of the perovskite photovoltaic cell provided by the invention comprises the following steps: (1) coating a temperature-sensitive material on the surface of pretreated transparent conductive glass, and drying to form a temperature-sensitive material layer; (2) sequentially preparing a hole transport layer, a perovskite layer, an electron transport layer and an electrode layer on the surface of the prepared temperature-sensitive material layer; and (3) connecting the metal strip with the non-active area of the temperature-sensitive material layer in series, leading out a test end, packaging with optical glass or ultra-white glass, and calculating the temperature of the test end through the linear change of the resistance of the test end. According to the method, the temperature-sensitive material is introduced at the position, close to the light absorption layer (namely the p-n junction), of the inner side of the perovskite cell packaging glass, the influence of the glass and the environment temperature on the P-N junction temperature test can be effectively reduced, and therefore the more accurate and reliable perovskite photovoltaic cell P-N junction temperature can be obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and in particular relates to a method for testing the PN junction temperature of a perovskite photovoltaic cell. Background Art

[0002] In recent years, with the rapid growth in efficiency of perovskite solar cells, they have gradually become the most promising technology in the photovoltaic industry. Testing the PN junction temperature (or junction temperature for short) is crucial for the reliability, stability, and performance optimization of perovskite photovoltaic devices. It can be used to assess the thermal stability of perovskite cells during operation and has a crucial impact on the failure rate and lifespan of the devices. However, because perovskite cells are typically fabricated on glass substrates and their functional layers are relatively thin (typically <1μm), accurate and reliable measurement of their PN junction temperature is difficult.

[0003] Existing photovoltaic device PN junction temperature testing technology mainly relies on indirect measurement methods, such as: (1) backplane temperature estimation method, which estimates the PN junction temperature by measuring the backplane temperature of the solar cell module; (2) NOCT (Nominal Operating Cell Temperature) method, which calculates the actual operating temperature of the solar cell based on the linear relationship between the difference between the operating temperature of the solar cell and the ambient temperature and the solar irradiation; (3) thermal imager measurement method, which uses a thermal imager to measure the surface temperature of the solar cell module non-contactly. Although this cannot directly measure the temperature of the PN junction, it can provide useful information about the battery temperature distribution; (4) simulation and calculation method: Using computer simulation and calculation methods, combined with the physical model and operating conditions of the solar cell, the PN junction temperature can be predicted.

[0004] Currently, the most commonly used test in perovskite photovoltaic devices is the back glass temperature test. However, since the thickness of the glass mentioned above is much greater than the thickness of the battery functional layer film, there is a large difference between the PN junction temperature of the perovskite battery and the back glass temperature. Summary of the Invention

[0005] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, an embodiment of the present invention provides a method for testing the PN junction temperature of a perovskite photovoltaic cell.

[0006] The method for testing the PN junction temperature of a perovskite photovoltaic cell according to an embodiment of the present invention comprises the following steps:

[0007] (1) coating the temperature-sensitive material on the surface of the pre-treated transparent conductive glass and drying the pre-treated transparent conductive glass to form a temperature-sensitive material layer;

[0008] (2) sequentially preparing a hole transport layer, a perovskite layer, an electron transport layer and an electrode layer on the surface of the temperature-sensitive material layer prepared in step (1);

[0009] (3) Connecting the metal strip in series with the inactive area of ​​the temperature-sensitive material layer obtained in step (1), leading out the test end, and then encapsulating it with optical glass or ultra-white glass, and calculating the temperature of the test end through the linear change of the resistance of the test end.

[0010] The advantages and technical effects brought by the method for testing the PN junction temperature of a perovskite photovoltaic cell in an embodiment of the present invention are that the method of the embodiment of the present invention sets a temperature-sensitive material layer near the light-absorbing layer (i.e., the PN junction) on the inner side of the perovskite cell packaging glass, which can effectively reduce the influence of the glass and ambient temperature on the PN junction temperature test, thereby obtaining a more accurate and reliable perovskite photovoltaic cell PN junction temperature.

[0011] In some embodiments, in step (1), the transparent conductive glass is ITO glass or FTO glass;

[0012] And / or, in step (1), the temperature-sensitive material includes a PEDOT:PSS aqueous solution.

[0013] In some embodiments, in step (1), the concentration of the PEDOT:PSS aqueous solution is 0.9 to 1.4 wt %;

[0014] And / or, in step (1), the temperature-sensitive material further includes an inorganic filler, and the inorganic filler includes at least one of CNT or graphene.

[0015] In some embodiments, in step (1), the amount of inorganic filler added to the temperature-sensitive material is 0.05-0.1 wt%.

[0016] In some embodiments, in step (1), the temperature of the drying treatment is 100-110° C., and the time of the drying treatment is 10-30 minutes;

[0017] And / or, in step (1), the thickness of the temperature-sensitive material layer is 40 to 60 nm.

[0018] In some embodiments, in step (2), the raw material of the hole transport layer includes at least one of PEDOT:PSS, PTAA, P3HT or NiOx; the raw material of the perovskite layer includes a perovskite with a chemical formula of ABX3, wherein A is FA, Cs, MA, K or Rb, B is Pb or Sn, and X is I, Br or Cl; the raw material of the electron transport layer includes at least one of PCBM or C60; the raw material of the electrode layer includes at least one of Au, Ag, Cu, ITO or IWO.

[0019] In some embodiments, in step (2), the thickness of the hole transport layer is 20 to 40 nm; the thickness of the perovskite layer is 400 to 600 nm; the thickness of the electron transport layer is 60 to 80 nm; and the thickness of the electrode layer is 70 to 100 nm.

[0020] In some embodiments, in step (3), the metal strip is an Ag strip, a Cu strip, or an Al strip;

[0021] And / or, in step (3), the thickness of the metal strip is 5 to 20 μm.

[0022] In some embodiments, in step (3), the series connection method is welding or bonding using conductive tape.

[0023] In some embodiments, in step (3), the thickness of the optical glass or ultra-white glass is 1.1 to 3.2 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of a system for accurately measuring the PN junction temperature of a perovskite photovoltaic cell;

[0025] Figure 2 This is an image of the temperature of the perovskite photovoltaic cell prepared in Comparative Example 1 tested by an infrared thermal imager;

[0026] Figure numerals: 1-encapsulation layer, 2-electrode layer, 3-electron transport layer, 4-perovskite layer, 5-hole transport layer, 6-transparent conductive glass layer, 11-temperature-sensitive material layer, 12-metal strip. DETAILED DESCRIPTION

[0027] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0028] The method for testing the PN junction temperature of a perovskite photovoltaic cell according to an embodiment of the present invention comprises the following steps:

[0029] (1) coating the temperature-sensitive material on the surface of the pre-treated transparent conductive glass and drying the pre-treated transparent conductive glass to form a temperature-sensitive material layer;

[0030] (2) sequentially preparing a hole transport layer, a perovskite layer, an electron transport layer and an electrode layer on the surface of the temperature-sensitive material layer prepared in step (1);

[0031] (3) Connecting the metal strip in series with the inactive area of ​​the temperature-sensitive material layer obtained in step (1), leading out the test end, and then encapsulating it with optical glass or ultra-white glass, and calculating the temperature of the test end through the linear change of the resistance of the test end.

[0032] The advantages and technical effects brought by the method for testing the PN junction temperature of a perovskite photovoltaic cell in an embodiment of the present invention are that the method of the embodiment of the present invention sets a temperature-sensitive material layer near the light-absorbing layer (i.e., the PN junction) on the inner side of the perovskite cell packaging glass, which can effectively reduce the influence of the glass and ambient temperature on the PN junction temperature test, thereby obtaining a more accurate and reliable perovskite photovoltaic cell PN junction temperature.

[0033] In some embodiments, preferably, in step (1), the transparent conductive glass is ITO glass or FTO glass;

[0034] And / or, in step (1), the temperature-sensitive material includes a PEDOT:PSS aqueous solution.

[0035] In some embodiments, preferably, in step (1), the concentration of the PEDOT:PSS aqueous solution is 0.9 to 1.4 wt %;

[0036] And / or, in step (1), the temperature-sensitive material further includes an inorganic filler, and the inorganic filler includes at least one of CNT or graphene.

[0037] In some embodiments, preferably, in step (1), the amount of inorganic filler added to the temperature-sensitive material is 0.05-0.1 wt%.

[0038] In some embodiments, preferably, in step (1), the temperature of the drying treatment is 100-110° C., and the time of the drying treatment is 10-30 minutes;

[0039] And / or, in step (1), the thickness of the temperature-sensitive material layer is 40 to 60 nm.

[0040] In some embodiments, preferably, in step (2), the raw material of the hole transport layer includes at least one of PEDOT:PSS, PTAA, P3HT or NiOx; the raw material of the perovskite layer includes a perovskite with a chemical formula of ABX3, wherein A is FA, Cs, MA, K or Rb, B is Pb or Sn, and X is I, Br or Cl; the raw material of the electron transport layer includes at least one of PCBM or C60; the raw material of the electrode layer includes at least one of Au, Ag, Cu, ITO or IWO.

[0041] In some embodiments, preferably, in step (2), the thickness of the hole transport layer is 20 to 40 nm; the thickness of the perovskite layer is 400 to 600 nm; the thickness of the electron transport layer is 60 to 80 nm; and the thickness of the electrode layer is 70 to 100 nm.

[0042] In some embodiments, preferably, in step (3), the metal strip is an Ag strip, a Cu strip or an Al strip;

[0043] And / or, in step (3), the thickness of the metal strip is 5 to 20 μm.

[0044] In some embodiments, preferably, in step (3), the series connection method is welding or bonding using conductive tape.

[0045] In some embodiments, preferably, in step (3), the thickness of the optical glass or ultra-white glass is 1.1 to 3.2 mm.

[0046] The technical solution of the present invention is described in detail below with reference to specific embodiments and drawings.

[0047] Example 1

[0048] (1) 1.1 mm transparent ITO conductive glass was ultrasonically cleaned using detergent, deionized water, ethanol, acetone, and isopropanol in sequence. Each cleaning time was 20 min. The cleaned substrate was immersed in isopropanol solution and dried with a nitrogen gun before use.

[0049] (2) A 2.7 wt% PEDOT:PSS aqueous solution was diluted in a ratio of 1:1 and ultrasonically stirred to obtain a uniform solution. The diluted solution was dropped onto the ITO substrate at a spin coating speed of 3000 r / min for 30 s. After spin coating, the substrate was heated at 120°C for 20 minutes to obtain a temperature-sensitive material layer with a thickness of 50 nm.

[0050] (3) A 25 mg / mL Ni(NO3)2·6H2O aqueous solution was used as a precursor and dropped onto an ITO substrate at a spin coating speed of 4000 r / min for 30 s. After spin coating, the substrate was heated at 120°C for 15 minutes to obtain a hole transport layer with a thickness of 30 nm.

[0051] (4) Prepare 1.4M FA according to the stoichiometric ratio 0.8 MA 0.2 Pb(I 0.8 Br 0.2)3 solution, using a DMF:DMSO = 4:1 mixed solvent, was prepared by continuous sonication until the solute was completely dissolved and mixed uniformly. A perovskite film was prepared using a one-step spin coating method. The first stage was at a rate of 1000 rpm for 10 seconds, and the second stage was at a rate of 6000 rpm for 20 seconds. During the film formation process, chlorobenzene antisolvent was added dropwise after 20 seconds of coating. The first stage was annealed at 100°C for 10 minutes, and the second stage was 140°C for 20 minutes. The resulting perovskite layer had a thickness of 450 nm.

[0052] (5) After the perovskite layer is prepared, the perovskite film in the inactive area is wiped off with an isopropyl alcohol solution to prepare the subsequent electron transport layer and electrode layer.

[0053] (6) Using the evaporation method on the perovskite film, a C60 electron transport layer was prepared in the active area using a mask, and the vacuum degree was 8×10 -5 Pa, the evaporation temperature was 300 ° C, the evaporation rate was 2 nm / min, and the evaporation thickness was 50 nm; then the BCP electron transport layer was prepared by evaporation, and the vacuum degree was 5×10 -5 Pa, the evaporation rate is 0.5nm / min, and the evaporation thickness is 10nm.

[0054] (7) The Au back electrode was prepared by evaporation method, and the evaporation vacuum was 1.0×10 -4 Pa, the evaporation rate in the first stage is about 0.5nm / min, the time is 20min, the second stage is about 2.5nm / min, the time is 25min, and the thickness of the Au back electrode is about 70nm.

[0055] (8) A 0.02 mm thick ultra-thin silver foil strip was connected to the PEDOT:PSS in the inactive area by spot welding, and a POE film was laid flat on the surface of the perovskite battery. A 2 mm wide butyl adhesive was pasted around the periphery, and then ultra-white encapsulation glass was covered from the top. The encapsulated battery was placed in a laminator with an encapsulation pressure of 10 kPa, a temperature of 80 °C, and a time of 10 min.

[0056] The structure of the battery prepared in this embodiment is as follows Figure 1 As shown, the battery was placed in a constant temperature box. After the temperature stabilized, the square resistance of the PEDOT:PSS+ conductive strip was tested at 25°C to be 14.90Ω / sq, the square resistance was tested at 35°C to be 14.62Ω / sq, and the square resistance was tested at 45°C to be 14.34Ω / sq. The resistance temperature coefficient was calculated to be approximately -0.19% / °C.

[0057] The square resistance measured under light is 14.612Ω / sq, and the PN junction temperature is calculated to be 35.2℃.

[0058] Comparative Example 1

[0059] The method of Comparative Example 1 is the same as that of Example 1, except that step (2) is not required, and step (8) is as follows: POE film is laid flat on the surface of the perovskite battery, butyl glue with a width of 2 mm is adhered around it, and then ultra-white encapsulation glass is covered from the top, and the encapsulated battery is placed in a laminator with an encapsulation pressure of 12 kPa, a temperature of 80°C, and a time of 10 min.

[0060] The unpackaged battery obtained in step (7) of comparative example 1 is placed in a test fixture and suspended in the light field. The light source illuminates the front surface of the battery from bottom to top. Figure 2 As shown, the temperature of the back side of the cell was measured using an infrared thermal imager and was approximately 34.5°C. The temperature of the cell facing the light side was measured using a thermocouple and was approximately 37.4°C, while the temperature of the cell facing away from the light side was approximately 35.0°C (the existing test method cannot directly and accurately measure the junction temperature, so the temperature of the cell facing away from the light side is used to approximate the PN junction temperature. In the unpackaged case, the cell facing away from the light side is closer to the actual PN junction temperature).

[0061] The packaged battery obtained in step (8) of comparative example 1 is placed in a test fixture and suspended in a light field. The light source illuminates the front surface of the battery from bottom to top. The temperature of the battery cell facing the light is measured using a thermocouple to obtain a temperature of approximately 37.4°C, and a temperature of the back-facing surface is approximately 35.7°C (the existing test method cannot directly and accurately measure the junction temperature, so the back-facing surface temperature is used to approximately replace the PN junction temperature).

[0062] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0063] Although the above embodiments have been shown and described, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those skilled in the art are all within the scope of protection of the present invention.

Claims

1. A method for testing the PN junction temperature of a perovskite photovoltaic cell, characterized in that: The following steps are involved: (1) coating the temperature-sensitive material on the surface of the pre-treated transparent conductive glass and drying the pre-treated transparent conductive glass to form a temperature-sensitive material layer; (2) sequentially preparing a hole transport layer, a perovskite layer, an electron transport layer and an electrode layer on the surface of the temperature-sensitive material layer prepared in step (1); (3) Connecting the metal strip in series with the inactive area of ​​the temperature-sensitive material layer obtained in step (1), leading out the test end, and then encapsulating it with optical glass or ultra-white glass, and calculating the temperature of the test end through the linear change of the resistance of the test end.

2. The method for testing the PN junction temperature of a perovskite photovoltaic cell according to claim 1, wherein: In the step (1), the transparent conductive glass is ITO glass or FTO glass; And / or, in step (1), the temperature-sensitive material includes a PEDOT:PSS aqueous solution.

3. The method for testing the PN junction temperature of a perovskite photovoltaic cell according to claim 2, wherein: In the step (1), the concentration of the PEDOT:PSS aqueous solution is 0.9 to 1.4 wt %; And / or, in step (1), the temperature-sensitive material further includes an inorganic filler, and the inorganic filler includes at least one of CNT or graphene.

4. The method for testing the PN junction temperature of a perovskite photovoltaic cell according to claim 3, wherein: In the step (1), the amount of inorganic filler added to the temperature-sensitive material is 0.05 to 0.1 wt%.

5. The method for testing the PN junction temperature of a perovskite photovoltaic cell according to claim 1, wherein: In the step (1), the temperature of the drying treatment is 100-110° C., and the time of the drying treatment is 10-30 minutes; And / or, in step (1), the thickness of the temperature-sensitive material layer is 40 to 60 nm.

6. The method for testing the PN junction temperature of a perovskite photovoltaic cell according to claim 1, wherein: In the step (2), the raw material of the hole transport layer includes at least one of PEDOT:PSS, PTAA, P3HT or NiOx; the raw material of the perovskite layer includes a perovskite with a chemical formula of ABX3, wherein A is FA, Cs, MA, K or Rb, B is Pb or Sn, and X is I, Br or Cl; the raw material of the electron transport layer includes at least one of PCBM or C60; the raw material of the electrode layer includes at least one of Au, Ag, Cu, ITO or IWO.

7. The method for testing the PN junction temperature of a perovskite photovoltaic cell according to claim 1 or 6, characterized in that: In the step (2), the thickness of the hole transport layer is 20 to 40 nm; the thickness of the perovskite layer is 400 to 600 nm; the thickness of the electron transport layer is 60 to 80 nm; and the thickness of the electrode layer is 70 to 100 nm.

8. The method for testing the PN junction temperature of a perovskite photovoltaic cell according to claim 1, wherein: In the step (3), the metal strip is an Ag strip, a Cu strip or an Al strip; And / or, in step (3), the thickness of the metal strip is 5 to 20 μm.

9. The method for testing the PN junction temperature of a perovskite photovoltaic cell according to claim 1, wherein: In the step (3), the series connection method is welding or bonding with conductive tape.

10. The method for testing the PN junction temperature of a perovskite photovoltaic cell according to claim 1, wherein: In the step (3), the thickness of the optical glass or ultra-white glass is 1.1 to 3.2 mm.

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