Cadmium telluride battery and preparation method and application thereof

Abstract

The invention discloses a cadmium telluride battery and a preparation method and application thereof. The cadmium telluride battery comprises substrate glass, an FTO layer, a CdSe layer, a CdTe layer and a back electrode layer which are arranged in a stacked mode. The back electrode layer comprises a MoN layer, a metal Al layer and a metal Ti layer which are sequentially arranged in an overlapped mode. According to the cadmium telluride battery as well as the preparation method and the application thereof, a composite structure of molybdenum nitride (MoN), metal aluminum and metal titanium is adopted, so that the performance and the stability of the battery are improved.

Description

Technical Field

[0001] The present invention relates to the field of new energy technologies, and more particularly to a cadmium telluride solar cell, a preparation method thereof, and an application thereof. Background Art

[0002] Compared with crystalline silicon and other types of solar cells, CdTe thin-film solar cells have lower production costs. In addition, CdTe thin-film solar cells have a high degree of matching with the solar spectrum, can absorb more than 95% of sunlight, have standard manufacturing processes, low energy consumption, and can be recycled at the end of their life cycle. CdTe cells can generate electricity under both strong light and weak light conditions, and their performance is more excellent as the temperature increases. Currently, the commonly used back electrode materials mainly include metal aluminum and silver. These metal materials are widely used in cadmium telluride photovoltaic cells due to their good electrical conductivity and relatively low cost. However, metal aluminum and silver as back electrode materials also have certain limitations, especially in terms of stability and electrical conductivity. First, metal aluminum is easily affected by environmental factors, such as the presence of oxygen and moisture, resulting in the formation of an aluminum oxide layer on the aluminum surface. Moreover, the mechanical properties of aluminum under high-temperature conditions are poor, which may cause stress due to thermal expansion and contraction in an environment with large temperature changes, thereby affecting the contact between the back electrode and other layers of the photovoltaic cell. Second, although silver has excellent electrical conductivity, its cost is high and it is scarce, which limits its large-scale application. In addition, the stability of silver is also relatively poor, and it is easy to form silver compounds under high-temperature and high-humidity conditions, which may lead to the degradation of the silver electrode and a decrease in contact performance.

[0003] Therefore, although metal aluminum and silver can meet the basic requirements of photovoltaic cells in the short term, there are certain limitations in terms of stability and electrical conductivity. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a cadmium telluride battery, a preparation method thereof, and an application thereof, which adopt a composite structure of molybdenum nitride (MoN), metal aluminum, and metal titanium, improving the performance and stability of the battery.

[0005] The present invention also provides a preparation method for the above cadmium telluride battery.

[0006] The present invention also provides an application of the above cadmium telluride battery in ground photovoltaics, space photovoltaics, and wearable devices.

[0007] According to a first aspect of the present invention, there is provided a cadmium telluride battery, the cadmium telluride battery comprising a substrate glass, an FTO layer, a CdSe layer, a CdTe layer, and a back electrode layer which are stacked.

[0008] The back electrode layer includes a MoN layer, a metal Al layer, and a metal Ti layer that are sequentially stacked.

[0009] According to the first aspect of the present invention, it has at least the following beneficial effects:

[0010] The CdSe layer material has good light absorption characteristics and energy band structure. A solid solution of CdSexTe1-x is formed between the CdSe and CdTe layers. This structure effectively enhances the light absorption ability of the CdTe layer in the long-wave band. Through structural optimization, while the CdSe layer absorbs the long-wave spectrum, it helps to improve the photoelectric conversion efficiency, not only increasing the absorption of short-wave and long-wave spectra, but also increasing the fill factor and open-circuit voltage, thereby improving the conversion efficiency of the solar cell.

[0011] The material of the MoN layer has good chemical stability and conductivity. As a back electrode material, it helps to improve the stability and anti-decay ability of CdTe thin-film solar cells. At the same time, the MoN layer material not only improves the electrical contact performance of the battery, but also effectively prevents the degradation of the CdTe layer and extends the service life of the battery. The MZO layer forms a heterojunction structure with the CdTe layer, and the built-in electric field is weak. Using the CdSe layer as a buffer effectively avoids the negative impact of the too weak built-in electric field between the MZO and CdTe, thereby improving the fill factor and open-circuit voltage.

[0012] The metal aluminum layer is mainly used to enhance the conductivity of the back electrode and provide good adhesion. The low cost and easy processability of aluminum make it an ideal choice, which can ensure the basic conductivity of the electrode while maintaining a low cost. However, aluminum is prone to oxidation in high-temperature and humid environments. Therefore, it is necessary to add other materials to improve the stability of the electrode. The addition of the metal titanium layer effectively improves the corrosion resistance and thermal stability of the back electrode. Titanium can prevent the oxidation of the aluminum layer under high-temperature and humid conditions, thereby enhancing the long-term stability and reliability of the electrode. The corrosion resistance of titanium enables the electrode to maintain good electrical performance under various environmental conditions, extends the service life of the battery, enables the back electrode to maintain good performance in high-temperature environments, and has stronger adaptability. The molybdenum nitride layer significantly enhances the current collection ability of the electrode. As a conductive material, molybdenum nitride can improve the electron transport efficiency, thereby improving the overall photoelectric conversion efficiency of the battery. By combining molybdenum nitride with metal titanium, not only the conductivity and current collection ability of the electrode are improved, but also the corrosion resistance of the electrode is effectively enhanced. The synergistic effect of titanium and molybdenum nitride ensures that the electrode maintains stability and high performance during long-term use, thereby extending the service life of the battery. Thermal stability: The presence of the metal titanium layer enables the back electrode to maintain good performance in high-temperature environments and has stronger adaptability.

[0013] According to some embodiments of the present invention, the thickness of the CdSe layer is 50 - 200 nm.

[0014] According to some embodiments of the present invention, the thickness of the CdSe layer is 80 - 200 nm.

[0015] At the above thickness, while ensuring light absorption, excessive light absorption or light loss is avoided. If the layer thickness is too thin, the light absorption may be insufficient; if the layer thickness is too thick, the absorption of light in the layer may cause multiple reflections and increase the probability of carrier recombination, thereby reducing the efficiency.

[0016] According to some embodiments of the present invention, the thickness of the CdTe layer is 1 - 3 μm.

[0017] According to some embodiments of the present invention, the thickness of the CdTe layer is 2 - 3 μm.

[0018] The above thickness range enables the CdTe layer to effectively absorb incident light, thereby maximizing the photoelectric conversion efficiency.

[0019] According to some embodiments of the present invention, the thickness of the MoN layer is 10 - 100 nm.

[0020] According to some embodiments of the present invention, the thickness of the MoN layer is 10 - 50 nm.

[0021] According to some embodiments of the present invention, the thickness of the Al layer is 100 - 500 nm.

[0022] According to some embodiments of the present invention, the thickness of the Al layer is 200 - 500 nm.

[0023] According to some embodiments of the present invention, the thickness of the Ti layer is 50 - 300 nm.

[0024] According to some embodiments of the present invention, the thickness of the Ti layer is 100 - 300 nm.

[0025] The above thickness range helps to optimize the interface resistance and charge transport efficiency of the battery, and improve the stability and durability of the battery. The MoN layer can provide good protection, antioxidant ability, and light reflection effect within this thickness range, while avoiding performance losses caused by too large or too small layer thickness.

[0026] According to a second aspect of the present invention, a cadmium telluride battery is provided, comprising: an FTO layer, a CdSe layer, a CdTe layer, and a back electrode layer deposited sequentially from bottom to top on a substrate glass.

[0027] According to some embodiments of the present invention, the preparation method of the back electrode layer includes: depositing a MoN layer, a metal Al, and a metal Ti layer sequentially from bottom to top on the CdSe layer.

[0028] According to some embodiments of the present invention, the deposition method of the FTO layer includes using magnetron sputtering on the substrate glass to obtain the FTO layer.

[0029] According to some embodiments of the present invention, the deposition method of the CdSe layer includes chemical vapor deposition.

[0030] According to some embodiments of the present invention, the deposition temperature of the chemical vapor deposition is 300 - 450 °C.

[0031] According to some embodiments of the present invention, the deposition method of the CdTe layer includes chemical vapor deposition.

[0032] According to some embodiments of the present invention, the deposition temperature of the chemical vapor deposition is 450 - 550 °C.

[0033] According to some embodiments of the present invention, the deposition method of the MoN layer includes physical vapor deposition.

[0034] According to some embodiments of the present invention, the deposition temperature of the physical vapor deposition is 300 - 500 °C.

[0035] According to some embodiments of the present invention, the deposition method of the metal Al layer includes physical vapor deposition.

[0036] According to the third aspect of the present invention, there is provided an application of a cadmium telluride battery in terrestrial photovoltaics, space photovoltaics, and wearable devices.

[0037] Unless otherwise specified, the "about" in the present invention actually means an allowable error within the range of ±2%, for example, about 100 is actually 100 ± 2% × 100.

[0038] Unless otherwise specified, the "between... and..." in the present invention includes the endpoints, for example, "between 2 and 3" includes the endpoint values 2 and 3.

[0039] Other features and advantages of the present invention will be described in the subsequent specification, and part of them will become obvious from the specification or be understood by implementing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0041] Figure 1 is a schematic structural diagram of the cadmium telluride battery obtained in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] The following will clearly and completely describe the concept of the present invention and the technical effects produced in combination with the embodiments, so as to fully understand the purpose, features, and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative efforts all belong to the scope of protection of the present invention.

[0043] In the description of the present invention, the descriptions referring to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection 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 a suitable manner in any one or more embodiments or examples.

[0044] Embodiment 1

[0045] Referring to Figure 1 the structure shown, this example provides a cadmium telluride battery and its preparation method, specifically:

[0046] A cadmium telluride battery, where the cadmium telluride battery is a stack of a substrate glass, an FTO layer, a CdSe layer, a CdTe layer, and a back electrode layer;

[0047] The back electrode layer is a stack of a MoN layer, a metal Al layer, and a metal Ti layer in sequence.

[0048] The preparation method of the cadmium telluride battery is as follows:

[0049] S1. Clean the substrate glass with deionized water to ensure that the surface is free of impurities, dry it with nitrogen, and then deposit the FTO layer using magnetron sputtering. The sputtering conditions are: 300W, a sputtering power of 250°C, and a deposition time of 30 min. The thickness of the FTO layer is about 400 nm;

[0050] S2. On the FTO layer, deposit the CdSe layer using chemical vapor deposition. The CVD deposition conditions are: deposition at 350°C for 30 min. The thickness of the CdSe layer is about 100 nm;

[0051] On the CdSe layer, continue to deposit the CdTe layer using chemical vapor deposition. The deposition conditions are: deposition at 450°C for 60 min, and the thickness of the CdTe layer is about 3 μm;

[0052] S3. Deposit the MoN layer on the CdTe layer by physical vapor deposition. The deposition conditions are: 150W, deposition at 250°C for 15 min, and the thickness of the MoN layer is 50 nm;

[0053] S4. Deposit a metal aluminum layer on the MoN layer by physical vapor deposition. The deposition conditions are as follows: aluminum target: 99.99% purity, argon gas flow rate: 20 sccm, sputtering power: 200 W, deposition time: 20 min, and the thickness of the metal Al layer is 200 nm.

[0054] S5. Deposit a metal titanium layer on the metal Al layer by physical vapor deposition. The deposition conditions are as follows: titanium target: 99.99% purity, argon gas flow rate: 25 sccm, sputtering power: 100 W, deposition time: 10 min, and the thickness of the metal Ti layer is 130 nm.

[0055] S6. After depositing all the layers, perform an annealing treatment at 280 °C for 30 min.

[0056] Example 2

[0057] Reference Figure 1 Referring to the structure shown, this example provides a cadmium telluride cell and its preparation method, specifically:

[0058] A cadmium telluride cell, where the cadmium telluride cell is a stacked structure of a substrate glass, an FTO layer, a CdSe layer, a CdTe layer, and a back electrode layer;

[0059] The back electrode layer is a sequentially stacked structure of a MoN layer, a metal Al layer, and a metal Ti layer.

[0060] The preparation method of the cadmium telluride cell is as follows:

[0061] S1. Clean the substrate glass with deionized water to ensure that the surface is free of impurities, dry it with nitrogen, and then deposit the FTO layer by magnetron sputtering. The sputtering conditions are: 300 W, sputtering power at 250 °C, deposition time: 30 min, and the thickness of the FTO layer is about 400 nm;

[0062] S2. Deposit the CdSe layer on the FTO layer by chemical vapor deposition. The CVD deposition conditions are: deposition at 350 °C for 30 min, and the thickness of the CdSe layer is about 100 nm;

[0063] On the CdSe layer, continue to deposit the CdTe layer by chemical vapor deposition. The deposition conditions are: deposition at 450 °C for 60 min, and the thickness of the CdTe layer is about 2 μm;

[0064] S3. Deposit the MoN layer on the CdTe layer by physical vapor deposition. The deposition conditions are: 150 W, deposition at 250 °C for 15 min, and the thickness of the MoN layer is 50 nm;

[0065] S4. Deposit a metal aluminum layer on the MoN layer by physical vapor deposition. The deposition conditions are as follows: aluminum target: 99.99% purity, argon flow rate: 20 sccm, sputtering power: 200 W, deposition time: 20 min, and the thickness of the metal Al layer is 200 nm;

[0066] S5. Deposit a metal titanium layer on the metal Al layer by physical vapor deposition. The deposition conditions are as follows: titanium target: 99.99% purity, argon flow rate: 25 sccm, sputtering power: 100 W, deposition time: 10 min, and the thickness of the metal Ti layer is 170 nm.

[0067] S6. After depositing all the layers, perform an annealing treatment at 280 °C for 30 min.

[0068] Comparative Example 1

[0069] This example provides a cadmium telluride battery and its preparation method, specifically:

[0070] A cadmium telluride battery, where the cadmium telluride battery is a stack of a substrate glass, an FTO layer, a CdSe layer, a CdTe layer, and a back electrode layer;

[0071] The back electrode layer is a stack of a MoN layer and a metal Al layer arranged in sequence.

[0072] Test Example

[0073] In this example, the performance of the cadmium telluride batteries obtained in the examples and comparative examples was tested. They were placed under a standard solar irradiance for electrical performance testing. The results are shown in Table 1. The specific testing method is as follows:

[0074] The testing instruments and conditions used in the examples are as follows:

[0075] J-V curve: First, use a standard silicon solar cell (2×2 cm 2 , SRC-00019) to calibrate the current corresponding to the standard solar spectrum (AM1.5G, 100 mW / cm 2 ) under 1 sun. Then, use a test fixture to place the device under the calibrated test light source for irradiation, and automatically test the J-V characteristic curve of the cadmium telluride semiconductor optoelectronic device through a Keithley 2400 source meter and the corresponding configured software. Obtain the open-circuit voltage (0pencircuitvoltage, VOC), short-circuit current density (Short-circuit density, JSC), fill factor (Fillfactor, FF), and power conversion efficiency (Powerconversion efficiency, PCE) from the curve. The specific formulas are as follows:

[0076] FF = Pmax / Voc×Jsc = Vmax×Jmax / Voc*Jsc, PCE = Pmax / Pin = Voc×Jsc×FF / Pin;

[0077] Among them, Pmax is the maximum output power, VOC and JSC are the voltage and current density at the maximum power point respectively, and Pin is the incident light power.

[0078] During the J-V curve test, the test voltage is set from 1.2V (start) to -0.2V (end), the interval is 0.02V, and the delay time is 0.1s.

[0079] The test results are shown in Table 1.

[0080] Table 1 Performance of cadmium telluride solar cells obtained from examples and comparative examples

[0081]

[0082] Among them, Eff is the charge-discharge efficiency, Voc is the open-circuit voltage, Jsc is the short-circuit current, and FF is the fill factor.

[0083] Comparing the examples and comparative examples, within the scope provided by the present invention, the back electrode layer includes MoN, aluminum (Al) and titanium (Ti) layers, which provide a current collection channel and form good electrical contact with the CdTe layer, enhancing the efficiency and stability of the battery. At the same time, the excellent contact between the MoN layer and CdTe enables photo-generated electrons to be transferred more effectively from the CdTe layer to the external circuit, avoiding electron backflow or recombination caused by poor contact, and increasing the open-circuit voltage (Voc). In Comparative Example 1, the contact resistance of the back electrode layer increases, affecting the current transmission efficiency of the battery. At the same time, the stability of the battery in high-temperature and humid environments decreases; the back electrode material of the cadmium telluride battery provided by the present invention, combined with molybdenum nitride, metal aluminum and metal titanium, has good electrical conductivity, chemical stability and thermal stability, can effectively improve the reliability of photovoltaic cells, and has broad application prospects.

[0084] The above is the patent content regarding the use of molybdenum nitride, metal aluminum and metal titanium in cadmium telluride batteries. It is hoped that the present invention can provide new ideas and solutions for the development of photovoltaic cell technology.

[0085] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those of ordinary skill in the art. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A cadmium telluride battery, characterized in that: The cadmium telluride battery comprises a substrate glass, an FTO layer, a CdSe layer, a CdTe layer and a back electrode layer which are stacked; The back electrode layer includes a MoN layer, a metal Al layer and a metal Ti layer which are stacked in sequence.

2. The cadmium telluride battery according to claim 1, characterized in that: The thickness of the CdSe layer is 50-200 nm.

3. The cadmium telluride battery according to claim 1, characterized in that: The thickness of the CdTe layer is 1-3 μm.

4. The cadmium telluride battery according to claim 1, characterized in that: The thickness of the MoN layer is 10-100 nm.

5. A method for preparing a cadmium telluride battery according to any one of claims 1 to 4, characterized in that: include: The FTO layer, the CdSe layer, the CdTe layer and the back electrode layer are deposited in sequence from bottom to top on the lining substrate glass.

6. The preparation method according to claim 5, characterized in that: The method for preparing the back electrode layer comprises: depositing a MoN layer, a metal Al layer and a metal Ti layer in sequence from bottom to top on the CdSe layer.

7. The preparation method according to claim 5, characterized in that: The deposition method of the CdSe layer includes chemical vapor deposition; and / or the deposition temperature of the chemical vapor deposition is 300-450°C.

8. The preparation method according to claim 5, characterized in that: The deposition method of the CdTe layer includes chemical vapor deposition; and / or the deposition temperature of the chemical vapor deposition is 450-550°C.

9. The preparation method according to claim 5, characterized in that: The deposition method of the MoN layer includes physical vapor deposition; and / or the deposition temperature of the physical vapor deposition is 300-500°C.

10. Application of the cadmium telluride battery according to any one of claims 1 to 4 in surface photovoltaics, space photovoltaics and wearable devices.

Images