Photovoltaic cell, power generation equipment and terminal equipment

Abstract

The embodiment of the invention provides a photovoltaic cell, power generation equipment and terminal equipment. The photovoltaic cell is essentially a multi-junction photovoltaic cell and comprises a first cell and a second cell, and the first cell and the second cell are electrically isolated through a spectral transparent resistive layer, so that the first cell and the second cell can capture light of different wavebands and convert the light into electric energy. Based on the special design of the photovoltaic cell, the defects of a conventional multi-junction photovoltaic cell can be overcome, and the photovoltaic cell can be used for ground scenes and can achieve high photoelectric conversion efficiency.

Description

Technical Field

[0001] This application relates to the field of photovoltaic cells, specifically photovoltaic cells, power generation equipment, and terminal equipment. Background Technology

[0002] Currently, multi-junction photovoltaic (PV) cells have gained more attention due to their higher photoelectric conversion efficiency compared to single-junction solar cells. Multi-junction PV cells utilize multiple junctions with different bandgap widths to expand the spectral range that the PV cell can absorb. The industry generally optimizes the photoelectric conversion efficiency by controlling the thickness, material composition, and impurity concentration of each junction. However, currently, the application scenarios for multi-junction PV cells are all in space. Due to the relatively weak solar radiation on the ground and the short-wave attenuation of the solar spectrum, it is difficult to widely apply multi-junction PV cells in ground-based applications. Summary of the Invention

[0003] Therefore, embodiments of this application provide photovoltaic cells, power generation equipment, and terminal equipment. The photovoltaic cell is essentially a multi-junction photovoltaic cell, but its special design overcomes the shortcomings of conventional multi-junction photovoltaic cells, enabling it to be used in ground-based applications and achieve high photoelectric conversion efficiency.

[0004] The first aspect of this application provides a photovoltaic cell, including:

[0005] A first battery and a second battery are stacked together, with a spectrally transparent resistive layer disposed between the first battery and the second battery;

[0006] The first battery includes a first conductive structure, a first photoelectric conversion structure, and a second conductive structure stacked sequentially. The first photoelectric conversion structure is used to convert light within a first wavelength range into electricity. The first conductive structure and the second conductive structure are used to discharge the current generated by the first battery.

[0007] The second battery includes a third conductive structure, a second photoelectric conversion structure, and a fourth conductive structure stacked sequentially, with the third conductive structure disposed close to the first battery; the second photoelectric conversion structure is used to convert light in a second wavelength range into electricity; the third conductive structure and the fourth conductive structure are used to extract the current generated by the second battery;

[0008] The first wavelength range is ≥900nm, and the second wavelength range is <900nm; the spectrally transparent resistive layer is transparent to light within the second wavelength range; the room temperature resistivity of the spectrally transparent resistive layer is ≥10. 6 Ω·m;

[0009] The bandgap of the first photoelectric conversion structure is 1.8 eV-2.0 eV.

[0010] The photovoltaic cell provided in this application embodiment achieves physical isolation between the first and second cells through a spectrally transparent resistive layer, preventing series connection between them. The spectrally transparent resistive layer is transparent to light within a second wavelength range, enabling independent response to light within that range. Furthermore, both the first and second cells independently include conductive structures, allowing for parallel connection via electrode leads. This eliminates the minimum junction current effect of traditional multi-junction photovoltaic cells, thereby increasing power output. This photovoltaic cell can also be used in ground-based applications. In addition, limiting the bandgap of the first photoelectric conversion structure to 1.8 eV-2.0 eV allows for sufficient absorption and utilization of photons within the first wavelength range by the first cell, and also facilitates full utilization of light in attenuated wavelengths in low-light conditions by the second cell, reducing heat loss, achieving efficient energy distribution and utilization, and improving the photoelectric conversion efficiency of the photovoltaic cell.

[0011] In some embodiments of this application, the transmittance of the spectrally transparent resistive layer for light in the second wavelength range is ≥90%. Thus, the photovoltaic cell is more suitable for ground-based applications and can significantly improve the utilization rate of the photovoltaic cell 100 for light in the easily attenuated wavelength band (350nm-600nm).

[0012] In some embodiments of this application, the material of the spectrally transparent resistive layer includes one or more of silicon nitride, aluminum oxide, silicon oxide, silicon carbide, and modified transparent conductive oxides. This facilitates the fabrication of photovoltaic cells.

[0013] In some embodiments of this application, the thickness of the spectrally transparent resistive layer is 6 nm-45 μm. This allows the photovoltaic cell to achieve higher photoelectric conversion efficiency and also helps to reduce the overall thickness of the photovoltaic cell, thereby enhancing its market competitiveness.

[0014] In some embodiments of this application, the bandgap of the second photoelectric conversion structure is smaller than that of the first photoelectric conversion structure. This allows for the full utilization of incident photons of different energies, reduces heat loss, and further improves the photoelectric conversion efficiency of the photovoltaic cell.

[0015] In some embodiments of this application, the material of the first photoelectric conversion structure includes one or more of doped InGaN and doped InGaP.

[0016] In some embodiments of this application, the first battery further includes an anti-reflection layer disposed between the first conductive structure and the first photoelectric conversion structure; the anti-reflection layer is used to reduce the reflection of electromagnetic waves by the first battery. This can further improve the photoelectric conversion efficiency of the photovoltaic cell.

[0017] In some embodiments of this application, the second cell further includes a tunneling junction and a third photoelectric conversion structure stacked together; wherein the tunneling junction and the third photoelectric conversion structure are disposed between the second photoelectric conversion structure and the fourth conductive structure, with the tunneling junction disposed close to the second photoelectric conversion structure. This facilitates the normal operation of the photovoltaic cell and also helps to further improve the photoelectric conversion efficiency of the photovoltaic cell.

[0018] In some embodiments of this application, the first battery and the second battery are connected in parallel.

[0019] In some embodiments of this application, the photovoltaic cell has a photoelectric conversion efficiency of ≥30% for solar radiation.

[0020] The second aspect of this application provides a power generation device, which includes a photovoltaic cell provided in the first aspect of this application, and an inverter electrically connected to the photovoltaic cell; the inverter is used to convert the DC signal output by the photovoltaic cell into an AC signal, and then the converted AC signal can be connected to the power grid for use.

[0021] A third aspect of this application provides a terminal device, which includes a photovoltaic cell provided in the first aspect of this application, and electronic components electrically connected to the photovoltaic cell; the photovoltaic cell is used to supply power to the electronic components. Because it uses the photovoltaic cell provided in this application, the terminal device can be charged by solar radiation and has high efficiency, giving it superior market competitiveness.

[0022] In this application embodiment, the aforementioned terminal devices include, but are not limited to, consumer electronics products such as smartwatches and mobile communication devices, wearable electronic devices, and base stations. Attached Figure Description

[0023] Figure 1A This is a schematic diagram illustrating the all-day photovoltaic characteristics of multi-junction photovoltaic cells in related technologies.

[0024] Figure 1B This is the equivalent circuit diagram of a multi-junction photovoltaic cell in related technologies;

[0025] Figure 2 This is a schematic diagram of the structure of a photovoltaic cell provided in one embodiment of this application;

[0026] Figure 3 This is a schematic diagram of the structure of a photovoltaic cell provided in another embodiment of this application;

[0027] Figure 4 This is a schematic diagram of the structure of a photovoltaic cell provided in another embodiment of this application;

[0028] Explanation of reference numerals: 100 - Photovoltaic cell; 1 - First cell; 11 - First conductive structure; 12 - First photoelectric conversion structure; 13 - Second conductive structure; 3 - Spectrally transparent resistive layer; 2 - Second cell; 21 - Third conductive structure; 22 - Second photoelectric conversion structure; 23 - Fourth conductive structure; 24 - Tunneling junction; 25 - Third photoelectric conversion structure; 4 - Second spectrally transparent resistive layer; 5 - Third cell; 51 - Fifth conductive structure; 52 - Fourth photoelectric conversion structure; 53 - Sixth conductive structure. Detailed Implementation

[0029] To better understand the technical solution of this application, the following explanations are provided for some key terms involved in this application:

[0030] Multijunction photovoltaic cells: also known as multijunction solar cells; multijunction solar cells are typically composed of multiple single-junction cells and tunnel junctions. Each semiconductor material constitutes a single-junction cell, and the semiconductor materials of the multiple single-junction cells have different band gaps. The multiple single-junction cells are connected in series.

[0031] Band gap: Band gap, unit eV; the energy between the lowest energy level of the conduction band and the highest energy level of the valence band; in a solid, the energy band where free electrons exist is called the conduction band (which conducts electricity), and the energy band where free holes exist is called the valence band. For a bound electron to become a free electron or a hole, it must acquire enough energy to transition from the valence band to the conduction band; the minimum of these energies is the band gap.

[0032] Tunneling junction: The tunneling junction is an important component of semiconductor devices, and it can generate tunneling current.

[0033] Tunneling current: The current that occurs when the potential barrier of a semiconductor is close to the de Broglie wavelength of the charge carriers, resulting in the quantum tunneling effect of the charge carriers.

[0034] Currently, multi-junction photovoltaic cells are gaining attention due to their higher photoelectric conversion efficiency. However, current multi-junction photovoltaic cells are primarily geared towards aerospace needs. On the ground, short-wavelength (350nm-600nm) light intensity is attenuated by atmospheric mass (including solar elevation angle and atmospheric scattering). Compared to space, the ground is a low-light environment, especially with severe attenuation of short-wavelength light intensity in the early morning and evening (see [link to relevant documentation]). Figure 1A This makes multi-junction photovoltaic cells in related technologies unsuitable for ground-based applications. Furthermore, multi-junction photovoltaic cells typically consist of multiple stacked junctions, each with a different absorption spectrum, and these junctions are connected in series. (See [link to previous section]). Figure 1B , Figure 1BThis is the circuit equivalent diagram of a multi-junction photovoltaic cell based on related technologies. To further improve the efficiency of multi-junction photovoltaic cells, the industry has attempted to control the thickness, material composition, and impurity concentration of each junction; however, the current structural design of multi-junction photovoltaic cells still has flaws. The multiple junctions connected in series result in the photocurrent of the device being the minimum current among the multiple junction currents (minimum junction current effect), which limits the performance of multi-junction photovoltaic cells. Further increasing the number of junctions in related multi-junction photovoltaic cells leads to a stronger spectral sensitivity of the cell, and a more severe impact of the minimum junction current effect.

[0035] To address the aforementioned technical problems, this application provides a photovoltaic cell, please refer to [link to relevant documentation]. Figure 2 The photovoltaic cell 100 includes:

[0036] A first battery 1 and a second battery 2 are stacked together, with a spectrally transparent resistive layer 3 disposed between the first battery 1 and the second battery 2.

[0037] The first battery 1 includes a first conductive structure 11, a first photoelectric conversion structure 12, and a second conductive structure 13 stacked sequentially. The first photoelectric conversion structure 12 is used to convert light in a first wavelength range into electricity; the first conductive structure 11 and the second conductive structure 13 are used to discharge the current generated by the first battery 1.

[0038] The second battery 2 includes a third conductive structure 21, a second photoelectric conversion structure 22, and a fourth conductive structure 23 stacked sequentially. The third conductive structure 21 is disposed close to the first battery. The second photoelectric conversion structure 22 is used to convert light in a second wavelength range into electricity. The third conductive structure 21 and the fourth conductive structure 23 are used to discharge the current generated by the second battery.

[0039] The first wavelength range is ≥900nm, and the second wavelength range is <900nm; the spectrally transparent resistive layer 3 is transparent to light in the second wavelength range; that is, light in the second wavelength range can pass through the spectrally transparent resistive layer 3 and be transmitted to the second photoelectric conversion structure 22 of the second battery 2; the room temperature resistivity of the spectrally transparent resistive layer 3 is ≥10. 6The second photoelectric conversion structure 22 is used to convert light with a wavelength <900nm into electricity, with a wavelength of Ω·m to prevent electrical series connection between the first battery 1 and the second battery 2. It is understood that the first photoelectric conversion structure 12 is used to convert light with a wavelength ≥900nm into electricity. Specifically, the second wavelength range can be, for example, ≤850nm, ≤800nm, ≤700nm, ≤600nm, and in some specific embodiments, the second wavelength range is 350nm-600nm. In one embodiment of this application, the first battery 1 captures light with a wavelength ≥900nm, and light with a wavelength <900nm passes through the spectrally transparent resistive layer 3 and is captured by the second battery 2. The first battery 1 and the second battery 2 operate independently without electrical crosstalk, enabling the photovoltaic cell 100 to achieve high photoelectric conversion efficiency in ground-based scenarios.

[0040] The bandgap of the first photoelectric conversion structure 12 is 1.8 eV-2.0 eV. In the embodiments of this application, the bandgap refers to the bandgap of the photoelectric conversion structure at room temperature.

[0041] The photovoltaic cell 100 provided in this application embodiment can achieve physical isolation between the first cell 1 and the second cell 2 through the spectrally transparent resistive layer 3, avoiding the series connection of the first cell 1 and the second cell 2. In the application of the photovoltaic cell 100, sunlight enters from the side of the first cell 1 away from the second cell 2. The first cell 1 absorbs and utilizes light with a wavelength ≥900nm and converts it into electrical energy. The spectrally transparent resistive layer 3 is transparent to light in the second wavelength range. Therefore, the light transmitted to the second photoelectric conversion structure is mainly light with a wavelength <900nm, thereby achieving independent response to solar radiation in the easily attenuated wavelength band of sunlight. In addition, the first cell 1 and the second cell 2 each have conductive structures led out, so the first cell 1 and the second cell 2 can be connected in parallel by leading out electrodes. This can eliminate the minimum junction current effect of traditional multi-junction photovoltaic cells, improve the power of the cell, and the photovoltaic cell 100 can be applied in ground-based scenarios. Furthermore, limiting the bandgap of the first photoelectric conversion structure 12 to 1.8eV-2.0eV allows the photons of light within the first wavelength range to be fully absorbed and utilized by the first battery 1. It also makes it easier for the light in the easily attenuated wavelength range in low-light scenarios to be fully utilized by the second battery 2, reducing heat loss, achieving efficient energy distribution and utilization, and improving the photoelectric conversion efficiency of the photovoltaic cell 100.

[0042] Specifically, the bandgap of the first photoelectric conversion structure 12 can be, for example, 1.80 eV, 1.81 eV, 1.82 eV, 1.83 eV, 1.84 eV, 1.85 eV, 1.86 eV, 1.87 eV, 1.88 eV, 1.89 eV, 1.90 eV, 1.91 eV, 1.92 eV, 1.93 eV, 1.94 eV, 1.95 eV, 1.96 eV, 1.97 eV, 1.98 eV, 1.99 eV, or 2.0 eV. If the bandgap of the first photoelectric conversion structure 12 is too narrow, it is detrimental to the application of the photovoltaic cell 100 in ground-based scenarios. Furthermore, controlling the bandgap of the first photoelectric conversion structure 12 within the aforementioned range can also reduce the leakage current of the photovoltaic cell 100 and extend its service life.

[0043] Specifically, the room temperature resistivity of the spectrally transparent resistive layer 3 can be, for example, ≥10. 6 Ω·m, ≥5×10 6 Ω·m, ≥10 8 Ω·m, etc. If the room temperature resistivity of the aforementioned spectrally transparent resistive layer 3 is too low, it will damage the circuit design of the photovoltaic cell 100 and affect the normal operation of the photovoltaic cell 100. In this embodiment, room temperature refers to the ambient temperature when testing resistivity. In most cases, room temperature in this embodiment refers to 25±2℃. In this embodiment, the spectrally transparent resistive layer 3 is peeled off from the photovoltaic cell 100, and the material of the spectrally transparent resistive layer 3 is placed between the upper and lower electrodes (the two surfaces of the spectrally transparent resistive layer 3 in the thickness direction are directly opposite the two electrodes). After applying a pressure of 25MPa to the electrodes, a certain current is applied, and the voltage across the electrodes is tested, thereby calculating the room temperature resistivity of the spectrally transparent resistive layer 3.

[0044] To further adapt to ground-based scenarios and fully improve the utilization rate of photovoltaic cells 100 for light in the easily attenuated wavelength range (350nm-600nm) while reducing light loss, the transmittance of the spectrally transparent resistive layer 3 for light of the second wavelength is ≥90%. In some specific embodiments, the transmittance of the spectrally transparent resistive layer 3 for light with a wavelength ≤600nm is ≥90%, thus further improving the photoelectric conversion efficiency.

[0045] In some embodiments of this application, the material of the spectrally transparent resistive layer 3 includes, but is not limited to, one or more of silicon nitride, aluminum oxide, silicon oxide, silicon carbide, and modified transparent conductive oxide (TCO). Specifically, the high-resistivity transparent conductive oxide can be, for example, a material obtained by compensating for oxygen vacancies in a TCO. In some specific embodiments, the spectrally transparent resistive layer 3 is any one of a silicon nitride layer, an aluminum oxide layer, a silicon oxide layer, a silicon carbide layer, or a modified TCO layer with high-resistivity characteristics. This is beneficial for the fabrication of photovoltaic cells.

[0046] In some embodiments of this application, the thickness of the spectrally transparent resistive layer 3 is 6 nm-45 μm. That is, in the stacking direction of the first battery 1 and the second battery 2, the size of the spectrally transparent resistive layer 3 is 6 nm-45 μm. Specifically, the thickness of the spectrally transparent resistive layer 3 can be, for example, 6 nm, 8 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 22 μm, 25 μm, 28 μm, 30 μm, 32 μm, 35 μm, 38 μm, 40 μm, 42 μm, 45 μm, etc. In the photovoltaic cell 100 of this application embodiment, under the premise that the bandgap of the first photoelectric conversion structure 12 is 1.8eV-2.0eV, the thickness of the spectrally transparent resistive layer 3 can be controlled within the above range to achieve a high photoelectric conversion efficiency. It also helps to reduce the total thickness of the photovoltaic cell 100 (i.e., the size of the photovoltaic cell in the stacking direction of the first cell 1 and the second cell 2), thereby improving the thinness and lightness of the photovoltaic cell 100 and enhancing the market competitiveness of the photovoltaic cell 100.

[0047] Understandably, based on the structural design of the photovoltaic cell 100 in this application embodiment, during the application of the photovoltaic cell 100, light is incident from the side of the first cell 1 away from the second cell 2. Therefore, the first cell 1 is essentially the top cell of the photovoltaic cell, and the second cell 2 is the bottom cell. In some embodiments of this application, the bandgap width of the second cell 2 is smaller than the bandgap width of the first cell 1. The bandgap design, which is wider at the top and narrower at the bottom, facilitates the full utilization of incident photons of different energies, reduces heat loss, and further improves the photoelectric conversion efficiency of the photovoltaic cell 100.

[0048] In some embodiments of this application, the first photoelectric conversion structure 12 is a PN junction structure. A PN junction is a direct boundary or interface between a P-type semiconductor material and an N-type semiconductor material. A PN junction can be formed through a doped region within a single semiconductor material or through epitaxially grown doped materials that are in contact with each other. A PN junction includes at least one P-type semiconductor material region and at least one N-type semiconductor material region. In some specific embodiments, the first photoelectric conversion structure 12 includes multiple PN junctions, for example, 2-4 PN junctions. Those skilled in the art can determine the appropriate number based on actual production needs, and this application does not impose any limitations on this.

[0049] In some embodiments of this application, the material of the first photoelectric conversion structure 12 includes gallium arsenide-based materials, specifically including but not limited to one or more of doped InGaN and doped InGaP. The material of the first photoelectric conversion structure 12 may, for example, include one or more of InGaAsNSb and AlGaAsP. In embodiments of this application, the bandgap of the first photoelectric conversion structure 12 can be adjusted by regulating the type of dopant element in the material of the first photoelectric conversion structure 12 and the doping concentration of the dopant element.

[0050] In this embodiment, the size of the first photoelectric conversion structure 12 is not limited, and those skilled in the art can select and optimize it according to actual production conditions. For example, in the direction of the first battery 1 and the second battery 2, the size of the first photoelectric conversion structure 12 can be 1μm-250μm, but is not limited to this. In some embodiments, the first photoelectric conversion structure 12 is layered. Specifically, in the direction of the first battery 1 and the second battery 2, the size of the first photoelectric conversion structure 12 can be, for example, 1μm, 2μm, 5μm, 10μm, 20μm, 50μm, 80μm, 100μm, 120μm, 150μm, 180μm, 200μm, 220μm, 250μm, etc.

[0051] In this embodiment, the first conductive structure 11 can be layered or comb-shaped; the second conductive structure 13 can also be layered or comb-shaped. It is understood that the first conductive structure 11 and the second conductive structure 13 constitute the two electrodes of the first battery 1; in some specific embodiments, the first conductive structure 11 is comb-shaped, and the second conductive structure 13 is layered. This facilitates the contact area between the first conductive structure 11 and the first photoelectric conversion structure 12, improves light absorption and charge collection efficiency, and promotes uniform current distribution, avoiding localized overheating or current blockage in the first battery 1.

[0052] In this embodiment of the application, the first conductive structure 11 and the second conductive structure 13 respectively lead out the electrodes of the first battery 1. Figures 2 to 4 (not shown in the image), and one of them is a positive electrode and the other is a negative electrode. The current generated by the first battery 1 is led out through the positive electrode and the negative electrode of the first battery 1.

[0053] In this embodiment, the orthographic projection of the first conductive structure 11 along the stacking direction of the first battery 1 and the second battery 2 falls into the first photoelectric conversion structure 12. Specifically, the orthographic projection of the first conductive structure 11 may completely overlap with the first photoelectric conversion structure 12, or it may fall inside the first photoelectric conversion structure 12. Similarly, the orthographic projection of the second conductive structure 13 along the stacking direction of the second battery 2 and the first battery 1 falls into the first photoelectric conversion structure 12, and also falls into the second photoelectric conversion structure 22.

[0054] In this application embodiment, the materials of the first conductive structure 11 and the second conductive structure 13 are not limited, and can be any material used in the field for preparing electrodes of photovoltaic cells, such as conductive metals like silver, but are not limited thereto. In this application embodiment, the materials of the first conductive structure 11 and the second conductive structure 13 can be the same or different.

[0055] In some embodiments of this application, a chemical bond is formed between the material of the first conductive structure 11 and the material of the first photoelectric conversion structure 12. This results in a stable structure for the first battery 1. Specifically, the chemical bond can be, for example, a metallic bond. Similarly, in some embodiments, a chemical bond, such as a metallic bond, is formed between the material of the second conductive structure 13 and the material of the first photoelectric conversion structure 12. In some specific embodiments of this application, the materials of the first conductive structure 11 and the second conductive structure 13 respectively form chemical bonds with the material of the first photoelectric conversion structure 12.

[0056] In some embodiments of this application, the second photoelectric conversion structure 22 is a PN junction structure. In some specific embodiments, the second photoelectric conversion structure 22 includes multiple PN junctions, for example, 2-4 PN junctions. Those skilled in the art can determine this according to actual production needs, and this application does not impose any limitations on this. In some specific embodiments, the first photoelectric conversion structure 12 includes 1-4 PN junctions, and the second photoelectric conversion structure 22 includes 1-4 PN junctions. The number of PN junctions in the second photoelectric conversion structure 22 can be the same as or different from that in the first photoelectric conversion structure 12.

[0057] In some embodiments of this application, the second photoelectric conversion structure 22 includes a gallium arsenide-based material, specifically including, but not limited to, one or more of doped or undoped InGaN and doped or undoped InGaP. The material of the second photoelectric conversion structure 22 may, for example, include one or more of InGaP, InGaAsNSb, and AlGaAsP. The material of the second photoelectric conversion structure 22 may be the same as or different from that of the first photoelectric conversion structure 12.

[0058] Please see Figure 3 In some embodiments of this application, the first battery 1 further includes an anti-reflection layer disposed between the first conductive structure 11 and the first photoelectric conversion structure 12. Figures 2 to 4 (Not shown in the image), the antireflective layer is used to reduce the reflection of electromagnetic waves by the first battery 1. This further improves the photoelectric conversion efficiency of the photovoltaic cell 100. This application does not limit the material and size of the antireflective layer; the material of the antireflective layer can be any material known in the art that can be used for antireflective layers, and the size of the antireflective layer can be determined according to actual production conditions.

[0059] In some embodiments of this application, the second battery 2 further includes a tunnel junction 24 and a third photoelectric conversion structure 25 stacked together. The tunnel junction 24 and the third photoelectric conversion structure 25 are disposed between the second photoelectric conversion structure 22 and the fourth conductive structure 23, with the tunnel junction 24 disposed close to the second photoelectric conversion structure 22. This facilitates the normal operation of the photovoltaic cell 100 and also helps to further improve the photoelectric conversion efficiency of the photovoltaic cell 100.

[0060] In this embodiment, the tunnel junction 24 can be a layered structure. This application also does not limit the size of the tunnel junction 24. The material of the tunnel junction 24 can be selected from any material known in the art suitable for forming a tunnel junction, specifically materials suitable for forming a tunnel junction in gallium arsenide-based photovoltaic cells, such as one or more of silicon oxide, titanium oxide, and aluminum oxide, but not limited thereto.

[0061] In this embodiment, the bandgap of the third photoelectric conversion structure 25 is smaller than that of the second photoelectric conversion structure 22. The material of the third photoelectric conversion structure 25 can be a gallium arsenide-based material, such as one or more of doped or undoped InGaN and doped or undoped InGaP, but is not limited thereto. In some embodiments of this application, the third photoelectric conversion structure 25 is a layered structure. This application does not limit the size of the third photoelectric conversion structure 25. For example, in the stacking direction of the first battery 1 and the second battery 2, the size of the third photoelectric conversion structure 25 can be 1 μm to 250 μm, but is not limited thereto.

[0062] In some embodiments of this application, the third conductive structure 21 and the fourth conductive structure 23 respectively lead out the electrodes of the second battery, one of which is a positive electrode and the other is a negative electrode. The current generated by the second battery 2 is led out through the positive and negative electrodes of the second battery 2. In some specific embodiments, the first conductive structure 11 and the second conductive structure 13 lead out the positive and negative electrodes of the first battery 1, and the third conductive structure 21 and the fourth conductive structure 23 lead out the positive and negative electrodes of the second battery 2.

[0063] In some embodiments of this application, in ground-based scenarios, the photovoltaic cell 100 has a photoelectric conversion efficiency of ≥30% for solar radiation.

[0064] In some embodiments of this application, the first battery 1 and the second battery 2 are connected in parallel.

[0065] Please see Figure 4In other embodiments of this application, the photovoltaic cell further includes a third cell 5. The third cell 5 includes a fifth conductive structure 51, a fourth photoelectric conversion structure 52, and a sixth conductive structure 53 stacked together. The fourth photoelectric conversion structure 52 is used to convert light in the third wavelength range into electricity. The fifth conductive structure 51 is disposed close to the second cell, and the fifth conductive structure 51 and the sixth conductive structure 53 are used to conduct current generated by the third cell 5. The third wavelength range does not intersect with the second wavelength range, and the third wavelength range does not intersect with the first wavelength range. A second spectrally transparent resistive layer 4 is disposed between the third cell 5 and the second cell 2. The second spectrally transparent resistive layer 4 is transparent to light in the third wavelength range. The room temperature resistivity of the second spectrally transparent resistive layer 4 is ≥10. 6 Ω·m. At this time, the photovoltaic cell 100 includes a first cell 1, a second cell 2, and a third cell 5 stacked sequentially. The first cell 1 and the second cell 2 are electrically isolated from each other by a spectrally transparent resistive layer 3, and the second cell 2 and the third cell 5 are electrically isolated from each other by a second spectrally transparent resistive layer 4 disposed between the second cell 2 and the third cell 5. In some embodiments, the first conductive structure 11 and the second conductive structure 13 lead out the positive and negative electrodes of the first cell 1, the third conductive structure 21 and the fourth conductive structure 23 lead out the positive and negative electrodes of the second cell 2, and the fifth conductive structure 51 and the sixth conductive structure 53 lead out the positive and negative electrodes of the third cell 5. In some embodiments, the first cell 1, the second cell 2, and the third cell 5 are connected in parallel.

[0066] In this embodiment of the application, the photovoltaic cell 100 may further include other optical components suitable for photovoltaic cells in the field ( Figures 2 to 4 (Not shown in the image), for example, concentrators, filters, etc.; those skilled in the art can select according to the actual application needs.

[0067] In some embodiments of this application, the fabrication of the aforementioned photovoltaic cell 100 includes:

[0068] S1. Prepare a second battery; the second battery includes a third conductive structure, a second photoelectric conversion structure and a fourth conductive structure stacked sequentially.

[0069] S2. A spectrally transparent resistive layer and a second conductive structure are sequentially formed on the surface of the third conductive structure that is away from the second photoelectric conversion structure.

[0070] S3. Prepare a first photoelectric conversion structure on a substrate, bond the first photoelectric conversion structure to a second conductive structure, peel off the substrate, form a first conductive structure on the side of the first photoelectric conversion structure away from the second cell, form a first cell, and obtain a photovoltaic cell.

[0071] In some embodiments, when the photovoltaic cell further includes a third cell, the preparation steps of the third cell can be the same as those of the first cell. Specifically, the preparation of the photovoltaic cell includes:

[0072] S1. Prepare a second battery; the second battery includes a third conductive structure, a second photoelectric conversion structure and a fourth conductive structure stacked sequentially.

[0073] S2', A spectrally transparent resistive layer and a second conductive structure are sequentially formed on the surface of the third conductive structure that is away from the second photoelectric conversion structure; A second spectrally transparent resistive layer and a fifth conductive structure are sequentially formed on the surface of the fourth conductive structure that is away from the second photoelectric conversion structure.

[0074] S3. Prepare a first photoelectric conversion structure on a first substrate, bond the first photoelectric conversion structure to a second conductive structure, peel off the first substrate, and form a first conductive structure on the side of the first photoelectric conversion structure away from the second cell to form a first cell.

[0075] S4. A fourth photoelectric conversion structure is fabricated on the second substrate. The fourth photoelectric conversion structure is bonded to the fifth conductive structure. The second substrate is then peeled off, and a sixth conductive structure is formed on the surface of the fourth photoelectric conversion structure facing away from the second cell, thus forming the third cell and obtaining a photovoltaic cell. In this embodiment, the order of S3 and S4 is not limited; that is, the third cell can be fabricated first, followed by the first cell.

[0076] In this embodiment, the specific processes for each of the above steps are not limited, and those skilled in the art can choose according to the actual production situation.

[0077] This application also provides a power generation device, including the aforementioned photovoltaic cell and an inverter electrically connected to the photovoltaic cell. The inverter converts the DC signal output from the photovoltaic cell into an AC signal, which can then be fed into the power grid for use.

[0078] In this embodiment, the number of photovoltaic cells in the power generation equipment is not limited; there can be one or more. When the power generation equipment includes multiple photovoltaic cells, multiple inverters are also provided, with each inverter corresponding to a photovoltaic cell to improve the accuracy of signal conversion. In other embodiments, one inverter can be electrically connected to multiple photovoltaic cells. In this case, the inverter can convert and process the DC signals output by each photovoltaic module, thereby reducing the number of inverters and lowering the manufacturing cost of the power generation equipment. In this case, the multiple photovoltaic cells can be connected in series, in parallel, or a combination of series and parallel connections.

[0079] In this embodiment of the application, the power generation equipment may include photovoltaic modules and inverters, as well as other structures that can be used to realize the functions of the power generation equipment, which are not limited here.

[0080] In this application embodiment, the power generation equipment may be, but is not limited to, a ground-mounted power station or a building-integrated photovoltaic (BIPV) device.

[0081] This application also provides a terminal device, including a photovoltaic cell provided in this application embodiment, and electronic components electrically connected to the photovoltaic cell; the photovoltaic device is used to power the electronic components. Because it uses the photovoltaic cell provided in this application embodiment, the terminal device can be charged by solar radiation and has high efficiency, giving it superior market competitiveness.

[0082] In this application embodiment, the aforementioned terminal devices include, but are not limited to, consumer electronics products such as smartwatches and mobile communication devices, wearable electronic devices, and base stations.

[0083] It should be understood that the use of the terms "first," "second," and various numerical designations in this document is merely for descriptive convenience and is not intended to limit the scope of this application.

[0084] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after it are in an "or" relationship.

[0085] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0086] In this application, "-" indicates a range value, including the endpoint values ​​at both ends. For example, the value of a can be 0.5-15, meaning that the value of a can be between 0.5 and 15, and includes the endpoint values ​​of 0.5 and 15.

Claims

1. A photovoltaic cell, characterized in that, include: A first battery and a second battery are stacked together, with a spectrally transparent resistive layer disposed between the first battery and the second battery; The first battery includes a first conductive structure, a first photoelectric conversion structure, and a second conductive structure stacked sequentially. The first photoelectric conversion structure is used to convert light within a first wavelength range into electricity. The first conductive structure and the second conductive structure are used to discharge the current generated by the first battery. The second battery includes a third conductive structure, a second photoelectric conversion structure, and a fourth conductive structure stacked sequentially. The third conductive structure is disposed close to the first battery, and the second photoelectric conversion structure is used to convert light in a second wavelength range into electricity. The third conductive structure and the fourth conductive structure are used to extract the current generated by the second battery; The first wavelength range is ≥900nm, and the second wavelength range is <900nm; the spectrally transparent resistive layer is transparent to light within the second wavelength range; the room temperature resistivity of the spectrally transparent resistive layer is ≥10. 6 Ω·m; The bandgap of the first photoelectric conversion structure is 1.8 eV-2.0 eV.

2. The photovoltaic cell according to claim 1, characterized in that, The spectrally transparent resistive layer has a transmittance of ≥90% for light in the second wavelength range.

3. The photovoltaic cell according to claim 1 or 2, characterized in that, The material of the spectrally transparent resistive layer includes one or more of silicon nitride, aluminum oxide, silicon oxide, silicon carbide, and modified transparent conductive oxides.

4. The photovoltaic cell according to any one of claims 1-3, characterized in that, The thickness of the spectrally transparent resistive layer is 6 nm-45 μm.

5. The photovoltaic cell according to any one of claims 1-4, characterized in that, The bandgap of the second photoelectric conversion structure is smaller than that of the first photoelectric conversion structure.

6. The photovoltaic cell according to any one of claims 1-5, characterized in that, The material of the first photoelectric conversion structure includes one or more of doped InGaN and doped InGaP.

7. The photovoltaic cell according to any one of claims 1-6, characterized in that, The first battery further includes an anti-reflection layer disposed between the first conductive structure and the first photoelectric conversion structure; the anti-reflection layer is used to reduce the reflection of electromagnetic waves by the first battery.

8. The photovoltaic cell according to any one of claims 1-7, characterized in that, The second battery further includes a tunneling junction and a third photoelectric conversion structure stacked together; wherein the tunneling junction and the third photoelectric conversion structure are disposed between the second photoelectric conversion structure and the fourth conductive structure, and the tunneling junction is disposed close to the second photoelectric conversion structure.

9. The photovoltaic cell according to any one of claims 1-8, characterized in that, The first battery and the second battery are connected in parallel.

10. The photovoltaic cell according to any one of claims 1-9, characterized in that, The photovoltaic cell has a photoelectric conversion efficiency of ≥30% for solar radiation.

11. A power generation device, characterized in that, The power generation equipment includes a photovoltaic cell as described in any one of claims 1-10, and an inverter electrically connected to the photovoltaic cell; the inverter is used to convert the DC signal generated by the photovoltaic cell into an AC signal.

12. A terminal device, characterized in that, The terminal device includes a photovoltaic cell as described in any one of claims 1-10, and electronic components electrically connected to the photovoltaic cell; the photovoltaic cell is used to supply power to the electronic components.

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