Anti-radiation five-junction solar cell and preparation method thereof

Abstract

The invention relates to an anti-radiation five-junction solar cell and a preparation method thereof, and belongs to the technical field of semiconductor devices. The radiation-proof five-junction solar cell comprises a substrate, and a first buffer layer, a first component order change buffer layer, a fourth sub-cell, a second component order change buffer layer, a fourth tunnel junction, a fifth sub-cell and an electrode contact layer which are sequentially stacked on a first surface of the substrate, a second buffer layer, a third tunnel junction, a third sub-cell, a second tunnel junction, a second sub-cell, a first tunnel junction, a first sub-cell and a cap layer are sequentially stacked on the second surface of the substrate; and the base region thicknesses of the second sub-cell, the third sub-cell and the fourth sub-cell are smaller than the respective emitter region thicknesses. The anti-radiation five-junction solar cell comprises a plurality of sub-cells with quantum well structures, so that the anti-radiation performance of the solar cell can be effectively improved, and the last-stage use efficiency of the solar cell is further remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor device technology, and in particular to a radiation-resistant five-junction solar cell and its fabrication method. Background Technology

[0002] III-V multijunction solar cells are high-efficiency photovoltaic devices made of III-V compound semiconductors (such as GaAs, InP, GaInP, etc.) stacked in multiple heterostructures. Their core feature is that they utilize sub-cells with different band gaps to absorb different bands of the solar spectrum, thereby achieving ultra-high conversion efficiency by reducing carrier thermal losses during the energy conversion process.

[0003] Currently, multi-junction solar cells are mainly fabricated through semiconductor bonding (SBT) and inverted modification (IMM). Semiconductor bonding involves growing sub-cells of different material systems on independent substrates and achieving mechanical and electrical connections through surface activation bonding or metal interlayer bonding. Although it can integrate materials with large lattice mismatches, it requires two epitaxial processes on two substrates, resulting in high epitaxial costs. Furthermore, the chip fabrication process for bonding requires high-quality surface cleaning and passivation of the materials, making the process cumbersome and yielding low results. Inverted modification, on the other hand, involves epitaxy starting from the top cell and growing the bottom cell with lattice mismatch at the end. Although it does not require bonding, the large number of sub-cell junctions requires a long single epitaxial cycle, making the process difficult to control, easily leading to poor surface and performance yields, and high manufacturing costs.

[0004] In addition, the presence of high-energy radiation particles in the space environment can have a fatal impact on the performance of solar cell devices. When solar cells are used in the space environment, their efficiency degradation due to irradiation must be fully considered. Multijunction solar cells, which consist of multiple sub-cells connected in series, have a finer bandgap distribution and a more complex material system. Their sub-cells are more sensitive to irradiation degradation, making it more difficult to optimize irradiation performance and thus affecting the end-of-life efficiency of multijunction solar cells. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a radiation-resistant five-junction solar cell and its preparation method.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a radiation-resistant five-junction solar cell, comprising:

[0008] A substrate having a first surface and a second surface disposed opposite to each other;

[0009] A first buffer layer, a first set of step-change buffer layers, a fourth sub-cell, a second set of step-change buffer layers, a fourth tunnel junction, a fifth sub-cell, and an electrode contact layer are sequentially stacked on the first surface.

[0010] A second buffer layer, a third tunnel junction, a third sub-cell, a second tunnel junction, a second sub-cell, a first tunnel junction, a first sub-cell, and a cap layer are sequentially stacked on the second surface.

[0011] The base region thickness of the second, third, and fourth sub-cells is smaller than the thickness of their respective emitter regions;

[0012] The first sub-cell is an AlGaInP sub-cell;

[0013] The second sub-cell is a GaInP sub-cell with a quantum well structure;

[0014] The third sub-cell is a GaAs sub-cell with a quantum well structure;

[0015] The fourth sub-battery is an In with a quantum well structure. x Ga 1-x As for the sub-battery, 0.25≤x≤0.35 (for example, x can be, but is not limited to, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34 or 0.35, or fall within the range of any two of the above values);

[0016] The fifth sub-battery is In y Ga 1-y As is the sub-cell, 0.55≤y≤0.65 (for example, y can be, but is not limited to, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64 or 0.65, or fall within the range of any two of the above values).

[0017] This invention combines multiple sub-cells with quantum well structures to broaden the absorption spectrum of the corresponding sub-cells. By reducing the thickness of the base region of the sub-cells, the recombination probability of carriers and radiation defects is reduced, thereby improving the radiation resistance of the sub-cells. Furthermore, by using a structure where the emitter region is thicker than the base region, the pn junction region is positioned further back (away from the incident surface), allowing long-wavelength photons to be absorbed near the junction region, reducing carrier recombination losses in the long-wavelength band, and thus improving the long-wavelength radiation resistance of the sub-cells. At the same time, using highly radiation-resistant group III-V p-oxide materials as the first sub-cell, the second sub-cell, and the quantum well barrier layer further improves the radiation resistance of the five-junction solar cell, thereby increasing the end-of-life efficiency of the solar cell.

[0018] As an embodiment of the present invention, the doping concentration of the emitter region of the second sub-cell, the third sub-cell, and the fourth sub-cell is each independently 5 × 10⁻⁶. 16 cm -3 Up to 8×10 17 cm -3 The thickness of the emission region and / or the emission region are each independently between 500 nm and 3000 nm.

[0019] For example, the doping concentration of the emitter region of the second, third, and fourth sub-cells can be, but is not limited to, 5 × 10⁻⁶. 16 cm -3 6×10 16 cm -3 7×10 16 cm -3 8×10 16 cm -3 9×10 16 cm -3 1×10 17 cm -3 2×10 17 cm -3 3×10 17 cm -3 4×10 17 cm -3 5×10 17 cm -3 6×10 17 cm -3 7×10 17 cm -3 Or 8×10 17 cm -3 Or it falls within the range of any two of the above values.

[0020] For example, the thickness of the emission region of the second, third, and fourth sub-cells may, but is not limited to, 500nm, 700nm, 1000nm, 1200nm, 1400nm, 1600nm, 1800nm, 2000nm, 2200nm, 2400nm, 2600nm, 2800nm, or 3000nm, or fall within the range of any two of the above values.

[0021] As an embodiment of the present invention, a first quantum well is disposed between the emitter region and the base region of the second sub-battery;

[0022] The number of periods of the first quantum well is 5 to 300, for example, but not limited to 5, 10, 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280 or 300, or within the range of any two of the above values;

[0023] The well layer material of the first quantum well is (AlGa). 1-k In k As, 0 < k ≤ 0.2 (for example, k can be, but is not limited to, 0.2, 0.18, 0.16, 0.14, 0.12, 0.1, 0.08, 0.06, 0.04, 0.02 or 0.01, or be within the range of any two of the above values);

[0024] The barrier material of the first quantum well is GaAsP.

[0025] As an embodiment of the present invention, a second quantum well is provided between the emitter region and the base region of the third sub-cell;

[0026] The number of periods of the second quantum well is 5 to 300, for example, but not limited to 5, 10, 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280 or 300, or within the range of any two of the above values;

[0027] The well layer material of the second quantum well is In. L Ga 1-L As, 0.2 < L ≤ 0.25 (for example, L can be, but is not limited to, 0.21, 0.22, 0.23, 0.24 or 0.25, or fall within the range of any two of the above values);

[0028] The barrier material of the second quantum well is GaAsP.

[0029] As an embodiment of the present invention, a third quantum well is provided between the emitter region and the base region of the fourth sub-cell;

[0030] The number of periods of the third quantum well is 5 to 300, for example, but not limited to 5, 10, 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280 or 300, or within the range of any two of the above values;

[0031] The well layer material of the third quantum well is In. p Ga 1-pAs, 0.35 < p ≤ 0.55 (for example, p can be, but is not limited to, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54 or 0.55, or fall within the range of any two of the above values);

[0032] The barrier material of the third quantum well is GaAsP.

[0033] As an embodiment of the present invention, the second sub-cell sequentially comprises a p-type AlGaInP back electric field, a p-type GaInP base region, a first quantum well, an n-type GaInP emitter region, and an n-type AlInP window layer along the direction from the second tunnel junction to the first tunnel junction.

[0034] The doping concentration of the n-type GaInP emitter region is 5 × 10⁻⁶. 16 cm -3 Up to 8×10 17 cm -3 ;

[0035] The thickness of the n-type GaInP emitter region is greater than the thickness of the p-type GaInP base region;

[0036] The thickness of the n-type GaInP emitter region is 500 nm to 3000 nm.

[0037] As an embodiment of the present invention, the third sub-cell sequentially comprises a p-type AlGaAs back electric field, a p-type GaAs base region, a second quantum well, an n-type GaAs emitter region, and an n-type AlInP window layer along the direction from the third tunnel junction to the second tunnel junction.

[0038] The doping concentration of the n-type GaAs emitter region is 5 × 10⁻⁶. 16 cm -3 Up to 8×10 17 cm -3 ;

[0039] The thickness of the n-type GaAs emitter region is greater than the thickness of the p-type GaAs base region;

[0040] The thickness of the n-type GaAs emitter region is 500 nm to 3000 nm.

[0041] As an embodiment of the present invention, the fourth sub-cell sequentially contains AlIn along the direction from the first set of step-change buffer layers to the second set of step-change buffer layers. x Ga 1-x As window layer, n-type In x Ga 1-xAs emission region, third quantum well, p-type In x Ga 1-x As base region and p-type AlIn x Ga 1-x As back electric field;

[0042] The n-type In x Ga 1-x The doping concentration of As emitter region is 5 × 10⁻⁶. 16 cm -3 Up to 8×10 17 cm -3 ;

[0043] The n-type In x Ga 1-x As the thickness of the emission region is greater than that of p-type In x Ga 1-x Thickness of the As-based region;

[0044] The n-type In x Ga 1-x The thickness of the As emitter region ranges from 500 nm to 3000 nm.

[0045] As an embodiment of the present invention, the radiation-resistant five-junction solar cell satisfies at least one of the following:

[0046] (1) The first buffer layer is an n-type GaAs with a thickness of 500 nm and a doping concentration of 2 × 10⁻⁶. 18 cm -3 ;

[0047] (2) The first phase-change buffer layer is an n-type AlGaInAs with a thickness of 2000 nm and a doping concentration of 2 × 10⁻⁶. 18 cm -3 ;

[0048] (3) The second phase-change buffer layer is a p-type AlGaInAs with a thickness of 2000 nm and a doping concentration of 2 × 10⁻⁶. 18 cm -3 ;

[0049] (4) The fourth tunnel junction, along the direction from the second set of stepped buffer layers to the fifth sub-cell, contains components with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶. 20 cm -3 p-type AlInGaAs with a thickness of 20 nm and a doping concentration of 1×10⁻⁶ 19 cm -3 n-type AlInGaAs;

[0050] (5) The electrode contact layer is a 500 nm thick p-type InGaAs with a doping concentration of 5 × 10⁻⁶.18 cm -3 ;

[0051] (6) The second buffer layer is an n-type GaAs with a thickness of 500 nm and a doping concentration of 2 × 10⁻⁶. 18 cm -3 ;

[0052] (7) The third tunnel junction, along the direction from the second buffer layer to the third sub-cell, comprises layers with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶. 19 cm -3 n-type AlGaAs with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶ 20 cm -3 p-type AlGaAs;

[0053] (8) The second tunnel junction contains sequentially layers of 20 nm thickness and doping concentration of 1 × 10⁻⁶ along the direction from the third subcell to the second subcell. 19 cm -3 n-type GaInP with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶ 20 cm -3 p-type AlGaAs;

[0054] (9) The first tunnel junction comprises, along the direction from the second sub-cell to the first sub-cell, a layer with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶. 19 cm -3 n-type GaInP with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶ 20 cm -3 p-type AlGaAs;

[0055] (10) The substrate is a GaAs substrate.

[0056] Secondly, the present invention provides a method for preparing a radiation-resistant five-junction solar cell, comprising the following steps:

[0057] S1. A first buffer layer, a first set of step-change buffer layer, a fourth sub-cell, a second set of step-change buffer layer, a fourth tunnel junction, a fifth sub-cell, and an electrode contact layer are sequentially grown in reverse on the first surface of the substrate.

[0058] S2. On the second surface of the substrate, a second buffer layer, a third tunnel junction, a third subcell, a second tunnel junction, a second subcell, a first tunnel junction, a first subcell, and a cap layer are sequentially grown in the forward direction to obtain a radiation-resistant five-junction solar cell.

[0059] Alternatively, the above preparation method can be performed by metal-organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE) on the substrate.

[0060] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0061] This invention combines multiple sub-cells with quantum well structures to broaden the absorption spectrum of the corresponding sub-cells. By reducing the thickness of the base region of the sub-cells, the recombination probability of carriers and radiation defects is reduced, thereby improving the radiation resistance of the sub-cells. Furthermore, by employing a structure where the emitter region is thicker than the base region, the pn junction region is positioned further back, allowing long-wavelength photons to be absorbed near the junction region, reducing carrier recombination losses in the long-wavelength band, and thus improving the long-wavelength radiation resistance of the sub-cells. Simultaneously, using highly radiation-resistant group III-V p-oxide materials as the first sub-cell, the second sub-cell, and the quantum well barrier layer further enhances the radiation resistance of the five-junction solar cell, thereby improving the end-of-life efficiency of the solar cell. Attached Figure Description

[0062] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0063] Figure 1 This is a schematic diagram of the structure of a radiation-resistant five-junction solar cell according to one embodiment of the present invention. Detailed Implementation

[0064] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Unless otherwise specified, other materials and reagents used in the embodiments are commercially available.

[0065] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0066] In addition, the terms "first" and "second" in this invention are used to distinguish identical or similar items with essentially the same function. It should be understood that there is no logical or temporal dependency between "first", "second", and "nth", nor is there any limitation on the quantity or execution order.

[0067] The embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0068] <Preparation of Radiation-Resistant Five-Junction Solar Cells>

[0069] S1. Select a 4-inch double-sided polished n-type GaAs substrate and use metal-organic chemical vapor deposition (MOCVD) to sequentially form the first buffer layer, the first set of step change buffer layer, the fourth sub-cell, the second set of step change buffer layer, the fourth tunnel junction, the fifth sub-cell and the electrode contact layer on its upper surface in an inverted growth manner.

[0070] S2. Flip the n-type GaAs substrate 180°, and sequentially form a second buffer layer, a third tunnel junction, a third subcell, a second tunnel junction, a second subcell, a first tunnel junction, a first subcell, and a cap layer on its lower surface in a forward-growing manner to obtain a radiation-resistant five-junction solar cell (e.g., Figure 1 (As shown).

[0071] in:

[0072] 1) The first buffer layer is an n-type GaAs with a thickness of 500 nm and a doping concentration of 2 × 10⁻⁶. 18 cm -3 .

[0073] 2) The first phase-variable buffer layer is an n-type AlGaInAs with a thickness of 2000 nm and a doping concentration of 2 × 10⁻⁶. 18 cm -3 ;

[0074] The band gap of AlGaInAs material is not less than the band gap of the third sub-cell;

[0075] The first set of variable buffer layers includes at least one first overshoot layer, where the In content of the first overshoot layer is greater than that of the fourth sub-cell; the In content of the variable buffer layers between the first buffer layer and the first overshoot layer gradually increases, and the In content of the variable buffer layers between the first overshoot layer and the fourth sub-cell gradually decreases.

[0076] 3) The fourth sub-cell (QW) is an In-type cell with a quantum well structure. x Ga 1-x As (x = 0.3) sub-cell;

[0077] The fourth sub-cell contains AlIn sequentially along the growth direction. x Ga 1-x As(x=0.3) window layer, n-type In x Ga 1-x As (x = 0.3) emission region, third quantum well, p-type In x Ga 1-x As (x = 0.3) base region, p-type AlIn x Ga 1-xAs (x = 0.3) back electric field;

[0078] The well layer and barrier layer materials of the third quantum well are In, respectively. p Ga 1-p As (p = 0.4) and GaAsP, the quantum well structure has a period number of 50;

[0079] n-type In x Ga 1-x The doping concentration of As emitter region is 1×10⁻⁶. 17 cm -3 ;

[0080] n-type In x Ga 1-x The thickness of the As emission region is 1500 nm;

[0081] p-type In x Ga 1-x The thickness of the As base region is 100 nm.

[0082] 4) The second phase-change buffer layer is a 2000 nm thick p-type AlGaInAs with a doping concentration of 2 × 10⁻⁶. 18 cm -3 ;

[0083] The band gap of AlGaInAs material is not less than the band gap of the fourth sub-cell;

[0084] The second-order variable buffer layer contains at least one second overshoot layer, and the In content of the second overshoot layer is greater than that of the fifth sub-cell. The In content of the variable buffer layer between the fourth sub-cell and the second overshoot layer gradually increases, and the In content of the variable buffer layer between the second overshoot layer and the fifth sub-cell gradually decreases.

[0085] 5) The fourth tunnel junction, along its growth direction, successively contains components with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶. 20 cm -3 p-type AlInGaAs with a thickness of 20 nm and a doping concentration of 1×10⁻⁶ 19 cm -3 n-type AlInGaAs.

[0086] 6) The fifth sub-cell is In y Ga 1-y As (y = 0.58) sub-cell;

[0087] The fifth sub-cell contains AlIn sequentially along the growth direction. y Ga 1-y As(y=0.58) window layer, n-type In y Ga 1-yAs (y = 0.58) launch region, p-type In y Ga 1-y As (y = 0.58) base region, p-type AlIn y Ga 1-y As (y = 0.58) back electric field;

[0088] 7) The electrode contact layer is a 500 nm thick p-type InGaAs with a doping concentration of 5 × 10⁻⁶. 18 cm -3 .

[0089] 8) The second buffer layer is an n-type GaAs with a thickness of 500 nm and a doping concentration of 2 × 10⁻⁶. 18 cm -3 .

[0090] 9) The third tunnel junction, along the growth direction, successively contains components with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶. 19 cm -3 n-type AlGaAs with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶ 20 cm -3 p-type AlGaAs.

[0091] 10) The third sub-cell (QW) is a GaAs sub-cell with a quantum well structure;

[0092] The third sub-cell, along the growth direction, sequentially comprises a p-type AlGaAs back electric field, a p-type GaAs base region, a second quantum well, an n-type GaAs emitter region, and an n-type AlInP window layer;

[0093] The well layer and barrier layer materials of the second quantum well are In, respectively. L Ga 1-L As (L=0.21), GaAsP, the quantum well structure has a period number of 50;

[0094] The doping concentration of the n-type GaAs emitter region is 1×10⁻⁶. 17 cm -3 ;

[0095] The thickness of the n-type GaAs emitter region is 1500 nm;

[0096] The thickness of the p-type GaAs base region is 100 nm.

[0097] 11) The second tunnel junction, along its growth direction, sequentially contains components with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶. 19 cm -3 n-type GaInP with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶ 20 cm -3 p-type AlGaAs.

[0098] 12) The second sub-cell (QW) is a GaInP sub-cell with a quantum well structure;

[0099] The second sub-cell sequentially comprises a p-type AlGaInP back electric field, a p-type GaInP base region, a first quantum well, an n-type GaInP emitter region, and an n-type AlInP window layer along the growth direction.

[0100] The well layer and barrier layer materials of the first quantum well are (AlGa). 1-k In k As (k = 0.1), GaAsP, the quantum well structure has a period number of 50;

[0101] The doping concentration of the n-type GaInP emitter region is 1×10⁻⁶. 17 cm -3 ;

[0102] The thickness of the n-type GaInP emitter region is 600 nm;

[0103] The thickness of the p-type GaInP base region is 50 nm.

[0104] 13) The first tunnel junction, along its growth direction, sequentially contains components with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶. 19 cm -3 n-type GaInP with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶ 20 cm -3 p-type AlGaAs.

[0105] 14) The first sub-cell is an AlGaInP sub-cell;

[0106] The first sub-cell, along its growth direction, sequentially comprises a p-type AlGaInP back electric field, a p-type AlGaInP base region, an n-type AlGaInP emitter region, and an n-type AlInP window layer.

[0107] 15) The cap layer is an n-type GaAs with a thickness of 500 nm and a doping concentration of 5 × 10⁻⁶. 18 cm -3 .

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A radiation-resistant five-junction solar cell, characterized in that, include: A substrate having a first surface and a second surface disposed opposite to each other; A first buffer layer, a first set of step-change buffer layers, a fourth sub-cell, a second set of step-change buffer layers, a fourth tunnel junction, a fifth sub-cell, and an electrode contact layer are sequentially stacked on the first surface. A second buffer layer, a third tunnel junction, a third sub-cell, a second tunnel junction, a second sub-cell, a first tunnel junction, a first sub-cell, and a cap layer are sequentially stacked on the second surface. The base region thickness of the second, third, and fourth sub-cells is smaller than the thickness of their respective emitter regions; The first sub-cell is an AlGaInP sub-cell; The second sub-cell is a GaInP sub-cell with a quantum well structure; The third sub-cell is a GaAs sub-cell with a quantum well structure; The fourth sub-battery is an In with a quantum well structure. x Ga 1-x As a sub-cell, 0.25≤x≤0.35; The fifth sub-battery is In y Ga 1-y As for the sub-cell, 0.55≤y≤0.

65.

2. The radiation-resistant five-junction solar cell as described in claim 1, characterized in that, The doping concentration of the emitter region of the second, third, and fourth sub-cells is independently 5 × 10⁻⁶. 16 cm -3 Up to 8×10 17 cm -3 The thickness of the emission region and / or the emission region are each independently between 500 nm and 3000 nm.

3. The radiation-resistant five-junction solar cell as described in claim 1, characterized in that, A first quantum well is disposed between the emitter region and the base region of the second sub-cell; The number of periods in the first quantum well is between 5 and 300; The well layer material of the first quantum well is (AlGa). 1-k In k As, 0 < k ≤ 0.2; The barrier material of the first quantum well is GaAsP.

4. The radiation-resistant five-junction solar cell as described in claim 1, characterized in that, A second quantum well is provided between the emitter region and the base region of the third sub-cell; The second quantum well has a period number of 5 to 300; The well layer material of the second quantum well is In. L Ga 1-L As, 0.2 < L ≤ 0.25; The barrier material of the second quantum well is GaAsP.

5. The radiation-resistant five-junction solar cell as described in claim 1, characterized in that, A third quantum well is provided between the emitter region and the base region of the fourth sub-cell; The third quantum well has a period number of 5 to 300; The well layer material of the third quantum well is In. p Ga 1-p As, 0.35 < p ≤ 0.55; The barrier material of the third quantum well is GaAsP.

6. The radiation-resistant five-junction solar cell as described in claim 1, characterized in that, The second sub-cell sequentially comprises a p-type AlGaInP back electric field, a p-type GaInP base region, a first quantum well, an n-type GaInP emitter region, and an n-type AlInP window layer along the direction from the second tunnel junction to the first tunnel junction; The doping concentration of the n-type GaInP emitter region is 5 × 10⁻⁶. 16 cm -3 Up to 8×10 17 cm -3 ; The thickness of the n-type GaInP emitter region is greater than the thickness of the p-type GaInP base region; The thickness of the n-type GaInP emitter region is 500 nm to 3000 nm.

7. The radiation-resistant five-junction solar cell as described in claim 1, characterized in that, The third sub-cell sequentially comprises a p-type AlGaAs back electric field, a p-type GaAs base region, a second quantum well, an n-type GaAs emitter region, and an n-type AlInP window layer along the direction from the third tunnel junction to the second tunnel junction; The doping concentration of the n-type GaAs emitter region is 5 × 10⁻⁶. 16 cm -3 Up to 8×10 17 cm -3 ; The thickness of the n-type GaAs emitter region is greater than the thickness of the p-type GaAs base region; The thickness of the n-type GaAs emitter region is 500 nm to 3000 nm.

8. The radiation-resistant five-junction solar cell as described in claim 1, characterized in that, The fourth sub-cell contains AlIn sequentially along the direction from the first set of stepped buffer layers to the second set of stepped buffer layers. x Ga 1-x As window layer, n-type In x Ga 1-x As emission region, third quantum well, p-type In x Ga 1-x As base region and p-type AlIn x Ga 1-x As back electric field; The n-type In x Ga 1-x The doping concentration of As emitter region is 5 × 10⁻⁶. 16 cm -3 Up to 8×10 17 cm -3 ; The n-type In x Ga 1-x As the thickness of the emission region is greater than that of p-type In x Ga 1-x Thickness of the As-based region; The n-type In x Ga 1-x The thickness of the As emitter region ranges from 500 nm to 3000 nm.

9. The radiation-resistant five-junction solar cell as described in claim 1, characterized in that, The radiation-resistant five-junction solar cell satisfies at least one of the following: (1) The first buffer layer is an n-type GaAs with a thickness of 500 nm and a doping concentration of 2 × 10⁻⁶. 18 cm -3 ; (2) The first phase-change buffer layer is an n-type AlGaInAs with a thickness of 2000 nm and a doping concentration of 2 × 10⁻⁶. 18 cm -3 ; (3) The second phase-change buffer layer is a p-type AlGaInAs with a thickness of 2000 nm and a doping concentration of 2 × 10⁻⁶. 18 cm -3 ; (4) The fourth tunnel junction, along the direction from the second set of stepped buffer layers to the fifth sub-cell, contains components with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶. 20 cm -3 p-type AlInGaAs with a thickness of 20 nm and a doping concentration of 1×10⁻⁶ 19 cm -3 n-type AlInGaAs; (5) The electrode contact layer is a 500 nm thick p-type InGaAs with a doping concentration of 5 × 10⁻⁶. 18 cm -3 ; (6) The second buffer layer is an n-type GaAs with a thickness of 500 nm and a doping concentration of 2 × 10⁻⁶. 18 cm -3 ; (7) The third tunnel junction, along the direction from the second buffer layer to the third sub-cell, comprises layers with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶. 19 cm -3 n-type AlGaAs with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶ 20 cm -3 p-type AlGaAs; (8) The second tunnel junction contains sequentially layers of 20 nm thickness and doping concentration of 1 × 10⁻⁶ along the direction from the third subcell to the second subcell. 19 cm -3 n-type GaInP with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶ 20 cm -3 p-type AlGaAs; (9) The first tunnel junction comprises, along the direction from the second sub-cell to the first sub-cell, a layer with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶. 19 cm -3 n-type GaInP with a thickness of 20 nm and a doping concentration of 1 × 10⁻⁶ 20 cm -3 p-type AlGaAs; (10) The substrate is a GaAs substrate.

10. A method for preparing a radiation-resistant five-junction solar cell according to any one of claims 1 to 9, comprising the following steps: S1. On the first surface of the substrate, a first buffer layer, a first set of step change buffer layer, a fourth sub-cell, a second set of step change buffer layer, a fourth tunnel junction, a fifth sub-cell, and an electrode contact layer are grown in reverse order. S2. On the second surface of the substrate, a second buffer layer, a third tunnel junction, a third subcell, a second tunnel junction, a second subcell, a first tunnel junction, a first subcell, and a cap layer are sequentially grown in the forward direction to obtain a radiation-resistant five-junction solar cell.

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