Laminated structure, carrier selection layer, solar cell, and method for manufacturing laminated structure

Abstract

To suppress hydrogen blistering in a carrier selection layer.SOLUTION: The laminated structure 1 is constituted by laminating a first semiconductor layer 11 containing hydrogen, an intermediate layer 12 containing intrinsic hydrogenated amorphous silicon, and a second semiconductor layer 13 having physical characteristics different from those of the first semiconductor layer in this order. The intermediate layer 12 is formed between the first semiconductor layer 11 and the second semiconductor layer 13.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a laminated structure, a carrier selection layer, a solar cell, and a method for manufacturing the laminated structure. [Background technology]

[0002] As silicon-based solar cells that exhibit high conversion efficiency, TOPCon (Tunnel Oxide Passivated Contact) solar cells (see, for example, Non-Patent Document 1) and NATURE contact (NAnocrystalline Transport path in Ultra-thin Dielectrics for REinforced Passivating contact) solar cells (see, for example, Patent Document 1) have been devised. These silicon-based solar cells are equipped with high-performance carrier selection layers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-163787

[0004] [Non-Patent Document 1] Frank Feldmann et al, "Efficient carrier-selective p- and n- contacts for Si solar cells", Solar Energy Materials & Solar Cells, 2014, vol. 131, pp. 100-104 [Non-patent document 2] S. Choi et al, "Formation and suppression of hydrogen blisters in tunnelling oxide passivating contact for crystalline silicon solar cells", Scientific Reports. 10, 9672 (2020). Summary of the Invention [Problem to be solved by the invention]

[0005] In the carrier selection layer of TOPCon solar cells, a thin tunnel oxide protective film made of silicon oxide is formed between the silicon and metal electrodes to reduce recombination loss between the silicon surface of the cell and the metal electrodes. The carrier selection layer of NATURE contact solar cells is made of silicon oxide (SiO ) to achieve carrier transport through a thicker oxide film than that of TOPCon solar cells. x ) The protective film is made of a composite film that uses silicon nanocrystals generated in the film as a carrier transport path.

[0006] However, in current TOPCon solar cells and NATURE contact solar cells, it is known that hydrogen blistering, which occurs due to the aggregation of hydrogen in the film, reduces the performance of the solar cell (see, for example, Non-Patent Document 2).

[0007] The present disclosure has been made in light of these circumstances, and its purpose is to suppress hydrogen blistering in a carrier selection layer. [Means for solving the problem]

[0008] To solve the above problems, a stacked structure according to one embodiment of the present invention is configured by stacking, in this order, a first semiconductor layer containing hydrogen, an intermediate layer containing intrinsic hydrogenated amorphous silicon, and a second semiconductor layer having physical properties different from those of the first semiconductor layer, with the intermediate layer being formed between the first semiconductor layer and the second semiconductor layer.

[0009] In one embodiment, the intrinsic hydrogenated amorphous silicon of the layered structure may be 70 at % to 85 at % silicon and 15 at % to 30 at % hydrogen.

[0010] In one embodiment, the intrinsic hydrogenated amorphous silicon of the stack structure preferably has a hydrogen density of 1×10 21 / cm 3 More than 1×10 22 / cm 3 or less, preferably a hydrogen density of 5×10 21 / cm 3 More than 6 x 10 21 / cm 3 The following amorphous structure may be adopted:

[0011] In an embodiment, the second semiconductor layer of the stack may comprise hydrogen.

[0012] In one embodiment, the first semiconductor layer of the stacked structure may be a heavily doped polycrystalline silicon layer, and the second semiconductor layer may be a hydrogenated amorphous silicon oxide layer or a heavily doped polycrystalline silicon layer.

[0013] In an embodiment, the second semiconductor layer of the stack may be free of hydrogen.

[0014] In an embodiment, the first semiconductor layer of the stack may be a heavily doped polycrystalline silicon layer and the second semiconductor layer may be a silicon oxide layer.

[0015] Another aspect of the present invention is a carrier selection layer for a solar cell, the carrier selection layer comprising any one of the stacked structures described above.

[0016] One embodiment is a carrier selection layer for a NATURE contact solar cell, comprising the above-described carrier selection layer.

[0017] One embodiment is a carrier selection layer for a TOPCon type solar cell comprising the carrier selection layer described above.

[0018] Yet another aspect of the present invention is a solar cell, which includes any one of the carrier selection layers described above.

[0019] One embodiment is a NATURE contact solar cell that includes the carrier selection layer described above.

[0020] One embodiment is a TOPCon solar cell with the carrier selection layer described above.

[0021] Another aspect of the present invention is a method for manufacturing a layered structure, comprising the steps of depositing, in order, a first oxygen-rich hydrogenated amorphous silicon oxide layer, a second oxygen-poor hydrogenated amorphous silicon oxide layer, a third oxygen-rich hydrogenated amorphous silicon oxide layer, an intermediate layer containing intrinsic hydrogenated amorphous silicon, and a heavily doped amorphous silicon layer on a silicon substrate, and annealing the silicon substrate on which the precursor has been prepared. Note that the layers may be deposited on both sides or only one side of the silicon substrate.

[0022] Any combination of the above components, and conversion of the present disclosure into a method, device, system, recording medium, computer program, etc., are also valid aspects of the present disclosure. [Effects of the Invention]

[0023] According to the present disclosure, hydrogen blistering in the carrier selection layer can be suppressed. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a cross-sectional view of a laminated structure according to a first embodiment. [Figure 2] FIG. 10 is a cross-sectional view of a laminated structure according to a comparative example. [Figure 3]Fig. 3(a) is a schematic diagram showing the state of the laminated structure after film formation, and Fig. 3(b) is a schematic diagram showing the state of the laminated structure after annealing treatment. [Figure 4] Figure 4(a) is a laser microscope image of the laminated structure after film formation, viewed from above. Figure 4(b) is a laser microscope image of the laminated structure after annealing, viewed from above. [Figure 5] 5A and 5B are cross-sectional views of a carrier selection layer for a NATURE contact solar cell according to a third embodiment, in which Fig. 5A shows the carrier selection layer after deposition, and Fig. 5B shows the carrier selection layer after annealing. [Figure 6] FIG. 10 is a cross-sectional view of a carrier selection layer for a TOPCon solar cell according to a third embodiment. [Figure 7] FIG. 10 is a cross-sectional view of a NATURE contact solar cell according to a third embodiment. [Figure 8] FIG. 10 is a cross-sectional view of a TOPCon solar cell according to a third embodiment. [Figure 9] FIG. 1 shows experimental results of carrier selectivity. [Figure 10] FIG. 10 is a diagram showing experimental results of passivation performance. [Figure 11] These are laser microscope images of top views of samples made with varying thicknesses of a heavily doped amorphous silicon layer and an intermediate layer comprising intrinsic hydrogenated amorphous silicon. [Figure 12] Transmission electron microscope images of the carrier selection layer viewed from the side without (left) and with (right) an intermediate layer containing intrinsic hydrogenated amorphous silicon. [Figure 13] Top-down laser microscope images of solar cells made with varying thicknesses of a heavily doped amorphous silicon layer and an intermediate layer containing intrinsic hydrogenated amorphous silicon. [Figure 14] 14 is a graph showing the current-voltage characteristics of each solar cell shown in FIG. 13. DETAILED DESCRIPTION OF THE INVENTION

[0025] The present disclosure will be described below based on preferred embodiments with reference to the drawings. In the embodiments and modified examples, identical or equivalent components and parts are designated by the same reference numerals, and redundant description will be omitted where appropriate. The dimensions of the parts in the drawings are enlarged or reduced as appropriate for ease of understanding. Some elements that are not important for explaining the embodiments are omitted from the drawings. Terms including ordinal numbers such as "first," "second," etc. are used to describe various components, but these terms are used only to distinguish one component from another, and do not limit the components.

[0026] [First embodiment: laminated structure] FIG. 1 is a cross-sectional view of a stacked structure 1 according to a first embodiment. The stacked structure 1 is configured by stacking a first semiconductor layer 11, an intermediate layer 12, and a second semiconductor layer 13 in this order. The first semiconductor layer 11 contains hydrogen. The intermediate layer 12 contains intrinsic hydrogenated amorphous silicon. The second semiconductor layer 13 has physical properties different from those of the first semiconductor layer 11. The intermediate layer 12 is formed between the first semiconductor layer 11 and the second semiconductor layer 13.

[0027] The first semiconductor layer 11 is a semiconductor layer containing hydrogen. As a non-limiting example, the first semiconductor layer may be p-type hydrogenated amorphous silicon (p + -a-Si:H) or the like.

[0028] The intermediate layer 12 is a layer containing intrinsic hydrogenated amorphous silicon. As a non-limiting example, such intrinsic hydrogenated amorphous silicon may be intrinsic hydrogenated amorphous silicon having silicon content of 70 at% to 85 at% and hydrogen content of 15 at% to 30 at%. Alternatively, as another non-limiting example, the intrinsic hydrogenated amorphous silicon may preferably have a concentration of 1×10 21 / cm 3 More than 1×10 22 / cm 3 or less, preferably a hydrogen density of 5×10 21 / cm 3 More than 6 x 10 21 / cm 3 It may be intrinsic hydrogenated amorphous silicon having the following amorphous structure:

[0029] The second semiconductor layer 13 is a semiconductor layer having physical properties different from those of the first semiconductor layer 11. The second semiconductor layer 13 may or may not contain hydrogen. As a non-limiting example, when the second semiconductor layer 13 contains hydrogen, it may be hydrogenated amorphous silicon oxide (a-SiO y :H), etc. As a non-limiting example, when the second semiconductor layer 13 does not contain hydrogen, it may be silicon oxide (SiO x ) etc.

[0030] [Effects of the embodiment] The effects of the laminated structure of the embodiment will be described below. FIG. 2 is a cross-sectional view of a laminated structure 2 according to a comparative example for comparison with the embodiment. The laminated structure 2 is configured by laminating a first semiconductor layer 11 and a second semiconductor layer 13. Typically, the laminated structure 2 is a laminated structure that constitutes a carrier selection layer of a conventional NATURE contact type solar cell. In this case, the first semiconductor layer 11 is made of p-type hydrogenated amorphous silicon (p + -a-Si:H, and the second semiconductor layer 13 is hydrogenated amorphous silicon oxide (a-SiO y :H). In this case, both the first semiconductor layer 11 and the second semiconductor layer 13 contain hydrogen.

[0031] FIG. 3(a) is a schematic diagram showing the state of the stacked structure 2 after film formation. White circles represent hydrogen in the film (semiconductor layer). As shown in the figure, blisters (bulges) have formed in the first semiconductor layer 11 and the second semiconductor layer after film formation due to the aggregation of hydrogen in the film. In this specification, the occurrence of such blisters is sometimes referred to as hydrogen blistering.

[0032] Fig. 3(b) is a schematic diagram showing the state of the stacked structure 2 of Fig. 3(a) after annealing. As shown in the figure, after annealing, the portions where blisters have occurred burst, and a portion of the first semiconductor layer 11 is missing.

[0033] Fig. 4(a) is a laser microscope image taken from above of the laminated structure 2 after film formation. Fig. 4(b) is a laser microscope image taken from above of the laminated structure 2 after annealing treatment. In these images, areas where blisters have occurred and areas where the first semiconductor layer 11 has been missing can be observed.

[0034] Such hydrogen blistering can cause degradation of passivation performance and carrier selection performance when the laminated structure 2 is used as, for example, a carrier selection layer.

[0035] 1, the occurrence of blisters is suppressed by the formation of intermediate layer 12 containing intrinsic hydrogenated amorphous silicon between first semiconductor layer 11 and second semiconductor layer 13. This is thought to be because the intrinsic hydrogenated amorphous silicon in intermediate layer 12 improves the adhesion between first semiconductor layer 11 and second semiconductor layer 13, suppressing the aggregation of hydrogen.

[0036] As described above, according to this embodiment, hydrogen blistering in the stacked structure can be suppressed.

[0037] [Second embodiment: Carrier selection layer] The laminated structure of the above embodiment can be applied to a carrier selection layer of a solar cell or the like.

[0038] [NATURE Carrier selection layer for contact-type solar cells] FIG. 5 is a cross-sectional view of the carrier selection layer 3 for the NATURE contact type solar cell according to this embodiment.

[0039] 5(a) shows the carrier selection layer 3 after deposition. The carrier selection layer 3 after deposition is composed of a crystalline silicon (c-Si) substrate 311 and a first hydrogenated amorphous silicon oxide layer (a-SiO y :H) 312 and a second hydrogenated amorphous silicon oxide layer (a-SiO x :H) 313 and a third hydrogenated amorphous silicon oxide layer (a-SiO y :H) 314, an intermediate layer 315 comprising intrinsic hydrogenated amorphous silicon (ia-Si:H), and a heavily doped amorphous silicon layer 316 (e.g., p-type hydrogenated amorphous silicon, p + a first hydrogenated amorphous silicon oxide layer (a-SiO y :H) 312 and a third hydrogenated amorphous silicon oxide layer (a-SiO y :H) 314 is a second hydrogenated amorphous silicon oxide layer (a-SiO x :H)313 is more oxygen-rich (x <y)。

[0040] FIG. 5(b) shows the carrier selection layer 3 after the annealing treatment. This annealing treatment forms an oxygen-poor second hydrogenated amorphous silicon oxide layer (a-SiO x In the amorphous silicon layer (p + The annealing process of the a-Si:H316 results in a highly doped polycrystalline silicon layer (p + The film is then changed to poly-Si) 317. As a result, a conductive protective film containing silicon nanodots 318 therein is formed, and the carrier selection layer 3 is fabricated.

[0041] In this case, a heavily doped amorphous silicon layer (p + -a-Si:H)316 or heavily doped polycrystalline silicon layer (p + The hydrogenated amorphous silicon oxide layer (a-SiO ) 317, which corresponds to the second semiconductor layer, contains hydrogen. y :H)312 contains hydrogen.

[0042] By forming intermediate layer 315 containing intrinsic hydrogenated amorphous silicon between third hydrogenated amorphous silicon oxide layer 314 and polycrystalline silicon layer 317, carrier selection layer 3 can suppress hydrogen blistering, unlike carrier selection layers for conventional NATURE contact solar cells.

[0043] [Carrier selection layer for TOPCon solar cells] 6 is a cross-sectional view of the carrier selection layer 4 for the TOPCon solar cell according to this embodiment. The carrier selection layer 4 is formed by stacking a crystalline silicon (c-Si) substrate 411 and a silicon oxide layer (SiO x ) 412, an intermediate layer 413 comprising intrinsic hydrogenated amorphous silicon (ia-Si:H), and a heavily doped amorphous silicon layer 414 (e.g., p-type hydrogenated amorphous silicon, p + -a-Si:H) and a heavily doped amorphous silicon layer (p + The -a-Si:H) 414 functions as a carrier transport layer, and the silicon oxide layer (SiO x ) 412 serves as a passivation layer. x ) 412 is preferably a thin film of about 1 to 2 nm.

[0044] In this case, a heavily doped amorphous silicon layer (p + The silicon dioxide layer (SiO 2 ) 414 corresponds to the second semiconductor layer. x ) 412 may or may not contain hydrogen.

[0045] Silicon oxide layer (SiO x ) 412 and a heavily doped amorphous silicon layer (p + The carrier selection layer 4 is formed with an intermediate layer 413 containing intrinsic hydrogenated amorphous silicon between the carrier selection layer 413 and the amorphous silicon (a-Si:H) 414, which allows the carrier selection layer 4 to suppress hydrogen blistering, unlike carrier selection layers for conventional TOPCon solar cells.

[0046] [Third embodiment: solar cell] The third embodiment is a solar cell including the carrier selection layer according to the second embodiment. Below, a NATURE contact solar cell and a TOPCon solar cell are described as representative examples. However, the present disclosure is not limited to these, and the stacked structure according to the present disclosure can be applied to any suitable solar cell.

[0047] [NATURE contact type solar cell] FIG. 7 is a cross-sectional view of a non-limiting example of a NATURE contact type solar cell 5 according to this embodiment. The NATURE contact type solar cell 5 has an Ag electrode 519 and n-type hydrogenated amorphous silicon (n + -a-Si:H) 518 and a hydrogenated amorphous silicon oxide layer (a-SiO x :H)516 and an oxygen-rich hydrogenated amorphous silicon oxide layer (a-SiO y :H)514 and an oxygen-poor hydrogenated amorphous silicon oxide layer (a-SiO x :H)513 and an oxygen-rich hydrogenated amorphous silicon oxide layer (a-SiO y :H) 512, a crystalline silicon (c-Si) substrate 511, and an oxygen-rich hydrogenated amorphous silicon oxide layer (a-SiO y :H)512 and an oxygen-poor hydrogenated amorphous silicon oxide layer (a-SiO y :H)513 and an oxygen-rich hydrogenated amorphous silicon oxide layer (a-SiO y :H) 514, an intermediate layer 515 including intrinsic hydrogenated amorphous silicon (ia-Si:H), and p-type hydrogenated amorphous silicon (p + The silicon dioxide layer 517 is made of an oxygen-poor hydrogenated amorphous silicon dioxide (a-SiO y Silicon nanodots 521 are formed inside the 513 (H).

[0048] According to this embodiment, it is possible to realize a NATURE contact solar cell in which hydrogen blistering in the carrier selection layer is suppressed.

[0049] [TOPCon type solar cell] FIG. 8 is a cross-sectional view of a non-limiting example of a TOPCon solar cell 6 according to this embodiment. The TOPCon solar cell 6 includes an electrode 611, a SiN / AlO layer 612, and a p-type amorphous silicon layer (p + a-Si:H) 613, an intermediate layer 614 containing intrinsic hydrogenated amorphous silicon (ia-Si:H), and a silicon oxide layer (SiO x ) 615, a crystalline silicon (c-Si) substrate 616, and an n-type amorphous silicon layer (n + The layer is made up of a-Si:H 617 and SiN 618 laminated in this order.

[0050] According to this embodiment, a TOPCon solar cell in which hydrogen blistering in the carrier selection layer is suppressed can be realized.

[0051] [Fourth embodiment: manufacturing method of laminated structure] The fourth embodiment is a method for manufacturing a stacked structure. A non-limiting example of the method for manufacturing a stacked structure according to this embodiment is described below. First, a silicon substrate manufactured using the Cz method is prepared. The silicon substrate is preferably an n-type single crystal silicon substrate. This silicon substrate is then cleaned with an appropriate cleaning solution.

[0052] Next, a first oxygen-rich hydrogenated amorphous silicon oxide layer (a-SiO ) is deposited on the silicon substrate, for example, by a plasma-enhanced chemical vapor deposition (PECVD) process. y :H), an oxygen-poor second hydrogenated amorphous silicon oxide layer (a-SiO x :H), an oxygen-rich third hydrogenated amorphous silicon oxide layer (a-SiO y :H), an intermediate layer containing intrinsic hydrogenated amorphous silicon (ia-Si:H) and a heavily doped amorphous silicon layer (p +The precursor is prepared by depositing the layers (a-Si:H) in this order (step S1). The above layers may be deposited on both sides of the silicon substrate or on only one side.

[0053] Thereafter, the silicon substrate on which the precursor has been prepared is annealed under appropriate process conditions (for example, gas flow: 100 sccm, pressure: 3.0 kPa, annealing temperature: 750° C., processing time: 30 minutes) (step S2).

[0054] According to this embodiment, it is possible to manufacture a stacked structure in which hydrogen blistering is suppressed.

[0055] [Verification experiment] The inventors conducted an experiment to verify the effectiveness of this embodiment, and the results are shown below.

[0056] The samples used in the experiment are as follows. Precursors were prepared by plasma-enhanced chemical vapor deposition (PECVD) on p-type c-Si (100) substrates that had been washed with hydrofluoric acid. The precursors of the composite film and the heavily doped amorphous silicon layer (p + An intermediate layer containing intrinsic hydrogenated amorphous silicon (ia-Si:H) was inserted between the p-a-Si layer and the p-a-Si layer at three thicknesses: 1 nm, 2 nm, and 4 nm. + The -a-Si layer was deposited under four conditions of thickness: 10 nm, 30 nm, 52 nm, and 117 nm. In other words, a total of 12 samples were produced. Then, heat treatment was performed at 750°C for 30 minutes in a mixed atmosphere of 297% N and 23% H, and SiO x Silicon nanocrystals were formed in the matrix.

[0057] The recombination current density J0 was calculated using the QSSPC method (quasi-steady state photoconductivity measurement method). After that, Al electrodes were formed on both sides by vacuum deposition, and the contact resistance ρ c The carrier selection performance is calculated from these two values ​​using the following equation: S 10 =log 10 (V th / J0ρc ) Here, V th is the thermoelectric power at 25°C.

[0058] The measurement results of carrier selectivity are shown in Figure 9. It can be seen that, for all thicknesses of the highly doped amorphous silicon layer, the presence of an intermediate layer containing intrinsic hydrogenated amorphous silicon generally improves carrier selectivity.

[0059] Figure 10 shows the results of measuring iVoc (implied Voc) using the QSSPC method. iVoc corresponds to the ideal open-circuit voltage before the carrier selection layer is made into a solar cell (i.e., before electrode deposition) and represents the passivation performance. Here again, it can be seen that the passivation performance is generally improved by the presence of an intermediate layer containing intrinsic hydrogenated amorphous silicon, regardless of the thickness of the highly doped amorphous silicon layer.

[0060] Figure 11 shows laser microscope images of the above samples taken from above when the thickness of the heavily doped amorphous silicon layer (p-layer) was 10 nm, 30 nm, 52 nm, and 117 nm, and when the thickness of the intermediate layer (i-layer) containing intrinsic hydrogenated amorphous silicon was 0 nm, 1 nm, 2 nm, and 4 nm. In each image, the left side of the central dotted line is after deposition, and the right side is after annealing. It can be seen that the thicker the p-layer, the more likely it is that blisters will occur, but if the i-layer is sufficiently thick (for example, 4 nm), the occurrence of blisters can be suppressed.

[0061] FIG. 12 shows transmission electron microscope images of the carrier selection layer viewed from the side without (left) and with (right) an intermediate layer containing intrinsic hydrogenated amorphous silicon.

[0062] Figure 13 shows the structure of a heavily doped amorphous silicon layer (p +These are laser microscope images taken from above of solar cells fabricated using the above samples when the thickness of the intermediate layer containing intrinsic hydrogenated amorphous silicon (ia-Si) is 30nm, 60nm, and 120nm, and when the thickness of the intermediate layer containing intrinsic hydrogenated amorphous silicon (ia-Si) is 0nm, 1nm, and 4nm. Here again, it can be seen that the presence of the intermediate layer helps to suppress the occurrence of blisters.

[0063] Figure 14 is a graph showing the current-voltage characteristics of each solar cell shown in Figure 13. The legend (x, y) indicates the thickness (nm) of the intermediate layer containing intrinsic hydrogenated amorphous silicon, and the thickness (nm) of the heavily doped amorphous silicon layer. Of these nine solar cells, three (solid plots) showed no hydrogen blistering and maintained a constant current even when the voltage was increased, indicating good solar cell performance. On the other hand, the remaining six (open plots) showed hydrogen blistering and showed a drop in current when the voltage was increased, indicating poor solar cell performance.

[0064] [Each aspect of the present disclosure] Each aspect of the present disclosure is summarized below. A stacked structure according to one aspect of the present disclosure is configured by stacking, in this order, a first semiconductor layer containing hydrogen, an intermediate layer containing intrinsic hydrogenated amorphous silicon, and a second semiconductor layer having physical properties different from those of the first semiconductor layer. The intermediate layer is formed between the first semiconductor layer and the second semiconductor layer.

[0065] According to this aspect, it is possible to provide a laminated structure that suppresses hydrogen blistering in the carrier selective layer.

[0066] In one embodiment, the intrinsic hydrogenated amorphous silicon of the layered structure contains silicon at 70 at % or more and 85 at % or less, and hydrogen at 15 at % or more and 30 at % or less.

[0067] According to this aspect, the composition of the intrinsic hydrogenated amorphous silicon can be specified to fabricate the stacked structure.

[0068] In one embodiment, the intrinsic hydrogenated amorphous silicon of the layered structure has a hydrogen density of 1×10 21 / cm 3 More than 1×10 22 / cm 3 In another embodiment, the intrinsic hydrogenated amorphous silicon of the stacked structure has a hydrogen density of 5×10 21 / cm 3 More than 6 x 10 21 / cm 3 It has the following amorphous structure:

[0069] According to this aspect, the composition of the intrinsic hydrogenated amorphous silicon can be specified to fabricate the stacked structure.

[0070] In one embodiment, the second semiconductor layer of the stacked structure comprises hydrogen.

[0071] According to this aspect, when both semiconductor layers contain hydrogen, a stacked structure can be fabricated.

[0072] In one embodiment, the first semiconductor layer of the stacked structure is a heavily doped polycrystalline silicon layer, and the second semiconductor layer is a hydrogenated amorphous silicon oxide layer or a heavily doped polycrystalline silicon layer.

[0073] According to this aspect, the laminated structure can be fabricated by specifying the material of the semiconductor layer.

[0074] In one embodiment, the second semiconductor layer of the stacked structure does not contain hydrogen.

[0075] According to this aspect, a stacked structure can be fabricated when one of the semiconductor layers does not contain hydrogen.

[0076] In one embodiment, the first semiconductor layer of the stacked structure is a heavily doped polycrystalline silicon layer and the second semiconductor layer is a silicon oxide layer.

[0077] According to this aspect, the laminated structure can be fabricated by specifying the material of the semiconductor layer.

[0078] Another aspect of the present invention is a carrier selection layer for a solar cell, the carrier selection layer comprising any one of the stacked structures described above.

[0079] According to this embodiment, it is possible to provide a carrier selection layer that suppresses hydrogen blistering.

[0080] One embodiment is a carrier selection layer for a NATURE contact solar cell.

[0081] According to this embodiment, it is possible to provide a carrier selection layer for a NATURE contact type solar cell that suppresses hydrogen blistering.

[0082] One embodiment is a carrier selection layer for a TOPCon type solar cell.

[0083] According to this embodiment, it is possible to provide a carrier selection layer for a TOPCon type solar cell that suppresses hydrogen blistering.

[0084] Yet another aspect of the present invention is a solar cell, which includes any one of the carrier selection layers described above.

[0085] According to this embodiment, it is possible to provide a solar cell in which hydrogen blistering is suppressed.

[0086] One embodiment is a NATURE contact solar cell.

[0087] According to this embodiment, it is possible to provide a NATURE contact type solar cell in which hydrogen blistering is suppressed.

[0088] One embodiment is a TOPCon solar cell.

[0089] According to this embodiment, it is possible to provide a TOPCon solar cell in which hydrogen blistering is suppressed.

[0090] Another aspect of the present invention is a method for manufacturing a layered structure, comprising the steps of depositing, in order, a first oxygen-rich hydrogenated amorphous silicon oxide layer, a second oxygen-poor hydrogenated amorphous silicon oxide layer, a third oxygen-rich hydrogenated amorphous silicon oxide layer, an intermediate layer containing intrinsic hydrogenated amorphous silicon, and a heavily doped amorphous silicon layer on a silicon substrate, and annealing the silicon substrate on which the precursor has been prepared. Note that the layers may be deposited on both sides or only one side of the silicon substrate.

[0091] According to this aspect, a laminate structure that suppresses hydrogen blistering in the carrier selective layer can be manufactured by specifying a procedure.

[0092] The present disclosure has been described above based on the embodiments. These embodiments are merely examples, and those skilled in the art will understand that various modifications are possible in the combination of each component and each processing process, and that such modifications are also within the scope of the present disclosure. When understanding the technical concepts abstracted from the embodiments and modifications, the technical concepts should not be interpreted as being limited to the content of the embodiments and modifications. The above-described embodiments and modifications are merely illustrative examples, and many design modifications, such as changing, adding, or deleting components, are possible. In the embodiments, the term "embodiment" is used to emphasize that such design modifications are possible. However, design modifications are also permitted even in content not labeled as such. [Explanation of symbols]

[0093] 1. A laminated structure according to an embodiment, 2. Laminated structure according to a comparative example; 3. Career selection demographic 4. Career selection demographic 5...NATURE contact type solar cell, 6...TOPCon type solar cell, 11. A first semiconductor layer; 12. Middle class, 13... A second semiconductor layer; 311··Crystalline silicon (c-Si) substrate, 312··First hydrogenated amorphous silicon oxide layer (a-SiO y :H), 313··Second hydrogenated amorphous silicon oxide layer (a-SiO x :H), 314··The third hydrogenated amorphous silicon oxide layer (a-SiO y :H), 315··An intermediate layer containing intrinsic hydrogenated amorphous silicon (ia-Si:H); 316··Heavily doped amorphous silicon layer (p + -a-Si:H), 317··Heavily doped polycrystalline silicon layer (p + -poly-Si), 318··Silicon nanodots, 411··Crystalline silicon (c-Si) substrate, 412··Silicon oxide layer (SiO x ), 413··An intermediate layer containing intrinsic hydrogenated amorphous silicon (ia-Si:H); 414··Heavily doped amorphous silicon layer (p + -a-Si:H), 511··Crystalline silicon (c-Si) substrate, 512··Oxygen-rich hydrogenated amorphous silicon oxide layer (a-SiO y :H), 513··Oxygen-poor hydrogenated amorphous silicon oxide layer (a-SiO y :H), 514··Oxygen-rich hydrogenated amorphous silicon oxide layer (a-SiO y :H), 515··An intermediate layer containing intrinsic hydrogenated amorphous silicon (ia-Si:H); 516··Hydrogenated amorphous silicon oxide layer (a-SiO x :H), 517··p-type hydrogenated amorphous silicon (p + -a-Si:H), 518··n-type hydrogenated amorphous silicon (n + -a-Si:H), 519...Ag electrode, 520...Al electrode, S1: forming a precursor by depositing, in order, a first oxygen-rich hydrogenated amorphous silicon oxide layer, a second oxygen-poor hydrogenated amorphous silicon oxide layer, a third oxygen-rich hydrogenated amorphous silicon oxide layer, an intermediate layer containing intrinsic hydrogenated amorphous silicon, and a heavily doped amorphous silicon layer on a silicon substrate; S2: A step of annealing the silicon substrate on which the precursor has been prepared in step S1.

Claims

1. a first semiconductor layer containing hydrogen; an intermediate layer comprising intrinsic hydrogenated amorphous silicon; a second semiconductor layer having physical properties different from those of the first semiconductor layer; are stacked in this order, The intermediate layer is formed between the first semiconductor layer and the second semiconductor layer.

2. 2. The stacked structure according to claim 1, wherein the intrinsic hydrogenated amorphous silicon contains silicon in an amount of 70 at % to 85 at % and hydrogen in an amount of 15 at % to 30 at %.

3. The intrinsic hydrogenated amorphous silicon has a hydrogen density of 1×10 ２１ / cm ３ 1x10 or more ２２ / cm ３ 2. The laminated structure according to claim 1, which has the following amorphous structure:

4. 2. The stacked structure according to claim 1, wherein the second semiconductor layer contains hydrogen.

5. the first semiconductor layer is a heavily doped polycrystalline silicon layer; 5. The stacked structure according to claim 4, wherein the second semiconductor layer is a hydrogenated amorphous silicon oxide layer or a highly doped polycrystalline silicon layer.

6. 2. The stacked structure according to claim 1, wherein the second semiconductor layer does not contain hydrogen.

7. the first semiconductor layer is a heavily doped polycrystalline silicon layer; 7. The stacked structure according to claim 6, wherein the second semiconductor layer is a silicon oxide layer.

8. A carrier selection layer for a solar cell, comprising the laminate structure according to claim 1 .

9. A carrier selection layer for a NATURE contact solar cell, comprising the laminated structure according to claim 5 .

10. A carrier selection layer for a TOPCon solar cell, comprising the stacked structure according to claim 7.

11. A solar cell comprising the carrier selection layer according to claim 8.

12. A NATURE contact solar cell comprising the carrier selection layer according to claim 9.

13. A TOPCon solar cell comprising the carrier selection layer according to claim 10.

14. forming a precursor by depositing, in order, on a silicon substrate, a first oxygen-rich hydrogenated amorphous silicon oxide layer, a second oxygen-poor hydrogenated amorphous silicon oxide layer, a third oxygen-rich hydrogenated amorphous silicon oxide layer, an intermediate layer comprising intrinsic hydrogenated amorphous silicon, and a heavily doped amorphous silicon layer; annealing the silicon substrate on which the precursor is prepared; A method for producing a laminated structure, comprising:

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