Double-sided Poly solar cell containing window layer and preparation method of double-sided Poly solar cell
By introducing AlGaAs film as a window layer in the P-type double-sided polysilicon cell, the shortcomings of the battery in terms of high-energy photon absorption and heat carrier effects are solved, and the efficiency of the solar cell is significantly improved.
Patent Information
- Application Number
- CN202411491791.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-24
- Publication Date
- 2025-02-07
AI Technical Summary
P-type double-sided polysilicon cells have shortcomings in photon absorption and heat carrier effects, resulting in inefficiency.
An AlGaAs film was introduced as a window layer between the N-type polysilicon layer and the front anti-reflection layer, and the film was deposited by the MOCVD process.
The effect of high-energy photon absorption is increased, and the heat carrier effect is reduced, thereby improving the efficiency of double-sided Poly solar cells.
Smart Images
Figure CN119403284A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of photovoltaic cells, and in particular to a double-sided Poly solar cell containing a window layer and a preparation method thereof. Background Art
[0002] P-type double-sided polycrystalline silicon (Poly) cell is a cell with tunnel oxide layer (SiO x The doped polysilicon layer (Poly-Si layer) is formed on the surface of the silicon substrate, and a heavily doped polysilicon layer (Poly-Si layer) is grown on the surface, and the two together form a passivation contact structure. The tunneling oxide layer allows high-concentration majority carriers (majority carriers) to pass through in the form of quantum tunneling, but blocks minority carriers; the doped Poly-Si can change the energy band position of silicon, turning it into P-type / N-type Poly-Si, blocking electrons / holes from approaching. Therefore, P-type bifacial polysilicon cells have better passivation ability and conversion efficiency, and have become the first choice for large-scale mass production of photovoltaic cells.
[0003] However, in the P-type bifacial Poly cell structure, the light absorption coefficient of the N-type polysilicon layer (N-Poly-Si layer) is high, the photon absorption is concentrated on the surface, and most carriers are recombined by the surface recombination center and cannot be collected as the current of the solar cell. Therefore, it is urgent to develop a P-type bifacial polysilicon (Poly) cell that can improve the absorption effect of high-energy photons and reduce the hot carrier effect.
[0004] In view of this, the present invention is proposed. Summary of the invention
[0005] The purpose of the present invention is to provide a double-sided Poly solar cell with a window layer and a preparation method thereof. The double-sided Poly solar cell has an AlGaAs film disposed between an N-type polysilicon layer and a front anti-reflection layer as a window layer, which increases the absorption effect of high-energy photons and reduces the hot carrier effect, thereby effectively improving the efficiency of the double-sided Poly solar cell.
[0006] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:
[0007] In a first aspect, the present invention provides a double-sided Poly solar cell containing a window layer, wherein the double-sided Poly solar cell containing a window layer comprises a P-type silicon substrate; and the front side of the P-type silicon substrate comprises a front tunneling oxide layer, an N-type polysilicon layer and a front anti-reflection layer stacked in sequence;
[0008] Wherein, a window layer is arranged between the N-type polysilicon layer and the front anti-reflection layer, and the window layer is an AlGaAs film.
[0009] Preferably, the thickness of the window layer is 200-300 nm.
[0010] Preferably, the thickness of the front tunneling oxide layer is 0.5-2.0 nm.
[0011] Preferably, the N-type polysilicon layer is a boron-doped polysilicon layer.
[0012] Preferably, the thickness of the N-type polysilicon layer is 60-120 nm.
[0013] Preferably, the boron doping concentration in the boron-doped polysilicon layer is 1E20-5E20 cm -3 .
[0014] Preferably, the front anti-reflection layer is a silicon nitride film.
[0015] Preferably, the thickness of the front anti-reflection layer is 40-100 nm.
[0016] Preferably, the back side of the P-type silicon substrate comprises a back side tunneling oxide layer, a P-type polysilicon layer, a back side passivation layer and a back side anti-reflection layer stacked in sequence.
[0017] Preferably, the back tunneling oxide layer has a thickness of 0.5-2.0 nm.
[0018] Preferably, the P-type polysilicon layer is a phosphorus-doped polysilicon layer.
[0019] Preferably, the thickness of the P-type polysilicon layer is 80-150 nm.
[0020] Preferably, the phosphorus doping concentration in the phosphorus-doped polysilicon layer is 1E20-5E20 cm -3 .
[0021] Preferably, the back passivation layer is an aluminum oxide film.
[0022] Preferably, the back passivation layer has a thickness of 5-10 nm.
[0023] Preferably, the back anti-reflection layer is a silicon nitride film.
[0024] Preferably, the thickness of the back anti-reflection layer is 50-100 nm.
[0025] In a second aspect, the present invention provides a method for preparing a double-sided Poly solar cell containing a window layer as described in the first aspect, the preparation method comprising:
[0026] The window layer is prepared by depositing an AlGaAs film on the surface of the N-type polysilicon layer through a MOCVD process.
[0027] Preferably, the gases required in the deposition process include: gallium source gas, aluminum source gas and arsenic source gas.
[0028] Preferably, the gallium source gas includes any one of trimethylgallium, triethylgallium or triisopropylgallium, or a combination of at least two thereof, preferably triethylgallium.
[0029] Preferably, the aluminum source gas includes any one of trimethylaluminum, triethylaluminum, dimethylaluminum alkoxide or dimethylaluminum hydride, or a combination of at least two thereof, preferably trimethylaluminum.
[0030] Preferably, the arsenic source gas comprises arsine and / or tert-butyl arsine, preferably arsine.
[0031] Preferably, the flow ratio of the gallium source gas, the aluminum source gas and the arsenic source gas is (2.5-3.0):(0.8-1.2):(3.0-3.5).
[0032] Preferably, the flow rate of the gallium source gas is 2500-3000 sccm.
[0033] Preferably, the flow rate of the aluminum source gas is 800-1200 sccm.
[0034] Preferably, the flow rate of the arsenic source gas is 3000-3500 sccm.
[0035] Preferably, the deposition pressure is 1000-2000 mTorr, preferably 1500-1700 mTorr.
[0036] Preferably, the deposition temperature is 550-650°C.
[0037] Preferably, the deposition time is 3500-3700 s.
[0038] Compared with the prior art, the present invention has the following beneficial effects:
[0039] The double-sided Poly solar cell of the present invention provides an AlGaAs film as a window layer between the N-type polysilicon layer and the front anti-reflection layer, which increases the absorption effect of high-energy photons and reduces the hot carrier effect, thereby effectively improving the efficiency of the double-sided Poly solar cell. BRIEF DESCRIPTION OF THE DRAWINGS
[0040] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0041] Figure 1 It is a schematic structural diagram of a double-sided Poly solar cell containing a window layer according to the present invention.
[0042] Among them, 100 is a P-type silicon substrate, 101 is a front tunneling oxide layer, 102 is an N-type polysilicon layer, 103 is a window layer, 104 is a front anti-reflection layer, 105 is a back tunneling oxide layer, 106 is a P-type polysilicon layer, 107 is a back passivation layer, and 108 is a back anti-reflection layer. DETAILED DESCRIPTION
[0043] Unless otherwise defined herein, scientific and technical terms used in conjunction with the present invention shall have the meanings commonly understood by those of ordinary skill in the art. The meaning and scope of the terms should be clear, however, in the case of any potential ambiguity, the definitions provided herein take precedence over any dictionary or external definitions. In this application, unless otherwise stated, the use of "or" means "and / or". In addition, the use of the term "including" and other forms is non-limiting.
[0044] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0045] It should be noted that specific details are described in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in a variety of other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.
[0046]
Term Explanation
[0047] “Dopant concentration”: the number of atoms per cubic centimeter; for example, the unit is 1E20 atoms cm -3 It means that there are 1×10 in each cubic centimeter. 20 atoms.
[0048] “PECVD”: stands for Plasma Enhanced Chemical Vapor Deposition, which enhances the activity of chemical vapor reactants through plasma activation, increases surface reaction rates, and significantly reduces the film deposition temperature through high-energy ions.
[0049] "MOCVD": stands for Metal Organic Chemical Vapor Deposition technology. MOCVD equipment is a commonly used equipment for growing semiconductor compounds and is widely used in the semiconductor electronic device manufacturing industry.
[0050] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0051] In a first aspect, the present invention provides a double-sided Poly solar cell comprising a window layer, such as Figure 1 As shown, the double-sided Poly solar cell containing a window layer includes a P-type silicon substrate 100;
[0052] The front side of the P-type silicon substrate includes a front tunneling oxide layer 101, an N-type polysilicon layer 102 and a front anti-reflection layer 104 stacked in sequence;
[0053] A window layer 103 is provided between the N-type polysilicon layer 102 and the front anti-reflection layer 104 , and the window layer 103 is an AlGaAs film.
[0054] In the present invention, the double-sided Poly solar cell is provided with an AlGaAs film as a window layer between the N-type polycrystalline silicon layer and the front anti-reflection layer. The band gap width of AlGaAs is 2.1eV, while the band gap width of silicon is 1.12eV, thereby increasing the absorption effect of high-energy photons and reducing the hot carrier effect, thereby effectively improving the efficiency of the double-sided Poly solar cell.
[0055] As an optional embodiment of the present invention, the thickness of the window layer 103 is 200-300 nm, for example, it can be 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, 300 nm, etc.
[0056] As an optional embodiment of the present invention, the thickness of the front tunneling oxide layer 101 is 0.5-2.0 nm, for example, it can be 0.5 nm, 0.6 nm, 0.8 nm, 1.2 nm, 1.4 nm, 1.6 nm, 1.8 nm, 2.0 nm, etc.
[0057] As an optional implementation of the present invention, the N-type polysilicon layer 102 is a boron-doped polysilicon layer.
[0058] As an optional embodiment of the present invention, the thickness of the N-type polysilicon layer 102 is 60 to 120 nm, for example, it can be 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, etc.
[0059] As an optional embodiment of the present invention, the boron doping concentration in the boron doped polysilicon layer is 1E20-5E20cm -3 , for example, could be 1E20 cm -3 , 1.5E20 cm -3 , 2E20 cm -3 , 2.5E20 cm -3 、3E20 cm -3 、3.5E20 cm -3 、4E20 cm -3 、4.5E20 cm -3 、5E20 cm -3 wait.
[0060] As an optional embodiment of the present invention, the front anti-reflection layer 104 is a silicon nitride film.
[0061] As an optional embodiment of the present invention, the thickness of the front anti-reflection layer 104 is 40 to 100 nm, for example, it can be 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, etc.
[0062] As an optional embodiment of the present invention, Figure 1 As shown, the back side of the P-type silicon substrate 100 includes a back side tunneling oxide layer 105 , a P-type polysilicon layer 106 , a back side passivation layer 107 and a back side anti-reflection layer 108 which are stacked in sequence.
[0063] As an optional embodiment of the present invention, the thickness of the back tunneling oxide layer 105 is 0.5 to 2.0 nm, for example, it can be 0.5 nm, 0.6 nm, 0.8 nm, 0.9 nm, 1.0 nm, 1.2 nm, 1.4 nm, 1.6 nm, 1.8 nm, 2.0 nm, etc.
[0064] As an optional implementation of the present invention, the P-type polysilicon layer 106 is a phosphorus-doped polysilicon layer.
[0065] As an optional embodiment of the present invention, the thickness of the P-type polysilicon layer 106 is 80 to 150 nm, for example, it can be 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 145 nm, 150 nm, etc.
[0066] As an optional embodiment of the present invention, the phosphorus doping concentration in the phosphorus-doped polysilicon layer is 1E20-5E20cm -3 , for example, could be 1E20 cm -3 , 1.5E20 cm -3 , 2E20 cm -3 , 2.5E20 cm -3 、3E20 cm -3 、3.5E20 cm -3 、4E20 cm -3 、4.5E20 cm -3 、5E20 cm -3 wait.
[0067] As an optional embodiment of the present invention, the back passivation layer 107 is an aluminum oxide film.
[0068] As an optional implementation manner of the present invention, the thickness of the back passivation layer 107 is 5 to 10 nm, for example, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, etc.
[0069] As an optional embodiment of the present invention, the back anti-reflection layer 108 is a silicon nitride film.
[0070] As an optional embodiment of the present invention, the thickness of the back anti-reflection layer 108 is 50 to 100 nm, for example, it can be 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, etc.
[0071] In a second aspect, the present invention provides a method for preparing a double-sided Poly solar cell containing a window layer as described in the first aspect, the preparation method comprising:
[0072] The window layer 103 is prepared by depositing an AlGaAs film on the surface of the N-type polysilicon layer 102 through a MOCVD process.
[0073] As an optional embodiment of the present invention, the gases required in the deposition process include: gallium source gas, aluminum source gas and arsenic source gas.
[0074] As an optional embodiment of the present invention, the gallium source gas includes any one of trimethylgallium, triethylgallium or triisopropylgallium, or a combination of at least two of them, preferably triethylgallium.
[0075] As an optional embodiment of the present invention, the aluminum source gas includes any one of trimethylaluminum, triethylaluminum, dimethylaluminum alkoxide or dimethylaluminum hydride, or a combination of at least two thereof, preferably trimethylaluminum.
[0076] As an optional embodiment of the present invention, the arsenic source gas includes arsine and / or tert-butyl arsine, preferably arsine.
[0077] As an optional embodiment of the present invention, the flow ratio of gallium source gas, aluminum source gas and arsenic source gas is (2.5-3.0):(0.8-1.2):(3.0-3.5);
[0078] Here, “2.5-3.0” may be, for example, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, etc.;
[0079] Here, “0.8-1.2” can be, for example, 0.8, 0.9, 1.0, 1.1, 1.2, etc.;
[0080] Here, “3.0-3.5” may be, for example, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, etc.
[0081] As an optional embodiment of the present invention, the flow rate of the gallium source gas is 2500-3000sccm, for example, it can be 2500sccm, 2550sccm, 2600sccm, 2650sccm, 2700sccm, 2750sccm, 2800sccm, 2850sccm, 2900sccm, 2950sccm, 3000sccm, etc.
[0082] As an optional embodiment of the present invention, the flow rate of the aluminum source gas is 800-1200 sccm, for example, it can be 800 sccm, 850 sccm, 900 sccm, 950 sccm, 1000 sccm, 1050 sccm, 1100 sccm, 1150 sccm, 1200 sccm, etc.
[0083] As an optional embodiment of the present invention, the flow rate of the arsenic source gas is 3000-3500sccm, for example, it can be 3000sccm, 3050sccm, 3100sccm, 3150sccm, 3200sccm, 3250sccm, 3300sccm, 3350sccm, 3400sccm, 3450sccm, 3500sccm, etc.
[0084] As an optional embodiment of the present invention, the deposition pressure is 1000-2000mTorr, for example, it can be 1000mTorr, 1100mTorr, 1200mTorr, 1300mTorr, 1400mTorr, 1500mTorr, 1600mTorr, 1700mTorr, 1800mTorr, 1900mTorr, 2000mTorr, etc., preferably 1500-1700mTorr.
[0085] As an optional embodiment of the present invention, the deposition temperature is 550-650°C, for example, it can be 550°C, 560°C, 570°C, 580°C, 590°C, 600°C, 610°C, 620°C, 630°C, 640°C, 650°C, etc.
[0086] As an optional embodiment of the present invention, the deposition time is 3500-3700s, for example, it can be 3500s, 3520s, 3540s, 3560s, 3580s, 3600s, 3620s, 3640s, 3660s, 3680s, 3700s, etc.
[0087] It should be noted that, before preparing the above-mentioned AlGaAs film (window layer), the substrate cell includes a P-type silicon substrate 100; and the front surface of the P-type silicon substrate 100 includes a front tunneling oxide layer 101 and an N-type polysilicon layer 102 deposited in sequence, and the back surface of the P-type silicon substrate 100 includes a back tunneling oxide layer 105 and a P-type polysilicon layer 106 deposited in sequence.
[0088] As an optional embodiment of the present invention, the above-mentioned substrate battery sheet is prepared by the following steps:
[0089] (a) depositing a double-sided tunnel oxide layer on the P-type silicon substrate by a PECVD process, and then depositing a double-sided amorphous silicon layer;
[0090] (b) using a boron diffusion process to dope the amorphous silicon layer on the front side of the cell obtained in step (a) with boron to obtain a boron-doped polysilicon layer, and further forming a BSG mask layer on the surface of the boron-doped polysilicon layer; and then removing the tunneling oxide layer and the amorphous silicon layer on the back side of the cell;
[0091] (c) using a PECVD process to deposit a tunnel oxide layer and an amorphous silicon layer on the back side of the cell obtained in step (b);
[0092] (d) using a phosphorus diffusion process to phosphorus-dope the amorphous silicon layer on the back side of the cell obtained in step (c) to obtain a phosphorus-doped polysilicon layer, and further forming a PSG mask layer on the surface of the phosphorus-doped polysilicon layer; then removing the BSG mask layer on the front side of the cell, the PSG mask layer on the back side, and the polysilicon layer at the edge;
[0093] (e) annealing the cell obtained in step (d) to obtain the substrate cell;
[0094] Among them, the substrate cell obtained in step (e) includes a P-type silicon substrate 100; and the front surface of the P-type silicon substrate 100 includes a front tunneling oxide layer 101 and an N-type polysilicon layer 102 deposited in sequence, and the back surface of the P-type silicon substrate 100 includes a back tunneling oxide layer 105 and a P-type polysilicon layer 106 deposited in sequence.
[0095] As an optional embodiment of the present invention, the method for preparing a double-sided Poly solar cell containing a window layer comprises the following steps:
[0096] The PECVD process is used to deposit the surface of the window layer 103 to obtain the front anti-reflection layer 104 .
[0097] As an optional embodiment of the present invention, the method for preparing a double-sided Poly solar cell containing a window layer comprises the following steps:
[0098] ALD process is used to deposit on the surface of the P-type polysilicon layer 106 to obtain the back passivation layer 107;
[0099] The back anti-reflection layer 108 is obtained by depositing the back passivation layer 107 on its surface using a PECVD process.
[0100] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0101] Example 1
[0102] This embodiment provides a double-sided Poly solar cell containing a window layer, and the double-sided Poly solar cell containing a window layer is prepared by the following steps:
[0103] (1) A double-sided Poly substrate cell is provided, wherein the double-sided Poly substrate cell comprises a P-type silicon substrate; wherein the front surface of the P-type silicon substrate comprises a 0.8 nm front tunneling oxide layer and a 110 nm N-type polysilicon layer deposited in sequence; the N-type polysilicon layer is a boron-doped polysilicon layer, and the boron doping concentration is 5E20 cm -3 The back surface of the P-type silicon substrate includes a 0.8 nm back tunneling oxide layer and a 11 nm P-type polysilicon layer deposited in sequence; the P-type polysilicon layer is a phosphorus-doped polysilicon layer, and the phosphorus doping concentration is 2E20 cm -3 .
[0104] (2) depositing an AlGaAs film on the surface of the N-type polysilicon layer of the double-sided Poly substrate cell provided in step (1) by an MOCVD process to prepare a 220 nm window layer;
[0105] The gases required in the deposition process include triethylgallium, trimethylaluminum and arsenic; the flow rate of triethylgallium is 3000sccm, the flow rate of trimethylaluminum is 1000sccm, and the flow rate of arsenic is 3000sccm; the deposition pressure is 1500mTorr, the deposition temperature is 600°C, and the deposition time is 3500sccm.
[0106] (3) using an ALD process to deposit the surface of the P-type polysilicon layer on the back side of the cell provided in step (2) to obtain the back side passivation layer; and then using a PECVD process to deposit the surface of the window layer and the back side passivation layer to obtain a front side anti-reflection layer and a back side anti-reflection layer;
[0107] The front anti-reflection layer is a 77nm silicon nitride film; the back passivation layer is a 4nm aluminum oxide film, and the back anti-reflection layer is an 82nm silicon nitride film.
[0108] Example 2
[0109] This embodiment provides a double-sided Poly solar cell containing a window layer, and the double-sided Poly solar cell containing a window layer is prepared by the following steps:
[0110] (1) A double-sided Poly substrate cell is provided, wherein the double-sided Poly substrate cell comprises a P-type silicon substrate; wherein the front surface of the P-type silicon substrate comprises a 0.9 nm front tunneling oxide layer and a 115 nm N-type polysilicon layer deposited in sequence; the N-type polysilicon layer is a boron-doped polysilicon layer, and the boron doping concentration is 5E20 cm -3The back surface of the P-type silicon substrate includes a 0.9 nm back tunneling oxide layer and a 115 nm P-type polysilicon layer deposited in sequence; the P-type polysilicon layer is a phosphorus-doped polysilicon layer, and the phosphorus doping concentration is 2E20 cm -3 .
[0111] (2) depositing an AlGaAs film on the surface of the N-type polysilicon layer of the double-sided Poly substrate cell provided in step (1) by an MOCVD process to prepare a 225 nm window layer;
[0112] The gases required in the deposition process include triethylgallium, trimethylaluminum and arsenic; the flow rate of triethylgallium is 3000sccm, the flow rate of trimethylaluminum is 1000sccm, and the flow rate of arsenic is 3000sccm; the deposition pressure is 1500mTorr, the deposition temperature is 600°C, and the deposition time is 3600sccm.
[0113] (3) using an ALD process to deposit the surface of the P-type polysilicon layer on the back side of the cell provided in step (2) to obtain the back side passivation layer; and then using a PECVD process to deposit the surface of the window layer and the back side passivation layer to obtain a front side anti-reflection layer and a back side anti-reflection layer;
[0114] The front anti-reflection layer is a 77nm silicon nitride film; the back passivation layer is a 4nm aluminum oxide film, and the back anti-reflection layer is an 82nm silicon nitride film.
[0115] Example 3
[0116] This embodiment provides a double-sided Poly solar cell containing a window layer, and the double-sided Poly solar cell containing a window layer is prepared by the following steps:
[0117] (1) A double-sided Poly substrate cell is provided, wherein the double-sided Poly substrate cell comprises a P-type silicon substrate; wherein the front surface of the P-type silicon substrate comprises a 0.9 nm front tunneling oxide layer and a 115 nm N-type polysilicon layer deposited in sequence; the N-type polysilicon layer is a boron-doped polysilicon layer, and the boron doping concentration is 5E20 cm -3 The back surface of the P-type silicon substrate includes a 0.9 nm back tunneling oxide layer and a 115 nm P-type polysilicon layer deposited in sequence; the P-type polysilicon layer is a phosphorus-doped polysilicon layer, and the phosphorus doping concentration is 2E20 cm -3 .
[0118] (2) depositing an AlGaAs film on the surface of the N-type polysilicon layer of the double-sided Poly substrate cell provided in step (1) by an MOCVD process to prepare a 230 nm window layer;
[0119] The gases required in the deposition process include triethylgallium, trimethylaluminum and arsenic; the flow rate of triethylgallium is 3000sccm, the flow rate of trimethylaluminum is 1000sccm, and the flow rate of arsenic is 3000sccm; the deposition pressure is 1500mTorr, the deposition temperature is 600°C, and the deposition time is 3700sccm.
[0120] (3) using an ALD process to deposit the surface of the P-type polysilicon layer on the back side of the cell provided in step (2) to obtain the back side passivation layer; and then using a PECVD process to deposit the surface of the window layer and the back side passivation layer to obtain a front side anti-reflection layer and a back side anti-reflection layer;
[0121] The front anti-reflection layer is a 77nm silicon nitride film; the back passivation layer is a 4nm aluminum oxide film, and the back anti-reflection layer is an 82nm silicon nitride film.
[0122] Example 4
[0123] This embodiment provides a double-sided Poly solar cell containing a window layer, and the double-sided Poly solar cell containing a window layer is prepared by the following steps:
[0124] (1) A double-sided Poly substrate cell is provided, wherein the double-sided Poly substrate cell comprises a P-type silicon substrate; wherein the front surface of the P-type silicon substrate comprises a 0.9 nm front tunneling oxide layer and a 115 nm N-type polysilicon layer deposited in sequence; the N-type polysilicon layer is a boron-doped polysilicon layer, and the boron doping concentration is 5E20 cm -3 The back surface of the P-type silicon substrate includes a 0.9 nm back tunneling oxide layer and a 115 nm P-type polysilicon layer deposited in sequence; the P-type polysilicon layer is a phosphorus-doped polysilicon layer, and the phosphorus doping concentration is 2E20 cm -3 .
[0125] (2) depositing an AlGaAs film on the surface of the N-type polysilicon layer of the double-sided Poly substrate cell provided in step (1) by an MOCVD process to prepare a 235 nm window layer;
[0126] The gases required in the deposition process include triethylgallium, trimethylaluminum and arsenic; the flow rate of triethylgallium is 3000sccm, the flow rate of trimethylaluminum is 1000sccm, and the flow rate of arsenic is 3000sccm; the deposition pressure is 1500mTorr, the deposition temperature is 580°C, and the deposition time is 3700sccm.
[0127] (3) using an ALD process to deposit the surface of the P-type polysilicon layer on the back side of the cell provided in step (2) to obtain the back side passivation layer; and then using a PECVD process to deposit the surface of the window layer and the back side passivation layer to obtain a front side anti-reflection layer and a back side anti-reflection layer;
[0128] The front anti-reflection layer is a 77nm silicon nitride film; the back passivation layer is a 4nm aluminum oxide film, and the back anti-reflection layer is an 82nm silicon nitride film.
[0129] Example 5
[0130] This embodiment provides a double-sided Poly solar cell containing a window layer, and the double-sided Poly solar cell containing a window layer is prepared by the following steps:
[0131] (1) A double-sided Poly substrate cell is provided, wherein the double-sided Poly substrate cell comprises a P-type silicon substrate; wherein the front surface of the P-type silicon substrate comprises a 1 nm front tunneling oxide layer and a 110 nm N-type polysilicon layer deposited in sequence; the N-type polysilicon layer is a boron-doped polysilicon layer, and the boron doping concentration is 5E20 cm -3 The back surface of the P-type silicon substrate includes a 1 nm back tunneling oxide layer and a 110 nm P-type polysilicon layer deposited in sequence; the P-type polysilicon layer is a phosphorus-doped polysilicon layer, and the phosphorus doping concentration is 2E20 cm -3 .
[0132] (2) depositing an AlGaAs film on the surface of the N-type polysilicon layer of the double-sided Poly substrate cell provided in step (1) by an MOCVD process to prepare a 235 nm window layer;
[0133] The gases required in the deposition process include triethylgallium, trimethylaluminum and arsenic; the flow rate of triethylgallium is 3000sccm, the flow rate of trimethylaluminum is 1000sccm, and the flow rate of arsenic is 3000sccm; the deposition pressure is 1500mTorr, the deposition temperature is 620°C, and the deposition time is 3700sccm.
[0134] (3) using an ALD process to deposit the surface of the P-type polysilicon layer on the back side of the cell provided in step (2) to obtain the back side passivation layer; and then using a PECVD process to deposit the surface of the window layer and the back side passivation layer to obtain a front side anti-reflection layer and a back side anti-reflection layer;
[0135] The front anti-reflection layer is a 77nm silicon nitride film; the back passivation layer is a 4nm aluminum oxide film, and the back anti-reflection layer is an 82nm silicon nitride film.
[0136] Example 6
[0137] This embodiment provides a double-sided Poly solar cell containing a window layer, and the double-sided Poly solar cell containing a window layer is prepared by the following steps:
[0138] (1) A double-sided Poly substrate cell is provided, wherein the double-sided Poly substrate cell comprises a P-type silicon substrate; wherein the front surface of the P-type silicon substrate comprises a 1 nm front tunneling oxide layer and a 110 nm N-type polysilicon layer deposited in sequence; the N-type polysilicon layer is a boron-doped polysilicon layer, and the boron doping concentration is 5E20 cm -3 The back surface of the P-type silicon substrate includes a 1 nm back tunneling oxide layer and a 105 nm P-type polysilicon layer deposited in sequence; the P-type polysilicon layer is a phosphorus-doped polysilicon layer, and the phosphorus doping concentration is 2E20 cm -3 .
[0139] (2) depositing an AlGaAs film on the surface of the N-type polysilicon layer of the double-sided Poly substrate cell provided in step (1) by an MOCVD process to prepare a 240 nm window layer;
[0140] The gases required in the deposition process include triethylgallium, trimethylaluminum and arsenic; the flow rate of triethylgallium is 3000sccm, the flow rate of trimethylaluminum is 1000sccm, and the flow rate of arsenic is 3000sccm; the deposition pressure is 1500mTorr, the deposition temperature is 640°C, and the deposition time is 3700sccm.
[0141] (3) using an ALD process to deposit the surface of the P-type polysilicon layer on the back side of the cell provided in step (2) to obtain the back side passivation layer; and then using a PECVD process to deposit the surface of the window layer and the back side passivation layer to obtain a front side anti-reflection layer and a back side anti-reflection layer;
[0142] The front anti-reflection layer is a 77nm silicon nitride film; the back passivation layer is a 4nm aluminum oxide film, and the back anti-reflection layer is an 82nm silicon nitride film.
[0143] Example 7
[0144] This embodiment provides a double-sided Poly solar cell containing a window layer, and the double-sided Poly solar cell containing a window layer is prepared by the following steps:
[0145] (1) A double-sided Poly substrate cell is provided, wherein the double-sided Poly substrate cell comprises a P-type silicon substrate; wherein the front surface of the P-type silicon substrate comprises a 1 nm front tunneling oxide layer and a 110 nm N-type polysilicon layer deposited in sequence; the N-type polysilicon layer is a boron-doped polysilicon layer, and the boron doping concentration is 6E20 cm -3 The back surface of the P-type silicon substrate includes a 1 nm back tunneling oxide layer and a 110 nm P-type polysilicon layer deposited in sequence; the P-type polysilicon layer is a phosphorus-doped polysilicon layer, and the phosphorus doping concentration is 2E20 cm -3 .
[0146] (2) depositing an AlGaAs film on the surface of the N-type polysilicon layer of the double-sided Poly substrate cell provided in step (1) by an MOCVD process to prepare a 245 nm window layer;
[0147] The gases required in the deposition process include triethylgallium, trimethylaluminum and arsenic; the flow rate of triethylgallium is 3000sccm, the flow rate of trimethylaluminum is 1000sccm, and the flow rate of arsenic is 3000sccm; the deposition pressure is 1700mTorr, the deposition temperature is 640°C, and the deposition time is 3700sccm.
[0148] (3) using an ALD process to deposit the surface of the P-type polysilicon layer on the back side of the cell provided in step (2) to obtain the back side passivation layer; and then using a PECVD process to deposit the surface of the window layer and the back side passivation layer to obtain a front side anti-reflection layer and a back side anti-reflection layer;
[0149] The front anti-reflection layer is a 77nm silicon nitride film; the back passivation layer is a 4nm aluminum oxide film, and the back anti-reflection layer is an 82nm silicon nitride film.
[0150] Example 8
[0151] This embodiment provides a double-sided Poly solar cell containing a window layer, and the double-sided Poly solar cell containing a window layer is prepared by the following steps:
[0152] (1) A double-sided Poly substrate cell is provided, wherein the double-sided Poly substrate cell comprises a P-type silicon substrate; wherein the front surface of the P-type silicon substrate comprises a 0.9 nm front tunneling oxide layer and a 105 nm N-type polysilicon layer deposited in sequence; the N-type polysilicon layer is a boron-doped polysilicon layer, and the boron doping concentration is 6E20 cm -3 The back surface of the P-type silicon substrate includes a 1 nm back tunneling oxide layer and a 105 nm P-type polysilicon layer deposited in sequence; the P-type polysilicon layer is a phosphorus-doped polysilicon layer, and the phosphorus doping concentration is 2E20 cm -3 .
[0153] (2) depositing an AlGaAs film on the surface of the N-type polysilicon layer of the double-sided Poly substrate cell provided in step (1) by an MOCVD process to prepare a 245 nm window layer;
[0154] The gases required in the deposition process include triethylgallium, trimethylaluminum and arsenic; the flow rate of triethylgallium is 2800sccm, the flow rate of trimethylaluminum is 1000sccm, and the flow rate of arsenic is 3200sccm; the deposition pressure is 1700mTorr, the deposition temperature is 640°C, and the deposition time is 3700sccm.
[0155] (3) using an ALD process to deposit the surface of the P-type polysilicon layer on the back side of the cell provided in step (2) to obtain the back side passivation layer; and then using a PECVD process to deposit the surface of the window layer and the back side passivation layer to obtain a front side anti-reflection layer and a back side anti-reflection layer;
[0156] The front anti-reflection layer is a 77nm silicon nitride film; the back passivation layer is a 4nm aluminum oxide film, and the back anti-reflection layer is an 82nm silicon nitride film.
[0157] Example 9
[0158] This embodiment provides a double-sided Poly solar cell containing a window layer, and the double-sided Poly solar cell containing a window layer is prepared by the following steps:
[0159] (1) A double-sided Poly substrate cell is provided, wherein the double-sided Poly substrate cell comprises a P-type silicon substrate; wherein the front surface of the P-type silicon substrate comprises a 0.8 nm front tunneling oxide layer and a 100 nm N-type polysilicon layer deposited in sequence; the N-type polysilicon layer is a boron-doped polysilicon layer, and the boron doping concentration is 6E20 cm -3The back surface of the P-type silicon substrate includes a 0.8 nm back tunneling oxide layer and a 100 nm P-type polysilicon layer deposited in sequence; the P-type polysilicon layer is a phosphorus-doped polysilicon layer, and the phosphorus doping concentration is 2E20 cm -3 .
[0160] (2) depositing an AlGaAs film on the surface of the N-type polysilicon layer of the double-sided Poly substrate cell provided in step (1) by an MOCVD process to prepare a 255 nm window layer;
[0161] The gases required in the deposition process include triethylgallium, trimethylaluminum and arsenic; the flow rate of triethylgallium is 2600sccm, the flow rate of trimethylaluminum is 1000sccm, and the flow rate of arsenic is 3400sccm; the deposition pressure is 1700mTorr, the deposition temperature is 640°C, and the deposition time is 3700sccm.
[0162] (3) using an ALD process to deposit the surface of the P-type polysilicon layer on the back side of the cell provided in step (2) to obtain the back side passivation layer; and then using a PECVD process to deposit the surface of the window layer and the back side passivation layer to obtain a front side anti-reflection layer and a back side anti-reflection layer;
[0163] The front anti-reflection layer is a 77nm silicon nitride film; the back passivation layer is a 4nm aluminum oxide film, and the back anti-reflection layer is an 82nm silicon nitride film.
[0164] Example 10
[0165] This embodiment provides a double-sided Poly solar cell with a window layer. The only difference from Embodiment 1 is that triethylgallium is replaced with trimethylgallium, and the flow rate of trimethylgallium is adjusted to 6000sccm, the flow rate of trimethylaluminum is adjusted to 3000sccm, and the flow rate of arsenic is adjusted to 8000sccm; the other steps are exactly the same as Embodiment 1.
[0166] Embodiment 11
[0167] This embodiment provides a double-sided Poly solar cell with a window layer. The only difference from Embodiment 1 is that trimethylaluminum is replaced with triethylaluminum, and the other steps are completely consistent with Embodiment 1.
[0168] Example 12
[0169] This embodiment provides a double-sided Poly solar cell with a window layer, which is different from the first embodiment only in that arsenic is replaced with tert-butyl arsenic, and the other steps are completely consistent with the first embodiment.
[0170] Example 13
[0171] This embodiment provides a double-sided Poly solar cell with a window layer. The only difference from Embodiment 1 is that the flow rate of the gallium source gas is 6000 sccm, the flow rate of the aluminum source gas is 5000 sccm, and the flow rate of the arsenic source gas is 8000 sccm. The other steps are exactly the same as those in Embodiment 1.
[0172] Embodiment 14
[0173] This embodiment provides a double-sided Poly solar cell with a window layer. The only difference from Embodiment 1 is that the flow rate of the gallium source gas is 3500 sccm, the flow rate of the aluminum source gas is 1000 sccm, and the flow rate of the arsenic source gas is 2500 sccm. The other steps are exactly the same as those in Embodiment 1.
[0174] Embodiment 15
[0175] This embodiment provides a double-sided Poly solar cell with a window layer. The only difference from Embodiment 1 is that the deposition pressure is 600 mTorr, and the other steps are completely consistent with Embodiment 1.
[0176] Example 16
[0177] This embodiment provides a double-sided Poly solar cell with a window layer. The only difference from Embodiment 1 is that the deposition pressure is 2000 mTorr, and the other steps are completely consistent with Embodiment 1.
[0178] Embodiment 17
[0179] This embodiment provides a double-sided Poly solar cell with a window layer. The only difference from Embodiment 1 is that the deposition temperature is 550° C., and the other steps are completely consistent with Embodiment 1.
[0180] Embodiment 18
[0181] This embodiment provides a double-sided Poly solar cell with a window layer. The only difference from Embodiment 1 is that the deposition temperature is 650° C., and the other steps are completely consistent with Embodiment 1.
[0182] Comparative Example 1
[0183] This comparative example provides a double-sided Poly solar cell, which is different from Example 1 only in that no window layer is provided and step (2) is not performed, and the other steps are completely consistent with Example 1.
[0184] Comparative Example 2
[0185] This comparative example provides a double-sided Poly solar cell, in which triethylgallium is no longer introduced in step (2), the flow rate of trimethylaluminum is adjusted to 2500 sccm, the flow rate of arsenic is adjusted to 4500 sccm, and the other steps are completely consistent with Example 1.
[0186] Comparative Example 3
[0187] This comparative example provides a double-sided Poly solar cell, in which trimethylaluminum is no longer introduced in step (2), the flow rate of triethylgallium is adjusted to 3500 sccm, the flow rate of arsenic is adjusted to 3500 sccm, and the other steps are completely consistent with Example 1.
[0188] Comparative Example 4
[0189] This comparative example provides a double-sided Poly solar cell, in which hydrogen arsenide is no longer introduced in step (2), the flow rate of triethylgallium is adjusted to 4500 sccm, the flow rate of trimethylaluminum is adjusted to 2500 sccm, and the other steps are completely consistent with Example 1.
[0190] Test Example 1
[0191] Test samples: double-sided Poly solar cells containing window layers provided in Examples 1 to 18, and double-sided Poly solar cells provided in Comparative Examples 1 to 4.
[0192] The specific test results are shown in Table 1 below:
[0193] Table 1
[0194]
[0195]
[0196] As shown in Table 1, the double-sided Poly solar cell of the present invention has an AlGaAs film as a window layer between the N-type polysilicon layer and the front anti-reflection layer, which increases the absorption effect of high-energy photons and reduces the hot carrier effect, thereby effectively improving the efficiency of the double-sided Poly solar cell.
[0197] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A double-sided Poly solar cell with a window layer, characterized in that: The double-sided Poly solar cell with a window layer comprises a P-type silicon substrate; and the front side of the P-type silicon substrate comprises a front tunneling oxide layer, an N-type polysilicon layer and a front anti-reflection layer stacked in sequence; Wherein, a window layer is arranged between the N-type polysilicon layer and the front anti-reflection layer, and the window layer is an AlGaAs film.
2. The double-sided Poly solar cell with a window layer according to claim 1, characterized in that: The thickness of the window layer is 200-300 nm; Preferably, the thickness of the front tunneling oxide layer is 0.5 to 2.0 nm; Preferably, the N-type polysilicon layer is a boron-doped polysilicon layer; Preferably, the thickness of the N-type polysilicon layer is 60 to 120 nm; Preferably, the boron doping concentration in the boron-doped polysilicon layer is 1E20-5E20 cm -3 ; Preferably, the front anti-reflection layer is a silicon nitride film; Preferably, the thickness of the front anti-reflection layer is 40-100 nm.
3. The double-sided Poly solar cell with a window layer according to claim 1, characterized in that: The back side of the P-type silicon substrate comprises a back side tunneling oxide layer, a P-type polysilicon layer, a back side passivation layer and a back side anti-reflection layer which are stacked in sequence.
4. The double-sided Poly solar cell with a window layer according to claim 3, characterized in that: The thickness of the back tunneling oxide layer is 0.5 to 2.0 nm; Preferably, the P-type polysilicon layer is a phosphorus-doped polysilicon layer; Preferably, the thickness of the P-type polysilicon layer is 80 to 150 nm; Preferably, the phosphorus doping concentration in the phosphorus-doped polysilicon layer is 1E20-5E20 cm -3 ; Preferably, the back passivation layer is an aluminum oxide film; Preferably, the thickness of the back passivation layer is 5 to 10 nm; Preferably, the back anti-reflection layer is a silicon nitride film; Preferably, the thickness of the back anti-reflection layer is 50-100 nm.
5. A method for preparing a double-sided Poly solar cell containing a window layer according to any one of claims 1 to 4, characterized in that: The preparation method comprises: The window layer is prepared by depositing an AlGaAs film on the surface of the N-type polysilicon layer through a MOCVD process.
6. The method for preparing a double-sided Poly solar cell containing a window layer according to claim 5, characterized in that: The gases required in the deposition process include: gallium source gas, aluminum source gas and arsenic source gas.
7. The method for preparing a double-sided Poly solar cell containing a window layer according to claim 6, characterized in that: The gallium source gas includes any one of trimethyl gallium, triethyl gallium or triisopropyl gallium or a combination of at least two thereof, preferably triethyl gallium; And / or, the aluminum source gas includes any one of trimethylaluminum, triethylaluminum, dimethylaluminum alkoxide or dimethylaluminum hydride, or a combination of at least two thereof, preferably trimethylaluminum; And / or, the arsenic source gas includes arsine and / or tert-butyl arsine, preferably arsine.
8. The method for preparing a double-sided Poly solar cell containing a window layer according to claim 6 or 7, characterized in that: The flow ratio of gallium source gas, aluminum source gas and arsenic source gas is (2.5-3.0):(0.8-1.2):(3.0-3.5); Preferably, the flow rate of the gallium source gas is 2500-3000 sccm; Preferably, the flow rate of the aluminum source gas is 800 to 1200 sccm; Preferably, the flow rate of the arsenic source gas is 3000-3500 sccm.
9. The method for preparing a double-sided Poly solar cell containing a window layer according to claim 5, characterized in that: The deposition pressure is 1000-2000 mTorr, preferably 1500-1700 mTorr.
10. The method for preparing a double-sided Poly solar cell containing a window layer according to claim 5, characterized in that: The deposition temperature is 550-650°C; And / or, the deposition time is 3500-3700s.