A nitrogen-containing crystalline silicon shingled double-sided solar cell and a preparation method thereof
By integrating a tantalum nitride back passivation layer and silicon nitride anti-reflection layers with specific precursors, the efficiency and bifaciality of crystalline silicon shingled solar cells are enhanced, addressing recombination and reflectivity issues while reducing production costs.
Patent Information
- Application Number
- CN201910694685.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2019-07-30
- Publication Date
- 2024-12-06
- Estimated Expiration
- 2039-07-30
AI Technical Summary
Existing crystalline silicon solar cells face challenges in reducing back recombination rates and reflectivity, which affect the efficiency and bifaciality of double-sided shingled solar cells, while also requiring complex processes and high production costs.
Incorporating a tantalum nitride back passivation layer and a second silicon nitride anti-reflection layer on the back of the solar cell, utilizing tantalum pentyl imide-tris dimethylamino tantalum and SiH4 gas for deposition, along with a metal grid electrode layer, to enhance electron transmission and reduce contact resistance.
The solution reduces back recombination rates and reflectivity, improves short-circuit current and bifaciality, simplifies the manufacturing process, and decreases production costs by increasing equipment utilization.
Smart Images
Figure CN110350051B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of crystalline silicon solar energy, and in particular relates to a nitrogen-containing crystalline silicon shingled double-sided solar cell and a preparation method thereof. Background Art
[0002] As the problem of environmental pollution has received great attention from people, traditional fossil energy has been gradually replaced by new energy, and solar energy has become the focus of people's attention in the field of new energy. Solar energy has the characteristics of being clean, safe to use, and easy to convert and utilize. Among the types of solar cells, crystalline silicon solar cells account for more than 85% of the market and are currently the main product of solar cells. The development and utilization of solar energy has accelerated the development of solar cell technology. Double-sided shingled crystalline silicon solar cells have appeared in the market. Double-sided shingled solar cells increase power generation, reduce the waste of substrate silicon wafers, and make full use of sunlight. They have great potential for application in photovoltaic building integration, and have now become a research hotspot for scientific research institutes and photovoltaic companies around the world. Summary of the invention
[0003] The purpose of the present invention is to provide a nitrogen-containing crystalline silicon shingled bifacial solar cell, wherein a tantalum nitride back passivation layer and a second silicon nitride anti-reflection layer are used on the back of the solar cell, thereby reducing the back recombination rate of the solar cell and the reflectivity of the incident light on the back, improving the efficiency of the back cell and the short-circuit current of the back cell, and the bifaciality of the solar cell. The selection of the tantalum nitride back passivation layer not only has the ability to selectively transmit electrons, but also can reduce the contact resistance of the back electrode printing. The silicon nitride anti-reflection layer and the tantalum nitride back passivation layer increase the equipment utilization rate, simplify the process, and manufacture a bifacial shingled solar module, which increases the power generation and reduces the production cost.
[0004] The technical solution adopted by the present invention is as follows:
[0005] A nitrogen-containing crystalline silicon shingled bifacial solar cell comprises, from top to bottom, a first silicon nitride anti-reflection layer 104, a p-type doping layer 101, an n-type silicon substrate layer 100, a tantalum nitride back passivation layer 102, and a second silicon nitride anti-reflection layer 103. A metal grid electrode layer 105 is also provided on the upper surface of the first silicon nitride anti-reflection layer and the lower surface of the second silicon nitride anti-reflection layer.
[0006] Furthermore, the tantalum source precursor of the tantalum nitride back passivation layer 102 is pentyl imide-tris dimethylamino tantalum, the nitrogen source precursor gas of the tantalum nitride back passivation layer 102 is pure ammonia or a combination of nitrogen and hydrogen, and the thickness of the tantalum nitride back passivation layer 102 is 50-120nm.
[0007] Furthermore, the silicon source of the first silicon nitride anti-reflection layer 104 and the second silicon nitride anti-reflection layer 103 comes from SiH4 gas, and the nitrogen source comes from at least one of ammonia, nitric oxide, and nitrogen. The thickness of the first silicon nitride anti-reflection layer is 80-120nm, and the thickness of the second silicon nitride anti-reflection layer is 20-80nm.
[0008] Furthermore, the p-type doping layer 101 is a boron source doping layer, the doping concentration of the boron source doping layer is 1016-1020 / cm3, and the thickness of the boron source doping layer is 200-500nm.
[0009] Furthermore, the n-type silicon substrate layer 100 is single crystal silicon or polycrystalline silicon, and the substrate thickness of the n-type silicon substrate layer 100 is 160-180 um.
[0010] Furthermore, a metal grid electrode layer is prepared on the upper surface of the first silicon nitride anti-reflection layer and the lower surface of the second silicon nitride anti-reflection layer using a screen printing process and a shingled double-sided solar cell screen. The metal grid electrode layer 105 is Cu or an alloy formed by Cu and at least one of Mo, W, Ti, Ni, Al, Mg, Ta, Sn, and Ag, or the metal grid electrode layer 105 is Ag or an alloy of Ag.
[0011] A method for preparing a nitrogen-containing crystalline silicon shingled bifacial solar cell comprises the following steps:
[0012] (1) Select an n-type silicon substrate, perform a cleaning and texturing step, and form a surface textured structure pyramid shape. The thickness of the n-type silicon substrate is 160 to 180 μm.
[0013] (2) On the upper surface of the n-type silicon substrate layer, a p-type doping layer 101 is prepared using a boron source diffusion device, and the boron source doping concentration is 10 16 ~10 20 / cm 3 , the thickness of the boron source doping layer is 200 to 500 nm;
[0014] (3) On the upper surface of the boron source doped layer, an atomic layer deposition (ALD) device is used to prepare a first silicon nitride anti-reflection layer 104, the silicon source precursor gas is SiH4, the nitrogen source precursor is ammonia, and the thickness of the first silicon nitride anti-reflection layer is 80 to 120 nm;
[0015] (4) on the lower surface of the n-type silicon substrate layer, using an atomic layer deposition (ALD) device to prepare a tantalum nitride back passivation layer, the tantalum source precursor is pentamido-tris(dimethylamino)tantalum, the nitrogen source precursor gas is a combination gas of nitrogen and hydrogen, the content ratio is 10:1, and the thickness of the tantalum nitride back passivation layer is 50 to 120 nm;
[0016] (5) on the lower surface of the tantalum nitride back passivation layer, a second silicon nitride anti-reflection layer 103 is prepared by using an atomic layer deposition (ALD) device, the silicon source precursor gas is from SiH4, the nitrogen source precursor is nitrogen, and the thickness of the second silicon nitride anti-reflection layer is 20 to 80 nm;
[0017] (6) A metal grid electrode layer is prepared on the upper surface of the first silicon nitride anti-reflection layer and the lower surface of the second silicon nitride anti-reflection layer using a screen printing process and a shingled double-sided solar cell screen. The metal grid electrode layer is Cu or an alloy formed by Cu and at least one of Mo, W, Ti, Ni, Al, Mg, Ta, Sn, and Ag, or the metal grid electrode layer is Ag or an alloy of Ag. The thickness of the metal grid electrode layer is 30um to 80um.
[0018] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:
[0019] 1. In the present invention, a tantalum nitride back passivation layer and a second silicon nitride anti-reflection layer are stacked on the back of the solar cell, which reduces the back recombination rate of the solar cell and the reflectivity of the incident light on the back, improves the efficiency of the back cell and the short-circuit current of the back cell, and the bifaciality of the solar cell.
[0020] 2. In the present invention, the tantalum nitride back passivation layer not only has the ability to select electron transmission, but also can reduce the contact resistance of the back electrode printing. The nitrogen source of the silicon nitride anti-reflection layer and the tantalum nitride back passivation layer is the same, and different cavities are set, so they can be prepared on the same equipment, which increases the utilization rate of the equipment, is simple in process, and manufactures a double-sided shingled solar module, increases power generation, and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;
[0022] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of the present invention;
[0023] Figure 3 It is a schematic diagram of the screen of the present invention;
[0024] Markings in the figure: 100-n-type silicon substrate layer, 101-boron source doping layer, 102-tantalum nitride back passivation layer, 102a-silicon dioxide layer, 103-second silicon nitride anti-reflection layer, 104-first silicon nitride anti-reflection layer, 105-metal gate electrode layer. DETAILED DESCRIPTION
[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0026] A nitrogen-containing crystalline silicon shingled bifacial solar cell comprises, from top to bottom, a first silicon nitride anti-reflection layer 104, a p-type doping layer 101, an n-type silicon substrate layer 100, a tantalum nitride back passivation layer 102, and a second silicon nitride anti-reflection layer 103. A metal grid electrode layer 105 is also provided on the upper surface of the first silicon nitride anti-reflection layer and the lower surface of the second silicon nitride anti-reflection layer.
[0027] Furthermore, the tantalum source precursor of the tantalum nitride back passivation layer 102 is pentyl imide-tris dimethylamino tantalum, the nitrogen source precursor gas of the tantalum nitride back passivation layer 102 is pure ammonia or a combination of nitrogen and hydrogen, and the thickness of the tantalum nitride back passivation layer 102 is 50-120nm.
[0028] Furthermore, the silicon source of the first silicon nitride anti-reflection layer 104 and the second silicon nitride anti-reflection layer 103 comes from SiH4 gas, and the nitrogen source comes from at least one of ammonia, nitric oxide, and nitrogen. The thickness of the first silicon nitride anti-reflection layer is 80-120nm, and the thickness of the second silicon nitride anti-reflection layer is 20-80nm.
[0029] Furthermore, the p-type doping layer 101 is a boron source doping layer, the doping concentration of the boron source doping layer is 1016-1020 / cm3, and the thickness of the boron source doping layer is 200-500nm.
[0030] Furthermore, the n-type silicon substrate layer 100 is single crystal silicon or polycrystalline silicon, and the substrate thickness of the n-type silicon substrate layer 100 is 160-180 um.
[0031] Furthermore, a metal grid electrode layer is prepared on the upper surface of the first silicon nitride anti-reflection layer and the lower surface of the second silicon nitride anti-reflection layer using a screen printing process and a shingled double-sided solar cell screen. The metal grid electrode layer 105 is Cu or an alloy formed by Cu and at least one of Mo, W, Ti, Ni, Al, Mg, Ta, Sn, and Ag, or the metal grid electrode layer 105 is Ag or an alloy of Ag.
[0032] Example 1
[0033] like Figure 1As shown, a nitrogen-containing crystalline silicon shingled bifacial solar cell of the present invention comprises, arranged in sequence from top to bottom, a first silicon nitride anti-reflection layer (104), a boron source doping layer (101), an n-type silicon substrate layer (100), a tantalum nitride back passivation layer (102), a second silicon nitride anti-reflection layer (103), and a metal grid electrode layer (105) arranged on the upper surface of the first silicon nitride anti-reflection layer and the lower surface of the second silicon nitride anti-reflection layer.
[0034] This embodiment is prepared by the following steps:
[0035] (1) Select an n-type single crystal silicon or polycrystalline silicon substrate, perform a cleaning and texturing step, and form a surface textured structure pyramid shape. The thickness of the n-type single crystal silicon or polycrystalline silicon substrate is 160 to 180 um.
[0036] (2) On the upper surface of the crystalline silicon substrate 100, a p-type boron source doping layer 101 is prepared using a boron source diffusion device, with a boron doping concentration of 10 16 ~10 20 / cm 3 , the thickness of the boron source doping layer is 200 to 500 nm.
[0037] (3) On the upper surface of the boron source doped layer 101, an atomic layer deposition (ALD) device is used to prepare a first silicon nitride anti-reflection layer 104. The silicon source precursor gas comes from SiH4, and the nitrogen source precursor is ammonia. The prepared silicon nitride anti-reflection layer contains H atoms, which saturate the dangling bonds on the surface of the silicon wafer and reduce the interface state density. The thickness of the first silicon nitride anti-reflection layer is 80 to 120 nm.
[0038] (4) On the lower surface of the crystalline silicon substrate 100, a tantalum nitride back passivation layer 102 is prepared by using an atomic layer deposition (ALD) device. The precursor of the tantalum source is pentamido-tris(dimethylamino)tantalum, and the nitrogen source precursor gas is a combination gas of nitrogen and hydrogen, with a content ratio of 10:1.
[0039] The tantalum nitride back passivation layer contains H atoms during preparation, which saturates the dangling bonds on the surface of the silicon wafer and reduces the interface recombination rate. Tantalum nitride has electron selective contact characteristics, which blocks the passage of hole minority carriers, reduces the recombination center of the back battery, improves the efficiency of the back battery and the short-circuit current of the back battery, and the bifaciality of the solar cell. The thickness of the tantalum nitride back passivation layer is 50 to 120 nm.
[0040] (5) On the lower surface of the tantalum nitride back passivation layer 102, an atomic layer deposition (ALD) device is used to prepare a second silicon nitride anti-reflection layer 103. The silicon source precursor gas comes from SiH4, and the nitrogen source precursor is nitrogen. The reflectivity of the back of the battery is reduced. The thickness of the second silicon nitride anti-reflection layer is 20 to 80 nm.
[0041] (6) A metal grid electrode layer 105 is prepared on the upper surface of the first silicon nitride anti-reflection layer 104 and the lower surface of the second silicon nitride anti-reflection layer 103 by using a screen printing process and a shingled double-sided solar cell screen. The metal grid electrode layer is Cu or an alloy formed by Cu and at least one of Mo, W, Ti, Ni, Al, Mg, Ta, Sn, and Ag, or the metal grid electrode layer is Ag or an alloy of Ag. The thickness of the metal grid electrode layer 105 is 30 um to 80 um.
[0042] Example 2
[0043] like Figure 2 As shown, a nitrogen-containing crystalline silicon shingled bifacial solar cell of the present invention comprises, arranged in sequence from top to bottom, a first silicon nitride anti-reflection layer (104), a boron source doping layer (101), an n-type silicon substrate layer (100), a silicon dioxide layer (102a), a tantalum nitride back passivation layer (102), a second silicon nitride anti-reflection layer (103), a metal grid electrode layer (105) arranged on the upper surface of the first silicon nitride anti-reflection layer and on the lower surface of the second silicon nitride anti-reflection layer.
[0044] This embodiment is prepared by the following steps:
[0045] (1) Select an n-type single crystal silicon or polycrystalline silicon substrate, perform a cleaning and texturing step, and form a surface textured structure pyramid shape. The thickness of the n-type single crystal silicon or polycrystalline silicon substrate is 160 to 180 um.
[0046] (2) On the upper surface of the crystalline silicon substrate 100, a p-type boron source doping layer 101 is prepared using a boron source diffusion device, with a boron doping concentration of 10 16 ~10 20 / cm 3 , the thickness of the boron source doping layer is 200 to 500 nm.
[0047] (3) On the upper surface of the boron source doped layer 101, an atomic layer deposition (ALD) device is used to prepare a first silicon nitride anti-reflection layer 104. The silicon source precursor gas comes from SiH4, and the nitrogen source precursor is ammonia. The prepared silicon nitride anti-reflection layer contains H atoms, which saturate the dangling bonds on the surface of the silicon wafer and reduce the interface state density. The thickness of the first silicon nitride anti-reflection layer is 80 to 120 nm.
[0048] (4) On the lower surface of the crystalline silicon substrate 100, the back side of the crystalline silicon cell is first polished using HF and additives, and then a low-temperature ozone oxidation device is used for an oxidation time of 60 to 90 seconds to form a dense silicon dioxide layer 102a for chemical passivation of the lower surface of the silicon wafer. The thickness of the silicon dioxide layer is 3 to 10 nm.
[0049] (5) On the lower surface of the silicon dioxide layer 102a, an atomic layer deposition (ALD) device is used to prepare a tantalum nitride back passivation layer 102. The precursor of the tantalum source is tantalum imide-tris(dimethylamino)pentanamide, and the nitrogen source precursor gas is a combination gas of nitrogen with a purity of 99.9%. The prepared tantalum nitride back passivation layer has electron selective contact characteristics, which blocks the passage of hole minority carriers, reduces the recombination center of the back battery, improves the efficiency of the back battery and the short-circuit current of the back battery, and the bifaciality of the solar cell. The thickness of the tantalum nitride back passivation layer is 50 to 120 nm.
[0050] (6) On the lower surface of the tantalum nitride back passivation layer 102, an atomic layer deposition (ALD) device is used to prepare a second silicon nitride anti-reflection layer 103. The silicon source precursor gas comes from SiH4, and the nitrogen source precursor is nitrogen. The reflectivity of the back of the battery is reduced. The thickness of the second silicon nitride anti-reflection layer is 20 to 80 nm.
[0051] (7) A metal grid electrode layer 105 is prepared on the upper surface of the first silicon nitride anti-reflection layer 104 and the lower surface of the second silicon nitride anti-reflection layer 103 by using a screen printing process and a shingled double-sided solar cell screen. The metal grid electrode layer is Cu or an alloy formed by Cu and at least one of Mo, W, Ti, Ni, Al, Mg, Ta, Sn, and Ag, or the metal grid electrode layer is Ag or an alloy of Ag. The thickness of the metal grid electrode layer 105 is 30 um to 80 um.
[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A nitrogen-containing crystalline silicon shingled bifacial solar cell, characterized in that: The invention comprises a first silicon nitride anti-reflection layer (104), a p-type doping layer (101), an n-type silicon substrate layer (100), a tantalum nitride back passivation layer (102), and a second silicon nitride anti-reflection layer (103) which are arranged in sequence from top to bottom; a metal grid electrode layer (105) is also arranged on the upper surface of the first silicon nitride anti-reflection layer (104) and the lower surface of the second silicon nitride anti-reflection layer (103); wherein: the metal grid electrode layer (105) is Cu or Cu and Mo, W, Ti, Ni, Al, The invention relates to an alloy formed by at least one of Mg, Ta, Sn and Ag, or the metal grid electrode layer (105) is Ag or an alloy of Ag; the silicon source of the first silicon nitride anti-reflection layer (104) and the second silicon nitride anti-reflection layer (103) is from SiH4 gas, and the nitrogen source is from at least one of ammonia, nitric oxide and nitrogen; the thickness of the first silicon nitride anti-reflection layer (104) is 80-120nm, and the thickness of the second silicon nitride anti-reflection layer (103) is 20-80nm.
2. A nitrogen-containing compound crystalline silicon shingled bifacial solar cell according to claim 1, characterized in that: The tantalum source precursor of the tantalum nitride back passivation layer (102) is pentamido-tris(dimethylamino)tantalum, the nitrogen source precursor gas of the tantalum nitride back passivation layer (102) is pure ammonia or a combination gas of nitrogen and hydrogen, and the thickness of the tantalum nitride back passivation layer (102) is 50-120nm.
3. A nitrogen-containing compound crystalline silicon shingled bifacial solar cell according to claim 1, characterized in that: The p-type doping layer (101) is a boron source doping layer, and the doping concentration of the boron source doping layer is 1016-1020 / cm 3 , the thickness of the boron source doping layer is 200-500nm.
4. A nitrogen-containing compound crystalline silicon shingled bifacial solar cell according to claim 1, characterized in that: The n-type silicon substrate layer (100) is single crystal silicon or polycrystalline silicon, and the substrate thickness of the n-type silicon substrate layer (100) is 160-180 um.
5. A method for preparing a nitrogen-containing crystalline silicon shingled bifacial solar cell, characterized in that: The following steps are involved: (1) selecting an n-type silicon substrate layer (100), performing a cleaning and texturing step, and forming a surface textured structure pyramid shape, wherein the thickness of the n-type silicon substrate layer (100) is 160-180 um; (2) on the upper surface of the n-type silicon substrate layer (100), a p-type doping layer (101) is prepared using a boron source diffusion device, with a boron source doping concentration of 1016-1020 / cm 3 , the thickness of the boron source doping layer is 200-500nm; (3) on the upper surface of the boron source doped layer, using an atomic layer deposition (ALD) device to prepare a first silicon nitride anti-reflection layer (104), wherein the silicon source precursor gas is SiH4, and the nitrogen source precursor is ammonia, and the thickness of the first silicon nitride anti-reflection layer (104) is 80-120 nm; (4) on the lower surface of the n-type silicon substrate layer (100), a tantalum nitride back passivation layer (102) is prepared using an atomic layer deposition (ALD) device, the tantalum source precursor is pentamido-tris(dimethylamino)tantalum, the nitrogen source precursor gas is a combination gas of nitrogen and hydrogen, the content ratio is 10:1, and the thickness of the tantalum nitride back passivation layer (102) is 50-120 nm; (5) on the lower surface of the tantalum nitride back passivation layer (102), a second silicon nitride anti-reflection layer (103) is prepared by using an atomic layer deposition (ALD) device, the silicon source precursor gas is SiH4, the nitrogen source precursor is nitrogen, and the thickness of the second silicon nitride anti-reflection layer (103) is 20-80 nm; (6) A metal grid electrode layer (105) is prepared on the upper surface of the first silicon nitride anti-reflection layer (104) and the lower surface of the second silicon nitride anti-reflection layer (103) by using a screen printing process and a shingled double-sided solar cell screen. The metal grid electrode layer (105) is Cu or an alloy formed by Cu and at least one of Mo, W, Ti, Ni, Al, Mg, Ta, Sn, and Ag. Alternatively, the metal grid electrode layer (105) is Ag or an alloy of Ag. The thickness of the metal grid electrode layer (105) is 30 um to 80 um.