CN219476690U - Back film layer structure of solar cell, solar cell and cell assembly - Google Patents
Back film layer structure of solar cell, solar cell and cell assembly Download PDFInfo
- Publication number
- CN219476690U CN219476690U CN202320541427.7U CN202320541427U CN219476690U CN 219476690 U CN219476690 U CN 219476690U CN 202320541427 U CN202320541427 U CN 202320541427U CN 219476690 U CN219476690 U CN 219476690U
- Authority
- CN
- China
- Prior art keywords
- film layer
- silicon nitride
- silicon
- silicon oxynitride
- refractive index
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Photovoltaic Devices (AREA)
Abstract
The present utility model relates to a back surface film layer structure of a solar cell, and a cell module, the back surface film layer structure sequentially including four film layers, i.e., a first silicon oxynitride film layer, a second silicon nitride film layer, a third silicon nitride film layer, and a fourth silicon oxynitride film layer, in a direction away from a silicon substrate, the film thickness of the second silicon nitride film layer being greater than or equal to the film thickness of each of the first silicon oxynitride film layer, the third silicon nitride film layer, and the fourth silicon oxynitride film layer. The first silicon oxynitride film has a film thickness of 5nm to 25nm and a refractive index of 1.2 to 1.9. The second silicon nitride film layer has a film thickness of 40nm to 80nm and a refractive index of 2.1 to 2.4. The third silicon nitride film layer has a film thickness of 20nm to 40nm and a refractive index of 1.9 to 2.2. The film thickness of the fourth silicon oxynitride film layer is 20nm to 40nm, and the refractive index is 1.5 to 1.9. The back reflectivity of the battery and the module can be reduced, the passivation performance is not output to the existing film layer, and the efficiency of absorbing sunlight on the back of the module made of the battery is higher, namely the double-sided rate of the battery and the module is higher.
Description
Technical Field
The present utility model relates to the field of solar cells, and more particularly to a back side film layer structure of a solar cell, a solar cell including the back side film layer structure, and a cell assembly including a plurality of such solar cells.
Background
Solar cells are an important way for people to generate electricity in the future, and solar cells manufactured by crystalline silicon are the main stream technology of photovoltaic industry for the next few years. The Plasma Enhanced Chemical Vapor Deposition (PECVD) technology is the mainstream film plating technology at present, and the uniformity and compactness of the film layer made by the technology are good. Different membrane structures can be prepared by adjusting characteristics such as specific gas type, flow and the like. For example, in solar cells (e.g., N-type cells), most backside film structures are currently formed using silicon nitride film structures.
Fig. 1 shows a schematic cross-sectional view of an N-type cell including a conventional backside film layer structure. As shown, the N-type battery 100 includes: a silicon substrate 101, an N-poly layer 102 disposed on the silicon substrate 101, and a conventional backside film layer structure disposed on the N-poly layer 102, the conventional backside film layer structure comprising, in order, in a direction away from the silicon substrate 101: a high refractive silicon nitride film layer 103, a medium refractive silicon nitride film layer 104, and a low refractive silicon nitride film layer 105, wherein the refractive indices of the three film layers gradually decrease in a direction away from the silicon substrate 101.
The silicon nitride film structure has good field passivation effect, such as good dielectric property (low dielectric constant, low loss) and high insulativity, because the high-compactness silicon nitride has good blocking capability to impurity ions. However, the refractive index of such a film structure is difficult to be 2.0 or less, and the optical reflectivity is just as much as a bottleneck, thus resulting in higher reflectivity of the back surface and lower double-sided rate of the battery.
Disclosure of Invention
In order to solve the above-mentioned problems in the prior art at least partially, the present utility model provides a novel back film structure of a solar cell, which can increase back light absorption, thereby improving cell efficiency and cell bifacial rate.
According to an aspect of the present utility model, there is provided a back surface film layer structure of a solar cell, wherein the back surface film layer structure includes four film layers, i.e., a first silicon oxynitride film layer, a second silicon nitride film layer, a third silicon nitride film layer, and a fourth silicon oxynitride film layer, in order in a direction away from a silicon substrate, the film thickness of the second silicon nitride film layer being greater than or equal to the film thickness of each of the first silicon oxynitride film layer, the third silicon nitride film layer, and the fourth silicon oxynitride film layer.
In a preferred embodiment, the film thickness of the third silicon nitride film layer or the film thickness of the fourth silicon oxynitride film layer may be half the film thickness of the second silicon nitride film layer.
In a preferred embodiment, the film thickness of the third silicon nitride film layer and the film thickness of the fourth silicon oxynitride film layer may be the same.
In a preferred embodiment, the film thickness of the third silicon nitride film layer may be smaller than the film thickness of the fourth silicon oxynitride film layer.
In a preferred embodiment, the film thickness of the first silicon oxynitride film layer may be smaller than the film thickness of the third silicon nitride film layer and the film thickness of the fourth silicon oxynitride film layer.
In a preferred embodiment, the film thicknesses of the second silicon nitride film layer, the third silicon nitride film layer, and the fourth silicon oxynitride film layer may be sequentially reduced.
In a preferred embodiment, the refractive index of each of the second silicon nitride film layer and the third silicon nitride film layer may be greater than or equal to the refractive index of each of the first silicon oxynitride film layer and the fourth silicon oxynitride film layer.
In a preferred embodiment, the refractive indices of the second silicon nitride film layer, the third silicon nitride film layer, and the fourth silicon oxynitride film layer may be sequentially reduced.
In a preferred embodiment, the refractive index of the first silicon oxynitride film layer may be smaller than the refractive index of the third silicon nitride film layer.
In a preferred embodiment, the first silicon oxynitride film layer may have a film thickness of 5nm to 25nm and a refractive index of 1.2 to 1.9.
In a preferred embodiment, the second silicon nitride film layer may have a film thickness of 40nm to 80nm and a refractive index of 2.1 to 2.4.
In a preferred embodiment, the third silicon nitride film layer may have a film thickness of 20nm to 40nm and a refractive index of 1.9 to 2.2.
In a preferred embodiment, the fourth silicon oxynitride film layer may have a film thickness of 20nm to 40nm and a refractive index of 1.5 to 1.9.
In a preferred embodiment, the first silicon oxynitride film may have a film thickness of 14nm and a refractive index of 1.6, the second silicon nitride film may have a film thickness of 49nm and a refractive index of 2.3, the third silicon nitride film may have a film thickness of 28nm and a refractive index of 2.1, and the fourth silicon oxynitride film may have a film thickness of 35nm and a refractive index of 1.7.
According to another aspect of the present utility model, there is provided a solar cell including: a silicon substrate; and a backside film layer structure according to the present utility model disposed on the backside of the silicon substrate.
According to still another aspect of the present utility model, there is provided a battery assembly including: a plurality of solar cells according to the utility model.
According to the back surface film layer structure of the solar cell, the solar cell (such as an N-type cell) comprising the back surface film layer structure and the cell assembly comprising a plurality of the solar cells, the back surface reflectivity of the cell and the cell assembly can be reduced, passivation performance is not input into the existing film layer, and the back surface of the cell assembly made of the solar cell assembly has higher sunlight absorption efficiency, namely the double-sided rate of the cell and the cell assembly is higher. For example, the reflectivity of the battery piece with the film layer structure operated by the PECVD machine is 5 to 10 percent lower than that of the battery piece of the current production line, the efficiency is 0.02 to 0.05 percent higher than that of the battery piece of the current production line, and the double-sided rate is improved by more than 1 percent.
Drawings
Fig. 1 is a schematic cross-sectional view of an N-type cell including a structure according to a conventional backside film layer; and
fig. 2 is a schematic cross-sectional view of a solar cell including a backside film layer structure according to one embodiment of the utility model.
Detailed Description
Next, a back surface film layer structure of a solar cell (here, an N-type cell is exemplified) according to an embodiment of the present utility model will be described in detail with reference to fig. 2.
Fig. 2 is a schematic cross-sectional view of an N-type cell 200 including a backside film layer structure in accordance with an embodiment of the utility model.
As shown in fig. 2, according to the present utility model, there is provided an N-type battery 200, the N-type battery 200 including: a silicon substrate 201; an N-poly layer 202 disposed on the silicon substrate 201; and a back side film layer structure disposed on the opposite side of the N-poly layer 202 from the silicon substrate 201. The back surface film structure includes four film layers, i.e., a first silicon oxynitride film layer 203, a second silicon nitride film layer 204, a third silicon nitride film layer 205, and a fourth silicon oxynitride film layer 206 in order in a direction away from the silicon substrate 201. Wherein the film thickness of the second silicon nitride film 204 is greater than or equal to the film thickness of each of the first silicon oxynitride film 203, the third silicon nitride film 205, and the fourth silicon oxynitride film 206.
It should be noted that the N-poly layer 202 is included because an N-type cell is illustrated as an example. In practice, the N-poly layer 202 may be other types of layers depending on the type of battery, as long as the backside film layer structure is disposed on the backside of the silicon substrate 201.
In a preferred embodiment, the film thickness of the third silicon nitride film layer 205 or the film thickness of the fourth silicon oxynitride film layer 206 may be half the film thickness of the second silicon nitride film layer 204.
In a preferred embodiment, the film thickness of the third silicon nitride film layer 205 and the film thickness of the fourth silicon oxynitride film layer 206 may be the same.
In a preferred embodiment, the film thickness of the third silicon nitride film layer 205 may be smaller than the film thickness of the fourth silicon oxynitride film layer 206.
In a preferred embodiment, the film thickness of the first silicon oxynitride film 203 may be smaller than the film thickness of the third silicon nitride film 205 and the film thickness of the fourth silicon oxynitride film 206.
In a preferred embodiment, the film thicknesses of the second silicon nitride film layer 204, the third silicon nitride film layer 205, and the fourth silicon oxynitride film layer 206 may be sequentially reduced.
In a preferred embodiment, the refractive index of each of the second silicon nitride film layer 204 and the third silicon nitride film layer 205 may be greater than or equal to the refractive index of each of the first silicon oxynitride film layer 203 and the fourth silicon oxynitride film layer 206.
In a preferred embodiment, the refractive indices of the second silicon nitride film layer 204, the third silicon nitride film layer 205, and the fourth silicon oxynitride film layer 206 may be sequentially reduced.
In a preferred embodiment, the refractive index of the first silicon oxynitride film 203 may be smaller than the refractive index of the third silicon nitride film 205.
In a preferred embodiment, the first silicon oxynitride film layer 203 may have a film thickness of 5nm to 25nm and a refractive index of 1.2 to 1.9.
In a preferred embodiment, the second silicon nitride film 204 may have a film thickness of 40nm to 80nm and a refractive index of 2.1 to 2.4.
In a preferred embodiment, the third silicon nitride film layer 205 may have a film thickness of 20nm to 40nm and a refractive index of 1.9 to 2.2.
In a preferred embodiment, the fourth silicon oxynitride film layer 206 may have a film thickness of 20nm to 40nm and a refractive index of 1.5 to 1.9.
In a preferred embodiment, the first silicon oxynitride film 203 may have a film thickness of 14nm and a refractive index of 1.6, the second silicon nitride film 204 may have a film thickness of 49nm and a refractive index of 2.3, the third silicon nitride film 205 may have a film thickness of 28nm and a refractive index of 2.1, and the fourth silicon oxynitride film 206 may have a film thickness of 35nm and a refractive index of 1.7.
Further, according to the present utility model, there may be provided a battery assembly, which may include: a plurality of solar cells according to the utility model. For example, when the cell assembly is an N-type solar cell assembly, it may include a plurality of N-type cells 200 according to the present utility model, for example. The plurality of N-type cells 200 may be connected in parallel or in series, for example.
Examples
In one embodiment according to the present utility model, there is provided a back surface film layer structure of a solar cell, the back surface film layer structure comprising four film layers in order in a direction away from a silicon substrate, namely, a first silicon oxynitride film layer, a second silicon nitride film layer, a third silicon nitride film layer, and a fourth silicon oxynitride film layer, wherein the film thickness of the first silicon oxynitride film layer is 5nm to 25nm, the refractive index is 1.2 to 1.9, the film thickness of the second silicon nitride film layer is 40nm to 80nm, the refractive index is 2.1 to 2.4, the film thickness of the third silicon nitride film layer is 20nm to 40nm, the refractive index is 1.9 to 2.2, and the film thickness of the fourth silicon oxynitride film layer is 20nm to 40nm, the refractive index is 1.5 to 1.9.
In one embodiment according to the present utility model, there is provided a solar cell including: a silicon substrate; and a back surface film layer structure provided on a back surface side of the silicon substrate, the back surface film layer structure sequentially including, in a direction away from the silicon substrate: the silicon nitride film comprises a first silicon oxynitride film layer, a second silicon nitride film layer, a third silicon nitride film layer and a fourth silicon oxynitride film layer, wherein the film thickness of the first silicon oxynitride film layer is 5nm to 25nm, the refractive index is 1.2 to 1.9, the film thickness of the second silicon nitride film layer is 40nm to 80nm, the refractive index is 2.1 to 2.4, the film thickness of the third silicon nitride film layer is 20nm to 40nm, the refractive index is 1.9 to 2.2, and the film thickness of the fourth silicon oxynitride film layer is 20nm to 40nm, and the refractive index is 1.5 to 1.9.
In one embodiment according to the present utility model, there is provided a battery assembly including: a plurality of solar cells connected in parallel or in series, each solar cell comprising: a silicon substrate; and a back surface film layer structure provided on a back surface side of the silicon substrate, the back surface film layer structure sequentially including, in a direction away from the silicon substrate: the silicon nitride film comprises a first silicon oxynitride film layer, a second silicon nitride film layer, a third silicon nitride film layer and a fourth silicon oxynitride film layer, wherein the film thickness of the first silicon oxynitride film layer is 5nm to 25nm, the refractive index is 1.2 to 1.9, the film thickness of the second silicon nitride film layer is 40nm to 80nm, the refractive index is 2.1 to 2.4, the film thickness of the third silicon nitride film layer is 20nm to 40nm, the refractive index is 1.9 to 2.2, and the film thickness of the fourth silicon oxynitride film layer is 20nm to 40nm, and the refractive index is 1.5 to 1.9.
The reflectivity of the battery piece with the film layer structure operated by the PECVD machine is 5 to 10 percent lower than that of the battery piece of the current production line, the efficiency is 0.02 to 0.05 percent higher than that of the battery piece of the current production line, and the double-sided rate is improved by more than 1 percent.
According to the back surface film layer structure of the solar cell and the N-type cell comprising the same, the back surface reflectivity of the cell and the back surface of the module can be reduced, passivation performance is not input into the existing film layer, and the back surface of the module made of the cell is higher in sunlight absorption efficiency, namely the double surface rate of the cell and the module is higher.
Finally, it should be noted that: the above embodiments are merely for illustrating the technical solution of the present disclosure, and are not limited thereto. Although the present disclosure has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present disclosure.
List of reference numerals:
100: n-type battery
101: silicon substrate
102: n-poly layer
103: high-folding silicon nitride film layer
104: middle-folded silicon nitride film layer
105: low-fold silicon nitride film
200: n-type battery
201: silicon substrate
202: n-poly layer
203: first silicon oxynitride film layer
204: second silicon nitride film layer
205: third silicon nitride film layer
206: fourth silicon oxynitride film layer
Claims (10)
1. The back surface film layer structure of the solar cell is characterized by sequentially comprising four film layers, namely a first silicon oxynitride film layer, a second silicon nitride film layer, a third silicon nitride film layer and a fourth silicon oxynitride film layer, along the direction away from a silicon substrate, wherein the film thickness of the second silicon nitride film layer is greater than or equal to the film thickness of each of the first silicon oxynitride film layer, the third silicon nitride film layer and the fourth silicon oxynitride film layer.
2. The backside film structure of claim 1, wherein a film thickness of the third silicon nitride film layer or a film thickness of the fourth silicon oxynitride film layer is half a film thickness of the second silicon nitride film layer.
3. The backside film structure of claim 1, wherein a film thickness of the third silicon nitride film layer is the same as a film thickness of the fourth silicon oxynitride film layer.
4. The backside film layer structure of claim 1, wherein a refractive index of each of the second silicon nitride film layer and the third silicon nitride film layer is greater than or equal to a refractive index of each of the first silicon oxynitride film layer and the fourth silicon oxynitride film layer.
5. The backside film structure of claim 1, wherein the first silicon oxynitride film has a film thickness of 5nm to 25nm and a refractive index of 1.2 to 1.9.
6. The backside film structure of claim 1, wherein the second silicon nitride film has a film thickness of 40nm to 80nm and a refractive index of 2.1 to 2.4.
7. The backside film structure according to claim 1, wherein the third silicon nitride film layer has a film thickness of 20nm to 40nm and a refractive index of 1.9 to 2.2.
8. The backside film structure according to claim 1, wherein the fourth silicon oxynitride film has a film thickness of 20nm to 40nm and a refractive index of 1.5 to 1.9.
9. A solar cell, comprising:
a silicon substrate; and
the backside film layer structure according to any one of claims 1 to 8, which is provided on a backside of the silicon substrate.
10. A battery assembly, comprising:
a plurality of solar cells according to claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320541427.7U CN219476690U (en) | 2023-03-20 | 2023-03-20 | Back film layer structure of solar cell, solar cell and cell assembly |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320541427.7U CN219476690U (en) | 2023-03-20 | 2023-03-20 | Back film layer structure of solar cell, solar cell and cell assembly |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219476690U true CN219476690U (en) | 2023-08-04 |
Family
ID=87464440
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320541427.7U Active CN219476690U (en) | 2023-03-20 | 2023-03-20 | Back film layer structure of solar cell, solar cell and cell assembly |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219476690U (en) |
-
2023
- 2023-03-20 CN CN202320541427.7U patent/CN219476690U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8957300B2 (en) | Substrate for photoelectric conversion device, photoelectric conversion device, and stacked photoelectric conversion device | |
| JP2006319068A (en) | Multi-junction silicone thin film photoelectric converter and its manufacturing method | |
| JP5795492B2 (en) | Thin film solar cell | |
| US8410355B2 (en) | Thin film photoelectric conversion device having a stacked transparent oxide and carbon intermediate layer | |
| JPWO2005011002A1 (en) | Silicon-based thin film solar cell | |
| JP2008181965A (en) | Laminated optoelectric converter and its fabrication process | |
| JPS6249672A (en) | Amorphous photovoltaic element | |
| CN102668102A (en) | Polarization resistant solar cell | |
| CN110957378A (en) | Back film for improving double-sided rate of P-type double-sided battery and preparation method thereof | |
| JP2008270562A (en) | Multi-junction type solar cell | |
| US5853498A (en) | Thin film solar cell | |
| CN110444634B (en) | P-type single crystal PERC double-sided battery and manufacturing method thereof | |
| US20110061729A1 (en) | Solar Cell and Method of Manufacturing the Same | |
| KR100906748B1 (en) | Solar cell and method for manufacturing the same | |
| CN219476690U (en) | Back film layer structure of solar cell, solar cell and cell assembly | |
| CN215771167U (en) | Solar cell and photovoltaic module | |
| CN202977429U (en) | Solar cell and anti-reflection film | |
| US20110030760A1 (en) | Photovoltaic device and method of manufacturing a photovoltaic device | |
| KR101032270B1 (en) | Photovoltaic device including flexible or inflexibel substrate and method for manufacturing the same | |
| Oyama et al. | Requirements for TCO substrate in Si-based thin film solar cells-toward tandem | |
| JP5469298B2 (en) | Transparent conductive film for photoelectric conversion device and method for producing the same | |
| WO2012171146A1 (en) | Thin film solar cell with new type anti-reflection layer and fabrication method thereof | |
| JP2006216624A (en) | Solar cell and its production process | |
| CN102157594A (en) | Nc-Si:H/SiNx superlattice quantum well solar battery | |
| KR100999177B1 (en) | Solar cell and method for manufacturing the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |