Solar cell and preparation method therefor

1 . A solar cell, comprising a silicon cell main body, a first transparent conductive oxide layer, a second transparent conductive oxide layer, an insulating passivation layer, a first electrode and a second electrode;

wherein the first transparent conductive oxide layer and the first electrode are located on a front surface of the silicon cell main body;

the second transparent conductive oxide layer and the second electrode are located on a back surface of the silicon cell main body;

the insulating passivation layer covers an edge of the back surface of the silicon cell main body;

wherein the insulating passivation layer covers the back surface of the silicon cell main body, and the second transparent conductive oxide layer covers the insulating passivation layer; and

at the edge of the back surface of the silicon cell main body, the second transparent conductive oxide layer and the first transparent conductive oxide layer are spaced apart from each other by the insulating passivation layer.

2 . The solar cell according to claim 1 , wherein a height of the second electrode is 12 μm to 15 μm.

3 . The solar cell according to claim 1 , wherein a thickness of the insulating passivation layer is 70 nm to 90 nm.

4 . The solar cell according to claim 1 , wherein the insulating passivation layer is one selected from Si 3 N 4 , MgF 2 , and SiO x .

5 . The solar cell according to claim 4 , wherein the insulating passivation layer is a Si 3 N 4 layer, and a refractive index of the Si 3 N 4 layer is 2.05 to 2.20.

6 . The solar cell according to claim 1 , wherein a width of the second electrode is 50 μm to 60 μm.

7 . The solar cell according to claim 1 , wherein the silicon cell main body comprises a silicon wafer, a first intrinsic amorphous silicon layer, a first doped amorphous silicon layer, a second intrinsic amorphous silicon layer, and a second doped amorphous silicon layer;

the first intrinsic amorphous silicon layer and the first doped amorphous silicon layer are sequentially disposed on a front surface of the silicon wafer, and the second intrinsic amorphous silicon layer and the second doped amorphous silicon layer are sequentially disposed on a back surface of the silicon wafer; and

at an edge of the second doped amorphous silicon layer, the second transparent conductive oxide layer and the first transparent conductive oxide layer are spaced apart from each other, and the insulating passivation layer covers the edge of the second doped amorphous silicon layer.

8 . A method for preparing the solar cell according to claim 1 , comprising the following steps of:

forming a first transparent conductive oxide layer and a first electrode on a front surface of a silicon cell main body;

forming a second transparent conductive oxide layer and a second electrode on a back surface of the silicon cell main body;

forming an insulating passivation layer on an edge of the back surface of the silicon cell main body,

wherein the step of forming the insulating passivation layer is performed after the step of forming the first transparent conductive oxide layer and prior to the step of forming the second transparent conductive oxide layer,

wherein the insulating passivation layer covers the back surface of the silicon cell main body, and the second transparent conductive oxide layer covers the insulating passivation layer; and

the first transparent conductive oxide layer and the second transparent conductive oxide layer are spaced apart from each other by the insulating passivation layer.

9 . The method according to claim 8 , wherein the insulating passivation layer is one selected from Si 3 N 4 , MgF 2 , and SiO x .

10 . The method according to claim 9 , wherein the insulating passivation layer is Si 3 N 4 , and a method for forming the insulating passivation layer comprises: introducing SiH 4 gas and NH 3 gas and then co-depositing to form a Si 3 N 4 layer with a thickness of 70 nm to 90 nm.

11 . The method according to claim 9 , wherein the insulating passivation layer is MgF 2 , and a method for forming the insulating passivation layer comprises: sputtering and depositing an MgF 2 layer with a thickness of 70 nm to 90 nm by magnetron sputtering.

12 . The method according to claim 9 , wherein the insulating passivation layer is SiO x , and a method for forming the insulating passivation layer comprises: introducing SiH 4 gas and N 2 O gas, and then co-depositing to form a SiO x layer with a thickness of 70 nm to 90 nm.

13 . The method according to claim 8 , wherein a method for preparing the silicon cell main body comprises:

depositing a first intrinsic amorphous silicon layer and a first doped amorphous silicon layer on a front surface of a silicon wafer; and

depositing a second intrinsic amorphous silicon layer and a second doped amorphous silicon layer on a back surface of the silicon wafer.

14 . The method according to claim 8 , wherein the method comprises the following steps of:

preparing a silicon cell main body, wherein the silicon cell main body comprises a silicon wafer, a first intrinsic amorphous silicon layer and a first doped amorphous silicon layer on a front surface of the silicon wafer, and a second intrinsic amorphous silicon layer and a second doped amorphous silicon layer on a back surface of the silicon wafer;

depositing a first transparent conductive oxide layer on the first doped amorphous silicon layer;

depositing an insulating passivation layer on the second doped amorphous silicon layer;

depositing a second transparent conductive oxide layer on the insulating passivation layer, wherein the first transparent conductive oxide layer is spaced apart from the second transparent conductive oxide layer; and

forming a first electrode on the first transparent conductive oxide layer, and forming a second electrode on the second transparent conductive oxide layer.

15 . The method according to claim 14 , wherein during depositing the insulating passivation layer on the second doped amorphous silicon layer, the insulating passivation layer further wraps around a side surface of the silicon cell main body to cover the first transparent conductive oxide layer on the side surface of the silicon cell main body.