US 12,419,135 B2
N-type TOPCon cell with double-sided aluminum paste electrodes, and preparation method for preparing N-type TOPCon cell with double-sided aluminum paste electrodes
Mingzhang Feng, Zhejiang (CN); Sheng He, Zhejiang (CN); and Wei-Chih Hsu, Zhejiang (CN)
Assigned to CHINT NEW ENERGY TECHNOLOGY CO., LTD., Zhejiang (CN)
Appl. No. 18/038,704
Filed by CHINT NEW ENERGY TECHNOLOGY CO., LTD., Zhejiang (CN)
PCT Filed May 25, 2021, PCT No. PCT/CN2021/095755
§ 371(c)(1), (2) Date May 24, 2023,
PCT Pub. No. WO2022/183603, PCT Pub. Date Sep. 9, 2022.
Claims priority of application No. 202110242438.0 (CN), filed on Mar. 5, 2021.
Prior Publication US 2024/0097057 A1, Mar. 21, 2024
Int. Cl. H10F 77/20 (2025.01); H10F 71/00 (2025.01); H10F 77/30 (2025.01); H10F 77/70 (2025.01)
CPC H10F 77/211 (2025.01) [H10F 71/129 (2025.01); H10F 77/215 (2025.01); H10F 77/311 (2025.01); H10F 77/703 (2025.01)] 14 Claims
OG exemplary drawing
 
1. A preparation method for preparing an N-type TOPCon cell with double-sided aluminum paste electrodes, wherein an N-type TOPCon cell comprises an N-type substrate; a P-type doped region layer, an AlOx layer and a first SiNxHy layer are successively provided, from inside to outside, on a front side of the N-type substrate; a tunnel oxide layer, an N-type doped polysilicon layer and a second SiNxHy layer are successively provided, from inside to outside, on a back side of the N-type substrate; front-side silver main grids and front-side aluminum fine grids are provided on the first SiNxHy layer, and back-side silver main grids and back-side aluminum fine grids are provided on the second SiNxHy layer;
wherein the method for preparing the N-type TOPCon cell with double-sided aluminum paste electrodes comprises:
texturing→B diffusion→BSG removal→alkali polishing→depositing a tunnel oxide layer and a polysilicon layer on a back side of a substrate by means of LPCVD→P diffusion on the back side of the substrate→PSG removal→plating removal→deposition of an AlOx preparatory layer and a first SiNxHy preparatory layer on a front side of the substrate→deposition of a second SiNxHy preparatory layer on the back side of the substrate→UV laser ablation on the front side of the substrate and the back side of the substrate→screen printing;
wherein the method for preparing the N-type TOPCon cell with double-sided aluminum paste electrodes comprises the following steps:
A, preparation of an N-type double-sided cell before metallization: using an N-type monocrystalline silicon wafer as the substrate, forming the P-type doped region layer on a front side of the N-type monocrystalline silicon wafer successively by means of B diffusion, depositing the AlOx preparatory layer and the first SiNxHy preparatory layer by means of PECVD, successively depositing the tunnel oxide layer and the polysilicon layer on a back side of the N-type monocrystalline silicon wafer by means of LPCVD, forming the N-type doped polysilicon layer by means of P diffusion, and depositing the second SiNxHy preparatory layer by means of PECVD;
B, performing UV laser ablation on a front surface of a preparatory cell prepared by a step A to remove part of passivation dielectric film of the AlOx preparatory layer and the first SiNxHy preparatory layer; and performing UV laser ablation on a back side of the cell prepared by the step A to remove part of passivation dielectric film of the second SiNxHy preparatory layer;
C, using aluminum paste to print and sinter a front surface of a preparatory cell prepared by a step B, so as to form a local contact point H-type front-side aluminum fine grid line electrode, wherein each of the front-side silver main grids is designed in a first segmented structure, the first segmented structure comprises a plurality of first g-id-grid segments, and the front-side silver main grids are distributed in aluminum fine grid lines; a number of the front-side aluminum fine grids is 106-122, each of the front-side aluminum fine grids has a width being 25-40 um and a height being 10-25 um; and each of the plurality of first grid segments of the front-side silver main grids has a length of 2-8 mm, a width of 0.1-2 mm and a height of 4-8 um, and a number of the front-side silver main grids is 5-12; and
D, using weak burn-through type aluminum paste to print and sinter the back side of the preparatory cell prepared by the step B or the step C, so as to form a local contact point H-type back-side aluminum fine grid line electrode, wherein a number of the back-side aluminum fine grids is 110-160, each of the back-side aluminum fine grids has a width being 40-160 um and a height being 10-25 um; and each of the back-side silver main grids are designed in a second segmented structure, and the second segmented structure comprises a plurality of second grid segments; each of the plurality of second segmented structure grid segments has a length of 2-8 mm, a width of 0.1-2 mm and a height of 4-8 um, and a number of the back-side silver main grids is 5-12.