CN-122002965-A - Solar cell, preparation method thereof and photovoltaic module

CN122002965ACN 122002965 ACN122002965 ACN 122002965ACN-122002965-A

Abstract

The invention relates to the technical field of batteries, and discloses a solar cell, a preparation method thereof and a photovoltaic module. The solar cell comprises a silicon substrate, a passivation contact structure arranged on the silicon substrate, wherein the passivation contact structure comprises a first dielectric layer, a nano silicon layer, a second dielectric layer, a first doped layer, a first functional layer and a first electrode which are sequentially arranged, the nano silicon layer is arranged to improve light absorption, enhance passivation effect and enhance blocking effect on diffusion of doped elements in the first doped layer to the silicon substrate, and the stacked structure formed by the first dielectric layer, the nano silicon layer and the second dielectric layer is sequentially arranged to play a role of double-layer protection, so that the depth and the concentration of diffusion of the doped elements in the first doped layer to the silicon substrate are reduced, the situation that the dielectric layer or the position with thinner local thickness of the first doped layer is burnt through by slurry is effectively avoided, the proportion of bright and dark sheets in luminescence detection is reduced, and the product yield and the product efficiency are improved.

Inventors

ZHAO YANLI
ZHANG WEIYANG
WANG PAN
LI CHEN
SHEN XIN
ZHANG HUACAN
TAO LINGLING

Assignees

通威太阳能（成都）有限公司

Dates

Publication Date: 20260508
Application Date: 20241108

Claims (10)

1. A solar cell includes a silicon substrate having a first conductivity type doping; A passivation contact structure disposed on the first surface of the silicon substrate, The passivation contact structure comprises a first dielectric layer, a nano silicon layer, a second dielectric layer, a first doping layer, a first functional layer and a first electrode which are sequentially arranged from the first surface of the silicon substrate towards one side far away from the silicon substrate, wherein the conductivity type of the first doping layer is the same as or opposite to that of the silicon substrate, and the conductivity type of the nano silicon layer is the same as that of the first doping layer.
2. The solar cell according to claim 1, wherein the thickness of the nano-silicon layer is 5 nm-7 nm, and/or the thickness uniformity of the nano-silicon layer is within 3%.
3. The solar cell according to claim 1, wherein the sheet resistance of the first doped layer is 43-47 Ω/sq and/or the sheet resistance of the first doped layer is within 5%.
4. The solar cell of claim 3, wherein the first doped layer comprises a first doped sub-layer arranged on one side of the second dielectric layer away from the nano-silicon layer and a second doped sub-layer arranged on one side of the first doped layer away from the second dielectric layer, the thickness of the first doped sub-layer is 40 nm-50 nm, and the thickness of the second doped sub-layer is 60 nm-80 nm.
5. The solar cell of claim 4, wherein a doping concentration of the second doped sub-layer is greater than a doping concentration of the first doped sub-layer.
6. The solar cell according to claim 5, wherein the first doped sub-layer has a doping concentration of 3e19cm -3 ～4e19cm -3 and the second doped sub-layer has a doping concentration of 4e21cm -3 ～5e21cm -3 .
7. The solar cell of claim 1, wherein the first conductivity type is N-type or P-type; And/or the thickness of the first dielectric layer and the thickness of the second dielectric layer are 1 nm-2 nm, and the thickness uniformity of the first dielectric layer and the thickness uniformity of the second dielectric layer are within 3%; And/or the solar cell further comprises an emitter layer, a passivation layer, a second functional layer and a second electrode which are sequentially arranged from the second surface of the silicon substrate towards one side far away from the silicon substrate, wherein the conductivity type of the emitter layer is opposite to that of the first doped layer, and the second surface is opposite to the first surface.
8. A method of manufacturing a solar cell according to any one of claims 1 to 7, comprising: depositing a first dielectric layer on a first surface of a silicon substrate; depositing a nano silicon layer on one side of the first dielectric layer far away from the silicon substrate; Depositing a second dielectric layer on one side of the nano silicon layer far away from the silicon substrate; depositing a first doping layer on one side of the second dielectric layer away from the silicon substrate; depositing a first functional layer on a side of the first doped layer away from the silicon substrate; and manufacturing a first electrode on one side of the first functional layer far away from the silicon substrate.
9. The method for preparing the solar cell according to claim 8, wherein the nano silicon layer is prepared by a plasma enhanced chemical vapor deposition method or a low pressure chemical vapor deposition method or a laser induced vapor deposition method or an atomic layer deposition method; and/or, depositing a first doped layer on the side of the second dielectric layer away from the silicon substrate, including: Depositing a first doped sub-layer on one side of the second dielectric layer away from the silicon substrate; depositing a second doped sub-layer on a side of the first doped sub-layer away from the silicon substrate; and/or, the preparation method further comprises: texturing is carried out on the second surface of the silicon substrate to form the silicon substrate with a textured structure on the second surface, wherein the second surface is opposite to the first surface; fabricating an emitter layer on the second surface of the silicon substrate; Depositing a passivation layer on a side of the emitter layer away from the silicon substrate; depositing a second functional layer on the side of the passivation layer away from the silicon substrate; manufacturing a second electrode on one side of the second functional layer far away from the silicon substrate; and/or, the preparation method further comprises: And sintering the solar cell to diffuse the doping elements in the first doping layer to the nano silicon layer.
10. A photovoltaic module comprising a solar cell according to any one of claims 1-7.

Description

Solar cell, preparation method thereof and photovoltaic module Technical Field The invention relates to the technical field of batteries, in particular to a solar battery, a preparation method thereof and a photovoltaic module. Background The passivation contact cell is a solar cell using an ultrathin oxide layer as a passivation layer structure. Compared with the PERC (PASSIVATED EMITTER AND REAR CELL, emitter back passivation) battery of the previous generation, the passivation contact battery takes an N-type silicon wafer as a substrate, a tunneling oxide layer is added on the back surface and a doped polysilicon layer is deposited, so that the passivation path is changed, carriers can be separated and transported without opening holes, carrier selective passivation contact is realized, the recombination or loss at the contact position of a back metal electrode and a crystalline silicon wafer is reduced to the greatest extent, and the conversion efficiency is improved. At present, because the manufacturing equipment of the tunneling oxide layer and the doped polysilicon layer is in a starting stage, the prepared tunneling oxide layer and doped polysilicon layer have the problems of poor film forming compactness, uneven film thickness and the like, and the local thin position of the tunneling oxide layer or the doped polysilicon layer causes the problems of slurry burning and phosphor internal expansion, so that the passivation performance of the tunneling oxide layer or the doped polysilicon layer is lost, a large amount of uneven light and shade phenomena of luminescence detection occur, and the yield and efficiency are reduced. Disclosure of Invention The invention provides a solar cell, a preparation method thereof and a photovoltaic module, which can solve the problem that a part of a dielectric layer or a doped layer is easy to burn through by slurry and the problem that doped elements in the doped layer are internally expanded, thereby reducing the proportion of bright and dark pieces in luminescence detection and improving the yield and efficiency of products. In order to solve the technical problems, the invention adopts a technical scheme that the solar cell comprises a silicon substrate, a silicon electrode and a silicon electrode, wherein the silicon substrate is provided with first conductivity type doping; A passivation contact structure disposed on the first surface of the silicon substrate, The passivation contact structure comprises a first dielectric layer, a nano silicon layer, a second dielectric layer, a first doping layer, a first functional layer and a first electrode which are sequentially arranged from the first surface of the silicon substrate towards one side far away from the silicon substrate, wherein the conductivity type of the first doping layer is the same as or opposite to that of the silicon substrate, and the conductivity type of the nano silicon layer is the same as that of the first doping layer. Optionally, the thickness of the nano silicon layer is 5 nm-7 nm, and/or the thickness uniformity of the nano silicon layer is within 3%. Optionally, the sheet resistance value of the first doped layer is 43-47 Ω/sq, and/or the sheet resistance uniformity of the first doped layer is within 5%. Optionally, the first doped layer includes a first doped sub-layer disposed on a side of the second dielectric layer away from the nano silicon layer, and a second doped sub-layer disposed on a side of the first doped layer away from the second dielectric layer, where the thickness of the first doped sub-layer is 40 nm-50 nm, and the thickness of the second doped sub-layer is 60 nm-80 nm. Optionally, the doping concentration of the second doped sub-layer is greater than the doping concentration of the first doped sub-layer. Optionally, the doping concentration of the first doping sub-layer is 3e19cm -3～4e19cm-3, and the doping concentration of the second doping sub-layer is 4e21cm -3～5e21cm-3. Optionally, the first conductivity type is N-type or P-type; And/or the thickness of the first dielectric layer and the thickness of the second dielectric layer are 1 nm-2 nm, and the thickness uniformity of the first dielectric layer and the thickness uniformity of the second dielectric layer are within 3%; And/or the solar cell further comprises an emitter layer, a passivation layer, a second functional layer and a second electrode which are sequentially arranged from the second surface of the silicon substrate towards one side far away from the silicon substrate, wherein the conductivity type of the emitter layer is opposite to that of the first doped layer, and the second surface is opposite to the first surface. In order to solve the technical problems, the invention adopts another technical scheme that the preparation method of the solar cell comprises the following steps: depositing a first dielectric layer on a first surface of a silicon substrate; depositing a nano silicon layer on one si