阅读说明：本技术 一种改善异质结太阳电池光电性能的方法 (Method for improving photoelectric performance of heterojunction solar cell ) 是由 俞健 李君君 何佳龙 李兵川 陈涛 黄跃龙 于 2019-11-14 设计创作，主要内容包括：本发明公开一种改善异质结太阳电池光电性能的方法,所述覆盖层具有表面减反射、载流子传导、电极选择性沉积掩膜之功能,步骤如下：(a)制备异质结太阳电池衬底；(b)沉积金属种子层栅极；(c)非栅极区域沉积覆盖层；(d)烘干覆盖层；(e)栅极区域电化学沉积金属电极；(f)覆盖层后处理；(g)烘干覆盖层。本发明所述之方法,能显著降低电化学沉积金属电极工艺复杂性,所用之聚合物覆盖层,处理后光电性能显著提高,亦可作为异质结太阳电池的透明导电薄膜,此方法既避免了常规异质结太阳电池电化学沉积电极去除掩膜的工艺,也可少用或不用透明导电薄膜,有利于提高异质结太阳电池转换效率、降低生产成本,在工业化生产中优势显著。(The invention discloses a method for improving the photoelectric property of a heterojunction solar cell, wherein a covering layer has the functions of surface antireflection, carrier conduction and electrode selective deposition masking, and the method comprises the following steps: (a) preparing a heterojunction solar cell substrate; (b) depositing a metal seed layer grid; (c) depositing a covering layer in the non-grid region; (d) drying the covering layer; (e) electrochemically depositing a metal electrode in the gate region; (f) post-treating the covering layer; (g) and drying the covering layer. The method can obviously reduce the complexity of the electrochemical deposition metal electrode process, the used polymer covering layer can obviously improve the photoelectric property after treatment, and can also be used as a transparent conductive film of the heterojunction solar cell.)

1. A method for improving the photoelectric property of a heterojunction solar cell is characterized by comprising the following steps:

(a) preparing a heterojunction (SHJ) solar cell substrate;

(b) depositing a metal seed layer;

(c) depositing a covering layer in the non-grid region;

(d) drying the covering layer;

(e) electrochemically depositing a metal electrode in the gate region;

(f) post-treating the cover layer;

(g) and drying the covering layer.

2. The method according to claim 1, wherein the method comprises the following steps: the material composition of the covering layer contains polymer, organic solvent and conductive particles.

3. The method according to claim 1, wherein the method comprises the following steps: in the step (c), the method for preparing the cover layer may include one or more of photolithography, inkjet printing, spin coating, screen printing, dry film lamination, slit spraying, plasma etching, laser ablation, and the like.

4. The method according to claim 1, wherein the method comprises the following steps: in the step (d), the temperature for drying the covering layer is 50-300 ℃; the time is 1min to 60 min; the drying atmosphere is air, oxygen, nitrogen, argon or nitrogen-hydrogen mixed gas.

5. The method according to claim 1, wherein the method comprises the following steps: after said step (d), the thickness of the cover layer is 0.05 μm to 50 μm.

6. The method according to claim 1, wherein the method comprises the following steps: in the step (e), the electrode preparation method may include one or more of electroplating, electroless plating, light-induced electroplating, inkjet printing, screen printing, dispensing, and the like.

7. The method according to claim 1, wherein the method comprises the following steps: in the step (f), the method for post-treating the coating layer may include one or more of anhydrous ethanol post-treatment, acetone post-treatment, isopropyl alcohol post-treatment, vinyl glycol post-treatment, glyceryl monostearate post-treatment, diethylene glycol monomethyl ether post-treatment, dimethyl sulfoxide post-treatment, chlorobenzene post-treatment, methanol post-treatment, formic acid post-treatment, xylene post-treatment, sulfuric acid post-treatment, hydrochloric acid post-treatment and the like; the post-treatment time is 1 min-20 min; the post-treatment temperature is 10-80 ℃.

8. The method of claim 2, wherein the method comprises: the covering layer has the functions of surface antireflection, carrier conduction and electrode selective deposition masking, and is made of one or a combination of a plurality of poly (3, 4-ethylenedioxythiophene) -polystyrene sulfonic acid or polyethylene terephthalate or polyethylene or polyvinyl chloride or polyimide or polymethyl methacrylate, metal nano-particles or nano-wires, polythiophene and polyanion compounds.

9. The method of claim 2, wherein the method comprises: the conductivity of the covering layer before post-treatment is not more than 10S/cm; the conductivity of the covering layer after post-treatment is more than 500S/cm.

Technical Field

The invention belongs to the technical field of heterojunction solar cells, and relates to a method for improving the photoelectric property of a heterojunction solar cell.

Background

The principle of the solar cell is a device for directly converting solar energy into electric energy based on the photovoltaic effect, and is also an important component in the practical application of solar energy. At present, crystalline silicon solar cells become the mainstream of the photovoltaic industry, more than 80% of crystalline silicon solar cells are on the market, and the further development of the crystalline silicon solar cells is restricted by the higher cost, the complex process flow, the low overall conversion efficiency, the poor high-temperature performance, the light-induced attenuation and the like in the production of the monocrystalline silicon.

The heterojunction solar cell is characterized in that intrinsic amorphous silicon thin films are sequentially deposited on two sides of an n-type or p-type monocrystalline silicon substrate to serve as passivation layers, and dangling bonds generated due to abrupt cut-off of crystal lattices on the surface of saturated monocrystalline silicon are used for reducing carrier recombination centers. The n-type amorphous silicon film and the p-type amorphous silicon film are sequentially deposited to serve as an emitter and a back surface electric field, in order to form a built-in electric field and generate a charge separation field, open-circuit voltage, a filling factor and conversion efficiency can be effectively improved, the cell not only utilizes the manufacturing process of a thin film cell, but also fully exerts the material characteristics of crystalline silicon and amorphous silicon, has the advantages of high conversion efficiency (about 27 percent at present), low-temperature process, double-sided power generation, high conversion efficiency (industrialization) which is more than or equal to 23 percent and the like, and becomes a hotspot for the development of solar cells.

Due to the excellent conductivity of a transparent conductive thin film (TCO) of a heterojunction (SHJ) solar cell, the electroplating selectivity of the SHJ solar cell is extremely poor, and a mask process is required to prepare an electrode. Common patterning mask techniques include photolithography, screen printing, and the like. The photolithography process can obtain a minute and precise pattern (the line width is generally hundreds of microns to tens of microns), but the photolithography process has a small area and a complex process, and comprises the steps of surface cleaning, spin coating of photoresist, pre-baking, alignment exposure, post-baking, developing, hard baking, photoresist removal and the like. The screen printing technique can print a patterned mask paste on a general solar cell area (156mm × 156mm), but the pattern size and accuracy are limited by the screen printing technique, and the line width size is typically several tens to several hundreds of micrometers. However, the above processes all require a step of removing the mask at a later stage, and the processes are complicated. The invention provides a method for improving the photoelectric property of a heterojunction solar cell, which can obviously reduce the complexity of the process of electrochemically depositing a metal electrode, the used polymer covering layer has excellent photoelectric property after treatment and can further exist as a transparent conductive thin film layer of the heterojunction solar cell.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for improving the photoelectric performance of a heterojunction solar cell.

In order to solve the technical problems, the technical scheme of the invention is as follows: a method for improving the photoelectric property of a heterojunction solar cell comprises the following steps:

(a) preparing a heterojunction (SHJ) solar cell substrate;

(b) depositing a metal seed layer grid;

(c) depositing a covering layer in the non-grid region;

(d) drying the covering layer;

(e) electrochemically depositing a metal electrode in the gate region;

(f) post-treating the covering layer;

(g) and drying the covering layer.

Furthermore, the material composition of the covering layer contains polymer, organic solvent and conductive particles.

Further, in the step (c), the method for preparing the cover layer may include one or more of photolithography, inkjet printing, spin coating, screen printing, dry film lamination, slit spraying, plasma etching, laser ablation, and the like.

Further, in the step (d), the temperature for drying the covering layer is 50-300 ℃; the time is 1min to 60 min; the drying atmosphere is air, oxygen, nitrogen, argon or nitrogen-hydrogen mixed gas.

Further, after the step (d), the thickness of the covering layer is 0.05 μm to 5 μm.

Further, in the step (3), the electrode preparation method may include one or more of electroplating, electroless plating, light-induced electroplating, inkjet printing, screen printing, dispensing, and the like.

Further, in the step (f), the method for post-treating the coating layer may include one or more of anhydrous ethanol post-treatment, acetone post-treatment, isopropyl alcohol post-treatment, vinyl glycol post-treatment, glyceryl monostearate post-treatment, diethylene glycol methyl ether post-treatment, dimethyl sulfoxide post-treatment, chlorobenzene post-treatment, methanol post-treatment, formic acid post-treatment, xylene post-treatment, sulfuric acid post-treatment, hydrochloric acid post-treatment, and the like; the post-treatment time is 1 min-80 min; the post-treatment temperature is 10-80 ℃.

Further, in the step (g), the cover layer has functions of surface antireflection, carrier conduction, and electrode selective deposition masking, and is made of one or more of poly (3, 4-ethylenedioxythiophene) -polystyrene sulfonic acid, polyethylene terephthalate, polyethylene, polyvinyl chloride, polyimide, polymethyl methacrylate, metal nanoparticles, nanowires, polythiophene, and polyanion.

Further, after the above step, the conductivity of the coating before post-treatment is not more than 10S/cm; the conductivity of the covering layer after post-treatment is more than 500S/cm.

After the technical scheme is adopted, compared with the traditional mask method, the method has simpler process steps; in addition, the process and material cost for coating the mask layer are very low, and the covering layer with excellent photoelectric property can be obtained by matching with the post-treatment step and further exists as the transparent conductive film layer of the heterojunction solar cell (SHJ).

Drawings

FIG. 1 is a schematic structural diagram of an SHJ solar cell employing the method;

fig. 2 is a process flow of the SHJ solar cell based on the method:

(a) an SHJ solar cell substrate;

(b) depositing a metal seed layer grid;

(c) depositing a covering layer in the non-grid region;

(d) electrochemically depositing a copper electrode in the gate region;

(e) electrochemically depositing tin in the gate region;

(f) post-treating the covering layer;

FIG. 3 is a schematic representation of the overburden before and after treatment:

(a) is shown before the cover layer is post-treated;

(b) shown after the cover layer is post-processed.

Detailed Description

In order that the contents of the present invention will be more clearly understood, the present invention will be described in further detail below with reference to embodiments in conjunction with the accompanying drawings.

As shown in fig. 1, the method for improving the photoelectric performance of the heterojunction solar cell of the present invention comprises the following steps:

(a) carrying out damage removal and surface texturing on the N-type monocrystalline silicon substrate layer;

(b) depositing intrinsic amorphous silicon thin films on both sides of the N-type monocrystalline silicon substrate layer;

(c) depositing a P-type amorphous silicon film and an N-type amorphous silicon film on the surfaces of the two deposited intrinsic amorphous silicon films respectively;

(d) depositing a tin-doped indium oxide transparent conductive film on the surface of the P-type amorphous silicon film;

(e) depositing a tin-doped indium oxide transparent conductive film on the surface of the N-type amorphous silicon film;

the tin-doped indium oxide transparent conductive film in the steps (d) and (e) can be prepared by methods such as PECVD, PVD, RPD (reactive plasma deposition) and the like, and the thickness is 1 nm-1000 nm;

(f) depositing a metal seed layer grid on the surface of the tin-doped indium oxide transparent conductive film, wherein the thickness is 1-100 nm;

(g) and preparing a covering layer material in the non-grid region according to a designed pattern, wherein the method for preparing the covering layer can comprise one or more of photoetching, ink-jet printing, spin coating, screen printing, dry film lamination, slit spraying, plasma etching, laser ablation and the like.

(h) Then drying is carried out, and the drying temperature is between 50 and 300 ℃; the time is 1min to 60 min; the drying atmosphere is air, oxygen, nitrogen, argon or nitrogen-hydrogen mixed gas; the thickness of the covering layer is 0.05-5 μm; as shown in fig. 3(a), the obtained covering layer has an electrical conductivity of not more than 10S/cm;

(i) and sequentially preparing Cu as a metal conducting layer and Sn as a protective layer on two sides of the grid of the metal seed layer, wherein the preparation method can comprise one or more of electroplating, chemical plating, light-induced electroplating, ink-jet printing, screen printing, dispensing and the like.

(j) (ii) after step (i), subjecting the cover layer to post-treatment, wherein the post-treatment method may comprise one or more of anhydrous ethanol post-treatment, acetone post-treatment, isopropanol post-treatment, vinyl glycol post-treatment, glyceryl monostearate post-treatment, diethylene glycol monomethyl ether post-treatment, dimethyl sulfoxide post-treatment, chlorobenzene post-treatment, methanol post-treatment, formic acid post-treatment, xylene post-treatment, sulfuric acid post-treatment, hydrochloric acid post-treatment and the like; the post-treatment time is 1 min-80 min; the post-treatment temperature is 10-80 ℃; as shown in FIG. 3(b), the resulting coating had a conductivity of greater than 500S/cm.

The covering layer with excellent photoelectric performance is obtained through the steps and can further exist as a transparent conductive thin film layer of the heterojunction solar cell, the method avoids the process of removing the mask of the electrochemical deposition electrode of the conventional heterojunction solar cell, the deposition thickness of the transparent conductive thin film can be reduced, the conversion efficiency of the heterojunction solar cell is improved, the production cost is reduced, and the method has obvious advantages in industrial scale production.

The above embodiments are described in further detail to solve the technical problems, technical solutions and advantages of the present invention, and it should be understood that the above embodiments are only examples of the present invention and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.