Laser grooving gate-buried electrode solar cell and method for preparing the same

A technology of solar cells and buried gate electrodes, which is applied in the field of solar cells, can solve the problems of unsatisfactory photoelectric conversion efficiency of solar cells, unsatisfactory passivation effect of solar cells, and low bonding strength between coating and substrate, so as to increase the passivation of front and rear surfaces The effect of improving the conversion efficiency of the battery and reducing the pollution of surface metal impurities

Inactive Publication Date: 2015-04-08
GUANGDONG AIKO SOLAR ENERGY TECH CO LTD
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AI Technical Summary

Problems solved by technology

[0005] However, the passivation effect of the existing laser-grooved buried grid electrode solar cells is not ideal, the surface metal impurities are seriously polluted, the bonding strength between the coating and the substrate is not high, and the reflectivity of the cell surface is high, resulting in low photoelectric conversion efficiency of solar cells. not ideal

Method used

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  • Laser grooving gate-buried electrode solar cell and method for preparing the same
  • Laser grooving gate-buried electrode solar cell and method for preparing the same

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preparation example Construction

[0041] see figure 1 , the invention provides a method for preparing a solar cell with a laser-grooved buried gate electrode, comprising:

[0042] S101. Texturing the silicon wafer with an alkaline solution

[0043] Since the reaction between alkaline solution and silicon (Si) will form anisotropic corrosion, the present invention uses alkaline solution to make texture with the following advantages: use the anisotropic physical properties of the single crystal structure to participate in the reaction to form a uniform low reflection Ratio textured pyramid-like surface topography greatly reduces photon reflection and increases light absorption.

[0044] The existing method of making texture is acid texture, the disadvantage is that the reflectivity is high and the uniformity of the texture is poor.

[0045] Preferably, the alkaline solution is NaOH, Na 2 SiO 4 and IPA mixed solution, NaOH : Na 2 SiO 4 : IPA = 1: 1-2 : 1-2, the texturing temperature is 80-90℃.

[0046] I...

Embodiment 1

[0099] P-type silicon with NaOH, Na 2 SiO 4 and IPA mixed solution (NaOH : Na 2 SiO 4 : IPA = 1: 1 : 1) Carry out texturing at 80°C;

[0100] Phosphorus oxychloride is used for light phosphorus diffusion on silicon wafers to form an N+ layer;

[0101] Use oxygen with a purity of 99% to form a thermal oxidation passivation film with a thickness of 15nm at a reaction temperature of 750°C;

[0102] Use Nd:YAG laser for slotting, the wavelength of the laser is 532nm, to obtain rectangular slots with a width of 25nm, a depth of 35um, and a spacing of 1mm;

[0103] Use a mixed solution of hydrofluoric acid and nitric acid (hydrofluoric acid: nitric acid = 1:2) to etch the slot holes at 25°C;

[0104] The wells are cleaned, including with SPM solution (H 2 SiO 4 :H 2 o 2 =3:1) for the first cleaning at a temperature of 100°C, with DHF solution (HF: H 2 O=1:90) at room temperature for the second wash with APM solution (NH 4 OH:H 2 o 2 :H 2 O=1: 1:5) for the third clean...

Embodiment 2

[0114] P-type silicon with NaOH, Na 2 SiO 4 and IPA mixed solution (NaOH : Na 2 SiO 4 : IPA = 1: 1.5 : 1.5) Carry out texturing at 85°C;

[0115] Phosphorus oxychloride is used for light phosphorus diffusion on silicon wafers to form an N+ layer;

[0116] Use oxygen with a purity of 99.9995% to form a thermal oxidation passivation film with a thickness of 20nm at a reaction temperature of 850°C;

[0117] Use Nd:YAG laser for slotting, the wavelength of the laser is 532nm, and a rectangular slot with a width of 30nm, a depth of 40um, and a spacing of 1.5mm is obtained;

[0118] Use a mixed solution of hydrofluoric acid and nitric acid (hydrofluoric acid: nitric acid = 1:2.5) to etch the slot holes at 30°C;

[0119] The wells are cleaned, including with SPM solution (H 2 SiO 4 :H 2 o 2 =4:1) for the first cleaning at a temperature of 110°C, with DHF solution (HF: H 2 O=1:100) at room temperature for the second wash with APM solution (NH 4 OH:H 2 o 2 :H 2 O=1: 1:4...

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Abstract

The present invention discloses a method for preparing a laser grooving gate-buried electrode solar cell, comprising: a) texturing a silicon wafer by an alkaline solution; b) performing light phosphorous diffusion to form a N+ layer; c) generating a thermal oxidation passivated film; d) grooving by a laser so as to obtain a slot; e) etching the slot; f) cleaning the slot; g) performing heavy phosphorous diffusion to form a N++ layer; h) evaporating and plating an aluminum film on the back surface; i) sintering the back surface to form an electric field; j) chemically plating silver to bury a gate; k) making a back electrode; l) evaporating and plating two antireflection layers on the front surface, the two antireflection layers comprising an MgF2 layer and a ZnS layer; m) acid etching to remove the edge; and n) sintering at a high temperature to form a laser grooving gate-buried electrode solar cell. Accordingly, the present invention further provides a laser grooving gate-buried electrode solar cell prepared by the aforementioned preparation method. The method of the present invention can simultaneously achieve the purposes of improving the passivation effect for the front and back surface, reducing contamination of the surfaces caused by metallic impurities, improving the bonding strength between the plated layers and the substrate and greatly decreasing the reflectance and the like.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to a solar cell with a laser-grooved buried grid electrode and a preparation method thereof. Background technique [0002] A solar cell is a device that effectively absorbs solar radiation energy and uses the photovoltaic effect to convert light energy into electrical energy. When sunlight shines on a semiconductor P-N junction (P-N Junction), a new hole-electron pair (V-E pair) is formed. , Under the action of the P-N junction electric field, holes flow from the N region to the P region, electrons flow from the P region to the N region, and a current is formed after the circuit is turned on. Because it is a solid semiconductor device that converts sunlight energy into electrical energy by using the photovoltaic effect of various potential barriers, it is also called a solar cell or a photovoltaic cell, and is an important component of a solar array power system. Solar cells ma...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L31/0224H01L31/18
CPCH01L31/02167H01L31/02168H01L31/022433H01L31/18Y02E10/50Y02P70/50
Inventor 秦崇德方结彬石强黄玉平何达能
Owner GUANGDONG AIKO SOLAR ENERGY TECH CO LTD
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