Method for preparing selective emitter by one-time diffusion

An emitter and selective technology, applied in the direction of climate sustainability, final product manufacturing, sustainable manufacturing/processing, etc., can solve the problems of complex process, difficult control, high production cost, etc., and achieve simple process, easy control, low cost effect

Inactive Publication Date: 2010-08-04
TRINA SOLAR CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is: in order to solve the existing method for preparing a selective emitter with complex process, difficult control and high production cost, the present invention provides a method for preparing a selective emitter by one-time diffusion

Method used

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  • Method for preparing selective emitter by one-time diffusion
  • Method for preparing selective emitter by one-time diffusion

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preparation example Construction

[0018] The preparation of the shallow diffusion junction here is to slowly etch the heavy diffusion area with an acid solution or an alkali solution, and the shallow diffusion area 2 is obtained by controlling the concentration ratio, time, and temperature of the acid solution or alkali solution. The acid solution here is HF acid and HNO 3 The mixed solution, in which the concentration of HF acid is 20-150g / l, HNO 3 The concentration is 20-350g / l; the alkali solution is KOH solution or NaOH solution, and the concentration of KOH solution or NaOH solution is 0.1wt%-5wt%; the corrosion time with acid solution or alkali solution is 1-30min, and the temperature is 5-90 ℃. In this way, by controlling the solution ratio, reaction temperature and time, the corrosion rate can be controlled at about 0.1um / min.

[0019] The structure of the selective emitter prepared by this method has no damage on the surface, the surface concentration of the shallow diffusion zone 2 is lower than th...

Embodiment 1

[0021] Select a P-type single-crystal silicon wafer with a crystal plane (100) and a doping concentration of 2.5Ωcm. The surface of the silicon wafer is textured by normal solar cell technology, and then re-diffused to obtain a sheet resistance of 25ohm / Sq. Plating an 80nm SiN film on the surface, and then printing a corrosive slurry on the non-electrode area, after washing off the etch, the concentration ratio is HNO 3 100g / l, 35g / l HF acid solution, the process temperature is 5°C, and the time is 5min. As the process progresses, the heavy diffusion region 1 not covered by the silicon nitride film 3 will be etched slowly. The total etching thickness is 0.6um, and then use 10% HF acid to wash away the SiN shielding film in the electrode area, and then perform other subsequent normal selective diffusion solar cell processes such as anti-reflection film coating, front and back electrode printing and sintering according to the process requirements .

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Abstract

The invention relates to the technical field of production methods of solar cells, in particular to a method for preparing a selective emitter by one-time diffusion, which sequentially comprises the following process steps: making texture on a silicon wafer, carrying out uniform heavy diffusion, depositing silicon nitride film on the surface of the silicon wafer after diffusing, and printing corrosive slurry in a non-metallic electrode region of the silicon wafer so as to etch the silicon nitride film; and finally, etching the silicon in the non-metallic electrode region with an acid solution or alkali solution to obtain a shallow diffusion region, and the electrode region being a heavy diffusion region. The heavy diffusion process can achieve double-sided gettering, the deposition temperature of the silicon nitride film is low, the whole process is simple and easy to control, the surface is not damaged and has no dead layer, and the cost is low.

Description

technical field [0001] The invention relates to the technical field of production methods of solar cells, in particular to a method for preparing a selective emitter by primary diffusion. Background technique [0002] In order to achieve high efficiency of solar cells, researchers from various countries are developing selective emitter solar cells to prepare perfect p-n junctions and ideal contacts, reducing optical loss and electrical loss in the process. [0003] The existing methods for preparing selective emitters are: [0004] (1) Uniform re-diffusion and selective etching on the surface of the silicon wafer. This process includes two processes: 1) uniform re-diffusion on the surface of the silicon wafer, and the junction is relatively deep; 2) the front electrode is screen-printed, and after metallization, a thin layer is etched with plasma in the non-electrode area, and the selective The emitter is also formed. However, plasma etching in this method requires relati...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L31/18
CPCY02P70/50
Inventor 张学玲金浩
Owner TRINA SOLAR CO LTD
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