Excessive-plating prevention dual-layer thin film as well as preparation method and application thereof

Abstract

The invention discloses an excessive-plating prevention dual-layer thin film which is characterized in that: one layer adjacent to the front surface of a silicon substrate is a silicon oxide or silicon nitride thin layer; and a layer above the silicon oxide or silicon nitride thin layer is a carbon-containing silicon-oxygen compound thin layer, wherein the carbon atom content in the carbon-containing silicon-oxygen compound thin layer is 5-10%, the refraction coefficient is 1.3-1.4, and the thickness is 20-200 nm. A preparation method of the dual-layer thin film comprises the following steps:depositing a silicon oxide or silicon nitride thin layer on the front surface of the cleaned silicon substrate; spraying or spinning a polysiloxane-based dielectric solution on the thin layer; and annealing to obtain the dual-layer thin film. A silicon solar cell comprising the dual-layer thin film is sequentially provided with a dual-layer thin film, a front electrode, an n<+> emitter, a p-type silicon area, a local back electric field p<+> and a back electrode downward from a sunlight irradiation surface, namely the front surface.

Description

technical field [0001] The invention relates to the technical field of solar energy, in particular to a thin film preventing overplating, a preparation method thereof and an applied silicon solar cell. Background technique [0002] "Overplating" means electroplating metal where it is not desired to be present. For solar cells that require selective plating, overplating has a great influence on their performance. On the one hand, depositing metal on other non-metal deposition areas will lead to an increase in metal shading, thereby reducing the amount of light entering the solar cell; on the other hand, overplating will lead to electrical short circuits and other problems. Overplating can also lead to waste of electroplating materials, especially for electroplating substances that are some special materials, such as precious metals Ag, Au, etc., resulting in an increase in the production cost of solar cells. [0003] Many conventional selective platings require multiple ste...

AI Technical Summary

Problems solved by technology

In these structures, the fundamental purpose is to realize the function of the double-layer anti-reflection film, and does not involve the content of preventing solar cells from overplating; It is etched by HF solution or other solutions containing F ions, which will cause the oxide layer to be corroded quickly or expose defects in the film: pinholes, cracks, etc., so it cannot meet the needs of those who need HF before preparing electrodes. Solution or other etching process requirements containing F ion solution can not achieve the purpose of preventing overplating, and at the same time the characteristics of its double-layer anti-reflection film will also disappear.

Many conventional masking methods or methods of processing silicon nitride films are not suitable, especially where HF or F ion etching is required on the front surface of the solar cell prior to metal deposition

However, there is no suitable method for the treatment of the battery after forming the overplating so that it can meet the requirements of commercialization.

Images