Multi-layer SiN for functional and optical graded ARC layers on crystalline solar cells

Abstract

Embodiments of the invention include a solar cell and methods of forming a solar cell. Specifically, the methods may be used to form a passivation / anti-reflection layer having combined functional and optical gradient properties on a solar cell substrate. The methods may include flowing a first process gas mixture into a process volume within a processing chamber generating plasma in the processing chamber at a power density of greater than 0.65 W / cm2 depositing a silicon nitride-containing interface sub-layer on a solar cell substrate in the process volume, flowing a second process gas mixture into the process volume, and depositing a silicon nitride-containing bulk sub-layer on the silicon nitride-containing interface sub-layer.

Description

technical field [0001] Embodiments of the invention relate generally to the fabrication of solar cells, and in particular to the passivation of silicon solar cells. Background technique [0002] Solar cells are photovoltaic modules that convert sunlight directly into electricity. The most common solar cell material is silicon (Si), in the form of single crystal, polycrystalline, polycrystalline substrate or amorphous film. Efforts are being made to reduce the cost of manufacturing solar cells and the cost of the resulting cells, while maintaining or increasing the overall efficiency of the solar cells produced. [0003] The efficiency of solar cells can be enhanced by using a passivation layer that also acts as an anti-reflective coating (ARC) on the emitter region in the silicon substrate forming the solar cell. When light passes from one medium to another (such as from air to glass or from glass to silicon), some light rays may reflect from the interface between the two ...

AI Technical Summary

Problems solved by technology

Large grains and the resulting long grain boundaries create a pathway for contaminants to enter the silicon through the passivation film, leading to cell failure

Therefore, higher deposition rates for producing larger quantities of solar cells per unit of time (these deposition rates can be used for plasma deposition processes) result in larger grains and thus pinholes

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