Novel P-type crystalline silicon cell back contact passivation preparation process

Abstract

The invention relates to the field of solar cell production. A novel P-type crystalline silicon cell back contact passivation preparation process comprises the steps: after laser grooving is conductedon the back face, in the process of preparing a boron heavily-doped layer through a back electrode and preparing the boron heavily-doped layer through the back electrode in a thermal diffusion mode,introducing N2 at the flow of 10 slm, increasing the temperature to 900 DEG C, and waiting for 5 min; carrying BBr3 in nitrogen under the condition that the flow of the nitrogen is kept unchanged, enabling the flow of the BBr3 to be 200-400 sccm, introducing 150-300 sccm of O2 while introducing the BBr3, and carrying out constant-rate variable-temperature deposition for 5-10min at the temperatureof 900-960 DEG C; after the temperature rises to 960 DEG C, introducing 610 slm of N2 and 46 slm of O2, and performing high-temperature propelling, wherein the time is 35 min; and finally, introducing10 slm of N2, performing cooling and withdrawing the boat at the temperature of 960-840 DEG C.

Description

technical field [0001] The invention relates to the field of solar cell production. Background technique [0002] Cells with PERC and PERL structures already have a relatively complete surface passivation structure, but the contact range on the back is limited to the opening area. In addition to increasing the complexity of the process, the opening process uses different processes and will also affect the surrounding area. The silicon material causes varying degrees of damage, which additionally increases the recombination of the metal contact area. Since the opening restricts the transport path of carriers, it deviates from the shortest path perpendicular to the contact surface and congests at the opening, which increases the loss of fill factor. Is there a way to reduce surface recombination without opening holes? This requires mentioning the Passivated Contact technology that has been in high demand in recent years. [0003] The advantages of back passivation contact s...

AI Technical Summary

Problems solved by technology

[0002] Cells with PERC and PERL structures already have a relatively complete surface passivation structure, but the contact range on the back is limited to the opening area. In addition to increasing the complexity of the process, the opening process uses different processes and will also affect the surrounding area. The silicon material causes varying degrees of damage, which additionally increases the recombination of the metal contact area

Since the opening restricts the transport path of carriers, it deviates from the shortest path perpendicular to the contact surface and congests at the opening, which increases the loss of fill factor

Is there a way to reduce surface recombination without opening holes?

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