A solar cell passivation anti-reflection film and a coating process thereof

Abstract

A solar cell passivation antireflection film the anti-reflection film is formed by superposing and combining four silicon nitride films, the silicon nitride film comprises a film layer1, a film layer2, a film layer 3 and a film layer 4 from the inside to the outside, the film layer 1 to the film layer 3 are uniform refractive index film layers, the film layer 4 is a refractive index gradually changed film layer, the gradual changing direction of the film layer 4 is gradually reduced from the inside to the outside. By controlling flow change rate of the ammonia gas and the silane of the film layer 4, the gradually changed film layer is manufactured. At that outermost lay of the antireflection film, a graded-index film layer is arranged, As that incident light enters the film layer and directly contacts the gradually changed film layer, the refraction gradient of the incident light entering the cell sheet is reduced, the light loss caused by the large-angle refraction of the incident light entering the SiNx film is improved, the interface defects between different dielectric layers are overcome, and the absorption of short-wave light is enhanced.

Description

technical field

[0001] The invention relates to a solar cell passivation anti-reflection film and a coating process thereof, belonging to the field of solar cell preparation. Background technique

[0002] At present, in the production and preparation of solar cells, the conventional PECVD coating process is a two-layer film, three-layer film or multi-layer film coating process, which is to deposit three layers of silicon nitride film layers with gradually decreasing refractive index on the surface of the solar cell. The gases used are silane and ammonia. This film layer structure strengthens the surface passivation of the battery to a certain extent, reduces the recombination speed of minority carriers, and enhances the absorption of light after multiple refractions, which has an effect of improving efficiency. With the gradual optimization of crystalline silicon cell technology, especially the gradual increase in diffusion resistance, the conventional two-layer or three-lay...

Examples

Embodiment 1

[0049] Example 1: Step 1: 5 Silicon substrates are kept in a vacuum environment, the coating temperature is maintained at 450°C, silane and ammonia gas are introduced to maintain the pressure of the furnace tube at 1600mTor, the ammonia gas flow rate is 5600 sccm, and the silane flow rate is 1450 sccm. The time is 100s, and the preparation of the film layer 1 is completed.

[0050] Step 2: Keeping the temperature and pressure constant, the flow rate of ammonia gas introduced is 5600 sccm, the flow rate of silane is 1100 sccm, the coating time is 95s, and the preparation of the second film layer is completed.

[0051] Step 3: keep the temperature and pressure constant, the flow rate of ammonia gas introduced is 6300 sccm, the flow rate of silane gas is 780 sccm, the coating time is 136s, and the preparation of the third film layer is completed.

[0052] Step four:

[0053] Preparation process of the last layer of gradient film: keep the coating temperature and pressure constan...

technical field

[0001] The invention relates to a solar cell passivation anti-reflection film and a coating process thereof, belonging to the field of solar cell preparation. Background technique

[0002] At present, in the production and preparation of solar cells, the conventional PECVD coating process is a two-layer film, three-layer film or multi-layer film coating process, which is to deposit three layers of silicon nitride film layers with gradually decreasing refractive index on the surface of the solar cell. The gases used are silane and ammonia. This film layer structure strengthens the surface passivation of the battery to a certain extent, reduces the recombination speed of minority carriers, and enhances the absorption of light after multiple refractions, which has an effect of improving efficiency. With the gradual optimization of crystalline silicon cell technology, especially the gradual increase in diffusion resistance, the conventional two-layer or three-lay...

Examples

Embodiment 1

[0049] Example 1: Step 1: 5 Silicon substrates are kept in a vacuum environment, the coating temperature is maintained at 450°C, silane and ammonia gas are introduced to maintain the pressure of the furnace tube at 1600mTor, the ammonia gas flow rate is 5600 sccm, and the silane flow rate is 1450 sccm. The time is 100s, and the preparation of the film layer 1 is completed.

[0050] Step 2: Keeping the temperature and pressure constant, the flow rate of ammonia gas introduced is 5600 sccm, the flow rate of silane is 1100 sccm, the coating time is 95s, and the preparation of the second film layer is completed.

[0051] Step 3: keep the temperature and pressure constant, the flow rate of ammonia gas introduced is 6300 sccm, the flow rate of silane gas is 780 sccm, the coating time is 136s, and the preparation of the third film layer is completed.

[0052] Step four:

[0053] Preparation process of the last layer of gradient film: keep the coating temperature and pressure constan...

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