Polycrystalline solar cell and preparation method and application thereof

The invention provides a polycrystalline solar cell and a preparation method and application thereof. The polycrystalline solar cell comprises a silicon wafer and a laminated silicon nitride film arranged on the surface of the silicon wafer, the laminated silicon nitride film comprises a first silicon nitride layer arranged on the surface of the silicon wafer and a second silicon nitride layer arranged on the surface of the first silicon nitride layer, the refractive index of the first silicon nitride layer is 2.3-2.4, and the refractive index of the second silicon nitride layer is 2.3-2.4. And the refractive index of the second silicon nitride layer is 2.1 to 2.15. When being used for a solar cell, the film can solve the problems that the appearance difference is large after texturing, the textured surface is difficult to control, and the gray and bluing at the component end after film coating are serious. The invention also provides a preparation method and application of the polycrystalline solar cell. 本发明