The invention discloses a PECVD (
Plasma Enhanced
Chemical Vapor Deposition) process gradient laminated anti-reflection film and a preparation method thereof, and relates to the field of solar cells. The content of PECVD deposition components at the film layer junction of the gradient laminated anti-reflection film is gradually changed. The preparation method comprises the following steps: sequentially depositing the film layer I, the film layer II and the film layer III through a PECVD (
Plasma Enhanced
Chemical Vapor Deposition) method, namely starting
auxiliary heating to preheat the furnace tube, starting vacuumizing, pre-depositing the film layer I, the film layer I, the film layer II and the film layer III, and evacuating residual gas in the furnace tube. Through the gradual change design of the laminated anti-reflection film, the
refractive index between the film
layers is changed in a gradient manner. Therefore, when light enters the
solar cell, smooth transition between different film
layers can be realized, and the
reflection loss of the light is effectively reduced.
Light reflection caused by sudden change of the
refractive index at the junctions of the film
layers made of different materials is avoided, the anti-reflection effect is improved, the light
absorption rate is increased, the short-circuit current and the open-circuit
voltage are increased, and the
photoelectric conversion efficiency is improved.