The invention relates to a back scattering surface of a thin-film
silicon solar cell and a preparation method of the back scattering surface. In the invention, a thin film which is used as the back scattering surface is a
composite film and is compounded by a
metal and an Ag film, wherein the
metal is in direct contact with a substrate and has a shape which is easy to change at a lower temperature; the thickness of the
metal film is in a range of 250-600 nm and the thickness of the Ag film is in a range of 20-50 nm; and the surface of the
composite film is of a rough structure shape with a submicron size. The structure is prepared by adopting a
physical vapor deposition method; in a high-vacuum environment, the method comprises the following steps of: under the condition of heating the substrate, depositing the metal film on the substrate and then depositing the Ag film to form the
composite film; or under the condition of the
room temperature, depositing the metal film on the substrate and then depositing the Ag film to form the composite film; and then carrying out vacuum heat treatment on the deposited composite film at a temperature in a range of 150-250 DEG C. According to the invention, the scattering property of the surface of the formed composite film is great, the temperature for changing the shape of the metal film is lower and the heat treatment temperature for reducing
surface roughening is reduced; meanwhile, the consumption of the
noble metal Ag is reduced and the manufacturing cost is reduced.