Shading layer, composite film layer and preparation method thereof

The invention discloses a light shielding layer, a composite film layer and a preparation method thereof, and relates to the technical field of radioactive element detection.The light shielding layer is prepared on the surface of a cadmium zinc telluride crystal and comprises a plurality of first light shielding layers and second light shielding layers which are alternately stacked, and the density of the first light shielding layers is larger than that of the second light shielding layers; the stress of the second shading layer is smaller than that of the first shading layer. The light shielding layer provided by the invention is formed in a mode of alternately laminating the plurality of first light shielding layers and the plurality of second light shielding layers, so that the stress release of the light shielding layer is realized, and the influence on the density of the light shielding layer is reduced to the minimum, so that the light shielding layer can be prepared under a low-temperature condition to