NOVELTY - Integrating light-trapping layer to thin-film solar cell involves obtaining substrate (10) and obtaining metal back reflector layer (11) and first transparent conductive oxide (TCO) layer (12) on substrate; obtaining first absorption layer (13) on first TCO layer through plasma process; obtaining second TCO layer (14) on first absorption layer by using mask; obtaining plasmonic nanostructured layer (15) on second TCO layer, where plasmonic nanostructured layer comprises nano-particles; obtaining third TCO layer (16) on the nanostructured layer by using mask; etching the absorption layer.    USE - For integrating a light-trapping layer to thin-film solar cell (claimed); used as light-inlet layer of silicon thin-film solar cell.    ADVANTAGE - The method provides good light-trapping effect under a best surface coverage ratio of nano-particles, and further enhances photocurrent density of a solar cell. The present method can be applied as a light-inlet layer of a Si thin-film solar cell, which has a gradient reflective structure for enhancing anti-reflective effect to inlet light; a periodic rough-surface structure for obtaining evanescent wave of surface plasmon at a transverse direction and increasing staying time of light in an absorption layer; has good integrity of all components; and a good reliability for long-time light-shining. Thus, the present method uses a composite light-trapping nano-material, where size and color of nano-particles and dielectric effects of TCO films are adjusted to change absorption bandwidth to an absorption layer for enhancing usage of the whole light bandwidths. Besides, the composite light-trapping nano-material decreases defects of interface between the absorption layer and the nano-material for improving electrical characteristics, decreasing pollution during fabricating nano-particles and integrating nano-particles into a thin-film solar cell as a light-inlet layer, an intermediate layer and a shaded layer. Thus, integrity and conversion ratio of a thin-film solar cell are effectively enhanced.    DETAILED DESCRIPTION - Integrating a light-trapping layer to a thin-film solar cell, involves (a) obtaining a substrate (10) and further obtaining a metal back reflector layer (11) and a first transparent conductive oxide (TCO) layer (12) on the substrate; (b) obtaining a first absorption layer (13) on the first TCO layer through a plasma process; (c) obtaining a second TCO layer (14) on the first absorption layer by using a mask; (d) obtaining a plasmonic nanostructured layer (15) on second TCO layer, where the plasmonic nanostructured layer comprises nano-particles; (e) obtaining a third TCO layer (16) on plasmonic nanostructured layer by using the mask; (f) etching the first absorption layer by using the third TCO layer as a shield; and (g) obtaining a metal grating (17) on third TCO layer by using another mask.    DESCRIPTION OF DRAWING(S) - The figure shows a flow view of method for integrating a light-trapping layer to a thin-film solar cell.    Substrate (10)    Metal back reflector layer (11)    First transparent conductive oxide layer (12)    First absorption layer (13)    Second transparent conductive oxide layer (14)    Plasmonic nanostructured layer (15)    Third TCO layer (16)    Metal grating (17)