Schematic illustration of the CNT/Si thin-film solar cell fabrication and sample images of Si films. (a) Schematic illustration of the fabrication process of the CNT/Si thin-film solar cells. (b) Optical image of a large area of Si film with a thickness of 20 μm. Inset is a solar cell made from Si thin film. (c) SEM image of a Si thin film showing a textured surface. (d) SEM image of a CNT/Si thin-film solar cell. White light interferometry surface topography image of a starting Si wafer (e), an etched Si thin film (f), and a CNT/Si thin-film solar cell (g).