fig3

Figure 3. (A) Photograph of the composite wet film on a flexible PI substrate prepared by tape casting; (B) Photograph of the solid film after drying; (C) Punched films (12 mm diameter) for performance testing after the FJH treatment; (D) XRD patterns of composite materials with different MWCNTs mass fractions (5-20 wt%), all characteristic peaks matching the standard card (JCPDS#49-1713); (E) Raman spectrum of the Bi_0.5Sb_1.5Te₃/20 wt% MWCNTs composite film. PI: Polyimide; XRD: X-ray diffraction; MWCNTs: multi-walled carbon nanotubes.