Supplementary Material

See the supplementary material for further details on the experimental preparation and power generation performance testing of the stretchable wavy structure TEG, the TEM-EDS elemental mapping images of Te-Ag NW in Figure S1, the measurement of the TE properties in Figures S2 and S3; and the comparison of the output performance of some reported Te-based TEGs, the room temperature TE properties of some previously reported p- and n-type Te-based TE films, the stretching performance between the reported TEGs and our work in Tables S1-S4.