Extended Data Fig. 2: In situ bending test by TEM.
From: Flexible solar cells based on foldable silicon wafers with blunted edges
a, A stress holder for the in situ bending test during TEM. b, A tungsten tip controlled by the piezomanipulator was used to handle the left side of the FIB c-Si foil. c, Before loading the bending force, the bend contours were randomly distributed on the c-Si foil. d, After loading the bending force, these bend contours collected in the sharp channels between pyramids (white arrows), indicating that most stress concentrated in these sharp channels. The yellow squares implied that most stress shifted to nearby sharp channels after the bending force was loaded. Here, the dark fringes resulted from stress-induced lattice deformations.
