Extended Data Fig. 6: Single-layer profiles of LEIS.
From: Spontaneous ordering of identical materials into a triboelectric series
Sequential probing and sputtering of the surface reveal no differences between pristine and contacted samples several atomic layers into the bulk (layer 0 being the outermost and layer 15 the innermost). By contrast, the plasma-treated sample shows substantial differences, notably an increased oxygen peak owing to the introduction of OH groups. Furthermore, the deeper layers of the plasma-treated sample approach those of the pristine sample, indicating that this change occurs primarily in the first few layers.
