Thickness effects on the lithiation of amorphous silicon thin films

The lithiation of thin film Si was investigated in an electrochemical cell, using in situ wafer curvature to monitor the evolution of in-plane stresses. Increasing the initial film thickness from 50 to 250 nm led to decreases in both the nominal flow stress and the Li capacity. These observations are consistent with relatively slow Li diffusion. The corresponding concentration gradients should have a substantial effect on the deformation and viscous flow that occur in lithiated Si.