Figure 2

(a,b) Cross-sectional SEM images of (a) solCIGS and (b) K-solCIGS thin films. Colored areas denote upper layer regions. (c,d) Circular averaged 1D GI-WAXS profiles of (c) solCIGS and (d) K-solCIGS thin films. (e) Box plots, showing variation range of Hall mobility (μ) of solCIGS and K-solCIGS devices. (f) Spatial distributions of the charge carrier density, estimated by C‒V measurement of solCIGS and K-solCIGS devices; modified with permission from ref 14, Copyright 2020, WILEY–VCH.