Development of scanning capacitance spectroscopy of CIGS solar cells

We successfully applied scanning capacitance spectroscopy (SCS) on CIGS solar cells. In SCS, a high-quality insulating layer is needed to block the AC and DC conductance between the probe and sample. A sample preparation procedure was developed on CIGS/CdS cross-sectional samples for optimal and reproducible results. Spectra taken with 10-nm intervals showed clear p- and n-type behaviors of CIGS and CdS, respectively. Rapid changes in spectra in the depletion region allowed us to locate the electrical junction with fine resolution of 10-30 nm.