Measuring relative carrier concentrations at the nanoscale using scanning microwave impedance microscopy: The case of CdTe solar cells

摘要

We present scanning microwave impedance microscopy as an analysis technique that can be used to map the relative carrier concentrations at the nanoscale in the semiconductors used for device applications. The specific application presented here is the analysis of PV-device grade CdTe, grown using rf-sputtering and close-spaced sublimation (CSS). We demonstrate a direct observation of carrier depletion along the grain boundaries in CdTe caused due to the CdCl2 annealing treatment, which is an important step in the device manufacture process.