Visualization and analysis of active dopant distribution in a p-i-n structured amorphous silicon solar cell using scanning nonlinear dielectric microscopy

Scanning nonlinear dielectric microscopy (SNDM) and super-higher-order (SHO-) SNDM were used for dopant profiling analysis of a cross-section of the p-i-n structure of an amorphous silicon solar cell. The p-i-n and zigzag structures of each layer boundary were visualized as carrier polarity and density images on 10-20 nm scale through a SNDM measurement. A capacitance-voltage curve was obtained at each pixel in the scan area through a SHO-SNDM measurement. The obtained SNDM and SHO-SNDM data suggest that the i-layer was not completely intrinsic, but was very-low-density p-type.