Spatially resolved photocurrent measurements of microstructured a-Si:H solar cells

The variation of electronic properties in an amorphous (a)-Si:H solar cell film deposited on a textured substrate is measured with sub-micrometer resolution (<500 nm). The experiments are performed using a high resolution laser beam induced current (LBIC) set-up where in addition to the photocurrent the light reflection is monitored. Fluctuations in photocurrent are correlated with surface structures of the cell. These variations are mainly caused by variations in the light intensity due to the lateral structure and lateral variation of the local electric field in the pin-junction. The results are discussed including resolution limits of the apparatus and atomic force image of the solar cell.