M. Boostandoost, L. Hao-Peng, U. Kerst, C. Boit, Technische Universität Berlin, Berlin, Germany; S. Gall, Berlin Helmholtz Center, Berlin, Germany

Summary: The light collection properties of thin film a-Si/p-Si solar cells with interdigitated mesa structure have been locally analysed in the infrared and compared to the visible spectrum using Light Beam Induced Current (LBIC) and Electroluminescence, band to band recombination in forward bias (EL) and intraband relaxation in reverse bias (ELR). The low absorption rate of IR light leads to a highly efficient collection at the corners of the mesa if the etch shape allows to couple the light horizontally into the cell, and to a reduced current when the laser is scanned over the active volume due to IR transmission and absorption properties of TCO and amorphous and thin poly Si layer.