The quantitative interpretation of a Light Beam Induced Current (LBIC) contrast profile (LBIC signal normalized to the signal infinitely far from the grain boundary) of a Grain Boundary (GB) allows the estimation of the diffusion length in the neighboring grains (left grain L1, right grain L2,) as well as the recombination strength of the GB characterized by its equivalent Surface Recombination Velocity (SRV) vs. The quantitative evaluation of L1, L2 and vs is very useful regarding e.g. the evaluation of the effectiveness of a hydrogenation step in a solar cell process. For this purpose, we developed a direct fitting procedure based on a particular solution of the minority carrier diffusion equation with suitable boundary conditions. This theory, initially developed by C. Donolato for analyzing EBIC and/or LBIC contrast profiles, had the limitation to assume the same diffusion length (Ldiff) for both neighboring grains which cannot account for non symmetrical contrast profile due to differing Ldiff and can thus lead to erroneous evaluation of Ldiff , in particular when the SRV of the GB is low. The present contribution fixes this problem by generalizing Donolato s theory for differing diffusion lengths on either side of the GB, and so allows non symmetrical profiles to be investigated
