Using the electron beam induced current mode of the scanning electron microscope, a technique has been developed to study the extent of hydrogen passivation and diffusion along grain boundaries in silicon ribbon grown by the edge‐defined film‐fed growth process. Passivation and diffusion depthsx, ranging from a few microns to more than 200 microns have been found. Grain boundary diffusivities of 10−8–10−9cm2/s have been measured. A finite width to the spatial distribution of recombination centers along the grain boundaries has been found and measurements of the surface recombination velocityS, indicate that, forS≥2×104cm/s, ln S∝x.