depth dependance of diffusion length

Combining several independent ELYMAT measuring modes (e.g. using lasers with differnt penetration depth allows to extract information on the depth dependance of the diffusion length.

As demonstrated in the above figure the real diffusion length profile is approximated by a step model. The step model is optimized by a least square fit, minimizing the difference between the measured photocurrents and the calculated photocurrents for the step model.

The number of steps, which may be fitted depends on the number of independent measurements .