Simultaneous measurement of bulk and surface recombination lifetimes on asymmetrical silicon samples

In this paper, a contactless, all-optical and non-destructive method for separating the minority carrier recombination lifetime and surface recombination velocities on asymmetrical silicon samples (that is with different surface recombination velocities on the front and back surface) at low injection level is presented. The technique can be described as a pump-probe method where the excess carrier density is probed by analyzing free carrier absorption transient following excitation pulses having several wavelengths. A novel theoretical approach to evaluate the recombinative parameters is extensively analyzed and numerical simulations, which validate the proposed methodology, are presented.