Differential surface photovoltage measurement of minority-carrier diffusion length in thin films

A new surface photovoltage technique is introduced for the determination of the minority-carrier diffusion length in thin semiconductor films. The technique eliminates the effect of a back surface barrier on the measurement by separating out the back barrier contribution to the total photovoltage signal. With a direct difference method based on a double lock-in technique, the measurement can be carried out in a single run.