Determination of minority carrier diffusion length in silicon wafers by a dual electrolyte cell

The use of a cell with two electrolytic compartments for the determination of minority carrier diffusion length in silicon wafers is discussed. The method is based on comparison of the limiting photocurrents recorded at the front (illuminated) and back (dark) compartment under suitable polarization conditions. Results obtained in different polarization arrangements for n- and p-Si are compared and discussed. It is shown that the diffusion length of holes in n-Si may be determined with good accuracy in the cell Pt1/1 M NH4F/silicon/1 M NH4F/ Pt2 without application of metal contacts to the Si wafer.