Use of near-surface channel conductance and differential capacitance versus potential measurements to correlate inversion layer formation with low effective surface recombination velocities at n-Si/liquid contacts

Near-surface channel conductance measurements, differential capacitance versus potential measurements, and surface recombination velocity measurements have been performed on (111)- and (100)-oriented n-type Si samples in contact with nitrogen and/or liquid electrolyte solutions containing I₂, I₂/I^-, ferrocene^+/0, or decamethylferrocene^+/0 in either methanol or tetrahydrofuran. Si/liquid contacts that displayed a low effective surface recombination velocity S corresponded to those that formed an inversion layer at the solid/liquid contact as indicated by channel conductance measurements or by differential capacitance versus potential measurements. Contacts that did not produce an inversion layer at the Si surface did not produce low effective S values. The observed behavior is consistent with the known energetics of Si/liquid contacts and provides an explanation for the low effective S values observed in these systems.