The present disclosure relates to methods for determining recombination characteristics at metallized semiconductor surfaces and of metallized semiconductor junctions, based on photo-conductance decay measurements. Dedicated test structures are used comprising a plurality of metal features in contact with a semiconductor surface at predetermined locations, the metal features being provided in a plurality of zones, each of the plurality of zones having a different metal coverage. The method comprises performing a photo-conductance decay measurement in each of the plurality of zones, thereby determining effective lifetimes for different injection levels as a function of metal coverage; and extracting the recombination characteristics from the measured effective lifetimes.
