Determination of surface recombination velocities of organic monolayers on silicon through Kelvin probe

We report the determination of the surface recombination velocity of electron-hole pairs for silicon samples passivated with organic monolayers using the Kelvin probe. The recombination velocity was determined from the surface photovoltage and incident photon flux. By scanning of the Kelvin probe tip over the sample, the change in surface recombination velocity can be measured allowing recombination lifetime mapping. Organic monolayers with different chain lengths and exhibiting various recombination lifetimes were synthesized through a two-step chlorination-alkylation technique. The estimated recombination lifetimes were compared against those obtained from an industrial standard technique and were found to be in good agreement.