Monitoring Atomic Layer Deposition by Potentiodynamic Electrochemical Impedance Spectroscopy of Multielement Adlayers

Atomic multilayer assembly monitoring is now possible using a method that has been extended from multiparametric characterization of changeable electroactive interfaces using potentiodynamic electrochemical impedance spectroscopy (PDEIS). The multilayers were created by depositing adlayers of Sb, Se, and Sn on Ag in a sequential fashion, and by depositing an adlayer of Zinc on an antimony underlayer that was supported by Silver. The multilayers were characterized using the potentiodynamic mode, which utilizes the relationship between AC circuit characteristics and electrode potential. The dependences show changes in the double electric layer at the interface, and in diffusion and charge transfer. While Ag/Sbad/Sead/Agad and Ag/Sead/Agad exhibit considerable similarity in the Faradaic part of the ac response, the dependencies of the distinctive variables of the Ag/Sbad/Sead/Snad (Ag/Sbad/Sead/Snad) composite threelayer differ significantly from those of the Ag/Sbad/Snad and Ag/Sead/Snad bilayers, respectively. The adlayer oxidation potential shifts dramatically when tin is deposited on a bi-chalcogen Ag/Sbad/Sead underlayer, proving that the upd of Sn, Ag, and Zn on chalcogen adlayers is irreversible. Silver can partially dissolve in the Ag adlayer oxidation potential when it penetrates the Ag/Sbad/Sead bilayer, unlike the Sn adlayer that forms on top of the Antimony-selenium bilayer and dissolves completely in the anodic scan within the stability scope of the chalcogen composite underlayer. Electrochemical nanotechnologies can utilize PDEIS for monitoring layer-by-layer deposition by leveraging the self-descriptive nature of potential dependences of circuit variables..