(Invited) Analysis of the Heterogeneous Charge-Transfer Kinetics for Adsorbed Redox Monolayers on Semiconductor

This presentation will describe our latest results in comprehensive modeling of the voltammetric response of redox active monolayers on semiconductor electrodes. The motivation is to provide more utility in voltammetric data that pertain to redox molecules adsorbed on semiconductors, as common in dye-sensitized photoelectrochemistry and artificial photosynthesis systems. First, a background on the prior art on kinetic analysis of redox monolayers on metal and semiconductor electrodes will be provided. Second, the mathematical model used in this work will be detailed, including a brief primer on the derivation of the expression that relates semiconductor surface energetics, surface traps, electrostatics, charge-transfer kinetics, and Marcus theory. Third, the voltammetric responses of several redox-active species physisorbed and chemisorbed on Si electrodes will be presented. The focus will be on responses collected in the dark and in non-aqueous electrolytes. Fourth, the extent of kinetic information that can be extracted from individual and sets of voltammograms will be described.