Lecture 14 Current-Potential Curves at Semiconductor Electrodes Reference. 1.R. Memming, Semiconductor Electrochemistry, Wiley-VCH, 2000 (e-book) 2.A.J. Bard and L.R. Faulkner, Electrochemical Methods: Fundamentals and Applications, Wiley, J. O’M. Bockris, A.K.N. Reddy, and M. Gamboa-Aldeco, Modern Electrochemistry, Kluwer Academic/Plenum Publishers, 2000 Lecture note

Recap: I-V Curves at Metal Electrodes

Recap: Metal-Electrolyte Interface At equilibriumUnder polarization Potential Controls Activation Energy

Recap: Bias Changes the Fermi Level

I-V Curves of Semiconductor Electrodes

Band Bending of Semiconductor

n-type Semiconductor-Electrolyte Interface

The activation energy is independent of the relative concentration of the redox system and also independent of the externally applied voltage!

Quantitative Derivation of Current-Potential Curves

Conduction Band Processes j c + : an electron transfer rate associated from a filled state in a redox system to an empty state in a SC.

j c - : an electron transfer rate associated from a filled state in a SC to an empty state in a redox system.

j v + : an electron transfer rate associated from a filled state in a redox system to an empty state in a SC. j v - : an electron transfer rate associated from a filled state in a SC to an empty state in a redox system. Valence Band Processes with

We will define another rate constants for each equations so that

I-V Relationship At equilibrium Conduction band process

I-V Curves of Semiconductor Electrodes

Light-induced Process

Next Meeting Current-Potential Curves at Semiconductor Electrodes: Part II