On the theory of electron transfer reactions at semiconductor electrode/liquid interfaces

Electron transfer reaction rate constants at semiconductor/liquid interface s are calculated using the Fermi Golden Rule and a tight-binding model for the semiconductors. The slab method and a z-transform method are employed i n obtaining the electronic structures of semiconductors with surfaces and a re compared. The maximum electron transfer rate constants at Si/viologen(2/+) and InP/Me(2)Fc(+/0) interfaces are computed using the tight-binding ty pe calculations for the solid and the extended-Huckel for the coupling to t he redox agent at the interface. These results for the bulk states are comp ared with the experimentally measured values of Lewis and co-workers, and a re in reasonable agreement, without adjusting parameters. In the case of In P/liquid interface, the unusual current vs applied potential behavior is ad ditionally interpreted, in part, by the presence of surface states. (C) 200 0 American Institute of Physics. [S0021-9606(00)70507-1].