Département de chimie moléculaire

We study porphyrin deriv. coated silicon nanowire field effect transistors (SiNW-FETs), which display a large, stable, and reproducible conductance increase upon illumination. The efficiency and the kinetics of the optical switching are studied as a function of gate voltage, illumination wavelength, and temp. The decay kinetics from the high- to the low-conductance state is governed by charge recombination via tunneling, with a rate depending on the state of the SiNW-FET. The comparison to porphyrin-sensitized carbon nanotube FETs allows the environment- and mol.-dependent photoconversion process to be distinguished from the charge-to-current transducing effect of the semiconducting channel. [on SciFinder(R)]