Peter Pacher

Photochemical control of the carrier mobility in pentacene-based organic thin-film transistors

We use a photoreactive interfacial layer of poly(endo,exo-bis(2-nitrobenzyl) bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate) (PBHND) between the gate dielectric and the pentacene active layer to tune the effective hole mobility in organic thin film transistors over approximately one order of magnitude. This can be explained by the photoconversion of the PBHND layer changing its surface energy and thus strongly impacting pentacene growth. A linear relationship between the mobility and the grain size is observed.

Effects of extending conjugation length on the two-photon absorption spectra of fluorene molecules

By systematically altering the structural properties of various fluorene-based molecules, we determine how these changes affect their two-photon absorbing capabilities. Here we emphasize the effects of conjugation extension, however other structural motifs were also investigated.