Solution-processable organic conductors and semiconductors for thin-film electronics

The ability to replace thermally-evaporated metal and organic semiconductors with solution-processable counterparts as active device components will lower capital and operational costs associated with thin-film electronics fabrication. We are examining the processing-structure-property relationships of these materials to assess their viability. Current research efforts in this area focus on water-dispersible, conductive polyaniline and several p-type solution-processable anthradithiophenes. These materials, respectively, find use as electrodes and active layers in organic transistors and solar cells.

Soft lithography and soft-contact lamination for plastic electronics

The chemical- and mechanical fragility of organic semiconductors calls for the development of non-invasive patterning technologies for establishing efficient electrical contact. Our group has developed nanotransfer printing (nTP), soft-contact lamination (scL) and stamp-and-spin-cast as means to fabricate functional organic thin-film devices. Research in this area continues to explore elastomeric-stamp-based patterning schemes for creating high-resolution functional features on rigid and flexible substrates over large areas. These features are either directly transferred onto or laminated against the electrically-active components to complete the circuits of organic transistors and solar cells.

Self-assembled monolayers facilitate interfacial engineering in organic solar cells

Previously, our efforts in this area entailed the understanding the assembly of conjugated molecules on metal and semiconductor surfaces. High-resolution spectroscopic techniques, including transmission and reflectance infra-red spectroscopy and synchrotron-based near-edge X-ray absorption fine structure spectroscopy were used to elucidate the ensemble-averaged structure and orientation of the molecular assembly. Current work builds on our previous know-how; we are exploiting the molecular dipoles induced by and surface energy presented by the organization of self-assembled monolayers to engineer the electrode-photo-active later interface in organic solar cells.

Funding Sources and Supporters