Patterning organic-inorganic thin-film transistors using microcontact printed templates

We report the simple, low-cost, and parallel fabrication of patterned organic-inorganic thin-film transistors (TFTs) by microcontact printing a molecular template on the substrate surface prior to film deposition. We printed molecules with hydrophobic tail groups on the gate oxide surfaces of TFTs to chemically, differentiate the substrate surface and confine the self-assembly of thin films, deposited from solutions flooded across the entire surface, to the transistor channels. TFTs are fabricated with good device characteristics and no current leakage. This process is more general to the patterning of other solution-deposited thin-film materials. © 2001 American Institute of Physics

Confocal microscopy study of texture transitions in a polymer stabilized cholesteric liquid crystal

The switching transition of polymer stabilized cholesteric texture liquid crystals is studied via confocal microscopy. This noninvasive probe enables the simultaneous imaging of the polymer network and the liquid crystal domain structure. We find that the two-stage switching often occurring in these systems results from the cholesteric experiencing two distinct environments: one consisting of very low polymer density, and the other strongly dominated by the polymer network. Fluctuations in the local polymer density produce effective random fields that broaden the transition