Solution-phase deposition of oligomeric TFT semiconductors

Until now, most organic-based FETs have been fabricated by subliming the active films onto device substrates at high vacuum, whereby useful orientational order and intergrain connectivity are obtained. For lower-cost devices, a major challenge is to duplicate this performance in semiconductors deposited from solution. We have prepared several thiophene-based compounds, both oligomers and thienoaromatics, that display high mobilities, in some cases equivalent to vacuum-deposited films, when cast from common solvents. The similarities between liquid- and vaporphase processed films suggest that oligomer solutions may be valuable for the production of all-organic electronic circuitry.