A simple surface treatment technique developed by researchers at the National Institute of Standards and Technology (NIST), Penn State, and the University of Kentucky promises a low-cost method to produce arrays of organic electronic transistors on polymer sheets, paving the way for flexible displays and large biosensor arrays.
The researchers found that applying a special pretreatment compound to the contacts before applying the organic semiconductor could induce the molecules in solution to self-assemble into well-ordered crystals at the contact sites. These structures grow outwards to join across the field-effect-transistor channel, producing both good electrical properties and effective electrical isolation.
Organic transistors are considered desirable because they can be manufactured at room temperature, unlike traditional semiconductors that require high-temperature processing. They can also be fabricated on flexible substrates, making it possible to build displays that could be rolled up or folded. Another application is plastic sheets incorporating large detector arrays for medical monitoring or diagnostics in the field.