Researchers from the National Institute of Standards and Technology
(NIST) and Seoul National University (SNU) have learned how to tweak a new class of polymer-based semiconductors that could enable the design of practical,
large-scale manufacturing techniques for a wide range of printable, flexible electronic displays and other devices.
Organic semiconductors - carbon-based molecules that have similar electrical properties to conventional semiconducting materials like silicon and germanium - have traditionally been difficult to deposit in a stable, uniform film. Larger molecule polymer semiconductors, on the other hand, make excellent thin films but have limited semiconductor properties.
The SNU/NIST researchers used a neutron imaging technique that allowed them to observe how the distribution of small organic semiconductor molecules embedded in polymer films changed with depth. When the researchers substituted a polymer with higher molecular mass, the small organic molecules distributed themselves evenly at the top and bottom of the film. Having an active region of the film on the bottom is key for large-scale manufacturing, because it means the rest of the device-gate source drain can be laid down first and the delicate thin-film layer added last.
