The development of flexible plastic electronics for smart bandages, RFID tags, plastic solar cells, or light emitters for smart cards, has been hindered by the instability of transistors capable of maintaining the current needed to power the devices.
Bernard Kippelen and colleagues, Georgia Institute of Technology, USA, have described a new method of combining top-gate organic field-effect transistors with a bilayer gate insulator. This allowed the transistor to perform with incredible stability while exhibiting good current performance: No degradation was seen after 20,000 cycles of the transfer characteristics or after 24 hours under constant direct-current bias stress.
The bilayer dielectric was made of a fluorinated polymer, CYTOP, and a high-k metal-oxide layer created by atomic layer deposition. The transistor conduct ran at a voltage comparable to amorphous silicon, the current industry standard, but could be manufactured at temperatures below 150 °C and under a regular atmosphere, making it easier to fabricate than other transistors.
- Top-Gate Organic Field-Effect Transistors with High Environmental and Operational Stability
D. K. Hwang, C. Fuentes-Hernandez, J. Kim, W. J. Potscavage, S.-J. Kim, B. Kippelen,
Adv. Mater. 2011.