Researchers make high-performance FETs with Carbon 60

Researchers make high-performance FETs with Carbon 60

Using room-temperature processing, researchers at the Georgia Institute of Technology have fabricated high-performance field effect transistors (FETs) with thin films of Carbon 60, also known as fullerene. The circuitry could be used for displays, active electronic billboards, RFID tags, and other applications that use flexible substrates.

Georgia Tech researchers fabricated high-performance FETs with thin films of fullerene.

As an organic semiconductor material, C60 is attractive because it can provide high electron mobility — a measure of how fast current can flow. Previous reports have shown that C60 can yield mobility values as high as 6 cm2 /V/s. However, that record was achieved using a hot-wall epitaxy process requiring processing temperatures of 250°C — too hot for most flexible plastic substrates. Though the transistors produced by the Georgia Tech research team display slightly lower electron mobility (2.7 to 5 cm2 /V/s) they can be produced at room temperature. The researchers fabricated the transistors by depositing C60 molecules from the vapor phase into a thin film atop a silicon substrate onto which a gate electrode and gate dielectric had already been fabricated. The source and drain electrodes were then deposited on top of the C60 films through a shadow mask.

Now that they have demonstrated field-effect C60 transistors, the researchers plan to produce other electronic components such as inverters, ring oscillators, logic gates, and drivers for active matrix displays and imaging devices. For more information, visit http://www.gatech.edu.

Paul O’Shea