Fullerene based n-type organic thin-film transistors

Significant progress has been made in the area of p-type organic field effect transistors while progress in developing n-type materials and devices has been comparatively lacking, a limiting factor in the pursuit to develop complementary organic electronic circuits. Given the need for n-type organic semiconductors we have carried out studies using two different fullerene molecules, C60 and C70. Here, we report mobilities for C60 ranging from 0.02 cm2/V s up to 0.65 cm2/V s (depending on channel length), and mobilities from 0.003 cm2/V s up to 0.066 cm2/V s for C70. All devices were fabricated with organic films deposited under high vacuum but tested at ambient pressures under nitrogen.