Tomoko Hosokawa

Fabrication of ambipolar field-effect transistor device with heterostructure of C60 and pentacene

Ambipolar field-effect transistor (FET) device was fabricated with heterostructure of thin films of C60 and pentacene. Three types of device structures in the C60∕pentacene heterostructure FET device were studied in order to realize the best ambipolar properties. In the middle-contact type FET device of C60 and pentacene, the mobility μ in p-channel operation was estimated to be 6.8×10−2cm2V−1s−1, while the μ in n-channel operation was 1.3×10−3cm2V−1s−1. This ambipolar FET device is available for a practical building-block to form CMOS integrated circuits with low-power consumption, good-noise margins, and ease of design.

Fabrication and characteristics of C84 fullerene field-effect transistors

Fullerene field-effect transistors (FETs) were fabricated with thin films of C84, which showed n-channel normally-on depletion-type FET characteristics. The C84 FET device exhibited the highest mobility, μ, of 2.1×10−3 cm2 V−1 s−1 among normally-on fullerene FETs. The carrier transport of this FET device can be interpreted as thermally activated hopping transport. Carrier type (n-channel) and transport mechanism (hopping) reflect the electronic properties of the C84 molecule.