High-κ organometallic lanthanide complex as gate dielectric layer for low-voltage, high-performance organic thin-film transistors.

Low-voltage pentacene-based organic thin-film transistors (OTFTs) have been fabricated using the high- κ organometallic lanthanide complex, Tb(tta) 3 L 2NR (tta = 2-thenoyltrifluoroacetonate, L 2NR = (−)-4, 5-pinene bipyridine) as the gate dielectric material. The optimized gate insulator exhibits a low leakage current density of < 10 − 7 A cm − 2 under bias voltage of − 5 V, a smooth surface with RMS of about 0.40 nm, a high capacitance of 43 nF cm − 2 and an equivalent κ value of 7. The obtained OTFTs show high electric performance with carrier mobility of 0.20 cm 2 V − 1 s − 1 , on/off ratio of 4 × 10 5 , threshold voltage of − 0.6 V, and subthreshold slope of 0.7 V dec − 1 when operated at − 5 V. The results demonstrate the organometallic lanthanide complex is a promising candidate as gate insulator for low-voltage OTFTs. [ABSTRACT FROM AUTHOR]