Low-voltage organic field-effect transistors based on novel high-κ organometallic lanthanide complex for gate insulating materials

Abstract

A novel high-κ organometallic lanthanide complex, Eu(tta)3L (tta=2-thenoyltrifluoroacetonate, L = 4,5-pinene bipyridine), is used as gate insulating material to fabricate low-voltage pentacene field-effect transistors (FETs). The optimized gate insulator exhibits the excellent properties such as low leakage current density, low surface roughness, and high dielectric constant. When operated under a low voltage of −5 V, the pentacene FET devices show the attractive electrical performance, e.g. carrier mobility (μFET) of 0.17 cm2 V−1 s−1, threshold voltage (Vth) of −0.9 V, on/off current ratio of 5 × 103, and subthreshold slope (SS) of 1.0 V dec−1, which is much better than that of devices obtained on conventional 300 nm SiO2 substrate (0.13 cm2 V−1 s−1, −7.3 V and 3.1 V dec−1 for μFET, Vth and SS value when operated at −30 V). These results indicate that this kind of high-κ organometallic lanthanide complex becomes a promising candidate as gate insulator for low-voltage organic FETs.

Controllable Self-Assembly of PTCDI-C8 for High Mobility Low-Dimensional Organic Field-Effect Transistors

“…Very low V T of 0.7 V was observed. This is attributed to the used ultrathin high-k HfO 2 dielectric, which is consistent with the reported results . The highest mobility of 2.2 cm 2 ·V –1 ·s –1 was achieved, higher than the reported results for PTCDI-C8 (Table ), ,− and comparable with the recent reported high mobility of 2.67 cm 2 ·V –1 ·s −1 for BPE-PTCDI .…”

Low-voltage, High-performance Organic Field-Effect Transistors Based on 2D Crystalline Molecular Semiconductors

“…The decreased mobility in the device with HfO 2 is mainly due to the strong interaction at the interface between the conducting channel and high- κ dielectric 29 , 30 . This interaction results in the increased localization of the charge carriers 6 , 31 , 32 , which is consistent with the result that OFETs based SiO 2 exhibit a higher carrier mobility than that based on AlO x . Further studies on the charge carrier properties in our ultrathin molecular crystals is of great interest.…”