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

Publication date: 31 March 2017
Source:Thin Solid Films, Volume 626
Author(s): Qi Liu, Gang Lu, Yongjun Xiao, Yunwang Ge, Bo Wang
Low-voltage pentacene-based organic thin-film transistors (OTFTs) have been fabricated using the high-κ organometallic lanthanide complex, Tb(tta)3L2NR (tta=2-thenoyltrifluoroacetonate, L2NR =(−)-4, 5-pinene bipyridine) as the gate dielectric material. The optimized gate insulator exhibits a low leakage current density of <10⁻⁷ Acm⁻² under bias voltage of −5V, a smooth surface with RMS of about 0.40nm, a high capacitance of 43nFcm⁻² and an equivalent κ value of 7. The obtained OTFTs show high electric performance with carrier mobility of 0.20cm² V⁻¹ s⁻¹, on/off ratio of 4×10⁵, threshold voltage of −0.6V, and subthreshold slope of 0.7Vdec⁻¹ when operated at −5V. The results demonstrate the organometallic lanthanide complex is a promising candidate as gate insulator for low-voltage OTFTs.