Observation of hole injection boost via two parallel paths in Pentacene thin-film transistors by employing Pentacene: 4, 4″-tris(3-methylphenylphenylamino) triphenylamine: MoO3 buffer layer

Abstract

Pentacene organic thin-film transistors (OTFTs) were prepared by introducing 4, 4″-tris(3-methylphenylphenylamino) triphenylamine (m-MTDATA): MoO3, Pentacene: MoO3, and Pentacene: m-MTDATA: MoO3 as buffer layers. These OTFTs all showed significant performance improvement comparing to the reference device. Significantly, we observe that the device employing Pentacene: m-MTDATA: MoO3 buffer layer can both take advantage of charge transfer complexes formed in the m-MTDATA: MoO3 device and suitable energy level alignment existed in the Pentacene: MoO3 device. These two parallel paths led to a high mobility, low threshold voltage, and contact resistance of 0.72 cm2/V s, -13.4 V, and 0.83 kΩ at Vds = - 100 V. This work enriches the understanding of MoO3 doped organic materials for applications in OTFTs.