Controlling the electrical properties of pentacene-based organic inverter by ultraviolet

We report on the fabrication of pentacene-based organic inverter with two p-channel thin-film transistors (TFTs) on polymer/AlOx bilayer dielectric, which has been patterned by using high-energy ultraviolet (UV, 254nm) illumination. After pentacene-channel growth on the dielectric, our inverter showed a high-voltage gain of ∼8 under −6V supply voltage (VDD) but voltage transfer characteristics (VTC) curve is too marginal to guarantee a desirable inverter operation between 0 and −6V. When low-energy UV (352nm) was applied onto one of the two p-TFTs, which plays as a load in the inverter circuit, the VTC curve was adjusted to be more adequate for inverting operation due to the UV-induced modification on the threshold voltage and channel resistance of the load-TFT. Our UV-treated inverter also demonstrated much faster inverting dynamics than that of pristine inverter due to the lowered channel resistance of load-TFT.