High-gain pentacene-based inverter achieved through high and low energy ultraviolet treatments

The authors report on the fabrication of pentacene-based inverter with two p-channel thin-film transistors (TFTs) on polymer/AlOx bilayer dielectric, which has been patterned by high energy ultraviolet (UV) (254 nm) illumination. After pentacene channel growth on the dielectric, the inverter showed a high voltage gain of similar to 10 under -6 V supply voltage (V-DD) but at a transition voltage of -1 V which is too marginal to guarantee a desirable inverter operation between 0 and -6 V. When low energy UV (352 nm) was applied onto one of the two p TFTs, which plays as a load in the inverter circuit, the transition voltage shifted to an adequate value (-3 V) because the UV changes the threshold voltage of the load TFT to be lower. The UV-treated inverter demonstrated a high voltage gain of similar to 150 under a V-DD of -30 V. (C) 2007 American Institute of Physics.