Bias-stress effects of organic field-effect transistors with active layers of liquid crystalline polymers

Abstract

We have established a simple coating method of polymeric organic semiconductor films onto highly hydrophobic gate dielectric surfaces and fabricated bottom-gate/top-contact type organic field-effect transistors with an active layer of liquid crystalline polymer, poly(2,5-bis(3-hexadecylthiophene-2-yl)thieno[3,2-b]thiophene). The SiO2 gate dielectric surfaces were treated with octadecyltrichlorosilane (ODTS) or coated with an amorphous perfluoropolymer (CYTOP). Their bias-stress effects were examined in vacuum and air. By changing the coating material from ODTS to CYTOP, the operational stability was significantly improved in both vacuum and air.