Organic-inorganic hybrid dielectrics with low leakage current for organic thin-film transistors

Using a thermally cross-linkable organosiloxane-based organic-inorganic hybrid material, a solution-processable gate dielectric layer for organic thin-film transistors has been fabricated. The hybrid dielectric was synthesized by a sol-gel process, followed by heat treatment at below 190 degrees C. Dielectric strength of 1.4-1.65 MV/cm was measured and it was confirmed that the leakage current is governed by the Poole-Frenkel emission mechanism in which the silanol groups act as trap sites. An organic thin-film transistor utilizing the hybrid dielectric shows similar electrical performance to a transistor fabricated using surface-modified thermally grown SiO2. (c) 2006 American Institute of Physics.