[16p-P7-1~20] 12.4 Organic light-emitting devices and organic transistors

[16p-P7-14] Effect of low-molecular-weight cross-linking reagent on the carrier mobility of pentacene thin film transistors using UV-light cured polysilsesquioxane gate dielectric layers

〇Shuichi Okada¹, Yoshio Nakahara¹, Kazuyuki Uno¹, Ichiro Tanaka¹ (1.Wakayama univ.)

Keywords:organic thin film transistor, gate dielectric layer, polysilsesquioxane

We investigated the effect of trimethylolpropane triacrylate (TMPTA) that was used as a low-molecular-weight cross-linking reagent on the carrier mobility of pentacene thin film transistors, in which pentacene grain size was varied from ~0.5 to ~2.5 µm, fabricated with polysilsesquioxane gate dielectric layers cured by ultra violet light irradiation. When the pentacene grains were smaller than ~1 µm, the carrier mobility depended on the grain size as well as the TMPTA concentration. However, it depended only on the TMPTA concentration when grains were larger than ~1 µm; the carrier mobility was reduced by ~50 % by increasing the TMPTA concentration from 10 to 20 vol.% regardless of the grain size. It is considered that this lowered carrier mobility is due to the Coulomb interaction caused by polarization of the ester groups comprised in the TMPTA molecules.