Enhanced Mobility of Rubrene Thin-Film Transistors with a Polymer Dielectric on Plastic Substrate

We report on the fabrication of rubrene thin-film transistors (TFTs) with spin-coated poly-4-vinylphenol (PVP) dielectric on indium-tin oxide/plastic substrate. Under a specific growth condition of 80 ° C in situ vacuum anneal following thermal deposition, initial amorphous rubrene film was successfully transformed into crystalline phase, both on hydrophobic PVP and on Si O 2 ∕ p + - Si substrate, whose surface is relatively hydrophilic. The transformation or growth kinetics of the crystalline rubrene domain was much faster on PVP than on the Si O 2 gate dielectric. As a result, the rubrene TFT with PVP dielectric exhibited an order of magnitude higher field mobility ( ∼ 6 × 10 − 3 cm 2 ∕ V s ) than that of the other one with Si O 2 dielectric.