Carrier-mobility improvement for pentacene OTFT with LaZrO dielectric by using Pd gate

Pentacene organic thin-film transistor (OTFT) using Pd as gate electrode is proposed, with high-k LaZrO as gate dielectric. The Pd film is prepared by e-beam evaporation and then the LaZrO film is deposited by reactive sputtering in Ar/O2 ambience followed by an annealing in N2 at 400 °C. The OTFT achieves an obvious increase in carrier mobility (to 1.02 cm2/V·s), as compared with its counterpart with heavily-doped silicon gate (0.23 cm2/V·s). Moreover, both samples with LaZrO gate dielectric show higher carrier mobility than a sample with La2O3 gate dielectric and Pd gate electrode.