Field-effect transistors made by functionalized pentacene with logic gate applications

Funtionalized pentancene, 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene), field-effect transistors (FET) were made by thermal evaporation or solution deposition methods and the temperature dependent mobility was measured. The field-effect mobility (μFET) activation energy is gate voltage dependent. At low gate voltage, activated conduction is dominant with Ea ∼ 0.27 eV, slightly smaller than the bulk value, and the activation energy decreases with increasing gate voltage. This is ascribed to traps in the film. A non-monotonic temperature dependence is observed at high gate voltage (VG<−30 V) with Ea ∼ 60 – 170 meV at lower temperatures below the mobility maximum. Realization of simple logic gate circuits such as NOT (inverter), NOR, and NAND is demonstrated.