Field-Effect Transistors Made by Functionalized Pentacene with Logic Gate Applications

Funtionalized pentacene, 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.