Thermal behaviour and thin film properties of a bis-pyrene compound for organic thin film transistor applications

• 1,4-Bis(octyloxy)-2,5-bis(ethynylpyrene)benzene thin films are synthesized.
• Thermal behaviour of the compound is presented and discussed.
• The structure, morphology and electrical properties of the films are discussed.
• Substrate temperature is discussed with respect to the semiconducting properties.

Following the standard Sonogashira cross-coupling conditions, the reaction between 1,4-diiodo-2,5-bis(octyloxy)benzene with 2.2 equiv. of 1-ethynylpyrene afforded a yellowish bis-pyrene derivative, namely 1,4-bis(octyloxy)-2,5-bis(ethynylpyrene)benzene, that exhibits typical fluorescence and semiconducting properties. Thermal analysis studies are discussed, with emphasis made on the oxidative decomposition and thermal effects. Further on, thin films have been grown by vacuum thermal evaporation, on silicon and quartz substrates. The temperature's influence on the thin film's morphology and electrical properties is investigated. Finally, top-contact thin film transistor configurations are presented and the influence of substrate temperature is discussed with respect to the semiconducting properties.

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