Environmental Effects on the Performance of Small‐Molecule Organic Thin‐Film Transistors

Abstract

Abstract Electrical measurements are performed on a bottom‐gate bottom‐contact organic thin‐film transistor with 2,8‐difluoro‐5,11‐bis(triethylsilylethynyl) anthradithiophene (diF‐TES ADT) (diF‐TES ADT) as the active layer, varying the relative humidity of the environment surrounding the transistor. The results strongly indicate that water negatively impacts the electrical performance of the transistor and that the ingress of water is dynamic provided that the organic semiconductor layer is not encapsulated. It is found that the change can be reversed and the performance restored by removing the source of water. The drain current and threshold voltage of the transistor varied linearly when the relative humidity is changed from 35% to 7%, suggesting that the transistor can be used as a humidity sensor.

Keywords

• charge transport
• diF‐TES ADT
• organic semiconductors
• OTFT (organic thin‐film transistors)
• Sensor