ABSTRACT
Organic semiconductors continue to raise considerable excitement as potential alternative channel materials for traditional inorganic materials in thin-fi lm transistors (TFTs). Progress in the synthesis and purifi cation of organic semiconductors and in the processing of these materials into devices has enabled organic TFTs to be fabricated with fi eld-effect mobilities of ~1 cm2/V-s and current modulation of 105-108, comparable to those benchmarked by amorphous silicon [1,2]. The continued push to reduce the cost of electronic devices in existing applications and the opportunities and increasing demand to incorporate electronics in new applications have driven research in organic electronics. The reduced costs of organic devices originate largely from the simple, low-cost techniques by which organic materials may be deposited and patterned and by which devices may be fabricated. These are processes such as thermal evaporation and, preferably, solutionbased techniques, including spin-coating, dip-coating, and screen, inkjet, or microcontact printing. The low-temperature conditions, at or near room temperature, employed by these techniques enable organic semiconductors to be deposited on a wider range of substrate materials than typically possible for inorganic semiconductors, which opens opportunities to fabricate organic electronics on plastic substrates for fl exible applications [3-7]. The combination of low-cost and low-temperature processing makes organic TFTs attractive for cheap, large-area, lightweight, and fl exible applications, such as low-cost logic, identifi cation tags, smartcards, and many form factors incorporating displays.
