Organic and polymer transistors for electronics

investigated for a number of low-cost, large-area applications, particularly those that are compatible with flexible plastic circuits1-12. The organic materials that have been used as active semiconductor materials include both sublimed and solutionprocessed semiconductors such as pentacene6,7,13-24, oligothiophenes21,22,25-32, hexadecafluorocopper phthalocyanine28-33, polythiophene8,32,34-39, etc. This choice of materials opens up several possibilities to develop integrated circuit technologies based on organic transistors for various largearea, low-cost applications. Organic field-effect transistors (OFETs) have been proposed for applications such as display switches38, display drivers39,40, radio-frequency identification (RFID) tags1,9,10,22,41-43, and sensors44,45. Organic/polymer transistors have also been integrated with optical devices such as light-emitting diodes (LEDs), electrophoretic cells11,46,47, and liquid crystals 6,12,24,48, to name but a few examples. In recent years, the complexity of circuits made with organic transistors has increased, and the first large-scale (864 transistor) complementary circuits have been fabricated29. Researchers have reported active-matrix displays and electronic paper with hundreds or thousands of transistors46. The speed of ring oscillators is now in excess of 100 kHz and the clock speed of clocked sequential circuits such as registers is in the kilohertz range. There is a need to develop technologies for relatively fast circuits (~100 kHz clock rate) for use in RFID tags and display drivers. One way to accomplish this is with a Some of the major application areas for organic and polymeric transistors are reviewed. Organic complementary devices are promising on account of their lower power dissipation and ease of circuit design. The first organic large-scale integrated circuits have been implemented with this circuit approach. Organic transistor backplanes are ideally suited for electronic paper applications and other display schemes. Lowcost and other processing advantages, as well as improving performance, have led to organic-based radio frequency identification tag development. The chemical interaction between various organic and polymer semiconductors can be exploited in chemical and biological sensors based upon organic transistors.