OFET

An Organic Field-Effect Transistor (OFET) is a class of thin film transistors based on organic semiconductors.

Organic semiconductors were discovered in 1940 . Because they are low performance materials, the TFT structure is the best suited device configuration. Except a handful of isolated preliminary reports, work on organic thin-film transistors only emerged in the late 1980s using both polymers and small molecules . It is only when the mobility of organic semiconductors approached, and even surpassed, that of amorphous silicon that several industrial groups decided to embark into research programs on OTFTs.

Generally speaking, a TFT is composed of three parts – an insulator, a semiconducting thin film, and three electrodes. Two of the electrodes, the source and the drain electrodes, are in direct contact with the semiconductor; the third, the gate, is isolated from the semiconductor by the insulator layer. The basic fabrication scheme consists of piling up thin films of the different elements. Because most organic semiconductors are fragile materials, the deposition of organic semiconductors on the insulator is much easier than the opposite. So the large majority of current OTFTs are built according to the bottom-gate architecture.

The availability of organic semiconductor devices, combined with the power of synthetic organic chemistry, may open up the way to completely new device configuration, fabrication processes, and applications. One promising envision is OFET can be fabricated by solution processing method - for example, spin-coating, printing, and drop casting, which enables large area, low-cost production of organic electronics. New products include radio-frequency identification (RFID) tags , that might replace bar codes found on nearly all consumer products today, single-use electronics, low-cost sensors, and flexible displays.