Study Of Organic Field-effect Transistors And The View Of Application

Organic field-effect transistor(OFET)is a kind of novel electronic device, and is also a kind of active device using electric field to control the electric conductivity of solid materials. Organic field-effect transistor is attracting more and more interests because of its series of advantages over Inorganic field-effect transistor. Through more than ten years of development, huge progresses have been achieved in Organic field-effect transistor. Organic field-effect transistor has already become one of the most important organic electronic devices. Today, field-effect transistor is playing a very important role in electric circuits such as data storage circuit, amplification circuit, logic circuit, rectifier circuit, optic and electric integrated circuit, and flat panel display electronic device. In recent years, the research of organic electronics is being focused on the fields of organic semi-conductor etc. OFET has already been applied into fields of logic gate of annular oscillator, active drive circuit of organic indicator, organic sensor, organic memory device etc. The research on OFET will lay the foundation for the realization of wholly organic circuits. In the fields of electricity and electronics, organic materials have always been used as insulation materials. However, since the electric semi-conductivity of organic pigment was found in the 50's of 20 ith centuries, research on materials of electricity and electronics has quickly developed, for example, solar battery using Schottky contact effect of organic materials with metals, luminescent devices utilizing various luminescent materials, and organic semi-conductor field effect triode etc. For the sake of obtaining more knowledge about organic semi-conductor materials, we first briefly introduce organic semi-conductor materials including the development history of organic semi-conductor materials, advantages of organic semi-conductor materials, as well as familiar organic semi-conductor materials. We also simply depict development, application, and film technique of organic conductive materials, as well as theory of electrical conductivity of organic semi-conductor material. Materials used to manufacture electronic devices should have a high mobility. Common high polymers have very low mobility (only about 10 -4 cm2/V·s) because of randomness of molecular arrangement and a great of impurities and flaws, which dose not match for the requirement for manufacturing electronic devices. In the middle 90's of 20ith centuries, the unit crystal of pantacene is successfully manufactured with its mobility up to 3 cm2/V·s at the room temperature and up to 105 cm2/V·s at the low temperature of 1.7K. Pantacene is one of the most important materials that could be used to manufacture organic field-effect transistor, and is a kind of condensed ring compound made up of 5 paratactic benzene rings. Since 1960, its semi-conducting characteristic has attracted a lot of interests. Recently, the thin film transistor of polycrystal pantacene has been successfully made with the technique of molecular beam deposit at high vacuum, whose mobility at the room temperature is 3.8×10-2 cm2/V·s . Compared with inorganic semi-conductor field-effect transistor, pantacene field-effect transistor has a special property, namely the bipolar property. If a positive bias is applied on the gate electrode and an electronic passage is induced at the interface between the insulator layer and pantacene, an inversion layer would be generated; if a negative bias is applied on the gate electrode and a hole passage is induced at the interface, an accumulation layer would be generated. This property is...