| Organic Semiconductor |
Article Index for Organic |
Website Links For Organic |
Information AboutOrganic Semiconductor |
| CATEGORIES ABOUT ORGANIC SEMICONDUCTOR | |
| organic semiconductors | |
| conductive polymers | |
| molecular electronics | |
|
Two kinds of carriers mediate conductivity in organic semiconductors. These are π-electrons and unpaired electrons. Almost all organic solids are Insulator s. However, when their constituent molecules have π-conjugate Systems , electrons can move via π-electron Cloud overlaps. Polycyclic Aromatic Hydrocarbon s and Phthalocyanine salt crystals are examples of this type of organic semiconductor. In some organic molecules, even unpaired electrons can stay stable for a long time. In such cases, unpaired electrons will be the carriers. This type of semiconductor is also obtained by pairing an electron donor molecule and an electron acceptor molecule and is called a Charge Transfer Complex . For a history of the field, see: "An Overview of the First Half-Century of Molecular Electronics" by Noel S. Hush, Ann. N.Y. Acad. Sci. 1006: 1–20 (2003). Some key events: The study of a charge-transfer complexes began with the discovery of the strikingly high conductivity of Perylene-iodine Complex (8 Ωcm) in 1954 . In 1972 , the TTF-TCNQ Complex , whose conductivity is metallic, was synthesized. In 1980 , Superconductivity was observed in TMTSF-PF6 complex. McGinness, Corry, and Proctor first reported a high conductivity state, hallmark negative differential resistance in a Polyacetylene ( Melanin ) and the first organic semiconductor electronic device. This was a voltage-controlled switch (Science, vol 183, 853-855 (1974)). Their original "gadget" is now in the Smithsonian 's collection of early electronic devices. Organic semiconductors are attractive as active elements in Optoelectronic devices such as Organic Light Emitting Diode s (OLED), Organic Solar Cell s, Organic Field Effect Transistors (OFET), electrochemical transistors and recently also in biosensing applications. There are many strong points of organic semiconductors, such as easy fabrication, mechanical flexibility, and low cost. Melanin is a semiconducting polymer currently of high interest to researchers in the field of Organic Electronics in both its organic and synthesized forms. Both short chain , Poly(p-phenylene Vinylene) and F8BT. SEE ALSO |
|
|