Organic semiconductor: Difference between revisions
Deeceevoice (talk | contribs) self-edit; I hate "surmise." Sounds pretentious. Tweak. |
Removed some desinformation (note: Melanin is not a mainstream research topic in this area), added some information |
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An '''organic semiconductor''' is an [[Organic compound|organic]] |
An '''organic semiconductor''' is an [[Organic compound|organic]] compound that exhibits similar properties to inorganic [[semiconductors]]. That is, hole and electron conduction and a [[band gap]]. Similar to anorganic semiconductors, organic semiconductors can be doped. Highly doped organic semiconductors, for example [[Polyaniline]] (Ormecon) and [[PEDOT:PSS]], are also known as [[Organic metals]]. |
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Generally speaking, electronically neutral molecules gathered by [[Van der Waals force]] are composed of organic crystals. Therefore, almost all organic solids are [[insulator]]s, which do not conduct electricity easily. However, in crystals that consist of molecules that have the π-conjugate system, electrons can move via π-electron cloud overlaps. That is why these crystals can conduct electricity. Polycyclic [[aromatic hydrocarbon]]s and [[phthalocyanine]] salt crystals are examples of this type of organic semiconductor. |
As the origin of [[conductivity]], two kinds of carriers are well known. One is a [[Pi_bond#Pi_Bonds|π-electrons]] and the other is unpaired electrons. Generally speaking, electronically neutral molecules gathered by [[Van der Waals force]] are composed of organic crystals. Therefore, almost all organic solids are [[insulator]]s, which do not conduct electricity easily. However, in crystals that consist of molecules that have the π-conjugate system, electrons can move via π-electron cloud overlaps. That is why these crystals can conduct electricity. Polycyclic [[aromatic hydrocarbon]]s and [[phthalocyanine]] salt crystals are examples of this type of organic semiconductor. |
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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. |
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. |
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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-PF<sub>6</sub> complex. |
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-PF<sub>6</sub> complex. |
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Organic semiconductors are attractive as active elements in [[Optoelectronics|optoelectronic]] devices such as [[ |
Organic semiconductors are attractive as active elements in [[Optoelectronics|optoelectronic]] devices such as [[light emitting diode]]s (LED), [[solar cell]]s and also [[field effect transistor]]s (FET). There are many strong points of organic semiconductors, such as easy fabrication, mechanical flexibility, and low cost. |
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Both short chain ([[oligomers]]) and long chain ([[polymers]]) organic semiconductors are known. Typical examples for semiconducting oligomers are: [[Pentacene]], [[Anthracene]] and [[Rubrene]]. Some semiconducting polymers are: [[Poly(3-Hexylthiophene)|P3HT]], [[Poly(p-phenylvinylene)|PPV] and F8BT. |
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Also Melanin is an organic semiconductor. It is also a [[neuropeptide]], a [[polymer|polymeric]] substance that influences [[neural]] activity and mediates the conduction of light, heat and kinetic energy. As such, it is currently a subject of intense interest in biotech research and development, most notably in [[plastic electronics]] and [[nanotechnology]]. Research indicates that melanin, in both its organic and synthesized forms, may one day routinely supplant conventional inorganic materials like gallium arsenide and silicon in high-tech devices such as microchips. |
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==See also== |
==See also== |
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*[[Conductive polymers]] |
*[[Conductive polymers]] |
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*[[Melanin]] |
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[[Category:Molecular electronics]] |
[[Category:Molecular electronics]] |
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Revision as of 21:36, 11 March 2005
An organic semiconductor is an organic compound that exhibits similar properties to inorganic semiconductors. That is, hole and electron conduction and a band gap. Similar to anorganic semiconductors, organic semiconductors can be doped. Highly doped organic semiconductors, for example Polyaniline (Ormecon) and PEDOT:PSS, are also known as Organic metals.
As the origin of conductivity, two kinds of carriers are well known. One is a π-electrons and the other is unpaired electrons. Generally speaking, electronically neutral molecules gathered by Van der Waals force are composed of organic crystals. Therefore, almost all organic solids are insulators, which do not conduct electricity easily. However, in crystals that consist of molecules that have the π-conjugate system, electrons can move via π-electron cloud overlaps. That is why these crystals can conduct electricity. Polycyclic aromatic hydrocarbons 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.
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.
Organic semiconductors are attractive as active elements in optoelectronic devices such as light emitting diodes (LED), solar cells and also field effect transistors (FET). There are many strong points of organic semiconductors, such as easy fabrication, mechanical flexibility, and low cost.
Both short chain (oligomers) and long chain (polymers) organic semiconductors are known. Typical examples for semiconducting oligomers are: Pentacene, Anthracene and Rubrene. Some semiconducting polymers are: P3HT, [[Poly(p-phenylvinylene)|PPV] and F8BT.
Also Melanin is an organic semiconductor. It is also a neuropeptide, a polymeric substance that influences neural activity and mediates the conduction of light, heat and kinetic energy. As such, it is currently a subject of intense interest in biotech research and development, most notably in plastic electronics and nanotechnology. Research indicates that melanin, in both its organic and synthesized forms, may one day routinely supplant conventional inorganic materials like gallium arsenide and silicon in high-tech devices such as microchips.