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Chapter 3. Organic Conductor. Conductivity Of Organic Materials.

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Presentation on theme: "Chapter 3. Organic Conductor. Conductivity Of Organic Materials."— Presentation transcript:

1 Chapter 3. Organic Conductor

2 Conductivity Of Organic Materials

3 Conductivity  = en  n: number of carriers; m: mobility of the carriers

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10 Electronic structures of Organic Molecules (1) Core electrons. (2)  electrons, localized between two atoms. (3) n electrons, located at a particular heteroatom, usually have high orbital energy and could be promoted easily. (4)  electrons, delocalized over an array of atoms, usually have high MO energy and could be promoted easily.

11 Discovery of Conducting Organic Crystals

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26 Conductivity is controlled by the phthalocyanine ring. The metal core does not interfere the conductivity. Phthalocyanine channel I-I-

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29 Chain length: Si:120  30 Ge: 74  40 Sn:100  40

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31 Conjugated Polymers

32 Polyacetylene

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34 (1) Could a charge through delocalize through the  array? (2) Is there any one dimensional conductor in principle? (3) How a charge hop from one  array to another adjacent  array?

35 Electrical conductivity of polyacetylene Cis-PA  = 1.7 x 10 -9 S/cm Trans-PA  = 4.4 x 10 -5 S/cm I 2 doped  = 5.5 x 10 2 S/cm AsF 5 doped  = 1.2 x 10 3 S/cm Electrochemical Oxidation  = 1 x 10 3 S/cm Li doped  = 2 x 10 2 S/cm Na doped  = 10 1 -10 -2 S/cm

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43 Polyparaphenylene (PPP)

44 Drawbacks: low solubility. Alkyl side chain for enhancing solubility

45 When no of phenylene units is larger than 12, the material becomes metallic after doped

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47 Synthesis of Polythiophenes PEDOT.PSS

48 Polyaniline (PANI) Conductor Insulator

49 Preparation

50 Doping and Undoping PANI doped with H 3 PO 4 was found to be most stable.

51 Conductivity could go up to 200-400 S/cm after doping

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53 Poly-4-phenylene-(E)-vinylene (PPV) Highly insoluble Precursor for thin film formation

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55 Knoevenagel Condensation Wittig Horner reaction Hsieh, B. R. (Xerox)

56 Lithium Battery

57 Rechargeable Battery With PA electrode Oxidation (CH) x +xy(ClO 4 - ) [(CH) +y (ClO 4 - ) y]x + xye - Reduction (CH) x +xy(Li + ) + xye - [(CH) -y (Li + ) y]x

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60 Battery Structures based on PA (a)P type (CH) x anode/Li cathode (b)P type (CH) x anode/n type (CH) x cathode (c)n type (CH) x anode /Li cathode When the battery is doped at 6%, the Voltages are 3.7, 2.5, 1.2V respectively

61 Rechargeable Battery with poly-4-phenylene electrode

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63 Organic Photoconductors

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70 Scher-Montrol Theory on dispersive photocurrent

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75 Organic Photoconductors (1) Conjugated polymers (2) Polymers containing aromatic side-chains (3) Small molecules

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84 Organic Solar Cell

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86 Example

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91 Self-Organized Discotic Liquid Crystals for High-Efficiency Organic Photovoltaics

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