Physical Review Letters · 2006 · 60 citations · 10 references
EngineeringOrganic ElectronicsOrganic ChemistryCurrent-voltage CharacteristicsChemistryElectronic StructureCharge TransportCharge Carrier TransportPhysicsPower LawOrganic SemiconductorPhysical ChemistryQuantum ChemistryElectrochemistryOrganic Charge-transfer CompoundLayered Organic CrystalsElectronic MaterialsNatural SciencesCondensed Matter PhysicsApplied PhysicsScreening Length
The current-voltage characteristics of layered organic crystals theta-(BEDT-TTF)2MZn(SCN)4 (M = Cs, Rb) follow the power law with a large exponent (e.g., 8.4 at 0.29 K for M = Cs) over a wide range of currents in the low-temperature insulating state. The power-law characteristics are attributed to electric field-induced unbinding of electron-hole pairs that are thermally excited in the background of the two-dimensional charge order. The magnitude of crossover electric fields from Ohmic to the power-law characteristics indicates that the electron-electron Coulomb interaction is significantly long-ranged: The screening length is greater than 10 molecule sites.
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Charge Ordering in Organic ET Compounds
Journal of the Physical Society of Japan · 2000 · 345 citations · Full text