Electronic Transport Properties of Pentacene Single Crystals upon Exposure to Air

We report the effect of air exposure on the electronic properties of pentacene single crystals. Air can diffuse reversibly in and out of the crystals and controls the physical properties. We discern two competing mechanisms that modulate the electronic transport. The presence of oxygen increases the hole conduction, as in dark four O2 molecules introduce one charge carrier. This effect is enhanced by the presence of visible light. Contrarily, water, present in ambient air, is incorporated in the crystal lattice and forms trapping sites for injected charges.Comment: 16 pages, 3 figure

Charge-transfer induced surface conductivity for a copper based inorganic-organic hybrid

Inorganic-organic hybrids are receiving increasing attention as they offer the opportunity to combine the robust properties of inorganic materials with the versatility of organic compounds. We have studied the electric properties of an inorganic-organic hybrid with the chemical formula: CuCl4(C6H5CH2CH2NH3)2. This material is a ferromagnetic insulator that can easily be processed from solution. We show that the surface conductivity of the hybrid can be increased by five orders of magnitude by covering the surface with an organic electron donor. This constitutes a novel method to dope perovskite-based materials and study their charge transport properties.