title: Trap healing and ultralow-noise Hall effect at the surface of organic semiconductors.
abstract: Fundamental studies of intrinsic charge transport properties of organic semiconductors are often hindered by charge traps associated with static disorder present even in optimized single-crystal devices. Here, we report a method of surface functionalization using an inert non-conjugated polymer, perfluoropolyether (PFPE), deposited at the surface of organic molecular crystals, which results in accumulation of mobile holes and a 'trap healing' effect at the crystal/PFPE interface. As a consequence, a remarkable ultralow-noise, trp-free conduction regime characterized by intrinsic mobility and transport anisotropy emerges in organic single crystals, and Hall effect measurements with an unprecedented signal-to-noise ratio are demonstrated. This general method to convert trap-dominated organic semiconductors to intrinsic systems may enable the determination of intrinsic transport parameters with high accuracy and make Hall effect measurements in molecular crystals ubiquitous.
authors.affiliation: 1] Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA [2].
authors.forename: B
authors.initials: B
authors.lastname: Lee
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.forename: D
authors.initials: D
authors.lastname: Fu
authors.forename: H T
authors.initials: HT
authors.lastname: Yi
authors.forename: K
authors.initials: K
authors.lastname: Czelen
authors.forename: H
authors.initials: H
authors.lastname: Najafov
authors.forename: V
authors.initials: V
authors.lastname: Podzorov