title: Charge transport in electrically doped amorphous organic semiconductors.
abstract: This article reviews recent progress on charge generation by doping and its influence on the carrier mobility in organic semiconductors (OSs). The doping induced charge generation efficiency is generally low in OSs which was explained by the integer charge transfer model and the hybrid charge transfer model. The ionized dopants formed by charge transfer between hosts and dopants can act as Coulomb traps for mobile charges, and the presence of Coulomb traps in OSs broadens the density of states (DOS) in doped organic films. The Coulomb traps strongly reduce the carrier hopping rate and thereby change the carrier mobility, which was confirmed by experiments in recent years. In order to fully understand the doping mechanism in OSs, further quantitative and systematic analyses of charge transport characteristics must be accomplished.
authors: Department of Materials Science and Engineering, Seoul National University, Seoul, 151-744, South Korea.
authors: Seung-Jun
authors: SJ
authors: Yoo
authors: Department of Materials Science and Engineering, Seoul National University, Seoul, 151-744, South Korea.
authors: Jang-Joo
authors: JJ
authors: Kim
mesh_terms: D004560:Electricity; D004583:Electrons; D008094:Lithium / Q000737:chemistry; D009570:Nitriles / Q000737:chemistry; D009930:Organic Chemicals / Q000737:chemistry*; D011789:Quantum Theory; D012666:Semiconductors
chemical_list: D009570:Nitriles; D009930:Organic Chemicals; C013703:tetracyanoquinodimethane; D008094:Lithium
keywords: charge generation efficiency; charge mobilities; coulomb traps; doping; organic semiconductors