title: An organic thyristor.
abstract: Thyristors are a class of nonlinear electronic device that exhibit bistable resistance--that is, they can be switched between two different conductance states. Thyristors are widely used as inverters (direct to alternating current converters) and for the smooth control of power in a variety of applications such as motors and refrigerators. Materials and structures that exhibit nonlinear resistance of this sort are not only useful for practical applications: they also provide systems for exploring fundamental aspects of solid-state and statistical physics. Here we report the discovery of a giant nonlinear resistance effect in the conducting organic salt theta-(BEDT-TTF)2CsCo(SCN)4, the voltage-current characteristics of which are essentially the same as those of a conventional thyristor. This intrinsic organic thyristor works as an inverter, generating an alternating current when a static direct-current voltage is applied. Whereas conventional thyristors consist of a series of diodes (their nonlinearity comes from interface effects at the p-n junctions), the present salt exhibits giant nonlinear resistance as a bulk phenomenon. We attribute the origin of this effect to the current-induced melting of insulating charge-order domains, an intrinsically non-equilibrium phenomenon in the sense that ordered domains are melted by a steady flow.
authors.affiliation: Department of Applied Physics, Waseda University, Tokyo 169-8555, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Sawano
authors.forename: I
authors.initials: I
authors.lastname: Terasaki
authors.forename: H
authors.initials: H
authors.lastname: Mori
authors.forename: T
authors.initials: T
authors.lastname: Mori
authors.forename: M
authors.initials: M
authors.lastname: Watanabe
authors.forename: N
authors.initials: N
authors.lastname: Ikeda
authors.forename: Y
authors.initials: Y
authors.lastname: Nogami
authors.forename: Y
authors.initials: Y
authors.lastname: Noda