Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, Vol.252, 571-579, 1994
Optically Induced Transient Conductivity in Quasi-Metallic DCNQI Radical-Ion Salts
Multi-component conductivity changes in metallic radical ion salt films are induced by optical excitation. First experiments on polycrystalline films of the 2,5-dimethyl-dicyanoquinonediimine copper salt, (DMe-DCNQI)(2)Cu and the corresponding low-dimensional chloro-methyl and bromo-methyl salts, (ClMe-DCNQI)(2)Cu and (BrMe-DCNQI)(2)Cu, respectively, are presented. The time response of the conductivity consists of three components. These are interpreted a) by a possible contribution of higher conduction bands which might explain the fast response (tau<5 ns), b) by detrapping of charge carriers (tau>40 ns), and c) by a temperature effect (tau approximate to 1 ms). In single crystals, the fast response is also detected, while the other contributions are less pronounced.