Intrinsic negative-resistance effect in mixed-stack charge-transfer crystals

Abstract

A stable and reproducible negative-resistance effect has been observed in various mixed-stack organic charge-transfer crystals having ionicities close to the neutral-ionic phase boundary. Systematic studies on several kinds of single crystals indicate that this effect is an intrinsic property, arising from the dynamics of the charge-carrying defects with fluctuating molecular valence in the one-dimensional (1D) molecular stacks. A microscopic mechanism of the negative resistance is proposed taking account of the three-dimensional electrostatic interaction between 1D stacks.