Chiral-induced circularly polarized light emission from a single-molecule junction

Abstract

In the present work we theoretically analyze electroluminescence occurring in a biased single-molecule junction with a chiral bridge imitated by a helical chain. We show that optical transitions between electron states of the chiral linker may result in the emission of circular polarized light whose handedness depends on both direction of propagation and the polarity of the bias voltage provided that the coupling between the bridge sites is sufficiently strong. The mechanism controlling this specific light emission does not depend on the magnetic moments and spin-orbit interactions. It rather relies on the chiral properties of the bridge molecule and on the distribution of the bias voltage between the electrodes in the junction.