https://www.sciencedaily.com/releases/2021/03/210319183948.htm

Scientists were interested in observing the relationship between the structure of materials and their ability to conduct electricity. To this end, they measured the speed of propagation of electrons in crystals formed by these molecules. In their study, the authors compared two perylene diimide derivatives, which are semiconducting molecules of interest because of their use on flexible devices, smart clothes or foldable electronics. The two compounds encompassed within the study have similar chemical structure but featured very different conduction properties.

With the goal of determining what caused this difference, the research group was able to establish that the different molecular vibrations composing the material were responsible for the different electrical behaviour observed in devices. "For a current to flow through a material, electrons must 'hop' from one molecule to the neighbouring one. Depending on the level of 'movement' of the molecules, which depends on the amplitude and energy of the related vibrations (called phonons), the electrons can move more or less easily through the material," explains Professor Orgiu, whose research team is the first to demonstrate which vibrations have the greatest influence on electron flows.