Congratulations to group members Peter Banks and Mark Mancini on their recent publication in the Journal of Materials Chemistry C. This study was a joint effort between the Ruggiero Group and long-time collaborators and main developers of the CRYSTAL software package, Prof. Alessandro Erba and Dr. Jefferson Maul, of the University of Torino in Italy.

In this work, Peter and Mark worked on understanding how to use low-frequency vibrational spectroscopy, coupled with anharmonic solid-state density functional theory simulations, to extract the interatomic forces in a pair of organic semiconductor crystals. They then used these forces to determine the thermoelastic response, i.e., the materials’ elastic response as a function of temperature, in a completely contactless and non-destructive manner. This represents an important advance in the field of materials chemistry, as traditional mechanical measurements require challenging and delicate sample preparation and complex experimental apparatus.

Thermoelastic response of crystalline rubrene.
The thermoelastic response of crystalline rubrene, one of the most well-studied organic semiconducting solids. The results show that the Young’s moduli of rubrene soften considerably as temperature is increased, resulting in a more deformable solid at higher temperatures.

This work has an important impact for organic semiconductors in general, as these materials show great promise for use in flexible devices. The ‘flexible’ aspect requires a detailed understanding of the mechanical response of the material, in order to realize practical devices that operate as intended in real world applications.

This publication represents the culmination of two-years of undergraduate research for Mark Mancini, who worked under Prof. Adam Whalley before joining the Ruggiero Group. Mark was responsible for synthesizing and crystallizing the samples utilized in this study, as well as performing much of the characterization and calculations along with Peter. Mark was the recipient of the A. Paul Krapcho Chemistry Summer Fellowship, which was instrumental in this work.

Congratulations to everyone involved in this fantastic piece of work!

Categories: New Publication!