Atomic-resolved hierarchical structure of elastic ?-conjugated molecular crystal for flexible organic photonics

Achieving multifunctional elastic conjugated molecular crystals is a huge challenge for flexible optoelectronic application due to the difficulty in precise control of non-covalent interactions that cause an inherent rigidity and brittleness impression of crystals. Here, we demonstrated the atomic-resolved structural perturbations of a racemic fluorenol-carbazole (PhOH-Cz) elastic p-conjugated molecular crystal for flexible naked-eye-visible and color-tunable afterglow waveguide. Its outstanding elastic property is derived from the synergistic effect of interlayer hierarchical slippage and the intralayer molecule perturbations, which provide a physical platform to absorb and release the mechanical energy and avoid brittle fracture. The atomic-resolved structural perturbations in the bent elastic crystal visually confirmed the molecular movements leading to breaking and re-forming of hydrogen-bonding interactions. These exceptional observations will be useful to systematically investigate photophysical behavior of conjugated materials. Finally, the flexible naked-eye-visible and color-tunable afterglow wave guides that were fabricated confirmed the potential application of elastic crystal in flexible organic photonics.

Automated summary

This study demonstrates the atomic-resolved structural perturbations of an elastic conjugated molecular crystal, achieving flexible naked-eye-visible and color-tunable afterglow wave guides. The outstanding elastic property of the crystal is derived from the synergistic effect of interlayer hierarchical slippage and intralayer molecule perturbations, allowing for the absorption and release of mechanical energy to avoid brittle fracture. The observations provide insights into the photophysical behavior of conjugated materials and the potential application of elastic crystals in flexible organic photonics.