These rigid rod-shaped crystals, measuring about 0.5 mm in width and a few millimeters long, have an outsize glow thanks to the arrangement of the molecules within. Their vibrant fluorescence under ultraviolet light was captured on a phone camera by Bidyut Das, a postdoctoral research associate in Samir Kumar Sarkar’s laboratory at the Indian Institute of Technology Guwahati. The lab’s research focuses on creating luminescent organic materials. These particular crystals are made from a compound that has an electron-accepting segment flanked by two electron-donating segments. The molecules pack in such a way that they restrict each other’s movement within the crystal lattice. This confinement keeps the molecules from releasing energy through nonluminescent means and leads to much brighter fluorescence, a useful trait for applications such as organic light-emitting diodes.
Submitted by Bidyut Das