Phenothiazine-Based\nOrganic Single Crystal with Flexibility,\nPiezochromism, and Fluorescent Waveguide Properties

The development of organic single crystals with combined\nproperties,\nincluding flexibility, piezochromism, and optical waveguiding, holds\nparamount importance for advancing new optoelectronic devices. Herein,\na long, needle-shaped organic plastic crystal based on phenothiazine\nwas fabricated, and it emits bright yellow-green fluorescence under\nultraviolet light excitation. Investigations into its piezochromism\nproperty <i>via</i> a diamond anvil cell revealed that this\nphenothiazine-based material performed a pressure-induced emission\nenhancement effect under relatively low pressures (0–0.6 GPa).\nFurthermore, optical waveguide tests were conducted on the crystal\nin both linear and plastic deformation states, and the results revealed\nno significant attenuation of its light transmission properties. This\nphenothiazine-based crystal exhibits flexibility, piezochromism, and\noptical waveguiding properties, which will be valuable as a sensing\nmaterial for developing integrated pressure sensors.