  Amorphous nanoparticles (NPs) of diacetylene (DA) molecules were prepared by
using a reprecipitation method. After crystallization through solvent-vapor
annealing process, the highly crystalline DA NPs show different structural and
optical characteristics compared with the amorphous DA NPs. The single crystal
structure of DA NPs was confirmed by high-resolution transmission electron
microscopy (HR-TEM) and wide angle X-ray scattering (WAXS). The luminescence
color and photoluminescence (PL) characteristics of the DA NPs were measured
using color charge-coupled device (CCD) images and high-resolution laser
confocal microscope (LCM). The crystalline DA NPs emit bright green light
emission compared with amorphous DA NPs and the main PL peak of the crystalline
DA NPs exhibits relative narrow and blue shift phenomena due to enhanced
interaction between DA molecular in the nano-size crystal structure.
