Sharp and bright photoluminescence emission of single-crystalline diacetylene nanoparticles

Abstract

Amorphous nanoparticles (NPs) of diacetylene (DA) molecules were prepared by using a reprecipitation method. After crystallization through a 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 using high-resolution transmission electron microscopy (HR-TEM) and wide angle X-ray scattering (WAXS). The luminescence color and the 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 compared with amorphous DA NPs and the main PL peak of the crystalline DA NPs exhibits relatively narrow, blue-shift phenomena due to enhanced interactions between the DA molecules in the nano-size crystal structure.