Preparation of PTCDA one-dimensional nanostructures and modulation of their optical properties

3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) nanostructures were prepared on glass substrate in a molecular beam epitaxy (MBE) system via physical vapor deposition (PVD) method. Scanning/transmission electron microscopy (SEM/TEM), X-ray diffraction (XRD), ultraviolet visible absorption spectra (UV-vis) and photoluminescence emission (PL) techniques were applied for the systematic characterizations of the morphologies and optical properties of those nanostructures. It was found that the morphologies of PTCDA nanostructures were mainly affected by substrate temperature (Ts) and the formation of single crystalline PTCDA nanorods and nanowires were correlated well with the traditional vapor-solid (VS) nucleation mechanism. XRD study indicated that only the α-PTCDA was formed regardless of the Ts. However, differences in size and crystallinity of the nanostructures caused a subsequent change in their optical properties.