Perylene Tetracarboxylic Diimide (PTCDI) nanowires: Synthesis and characterization

Abstract

Perylene tetracarboxylic diimide (PTCDI) is a material widely used in organic thin-film-based electronic and optoelectronic devices, such as transistors, light-emitting diodes and photovoltaic cells. It has been reported recently that copper phthalocyanine (CuPc) solar cell performance can be significantly improved if CuPc forms nanowires instead of flat film surface. However, nanostructures of PTCDI reported up to date include only self-assembled nanobelts in a solution, which is not suitable for small molecule device applications. For organic solar cells based on small molecules, vapor deposition organic nanostructure fabrication is of considerably more interest. In this work, fabrication of PTCDI nanostructures by evaporating PTCDI powder in Ar flow has been performed. The nanostructures were grown on glass, quartz and ITO (indium-tin oxide) substrates which were located downstream from the source. The obtained nanostructures were characterized by scanning electron microscopy (SEM) and photoluminescence (PL). The effect of substrate type, substrate temperature, gas flow rate and fabrication time on the resulting nanostructures were investigated. The synthesis conditions had significant effect on the morphologies of the resulting nanostructures, and the optimal fabrication conditions for device applications are discussed.