Anisotropic perylenediimide/polycarbonate composites produced by a single batch solution based method

Abstract

The continuous anisotropic organic semiconductor/dielectric composites consisting of a top, unidirectionally oriented crystalline layer of perylenediimide derivative (2,9-di(pent-3-yl)-anthra[1,9-def:6,5,10-d′e′f′]diisoquinoline-1,3,8,10-tetrone) (PTCDI-C5(3)) and a bottom layer of poly(bisphenol A carbonate) (PC) support were obtained in a one batch solution process, with the use of the so called the zone-casting method. Scanning electron microscopy images have shown that the top PTCDI-C5(3) layer is made of long, parallel crystallites in the form of ribbons that exhibit birefringence when placed between a pair of crossed polarisers in the optical microscope. Furthermore, the polarised UV–Vis absorbance and photoluminescence experiments revealed that the alignment of the PTCDI-C5(3) molecules is caused by π–π interactions between the conjugated perylene cores, and their stacks are parallel to the long axis of the crystallites and to the polymer surface. The high value of the calculated polarisation ratio, which equals 0.64, constitutes a confirmation of a high degree of molecular order within the semiconducting component of the zone-cast composites.