New discotic-shaped azomethines with triphenylamine moieties: Thermal, structural behaviors and opto-electrical properties

Three discotic-shaped azomethines were prepared by condensation reactions of 4,4′,4″-triformyltriphenylamine with various aliphatic monoamines. Their chemical structures were confirmed by FTIR, 1H, 13C NMR spectroscopies, as well as elemental analysis. Thermal properties of the azomethines were examined by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction (WAXRD, SAXRD). Moreover, UV–vis properties of the thin films of the compounds were investigated on the quartz substrate without and with [6,6]-phenyl C61 butyric acid methyl ester (PC61BM). Current–voltage (I–V) measurements were performed on ITO/compound/Al, ITO/compound:PC61BM/Al and ITO/PEDOT:PSS/compound:PC61BM/Al devices in the dark and during irradiation with light (under illumination 1000 W/m2). Additionally, the compounds were tested using various AFM techniques.