Optical and structural study of thin film of polyazomethine with triphenylamine unit prepared via spin-coating method

Abstract

A conjugated aromatic polyazomethine (PAZ) with triphenylamine (TPA) unit in the main chain was obtained by high temperature solution polycondensation of diformyltriphenylamine with o-dianisidine (Fast blue B). A major feature of the PAZ containing TPA unit in the main chain is their complete solubility in comparison with PAZ obtained from terephthaldicarboxaldehyde and o-dianisidine (abbreviated hereinafter as PAZ1). Both polymers were analyzed by thermogravimetric analysis and FTIR spectroscopy. UV–vis absorption, X-ray diffraction (X-ray) and Atomic Force Microscopy (AFM) techniques were used to probe the optical properties and morphology of the thin films of the PAZ prepared by spin-coating technique on the glass and quartz substrate. Thickness of the PAZ thin layer on the glass and quartz substrate were determined by ellipsometer at the range 150–220 nm. The optical band gap value (E g) of the thin films PAZ was detected at 2.45 eV. The current–voltage (I–V) characteristic was measured to confirm semiconductor nature of the PAZ.