Diode characteristics and metal ion sensing features of a conjugated macromolecular system based on indolocarbazole-thiophene

A poly(indolocarbazole-thiophene) based high molecular weight polymer (ICZP3) was synthesized by Sonogashira coupling reaction and characterized by FTIR, H-1 NMR, C-13 NMR analysis. An enhanced solubility for it in organic solvents was achieved by the incorporation of alkyl chains on to the nitrogen atom of the backbone unit. It exhibits good thermal stability with interesting photonic performance, and processability. The incorporation of electron-transporting monomer moieties has been found to induce a balanced charge density in it, suitable for diode applications. Its conduction mechanism has been found to resemble well with the space charge limited current model, and involves Schottky type behaviour when assembled into an ITO/ICZP3/Al device fabricated. An interesting additional feature observed for ICZP3 is its very high Hg2+ sensing. The ICZP3 system is found to be a promising candidate for semiconductor applications and sensing.