Electrophoretically deposited polyaniline/ZnO nanoparticles for p–n heterostructure diodes

A p–n heterostructure diode of polyaniline (PANI) and ZnO nanoparticles was prepared by the electrophoretic deposition of PANI on ZnO nanoparticles thin film coated fluorine doped tin oxide (FTO) glass at room temperature. The morphological, structural and optical studies substantiated the penetration, bonding and the interaction of PANI molecules with ZnO nanoparticles thin film substrates. The prominent blue shift in UV-Vis spectra indicated the strong interaction between ZnO and PANI through the decreased degree of orbital overlap between ππ electrons of the phenyl rings with the lone pair of the nitrogen atom in the PANI molecules. The I–VI–V characteristics of PANI/ZnO heterostructure diode showed weak rectifying behavior with non-linear nature of I–VI–V curve of PANI/ZnO heterostructure device. The typical ohmic behavior was observed by the I–VI–V characterization of PANI/ZnO heterostructure at the interface of PANI and ZnO thin film layer without top Pt thin layer contact.