Influence of annealing on the structure formation and optical absorption parameters of 2-(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-ylimino)-2-(4-nitrophenyl) acetonitrile thin films

Abstract

The effect of annealing temperatures (343 and 425) K on structure formation and optical absorption of 2-(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-ylimino)-2-(4-nitrophenyl)acetonitrile (DOPNA) thin films has been reported. The structural properties are investigated by X-ray diffraction and transmission electron microscope techniques. The electronic transitions of DOPNA thin films are investigated in terms of ultravioletvisible (UV-vis) spectroscopy. The absorption coefficient of films has been calculated and analyzed in order to determine the type of inter-band electronic transition as well as the value of optical band gap for films. The films have been found to have indirect allowed optical band gap: which was found to decrease by increasing annealing temperatures.