Spectroscopic and microscopic studies of thermally treated Vanadyl 2,9,16,23-tetraphenoxy-29H,31H-phthalocyanine thin films

This paper reports the structure, morphology and optical properties of Vanadyl 2,9,16,23-tetraphenoxy-29H,31H-phthalocyanine (VOPcPhO) pristine and annealed thin films for photo-devices application. The VOPcPhO thin films have been prepared by spin-coating technique on glass substrates using VOPcPhO solution in chloroform. The UV/vis absorption spectra are used to study the optical properties while atomic force microscopy (AFM) is used to investigate the surface morphology and structure of the thin films. The AFM results show that the surface roughness increases with increase in annealing temperature making the annealed films more prone to high absorption rather than the pristine sample. The results also demonstrate that the thermal annealing processes on the VOPcPhO thin films significantly enhance the features of light absorption and surface morphology. Hence, VOPcPhO can be used in the organic solar cell or photodiode, where such features are of prime importance.