UV- Irradiation Induced Changes in Structural and Optical Characterization of Silicon Phthalocyanine Dichloride (SiPcCl2) Thin Films

In the current study, novel deposited SiPcCl 2 thin films as organic semiconductor were experimentally investigated. The films were prepared using thermal evaporation technique on substrates of glass and quartz materials and then exposed to UV-irradiation from 60 min to 350 min. The molecular chemical composition of SiPcCl 2 in powder form, as-deposited and ultraviolet irradiated films were analyzed using Fourier-transform infrared technique (FT-IR). The scanning electron microscope (SEM) images and X-ray diffraction (XRD) patterns confirmed the amorphous structure for deposited and UV-irradiated films. Furthermore, the indirect allowed transition with optical gap, E opt. of 1.77 eV was reduced to 1.65 eV by exposing to ultraviolet rays for 350 min. Some of the significant optical parameters for as-deposited film such as: molar extinction coefficient, (ξ molar = 7430 mol/cm), strength of electronic dipole ( q 2 = 0.35Å 2 ) and strength of oscillator ( f = 0.20) of the optical transitions have been estimated and also for irradiated films.