In the current study, novel deposited SiPcCl2 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 SiPcCl2 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, Eopt. 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, (ξmolar = 7430 mol/cm), strength of electronic dipole (q2 = 0.35A2) and strength of oscillator (f = 0.20) of the optical transitions have been estimated and also for irradiated films.