Abstract
N,N'-Dimethyl-3,4,9,10-perylenedicarboximide (PTCDI-C-1) thin films were first prepared by thermal evaporation technique. Then, the prepared films were irradiated with gamma rays at room temperature with different absorbed doses. The structure of PTCDI-C-1 films at different doses of gamma radiation was elucidated by x-ray diffraction. The results confirmed that PTCDI-C-1 film has a nanostructure morphology. The grain size was observed to decrease slightly with increasing the gamma radiation doses. The temperature dependence of the electrical conductivity was measured in the temperature range of 293-423 K. It was found that the obtained activation energy of PTCDI-C-1 films decreased with increasing gamma radiation dose. The optical parameters were obtained using spectrophotometric measurements. The single oscillator model of Wemple-Didomenico was adopted to study the normal dispersion of refractive index. The optical dispersion parameters of PTCDI-C-1 films such as dispersion energy, oscillator energy and the high frequency dielectric constant were calculated. Furthermore, the nonlinear susceptibility values of PTCDI-C-1 films at different gamma radiation dose were calculated. Also, the dielectric constants of the films were investigated in a large range of frequencies. The fundamental band gap energy values (3.91 eV < E-g2 < 4.00 eV) of PTCDI-C-1 film were decreased with increasing of gamma radiation doses (150 kGy > E-g2 > 50 kGy).