Optical and dielectric properties of 55 MeV carbon beam-irradiated polycarbonate films

Polycarbonate films were irradiated with 55 MeV carbon (C5+) beam at different fluences from 1 x 10(11) to 1 x 10(13) ions/cm(2). The structural, optical and dielectric properties are studied. The X-ray diffraction pattern shows the decrease in crystallinity and increase in average intermolecular spacing with an increase in fluence due to the formation of carbon nanoclusters in the polymer matrix. UV-VIS absorption spectra show that the band gap energy decreases upon irradiation. It depends on the ion fluence and growth of carbon nanoclusters. The Fourier transform infrared spectra evidenced cross-linking and chain scissoring both at high fluences. The dielectric constant decreases while dielectric loss and alternating current conductivity increase with fluence.