Modification of optical properties of polycarbonate by gamma irradiation

A detailed analysis of absorption, transmission, and reflection spectra of virgin and gamma-irradiated (50-800 kGy) polycarbonate polymer reveals that both indirect as well as direct band gap coexist in virgin and gamma-irradiated samples. The indirect band gap has been found to decrease from 3.00 eV (virgin sample) to 2.78 eV at a dose of 800 kGy. The emission behaviour of gamma-irradiated polycarbonate indicates a clear-cut emission peak in the visible region at -466 nm in the samples with a gamma dose of 400 kGy and above. The refractive index has a decreasing tendency as a result of the increasing gamma dose.