100 keV nitrogen ion beam implanted polycarbonate: A possibility for UV blocking devices

Abstract

Polycarbonate samples were implanted with 100 keV N + ions at fluences 10 15, 10 16 and 5 × 10 16 ions cm −2. Drastic alterations in UV–Visible transmittance spectra were observed which are interrelated with change in surface color and optical absorption of the implanted samples. UV–Visible transmission studies show that at ion fluence of 10 16 ions cm −2, transmission approaches to zero at about λ = 427 nm and below up to 200 nm. Optical band gap ( E OPT) reduces with increase in fluence and at maximum ion fluence of 5 × 10 16 N + cm −2, E OPT was determined to be 1.56 eV whereas for pristine its value was 3.00 eV. Raman analysis indicates the formation of amorphous carbon on the surface of polycarbonate at an ion fluence of 10 16 N + cm −2. Rise in fluence to 5 × 10 16 N + cm −2 results in enhancement in disorder on the surface of the host polymer. Modifications in the structural arrangements were found to be in strong association with changes in optical properties with increase in ion fluence and the same is discussed.