In the present work, our aim is to reveal the effect of Ar+implantation on the structural behaviour of Polyethylene terephthalate (PET) using Fourier Transform Infrared and UV-Visible Spectroscopic techniques. PET specimens were implanted with 200 keV Ar+ions in the fluence range of 1x1015to 1x1017ions cm-2. The structural changes have been observed due to change in the position and intensity of the bands in the FTIR spectra of both implanted and unimplanted specimens. A continuous decrease in optical energy gap (from 3.63 eV to 1.48 eV) and enhancement in Urbach energy (from 0.29 eV to 3.70 eV) with increasing ion dose have been observed. The structural changes have been correlated with the optical parameters observed in PET specimens as a result of implantation.

The present endeavor investigates the controlled surface modifications and evolution of self-assembled nano-dimensional defects on oblique Ar+ sputtered Si(111) surfaces which are important substrates for surface reconstruction. The defect formation started at off-normal incidences of 50° and then deflates into defined defect zones with decrease in oblique incidence, depending strongly on angle of ion incidence. Interestingly, it is observed that mean size & height decreases while average density of these defects increases with decreasing oblique incidence. Non-linear response of roughness of irradiated Si(111) with respect to oblique incidence is observed. Crystalline (c-Si) to amorphous (a-Si) phase transition under oblique argon ion irradiation has been revealed by Raman spectroscopy. Our analysis, thus, shows that high dose argon ion irradiation generates of self-assembled nano-scale defects and surface vacancies & their possible clustering into extended defect zones. Explicitly, ion beam-stimulated mass transport inside the amorphous layers governs the observed defect evolution. This investigation of crystalline (c-Si) coupled with amorphous (a-Si) phases of nano-structured surfaces provides insight into the potential applications in the nano-electronic and optoelectronic devices thus, initiating a new era for fabricating multitude of novel structures.

In this paper, we present the analysis of the dielectric (dielectric constant, dielectric loss, a.c. conductivity) and electrical properties (I–V characteristics) of pristine and nitrogen ion implanted polycarbonate. The samples of polycarbonate were implanted with 100 keV N+ ions with fluence ranging from 1 × 1015 to 1 × 1017 ions cm−2. The dielectric measurements of these samples were performed in the frequency range of 100 kHz to 100 MHz. It has been observed that dielectric constant decreases whereas dielectric loss and a.c. conductivity increases with increasing ion fluence. An analysis of real and imaginary parts of dielectric permittivity has been elucidated using Cole-Cole plot of the complex permittivity. With the help of Cole-Cole plot, we determined the values of static dielectric constant (εs), optical dielectric constant (ε∞), spreading factor (α), average relaxation time (τ0), and molecular relaxation time (τ). The I–V characteristics were studied using Keithley (6517) electrometer. The electrical conduction behaviour of pristine and implanted polycarbonate specimens has been explained using various models of conduction.

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